Condair 2558982 D MH2 Eng Engineering Manual

Your guide to selecting and specifying Nortec evaporative humidifiers / air coolers

MH

Series

Engineering

Manual

Includes technical specifications, guidelines, and options for selection and application of MHTC / MHB

Evaporative humidifiers / air coolers

2558982-D | 24 OCT 2011

Thank you for choosing Nortec.

Proprietary Notice

This document and the information disclosed herein are proprietary data of WALTER MEIER LTD. Neither this document nor the information contained herein shall be reproduced, used, or disclosed to others without the written authorization of WALTER MEIER LTD., except to the extent required for installation or maintenance of recipient’s equipment. All references to the Nortec name should be taken as referring to WALTER MEIER LTD.

Liability Notice

Nortec does not accept any liability for installations of humidity equipment installed by unqualified personnel or the use of parts/components/equipment that are not authorized or approved by Nortec.

Copyright Notice

Copyright 2011, WALTER MEIER LTD. All rights reserved.

Contents

1 Introduction

1 The MHTC/MHB Evaporative

Humidifier / Air Cooler

1 How the MH works

2 Humidification / Cooling

6 MH Humidifier Features

9 MH Specifications and

Dimensions

13 Specifying the MH

14 MH Specification Checklist

15 MH Model

15 Duct Module Size

15 Number of Stages

15 Media Boxes Thickness

17 Humidification Load

19 Specifying for Air Cooling

21 MH Controls

21 MH Series Options and

Accessories

24 Sample Specification

29 MH Installation

Requirements

30 Location – Duct Module

31 Location – MHTC Reflow

Hydraulic Unit

32 Plumbing

34 Electrical

35 MHTC/ MHB Controls

39 Control Wiring

36 Nortec Controls

39 Control Location

41 Nortec Links XPS (MHTC Only)

44 Warranty

The MHTC/MHB Evaporative Humidifier / Air Cooler

The MHTC / MHB is an evaporative type humidifier / air cooler that provides humidifier and cooling adiabatically. The MHTC/MHB uses evaporative media that is placed in the air stream of an air handler or duct. The media is wetted with potable, RO, or DI water. The energy in the air passing through the media evaporates some of the water. The result is an increase in the humidity of the air and a decrease in the temperature of the air.

The main applications of MH series humidifiers / air coolers are either humidification of buildings which have a high humidification load and which can also benefit from the adiabatic cooling effect or simply the adiabatic cooling of air for building temperature control. Since the

MH depends on the energy in the air passing through the evaporative media to evaporate water, the MH requires inlet air that is warm and dry for most efficient operation.

MH Media

One of the most unique features of all MH series humidifiers / air coolers is their patented synthetic v-profile evaporative media which does not break down over time and release microscopic fibers which could be a health hazard. In addition the MH media is treated with an antimicrobial agent and meets UL900 Class 1 flame and smoke in the USA, ULC-S111-07 Class

2 in Canada making it the best media available for evaporative humidification / air cooling.

How the MH works

Spray Bars

Media

Boxes

Overflow

P Trap

Stage 1

Drain Pan

Stage 2 Stage 3

Check Valve

Float

Conductivity

Sensor

To duct

Fill Valve

Spray Bar Lines

Staging Manifold

Staging Valves

Pressure

Equalization line

Drain

Figure 1: MHTC Reflow Schematic

Drain Valve

UV Light

Reservoir

Pump

1 | The Nortec MHTC / MHB

Media

Boxes

Stage 1

Spray Bars

Drain Pan

Stage 2 Stage 3

P Trap

Drain

Spray Bar Lines

Staging Valves

Staging Manifold

Check Valve

Figure 2: MHTC Flow / MHB Schematic

Humidification / Cooling

 When a demand is received, the MH will;

MHTC Reflow - turn on its pump and UV light and after a short delay activate staging valves as required to meet demand. Water will flow through the UV light, staging manifold, open staging valves, and spray bar lines to the spray bars.

MHTC Flow / MHB – Activate staging valves as required to meet demand. Water will flow through the staging manifold, open staging valves, and spray bar lines to the spray bars.

 Each spray bar has a series of holes which allow water to flow out over a section of evaporative media. As Water runs down the evaporative media some of it is evaporated by air passing through the media. As a result of the evaporation the humidity of the air is increased and the temperature of the air is decreased.

 Any water that is not evaporated collects in the drain pan and;

MHTC Reflow - flows back to the hydraulic unit reservoir to be recirculated. As water is evaporated the water level in the reservoir decreases and the float opens. The MH then refills until the float is closed.

MHTC Flow / MHB – flows down to drain. The MHTC Flow / MHB does not have a reservoir or pump and water simply flows through the staging valves when they are open using supply water pressure to generate flow.

 During operation the controller responds to changes in demand by opening and closing staging valves. This allows the MH to match its output to demand.

The Nortec MHTC / MHB | 2

 When demand is satisfied the MH will;

MHTC Reflow – turn off all staging valves and after a delay turn off the UV light and pump.

MHTC Flow / MHB – turn off all staging valves.

Water Management (MHTC Reflow only)

 During the evaporation process minerals are left behind by the evaporated water resulting in an increase in concentration in the remaining water. To prevent minerals from collecting in and fouling the evaporative media more water is supplied to the media than can be evaporated. The unevaporated water carries the minerals left by evaporated water to the reservoir.

 To prevent the mineral concentration from increasing to the point where excess water can no longer dissolve minerals left in the media by evaporated water, the MH will periodically flush the reservoir. The method used to determine when to flush the tank is configured using display and keypad. Two triggers can be set.

Trigger 1

Time – The MHTC flushes the tank at a specific time every day.

Periodic – The MHTC flushes the tank after a fixed number of operating hours.

Demand - The MHTC flushes the tank after a fixed number of weighted hours ( weighted hours = hours of operation x demand% )

Trigger 2

Cycle – The MHTC flushes the tank after a fixed number of fill cycles.

μ SSensor (requires optional conductivity sensor)– Flushes the tank when the conductivity sensor indicates the concentration of minerals exceeds a configured maximum value.

 In general more frequent drains result in less maintenance. The amount of water drained to control mineral concentration in the recirculating water can be configured in the MHTC’s software.

Pressure Equalization Line (MHTC Reflow only)

In order to ensure that water flows properly from duct module’s drain pan to the MHTC Reflow’s reservoir a pressure equalization line must be installed between the reservoir and the duct down stream of the duct module. The line ensures pressure in the reservoir and duct are equal and water flows properly from the drain pan to the reservoir.

UV Light

A UV light is standard on the MHTC Reflow and optional on the MHTC Flow / MHB. The UV light prevents bacteria in the supply water or reservoir from being introduced into the evaporative media. It does not kill bacterial that may be introduced into the media in the air stream.

Box Drying / Box Washing

In order to prevent bacteria from growing in the evaporative media the MH includes a box drying cycle that allows the media to dry out. The MH will periodically close all staging valves and allow the media to dry out regardless of demand.

In order to wash minerals from and prolong media life the MH includes a wash cycle which turns on all staging valves regardless of demand or control status and rinses the media.


MH Models

The MH2 is available in three models (see Figure 3: MH Models and Table Table 3: MH

Specifications).

 MHTC Reflow - provides state of the art control technology with staged output to match demand. The Reflow model also includes a hydraulic unit that provides maximum water conservation by recirculating unevaporated water.

 MHTC Flow - provides the same state of the art control technology including staging of output to match demand but without the hydraulic unit for recirculating water.

 MHB - provides basic operation without any user configurable features.

MHTC Reflow MHTC Flow MHB

Multi Stage

OR

Single Stage

Figure 3: MH Models

Each MH model is coupled with a duct module that contains the evaporative media used for humidifying / cooling the duct air. The duct module is basically the same for each model with the exception of the number of spray bars which are used for staging output.


MHTC Reflow vs MHTC Flow and MHB

All units run a small excess of water over the media during operation to wash minerals away and prolong media life. The MHTC Flow and MHB direct this water directly to drain, while the

MHTC REflow recaptures and reuses the water. The REflow is the most water efficient model and recommended for good quality potable water and treated water types. Flow models are recommended for areas with hard potable water, or where a central wastewater recovery strategy is being used. See Table 1: MHTC Reflow / MHTC Flow / MHB Features for a listing of the additional features provided by the MHTC Reflow.

MHTC Flow vs MHB

The main difference between the MHTC Flow and the MHB model is in their controls and user interface. The MHTC model’s Total Controller provides a graphic LCD screen and keypad, accepts additional control signals and has optional building management system connectivity

(BACnet, Lonworks, Johnson N2, and Modbus). The MHB controls provide the basic functionality required for operation. See Table 1: MHTC Reflow / MHTC Flow / MHB Features for a listing of the two control systems features. Figure 4 shows the differences in the MHTC’s and MHB’s user interface.

MHTC

MHB

LCD Display

Inside Control Box

Input Buttons

(MHTC used to navigate screens and for configuration,

MHB for factory configuration only.)

Software Drain

Button

(Initiates a software controlled drain)

Outside Control Box

Status LEDs

Lights

On/Off Switch

(Turns humidifier

On/Off)

Figure 4: MHTC and MHB User Interfaces


The MHTC LCD screen and keypad - allow easy configuration of all features of the MHTC humidifier such as control signals, box washing / drying, tank flushing, maintenance reminders, and others. The LCD screen also provides status information indicating current status and configuration, service and fault messages, and troubleshooting information. One of the key features of the MHTC controller is tracking operation and providing information about service requirements to make it easy to service and maintain the MHTC.

MH Humidifier Features

From their patented evaporative media and modular design to the MHTC’s advanced control system with optional internet based monitoring capability to the MHTC Reflows advanced water conservation technology all MH models include many advanced features that set them apart from other evaporative humidifiers / air coolers. The following list outlines some of the MH series key features.

Table 1: MHTC Reflow / MHTC Flow / MHB Features

General

Patented synthetic V-profile evaporative media

Stainless steel duct / media box frames, and drain pan

Operates on DI/RO, Potable, Softened Water

Optional low pressure drop mist eliminator

Recirculating water system

Direct water system

Wash cycles and box drying

Step-Control 1,2, or 3 stage

Ultra violet water treatment

Installation / Maintenance

All electrical components outside of duct

Modular easy to change media boxes

Programable maintenance settings

Wide range of water management options

Electronics

Graphic display screen with keypad input

LED status indicators

Remote status via dry points

Staged output based on modulating signal

Proportional and integral internal control from humidity sensor inputs

Manual capacity adjustment

On/Off operation

Compatible with all standard Industrial controls

BMS (Lonworks, BACnet, Johnson, Modbus)

Other

UL900 Class 1 Flame and Smoke USA

ULC-S111-07 Class 2 Flame and Smoke Canada

MHTC Reflow MHTC Flow MHB

X X X

X X X

X X X

Optional Optional Optional

X

X X

X X X

X X X

X X X

X X

X

X X

1-3 Stages 1-3 Stages 1 stage

X X

X X

X X X

X X

Option Option

X X X

X X X


MH Components

Right

Side Panel

Duct Seal

Mist

Eliminator

Intermediate

Member

Staging

Manifold

Fill

Valve

Check

Valve

Float

Conductivity

Sensor

Drain Outlet

Drain

Pan

Spray

Bars

Pressure

Equalization

Line

Staging

Valve

Spray Bar

Cap

Media Boxes

Display and Keypad

Drain Pan Drain

Drain Valve

Pump

UV Light

Reservoir

Figure 5: MH Humidifier Components

Control

Box

On/Off Switch

Water Lines

Pressure

Equalization

Line

Drain

Overflow

Hydraulic

Unit

High Voltage

Terminal Block

Fuse Block

Pump and UV

Light Relay

Transformer

Conductivity

Transmitter

Low Voltage

Terminal

Block

(Hydraulic

Unit )


Description of Components

Component

Check Valve

Conductivity Sensor

/Transmitter

Control Box /

Display and Keypad

Drain Pan

Drain Pan Drain

Drain Outlet

Drain Overflow

Drain Valve

Duct Seal

Fill Valve

Float

Fuse Block

High Voltage

Terminal Block

Hydraulic Unit Collects water from the drain pan and pumps, treats with UV light, and stages water to media. Fills and drains reservoir to control water quality.

Structural member supports media boxes. Intermediate

Member

Low Voltage

Terminal Block

Media Boxes

Table 2: Humidifier Components

Function of Component

Provides back flow protection for supply water line.

Sensor measures conductivity of water in the reservoir. Transmitter sends measured value to control box for use in water quality control.

Controls all functions of the humidifier’s operation and provides user interface for configuration of the humidifier.

Collects unevaporated water from media for recirculation or draining.

Drain pan connection to hydraulic unit reservoir.

Drain connection from the hydraulic unit.

Provides protection from overfilling the drain pan.

Drains water from the reservoir.

Prevents duct air flow from bypassing the humidifier.

Controls makeup water flow to humidifier based on float level.

Measures water level in reservoir to prevent over filling.

Overcurrent protection for pump and UV light.

Primary voltage connection on hydraulic unit and in control box.

Mist Eliminator

On/Off Switch

Pressure

Equalization Line

Pump

Pump and UV Light

Relay

Reservoir

Side Panel, Right

Spray Bar Cap/

Spray Bars

Staging Manifold /

Valve(s)

Transformer

Hydraulic Unit – connects control box inputs to the hydraulic unit.

Control Box – provides connection for control signals and safety loop.

Surface from which water is evaporated for humidification/cooling.

Available in 8 in. (20 cm) or 12 in. (30 cm) thickness.

Captures any water droplets that are carried off the media boxes with air flow in high duct speed applications.

Turns power On/Off to humidifier controller. Note: Turn off humidifier disconnect to shut off primary power to the humidifier.

Balances pressure in hydraulic unit reservoir with pressure in duct to ensure proper water flow to reservoir from drain pan.

Pumps water from the reservoir to the media boxes.

Turns on power to the UV light and pump based on signal from the control box.

Collects water from the drain pan for recirculation / draining.

Structural member supports media boxes and spray bar cap.

Distributes water to the media boxes and prevents water from spraying anywhere else.

Controls flow of water to media boxes based on demand.

UV Light

Water Lines

Steps primary voltage down to 24 VAC for the controller and internal components such as the fill valve and drain valve.

Eliminates any bacteria in the water being pumped to the media boxes.

Supply water lines from hydraulic unit to spray bars.


MH Specifications and Dimensions

Table 3: MH Specifications

MHB MHTC

Flow

MHTC

Reflow

Voltage

Control signals

Max No. of Stages

Water supply

Water drain

Control accuracy

Supply water pressure

Supply water temperature

Water quality

Max. allowable air velocity through media

Pressure drop

Ambient conditions (control unit)

Fire classification of evaporative media

120 VAC / 60 Hz 120 VAC / 60 Hz 120 VAC / 60 Hz

On/Off

Dry set of points

VDC 0-5, 1-5, 0-10,

2-10, 0-16, 3.2-16 mA 0-20, 4-20

VDC 0-5, 1-5, 0-10,

2-10, 0-16, 3.2-16 mA 0-20, 4-20

3 3 3

3/4 in. BPP, 1/2 in.

NPT adapter provided

1/2 in/ FPT 3/4 in. BPP, 1/2 in.

NPT adapter provided

2 in. (50.8 mm) OD tube

2 in. (50.8 mm) OD tube

2 in (50.8 mm) ID hose

Depends on air conditions, number of stages, and control setup

30-145 psi (2-10 Bar)

41-113 ºF (5-45 ºC)

Tap water, reverse osmosis, softened or fully demineralized water.

750 fpm (3.8 m/s)

1100 fpm (5.5 m/s) with mist eliminator.

Typically 0.44 IWC (250 Pa) @ 500 fpm (2.5 m/s) and 90% RH

34 –104 ºF (1- 40 ºC) Max 75% RH

UL900 Class 1 USA, ULC-S111-07 Class 2 Canada

4 x 5/16 in O

(8 mm)

12.0 in.

30.5 cm


16.7 in.

42.5 cm

17.5 in.

44.4 cm

Figure 6: MHTC Reflow/Flow Control Box Dimensions

6.2 in.

15.6 cm

14.3 in.

36.3 cm

11.5 in.

29.2 cm

9.3 in.

23.6 cm

5.4 in.

13.6 cm

4 x 0.31 in.

(8 mm)

Figure 7: MHB Control Box Dimensions

1-3 x Spray Bar

1/2 in. (12.7 mm)

Tube

12 in. (30 cm) Supplied

Cut to Desired Length

O

10.75 in.

27.3 cm

1.0 in.

2.7 cm

TYP

4.2 in.

10.7 cm

6.0 in.

15.2 cm

6 X O

W - 1.2 in (W - 3.2 cm)

0.2 in.

0.6 cm

W/2 - 0.6 in.

(W/2 - 1.6 cm)

Drain

2.0 in (50.8 mm)

Tube

Overflow

2 in. (50.8 mm)

Tube

4.1 in.

10.3 cm

2.8 in.

7 cm

0.6 in.

1.6 cm

15.8 in.

40.2 cm

16.6 in.

42.3 cm

4.9 in.

12.5 cm

8.4 in.

21.5 cm

H=24 - 144 in.

(0.6 - 3.7 m)

74.6 in.

189.6 cm

W = 24 - 144 in.

(0.6 - 3.6 m)

Figure 8: MH Duct Module Dimensions


Electrical

3 x 7/8 in.

(22 mm)

2.0 in.

5.2 cm

2.0 in.

5.1 cm

2.4 in.

6 cm

24.1 in.

61.3 cm

2.6 in.

6.7 cm

10.0 in.

25.5 cm

2.5 in.

6.4 cm

11.5 in.

29.2 cm

8.2 in.

20.8 cm

Press. Equal.

1/2 in. (13 mm)

Spray Bar

Connections

Hose Barb 1-3 x 1/2 in.

(13 mm) Hose Barb

Drain Pan

Connection

2 in. Tube

2.1 in.

5.3 cm

12.1 in.

30.7 cm

Drain

2 in. ID Hose

2.6 in.

6.7 cm

6.4 in.

16.4 cm

11.8 in.

29.9 cm

2.4 in.

6.1 cm

2.0 in.

5.2 cm

Figure 9: MHTC Reflow Hydraulic Unit Dimensions

1 - 3 x 1/2 in. OD

Barbed Hose

1.00

2.55

11.87

30.15

9.87

25.07

8.05

20.45

2 x 1/4 in. O

(6.4 mm)

1.31

3.33

11.88

30.16

2 x Water Tight

Strain Relief

Electrical Connection

Drain

1/2 in. NPT

1.32

3.36

Water Inlet

1/2 in. NPT

Figure 10: MHTC Flow/MHB Multi Stage Hydraulic Unit Dimensions

17.6 in.

44.6 cm

Water Inlet

3/4 in BSP

(1/2 in. NPT

Adapter provided)

15.6 in.

39.5 cm


Spray Bar

Connection

1/2 in (13 mm)

Hose Barb

4.3 in.

10.9 cm

Water Inlet

3/4 in GHT

1.8 in.

4.4 cm

2 x 0.3 in. O

(7.6 mm)

2.7 in.

6.8 cm

Figure 11: MHB Single Stage Hydraulic Unit


Specifying the MH

Humidifier / Air Cooler

14 MH Specification Checklist

15 MH Model

15 Duct Module Size

15 Number of Stages

15 Media Boxes Thickness

17 Specifying for Humidification

17 Humidification Load

17 Example: Mixed Air System

17 Example: Makeup Air System

18 Required Media Box Thickness for Humidification

19 Specifying for Air Cooling

19 Direct Air Cooling

20 Indirect Air Cooling

21 MH Controls

21 MH Series Options and Accessories

24 Sample Specification

13 | Specifying the MH Humidifier / Air Cooler

MH Specification Checklist

The following checklist can be used to specify the MH Series Humidifier / Air Cooler. A description of each selection is provided later on in this section.

Unit Tag: _______________ Zone _______________

Location or Elevation

MH Model

 MHTC Reflow

Duct Module Size



 in.  cm

Duct Width ______________

Number of Stages

 1  2

MHTC Flow

 3

 MHB

Duct Height

Humidification 

Air Before Humidification Temp

Air After Humidification

Required Effectiveness

Temp

Air Cooling 

Air Before Cooling

Air After Cooling

Required Effectiveness

Media Box Thickness

DB Temp

DB Temp

RH

RH

WB Temp

Duct Velocity

Control

8 in. (20 cm) Eff.

 Use 8 in. (20 cm) Media 

12 in. (30 cm) Eff.

Use 12 in. (30 cm) Media

Humidity

 Demand  Transducer  On/Off Signal Type _______

 By Others  By Nortec, Part No_______________

or

Temperature

 Demand  On/Off  By Others

Additional Options (Mist Eliminator, Links XPS, Air proving… See Table 6: Options and

Accessories)

_________________________________________________________________________________

_________________________________________________________________________________

Specifying the MH Humidifier / Air Cooler | 14

MH Model

The decision of which MH model to use depends primarily on the application, the need for advanced control capabilities, and the need to minimize water usage. Table 4 provides an overview of the items to consider when selecting the MH Model for your application.

Table 4: MH Model Selection

MH Model MHTC Reflow MHTC Flow MHB

Minimize water usage

Treated water

Potable water

Hard water

BMS Control

X

Best

X

X

X

Humidification Best

Cooling

Low Cost

X

X

X

X

Best

X

X

Best

Best

X

Duct Module Size

In order to minimise the air velocity through the media the duct module should be sized to match as closely as possible the cross section of the duct. Specifying a smaller duct module and blanking off large area of the duct will result in poor performance.

The MH duct module is available in sizes ranging from 24 W x 24 H to 144 W x 144 H. Duct modules are supplied in width increments of 4 inches and height increments of 3 in. See Figure

8: MH Duct Module Dimensions for duct module dimensions.

To provide installation clearance the duct width should be at least 1.5 in. (38 mm) wider and

0.5 in. (13 mm) taller than the specified duct module.

Max Module Unit Width = Duct Width – 1.5 in. (38 mm)

Max Module Unit Height = Duct Height – 0.5 in. (13 mm)

Number of Stages

Staging provides a means for the MH unit to match its output to demand and is primarily used in humidification applications. Both the MHTC Reflow and the MHTC Flow are available with between 1 and 3 stages. The MHB has only one stage available.

Media Boxes Thickness

The MH duct module is available with either 8 in. (20 cm) or 12 in. (30 cm) thick evaporative media boxes. The maximum effectiveness in humidification and cooling is dependent on the thickness of the media boxes and the velocity of the air through the boxes as shown in Figure

12: Maximum MH Effectiveness vs Air Velocity. The media box thickness that should be used depends on the effectiveness required to meet either the humidification or cooling load.

The effectiveness of the MH is defined as;

Effectiveness = (RH after – RH before)/(100% - RH before)

Where RH before and RH after are the relative humidity before and after the MH duct module.


Note: .

 See Required Media Box Thickness for Humidification on page 18 for an explanation of how to determine the required media box thickness for humidification.

 See Example Direct Cooling on page 19 for an explanation of how to determine the required media box thickness for air cooling applications..

100

95

90

94% at 500 fpm

85

84% at 500 fpm

80

75

70

500 fpm (2.5 m/s)

65

60

55

50

0

200 (1)

Velocity fpm (m/s)

400 (2) 500 600 (3)

12 in. (30 cm) Media

800 (4) 1000 (5)

8 in. (20 cm) Media

Figure 12: Maximum MH Effectiveness vs Air Velocity


Specifying for Humidification

Humidification Load

Although Nortec’s Humidifier Engineering and Load-sizing Program (HELP) does not currently allow selection of MH technology the Atomizing Nozzle selection can be used to calculate the humidification load. Figure 13: Mixed Air System Humidity Load shows a schematic from HELP calculating the load for an application in Chicago. The software can be downloaded from www.humidity.com. Nortec Publication 2553856 - Humidification Load Calculation also provides information on selecting a humidity setpoint, the effects of relative humidity, and methods for manually calculating the humidification load.

Example: Mixed Air System

Chicago Illinois, Mixed air system, room design conditions of 72ºF 50% RH, Air Volume of

50,000 cfm, makeup air volume of 7,500 cfm, 10 x 10 ft duct.

Figure 13: Mixed Air System Humidity Load

A) Outdoor Air = -1 ºF (-18 ºC) 53% RH 7,500 cfm

B) Return air = Room Design = 72 ºF (22 ºC) 50%RH, 42,500 cfm.

C) Mixed Air = Outdoor Air + Return Air = 61 ºF (16 ºC) 63% RH, 50,000 cfm

D) Preheated Air (before humidification) = 90 ºF (32 ºC) 24% RH

E) After Humidification = 85 ºF (29 ºC) 33% RH,

Based on these conditions the HELP software calculates a humidification load of 223 lb/hr.

Example: Makeup Air System

Figure 14: Makeup Air System Humidity Load shows the above system in Chicago if it were a makeup air system instead of a mixed air system.


A

Chicago Illinois

Makeup Air System

Calculated Load = 1723 lb/hr

B

D

C

Figure 14: Makeup Air System Humidity Load

A) Outdoor Air = -1 ºF (-18 ºC) 53% RH

B) Preheated Air (before humidification) = 90 ºF (32 ºC) 1% RH

C) After humidification = 54 ºF (12 ºC) 91%

D) Room Design = 72 ºF (22 ºC) 50% RH

Based on these conditions the HELP software calculates a humidification load of 1723 lb/hr.

Required Media Box Thickness for Humidification

Once the humidification load has been determined the correct media thickness must be chosen and the ability of the MH to satisfy the load confirmed. Except for makeup air systems or in cases of high makeup air volumes an 8 in (20 cm) thick media will usually be sufficient and should be used because of its lower pressure drop and lower cost. For the examples above;

1 Calculate the required effectiveness

Mixed Air System

Required Effectiveness = (RH after – RH before)/(100% - RH before)

= (33 – 24) / (100 – 24) = 12%

Makeup Air System

Required Effectiveness = (RH after – RH before)/(100% - RH before)

= (91 – 1) / (100 – 1) = 91%

2 Calculate the air velocity

V= 50,000 cfm / (10 ft x 10 ft) = 500 fpm

3 Use Figure 12: Maximum MH Effectiveness vs Air Velocity along with the calculated velocity to determine the required media box width and confirm the MH can satisfy the load.

Mixed Air System – 12% effectiveness required, therefore use 8 in. (20 cm) media box

Makeup Air System – 91% effectiveness required, Maximum effectiveness of 8 in. (20 cm) media box at 500 fpm is 84% so use 12 in. (30 cm) media box


Specifying for Air Cooling

Direct Air Cooling

Direct air cooling is normally used to cool the makeup air in an air handling system because trying to cool return air which has a high RH due to previously being cooled is not very effective.

The easiest way to determine the maximum cooling which can be achieved is to calculate the maximum effectiveness of the MH and then use a psychrometric chart to determine end conditions. Since the maximum cooling will always be achieved with the 12 in. (30 cm) media it is normally used. The maximum cooling that can be achieved is;

Max. Cooling = (outdoor dry bulb– outdoor Wet bulb) x Max effectiveness

Example Direct Cooling

Compare the maximum cooling of 12 in. (30 cm) and 8 in. (20 cm) thick media, Los Angeles

California, Air volume = 50,000 cfm, Duct size = 10 x 10 ft. (Figure 15)

52

54 56 BTU/lb(d.a) 58

30

28

40

42

50

44

10

R

46

90

% t

48 ur

R

H te d

80

%

RH

70

%

R

H

26

24

22

20

36

38

18

30

32

34

60

%

RH

50

%

RH

16

14

26

28

100%

94%

40%

RH

12

24

30%

RH 10

18

20

22

84%

20%

RH

8

14

12

10

16

61.6 63 66 88.9

10% RH

6

4

2

40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 104 106 108 110

Figure 15: Direct Cooling, Los Angeles

1 Calculate the Air Velocity

V= 50,000 cfm / (10 ft x 10 ft) = 500 fpm

2 Determine the maximum effectiveness - Use Figure 12: Maximum MH Effectiveness vs Air

Velocity along with the calculated velocity to determine maximum effectiveness of each media.

12 in. (30 cm) Media = 94%

8 in. (20 cm) Media = 84%

3 Determine the supply air conditions

ASHRAE cooling design conditions in Los Angeles California are DryBulb (DB) = 88.9 ºF,

Wet Bulb (WB) = 61.6 ºF.


4 Calculate the Maximum Cooling = (outdoor dry bulb– outdoor Wet bulb) x Max effectiveness

Max Cooling 12 in. (30 cm) Media = (88.9ºF – 61.6ºF) x 94% = 25.7 ºF

Max. Cooling 8 in. (20 cm) Media = (88.9ºF – 61.6ºF) x 84% = 22.9 ºF

5 Calculate the conditions of the air leaving the MH duct module by subtracting the maximum cooling from the supply dry bulb temperature and by using the psychrometric chart.

12 in. (30 cm) Media = 88.9ºF – 25.7ºF = 63ºF < RH of cooled air is 89% (from chart)

8 in. (20 cm) Media = 88.9ºF – 22.9ºF = 66ºF < RH of cooled air is 76% (from chart)

Indirect Air Cooling

Indirect cooling is an efficient way to reduce the air temperature of supply air without significantly increasing its relative humidity. In Indirect cooling the MH is used to cool a secondary air stream that then passes through a heat exchanger and cools a primary (supply) air stream. The secondary air stream is then exhausted. The maximum cooling that can be achieved depends on the efficiency of the heat exchanger, the maximum effectiveness of the

MH, and the outside air conditions.

Supply DB = DB Primary - (DB Primary – DB Secondary) x Heat Exchanger Efficiency

Where

DB Secondary = DB Outdoor – (DB Outdoor – WB Outdoor) x MH Effectiveness

Example Indirect Air Cooling

If the air stream in the direct cooling example above is used to cool a secondary air stream in an indirect cooling system, calculate the maximum cooling that can be achieved. Assume the primary and secondary air streams have equal volume and the secondary air stream is 74ºF

(40% RH) before cooling.

54 56 BTU/lb(d.a) 58

30

52

28

26

36

38

40

42

50

44

10

R

46

90

% t

48 ur

R

H te d

80

%

RH

70

%

R

H

24

22

20

18

32

34

60

%

RH

RH

16

24

26

28

30

94%

50

%

30%

RH

14

12

10

22

(Secondary)

40%

RH

14

16

18

20

80%

(Primary)

20%

RH

10% RH

8

6

4

12

10

2

40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 104 106 108 110

63 65 74 88.9

Figure 16: Indirect Air Cooling, Los Angeles


1 Calculate Dry Bulb of Secondary Air Stream - From the example above using 12 in. media;

DB Secondary = 63ºF

2 Calculate DB Supply using the equation above.

DB Supply = DB Primary - (DB Primary – DB Secondary) x Heat Exchanger Efficiency

DB Supply = 74 – (74 – 63) x 0.8 = 65ºF

MH Controls

See Nortec Controls on page 36 for a listing of controls offered by Nortec and installation requirements. MHTC models can be operated with one modulating input. The MHB does not have a modulating input. Both the MHTC and MHB can be operated as On/Off. Controls can be supplied by Nortec or by others. MH humidifiers /air coolers are compatible with the following control inputs.

Table 5: MH Series Control Signals

Control Signal MHTC MHB

0-10 V

2-10 V

0-5 V

1-5 V

Demand and Humidity Transducer




Demand

On/Off Dry Contact 24 VAC Dry Contact 24 VAC

MHTC control signal type can be configured by Nortec at the factory or can be user configured.

Configuration is done with the MHTC’sLCD and keypad.

MH Series Options and Accessories

Nortec provides a complete line of options and accessories for every humidification application.

Table 6: Options and Accessories lists options available for the MH Series with a brief description of their function.

Table 6: Options and Accessories

Option / Accessory

Mist Eliminator

Conductivity Sensor

Used For

Mist eliminators are available for all MH models. At higher velocities there is a chance that water droplets can be picked up by the air flowing through the media and carried into the air duct.

The mist eliminator acts a barrier to the droplets and prevents them from entering the duct. Mist eliminators should be used in applications where duct velocity is higher than 750 fpm (3.8 m/s).

Order together with MH Duct Module or specify MH Duct Module size to order separately.

A conductivity sensor is available for the MHTC Reflow which provides the ability to better control the amount of minerals that are suspended in the recirculating water. With the conductivity sensor installed the controller will flush the water only when the conductivity rises above a user configurable limit. This results in less waste water and longer media life.

2557295 – MH Conductivity Sensor Kit


UV Light

Option / Accessory

On/ Off Humidistats

Table 6: Options and Accessories (Continued)

Used For

A UV light is standard on the MHTC Reflow. A UV light can be ordered as an option for the MHTC Flow / MHB. The UV light prevents bacteria in the supply water from being introduced into the evaporative media. It does not kill bacterial that may be introduced into the media in the air stream.

2544952 - UV Light Kit

On/Off Humidistats are used to turn the humidifier on and off based on sensed RH. They can be mounted in the space being humidified or in the return air duct. The digital humidistat provides an LCD screen and keypad for setting the RH setpoint and displaying sensed RH.

Modulating Humidistats

Humidity Transducers

Outdoor Temperature Sensor

Air Proving Switches

(See On/Off Controls on page 36)

Modulating Humidistats are used to control the output of the humidifier based on sensed RH. They can be mounted in the space being humidified or in the return air duct. The digital humidistat provides an LCD screen and keypad for setting the RH setpoint and displaying sensed RH. They can be used for either controlling humidity or for high limit control. Modulating humidistats can only be used with MHTC models, not MHB.

(See Modulating Humidistats on page 36 )

Digital Humidity Transducers communicate RH in a space or duct to the humidifier. When used with an MHTC (not MHB) the humidifier displays the sensed RH on its LCD display screen, setpoints are entered using the humidifier keypad and the humidifier’s software calculates required output based on setpoint and sensed RH. Transducers are available for room or duct installation.

(See Humidity Transducers on page 37)

The outdoor temperature sensor is used in conjunction with

Nortec’s Digital humidistats to provide a humidity setpoint reset when outdoor temperature is very low. The setpoint is reduced to prevent condensation on windows and other parts of a buildings structure.

2520263 - Duct Mount Outdoor Temperature Sensor

(See Outdoor Temperature Reset on page 38)

Air proving switches are used to ensure humidification only occurs when air is moving in a duct. The air proving switch is installed in series with all other On/Off devices on the humidifier’s On/Off/security loop.

1329203 - Air Proving On/Off Duct Mounted

(See On/Off Controls on page 36)



Option / Accessory

High / Low Humidity Alarm Packages

Used For

Various alarm packages are available for indicating when humidity is outside of required limits. The packages include a mechanical humidistat and display panel with a light.

Control Setting at Factory

Nortec Links XPS

Control

Signal?

Double Check Valve

In Line Water Filter and replacement Filters

Condensate Pump

2533363 – High Duct Humidity Alarm Package

2533365 – Low Duct Humidity Alarm Package

2533364 – High Room Humidity Alarm Package

2533366 – Low Room Humidity Alarm Package

MHTC models can be factory ordered configured for the type of controls that will be used. Factory configuration eliminates the need to configure the MHTC in the field and makes it plug and play with respect to software configuration. Part numbers are available for each available control configuration.

(See Control Acceptance Configured at Factory on page 38)

Nortec Links II provides connectivity to BACnet, Lonworks,

Johnson N2, or Modbus building management systems. A separate part number must be selected to specify the type of building management system. (MHTC only)

Nortec Links XPS for MHTC, BACNET/IP

Nortec Links XPS for MHTC, BACNET/MSTP

Nortec Links XPS for MHTC, LONWORKS

Nortec Links XPS for MHTC, N2

(Consult Factory)

(See Nortec Links XPS (Optional MHTC Only)on page 41)

The MHTC models include a check valve in their hydraulic units to prevent back flow to the supply water system. The double check valve can be used as additional protection or on the MHB model.

1458807 - Double Check Valve For Water Inlet Line

The inline water filter can be used for supply water which contains a large amount of sediment that could block the MH fill valve or collect in the MH evaporative media.

1329505 - In-Line Water Filter 5 Micron Filter

1329561 - Replacement Water Filters 1 Micron

1329506 - Replacement Water Filters 5 Micron

The condensate pump can be used for pumping drain water from the MH where gravity feed to a drain is not possible.

1429527 - Drain Water Sump Pump (High Temperature)


Option / Accessory

Pocket Hyrgo Thermometer


Used For

The pocket hygro thermomenter provides a means for easily checking the humidity and temperature in a space and is a useful tool for troubleshooting humidity problems.

1469595 - Pocket Hygro-Thermometer Digital

Display

Note: All illustrations of options / accessories are provided strictly for the purpose of describing them. Actual appearance of each option accessory may differ from that shown.

Sample Specification

PART 1 - GENERAL

1.1 WORK INCLUDED

A. NORTEC In-duct/AHU Evaporative Humidifier / Cooler, MH Series humidifier[s] as indicated on drawing[s] and as indicated on schedule[s].

B. Complete and operable humidification/cooling system [which is designed to meet applicable building codes].

C. Equipment start-up and project inspection by qualified factory trained representative.

1.2 QUALITY ASSURANCE

A. Manufacturer: For each product specified, provide components by same manufacturer throughout.

B. Electrical Components, Devices, and Accessories: Listed and labeled as defined in

NFPA 70, Article 100, by a testing agency acceptable to authority having jurisdiction, and marked for intended use.

C. Comply with ARI 640, "Standard for Commercial and Industrial Humidifiers."

D. Products shall be supported with a warranty that ensures the product will be free from defects in materials and workmanship for a period of two years after shipment.

Excluding the media boxes, as they are a serviceable item whose effective operation life depends on the water quality and air filtration being supplied.

E. Commissioning of a system or systems specified in this section is part of the construction process. Documentation and testing of these systems, as well as training of the Owner's operation and maintenance personnel, is required in cooperation with the Commissioning Authority. Project Closeout is dependent on successful completion of all commissioning procedures, documentation, and issue closure. Refer to Project

Closeout, Section 01700, for substantial completion details. Refer to Section 01810,

Commissioning, for detailed commissioning requirements.

F. Products specified below are to be manufactured is an ISO 9001-2000 certified facility.

1.3 SUBMITTALS

A. Submit product data under provisions of Section 15010. Include product description, model, dimensions, component sizes, rough-in requirements, service sizes, and finishes. Include rated capacities, furnished specialties, and accessories.

B. Submit manufacturer's installation instructions.

C. Submit operation and maintenance data.


D. Submit coordination drawings. Detail fabrication and installation of humidifiers. Include piping details, plans, elevations, sections and details of components. Detail humidifiers and adjacent equipment.

E. Submit wiring diagrams including power, signal, and control wiring.

F. Submit minimum water quality requirements and water pressure requirements.

1.4 EXTRA MATERIALS

A.

Furnish extra materials described below that match products installed and that are packaged with protective covering for shipping and identified with labels describing contents.

1.5 REFERENCES

A. ANSI/NFPA 70 - National Electrical Code.

B. UL 900 – Standard for Air Filter Units.

C. NFPA 90A – Standard for the Installation of Air Conditioning and Ventilating Systems.

1.6 COORDINATION

A. Coordinate location and installation of humidifiers in ducts and air-handling units.

Revise locations and elevations to suit field conditions and to ensure proper humidifier operation.

PART 2 - PRODUCTS

2.1 IN-DUCT/AHU EVAPORTIVE HUMIDIFIER/COOLER - MH SERIES REFLOW and FLOW

A. General.

1. Adiabatic humidifier provides humidification and air-cooling using the principle of surface evaporation over a media. Designed for direct HVAC installation for air- handling systems or ductwork. Air downstream of humidifier is free of aerosols, cooler, and more humid.

2. Humidifier shall accept potable, softened, reverse osmosis and de-ionized water.

3. The packaged humidifier is designed around the patented UL 900 Class 1 V-Profile humidification boxes, which uses impregnated polyester as the humidifying medium. The V-Profile ensures a more efficient evaporation by improving the exchange between air and water.

4. The MH series uses an intuitive electronic controller, which monitors the operation of the system, controls output levels and initiates self-cleaning flushing cycles to ensure hygiene and a long life span of the media.

5. The humidifier shall be powered by 120 volts single phase power supply with low power consumption ranging from 0.20-0.60 kW.

6. Improved water conservation (Reflow model only) through either performing drains based on operating time and water added or optionally by monitoring conductivity of recalculating water to maintain a programmable maximum mineral concentration.

7. Optional building management system integration using Modbus, BACnet,

LonWorks protocols.

8. Optional Internet based monitoring and control.

B. Evaporative Media:

1. Media is made of a durable V-shaped polyester material, which absolutely free of fibreglass and is packaged in a stainless steel casing. The media design ensures that the air is not contaminated with glass fibre particles that are detrimental to health.


2. The V-profile of the humidifier box guides air flow over the complete surface of the media which promotes efficient evaporation and ensures low pressure loss.

3. The material has a flame retardant coating and fire protection is in compliance with

UL 900 Class 1 Flame and Smoke.

4. Evaporative media shall be easily removable for replacement or cleaning by simply lifting out the stainless steel media casings which are hooked into the humidifier frame. No tools are required for media removal.

5. The rate of evaporation shall depend on the air volume, air temperature, cross sectional area of the humidifier and the media depth. The depth of the evaporative media shall dictate the maximum effectiveness of up to 85% (8” media) or 95%

(12” media).

C. Mist Eliminator

1. A patented integral mist eliminator shall be used to prevent water droplets in cases where the face velocity across the media exceeds 750 ft/s (3.8 m/s). The mist eliminator allows face velocities operation up to 1080 fpm (5.5 m/s).

2. Material used in the mist eliminator must meet UL 900 Class 1 requirements.

3. See section B for more detail. Both the media and mist eliminators are engineered from the same specifications.

D. MH Total Control (TC) Management System

1. Unit includes an electronic control cabinet with NRTL-c approval to include electrical fuses, main switch, microprocessor control (MHTC models only) using a proportional-integral method for interpreting analog signals from a humidistat and or the building control systems.

2. The controller (MHTC models only) determines which stages should be activated to meet humidification loads. The controller activates self-maintenance cycles. This includes controlled flushing of the water tank in conjunction with filling cycles, and scheduled drain cycles to prevent bacteria growth in the water tank.

3. The controller (Reflow models only) activates self-maintenance cycles. This includes controlled flushing of the water tank in conjunction with filling cycles, and scheduled drain cycles to maintain cleanliness of the water tank.

4. The controller (MHTC models only) will manage programmable self-wash cycles.

This cycle reduces scaling on the media and ensures clean hygienic operation. In addition the controller must flushing water lines after a period of inactivity.

5. The full function control panel with back-lit graphic display (MHTC models only) shall feature the following user settings and features: a) Control panel powder coated with On/Off switch, auto drain switch, LED fault indicator, LED service indicator and LED power on b) Easy scroll through keypad with back-lit graphic display c) Display of relative humidity and setpoint d) Display of operating hours e) Capacity output f) Real-time date and time g) Error history indication h) Clean mode and media drying i) Limited capacity adjustment j) Inlet flush, drain time and drying cycles k) Adjustable maintenance intervals l) Remote relay testing m) Modbus standard host protocol


n) Terminal block installed for easy field connection of low voltage 24Vac control cable from prewired hydraulic unit with 30 feet (10M) of cabling included.

6. The control panel (MHTC models only) shall be capable of accepting the following humidity control methods: a) Humidistat/thermostat or BMS control b) 0-10Vdc, 0-5Vdc, 1-5Vdc, 2-10Vdc, 0-16Vdc, 0-20mA, or 4-20mA control signal c) On/Off 24 Vac safety loop for On/Off control, air proving or high limit d) Accepts Nortec Humidity Sensors or Controllers or Controls by others via DDC or

BMS. e) Integral timer programmable On/Off

E. Hydraulic Assembly (REflow model only)

1. For REflow models only a packaged pump hydraulic assembly will be included for recirculating water.

2. Air cooled electric sealed motor pump shall be powered by a 120 V 1phase 60 Hz connection.

3. Pump shall have stainless steel shaft and plastic housing to minimize corrosion and provide long service life. Pump shall be capable of running dry for short periods without damage.

4. Manifold block shall be configured to accept staging valves 1, 2, or 3 stages up to five banks of evaporative media. MHTC models only.

5. Adjustable volume control valves to provide even flow is always present to all media.

6. 24 Vac pressure regulated water inlet valve with a ¾” BSPP connection shall operated between 30-80 psi operating pressure.

7. Level control float for indication to control electronics when water tank is full and when tank needs to be refilled. then

8. Drain connection is a 1.25” (3.175 cm) ID.

9. Overflow protection in case of a level control or fill valve failure allows water to flow directly to drain.

F. Aerosol Breakdown and Hygiene Control

1. The Management System must be cable of real-time flushing, washing and drying cycles to be programmable via the control panel of the Management System. In the event of no call for humidity, the humidifier shall drain the tank and remain empty until a demand is present.

2. A multi-sided gradient in the base pan ensures complete water tank draining and drying.

3. The humidifier shall provide aerosol-free operation and is guaranteed by the hygroscopic properties of the humidifier media.

4. Optional UV lamp that continually sterilizes all water flowing to evaporative media with UV-C radiation.

5. Optional conductivity monitoring sensor ensures water quality is maintained at an optimal level and maximum life of the media is achieved.

G. Available Options and Accessories

1. UV water treatment

2. Conductivity monitoring sensor (REflow models only)

3. Pressure reduction valve (building side) consult factory

4. P/N 1329505 - In-Line Water filter c/w 5 micron filter

Nortec On/Off Controls:

5. P/N 2520273 - On/Off Dig. Duct Humidistat pkg

6. P/N 2520259 - On/Off Digital Wall Humidistat


7. P/N 1329203 - Switch Air Proving (duct airflow safety interlock)

Nortec Modulating Demand Controls:

8. P/N 25202660 - 10V Dig. Duct Humidistat pkg

9. P/N 15101420 - 10V Digital Wall Humidistat

Nortec Transducer Sensor Controls:

10. P/N 1509858 - 2-10V Dig Wall Humidity Sensor

11. P/N 1509857 - 2-10V Duct Humidity Sensor

12. Nortec LINKS2 and Nortec Online please consult factory

H. Standard of acceptance: Nortec MH Series Evaporative Humidifier / Cooler.

PART 3 - EXECUTION

3.1 EXAMINATION

A. Examine ducts, air-handling units, and conditions for compliance with requirements for installation tolerances and other conditions affecting performance.

B. Examine roughing-in for piping systems to verify actual locations of piping connections before humidifier installation.

C. Proceed with installation only after unsatisfactory conditions have been corrected.

3.2 INSTALLATION

A. Install humidifiers per manufacturers' instructions.

B. Install with required clearance for service and maintenance.

3.3 TESTING

A. Manufacturer's Field Service: Engage a factory-authorized service representative to inspect field-assembled components and equipment installation, including piping and electrical connections. Report results in writing.

1. Leak Test: After installation, charge system and test for leaks. Repair leaks and retest until no leaks exist.

2. Operational Test: After electrical circuitry has been energized, start units to confirm proper unit operation. Remove malfunctioning units, replace with new units, and retest.

3. Test and adjust controls and safeties. Replace damaged and malfunctioning controls and equipment.

3.4 TRAINING

A. Engage a factory-authorized service representative to train Owner's maintenance personnel to adjust, operate, and maintain humidifiers.

1. Train Owner's maintenance personnel on procedures and schedules for starting and stopping, troubleshooting, servicing, and maintaining equipment and schedules.

2. Review data in maintenance manuals. Refer to Division 1 Section "Contract

Closeout."

3. Review data in maintenance manuals. Refer to Division 1 Section "Operation and

Maintenance Data."

4. Schedule training with Owner, through Architect, with at least seven days advance notice.

END OF SECTION


MH Installation

Requirements

30 Location – Duct Module

31 Location – MHTC Reflow Hydraulic Unit

32 Plumbing

34 Electrical

35 MHTC/ MHB Controls

36 Nortec Controls

36 On/Off Controls

36 Modulating Humidistats

37 Humidity Transducers

38 Outdoor Temperature Reset

38 Control Acceptance Configured at Factory

39 Control Location

39 Control Wiring

41 Nortec Links XPS (Optional MHTC Only)

NOTE:

The following sections provide an outline of the installation requirements. For detailed installation instructions refer to MH

Series Installation and Operation Manual.

29 | MH Installation Requirements

Location – Duct Module

The MH Duct Module is shipped disassembled. The duct module is designed to be assembled in place on the floor of a duct or air handler. Assembly involves bolting together frame pieces and securing to the duct, hanging media boxes onto frame with mounting tabs, assembling and installing optional mist eliminator, and sealing between the duct module and duct walls.

 Mounting surface must be strong enough to support the full weight of the duct module, mist eliminator and water in the evaporative media and drain pan (see Table 3: MH

Specifications for approximate weights).

 To provide installation clearance the duct size should be min. 1.5 in. (38 mm) wider and 0.5 in. (13 mm) taller than the specified duct module.

 Provide a watertight section in the area of the duct module. If demineralised water is used use corrosion resistant materials.

 Air filters meeting ASHRAE 52.2 MERV 8 or 11 must be installed upstream of the MH.

 Ensure access door and space for replacing media boxes is provided downstream of the MH duct module. If installed, provide extra space for opening mist eliminator to access media.

 In case the outside of the duct or air handler walls are in contact with low ambient temperature insulate the outside of the duct to prevent condensation inside the duct.

 Clearance dimensions shown are for reference only and are the minimum required for maintenance. Consult local and national codes before final location and installation. Nortec does not accept responsibility for installation code violations.

20 in. (50 cm) min.

MH duct module

36 in. (90 cm) min.

sufficient space for media box removal

Air filters

ASHRAE 52.2

MERV 8, 11 or better

Even

Air

Flow

Heating coil

Clearance for P-trap height

Water tight section.

corrosion resistant if demineralised water is used

Figure 17: MH Duct Module Location

Access door downstream of

MH unit for media box replacement

Note: extra space required if mist eliminator is installed

MH Installation Requirements | 30

Note:

 A P-Trap equal to duct static pressure plus 2 inches must be installed on the drain pan overflow. Insure sufficient space is available. Use a stand to raise the drain pan in the duct if necessary.

 The Duct Module requires regular maintenance including replacement of media boxes. Ensure access and sufficient space is provided downstream of the unit to remove and install new media boxes.

Location – MHTC Reflow Hydraulic Unit

The MHTC Reflow Hydraulic Unit should be located adjacent to the duct or air handler containing the MH Duct Module. The Hydraulic Unit is designed to be floor mounted but can be installed on a stand or raised surface.

 Install the hydraulic unit as close as possible to the MH Duct Module to minimize length of drain and spray bar lines.

 Ensure the Hydraulic Unit is installed on a level surface.

 Install where there is sufficient access for removal of cover and servicing of unit.

2 in.

(5 cm)

Min. side clearance

5-95%

As close as possible to spray bars.

Mount

Hydraulic Unit Level

2 in.

(5 cm)

Min. side clearance

10 in.

(25 cm)

Min. front clearance

Can be placed as close to duct as possible leaving room for inlet water, drain and spray bar connections.

24 in. (60 cm) Min. top clearance

Floor mount to ensure duct module drain pan to hydraulic

unit connection and the drain line can be adequately sloped.

Drain below drain pan outlet.

Figure 18: MHTC Reflow Hydraulic Unit Installation Location / Clearance


Plumbing

 All water supply and drain line connections must be installed in accordance with local plumbing codes.

 Install water shut off valve and union before humidifier to facilitate servicing.

 P Trap is required on the drain of the MHTC Flow / MHB and on the overflow of the MHTC

Reflow. Min. height is 6 in. (15 cm) or duct static pressure + 2 in..

 Insure drain line and overflow line are min 1.25 in. (32 mm) ID.

 Spray bar elbows are provided over size so they can be cut down to required length.

 High hardness supply water will require increased maintenance and more frequent replacement of evaporative media.

 Unit damage caused by water quality outside of the specified ranges is not covered under warranty.

Note:

 Supply untreated potable water, reverse osmosis water, fully demineralised water or partly softened water. Do not treat water with corrosion inhibitors, disinfectants or other chemicals.

 If fully demineralised water is used then use plastic or stainless steel components for all plumbing connections.

Note: Single stage appearance

Figure 19: MHTC Flow / MHB Plumbing Installation


Spray bar Elbow(s)

1/2 in (13 mm) OD tube.

Cut to required length.

Pressure Equalization Line

3/8 in.(9.5 mm) ID hose.

Connect to nipple on reservoir and to port in duct wall (by others) downstream of duct module.

Drain Pan Connection

Use 2 in. (51 mm) ID hose cuff (provided). Slope 1/2 in.

(13 mm) per 12 in. (30 cm)

min.

Overflow

Use 2 in. (51 mm) ID hose cuff (provided)

Spray Bar Lines

1/2 in.(13 mm) ID EPDM hose or better.

Connect staging valve(s) to spray barb elbows with hose (by others).

Staging Valve(s)

1/2 in (13 mm) OD hose barb

P Trap

6 in. (15 cm) min or duct static pressure + 2 in.

whichever is greater.

Figure 20: MHTC Reflow Plumbing Installation

Water Inlet

3/4 in. BSP

(1/2 in. NPT adapter provided)

Drain

2 in. (50.8 mm). ID hose cuff

Always install a water shut-off valve and union

1.25 in. (32 mm) ID min.

Maintain slope


Electrical

Note:

All MH models operate on 120 VAC, single phase, 60 HZ power. Refer to specification label for power requirements.

Note:

1 Dedicated external fused

disconnect must be installed.

.

circuit protection as indicated

on the specification label.

2 Ensure that adequate power is

available to carry full MH

amp draw as indicated on the

specification label.

3 All wiring must be in accordance

with national and local electrical

codes.

4 For MHTC Reflow and Flow wire

hydraulic unit as shown .

120 VAC

Single Phase Supply

Ground

L1

Neutral

MHPrimary Power

Dedicated circuit breaker or fused disconect.

E

X

T

I

N

T

Ground

L1

Neutral

Control Panel

Install wiring (by others) between control panel and hydraulic unit terminal blocks.

Connect corresponding numbered terminals.

High voltage terminal block

Hydraulic Unit

Figure 21: MHTC Reflow Electrical Primary Power and Hydraulic Unit Wiring


MHTC/ MHB Controls

Humidification controls are available from Nortec as accessories or can be supplied by others.

Temperature controls for cooling applications are not available from Nortec and must be supplied by others. The following information is relevant to all controls, factory supplied or otherwise.

 The MHTC can be operated with one modulating demand input or one transducer input.

 The MHB can be operated with one modulating input.

 Both the MHTC and MHB can be operated as On/Off.

 The MHTC humidifier control type can be configured via its LCD and keypad.

 Both the MHTC and the MHB include a 24 VAC safety input which must be made in order for the humidifiers to operate and which is used for controlling On/Off operation.

The MH humidifier can be configured to operate with the following control configurations.

Table 7: Humidifier Control Configurations

Single

Channel

Configurations

Modulating Demand

On/Off Safety**

Transducer Control

On/Off Safety**

MHTC

0-5*, 1-5, 0-10*, 2-10,

0*-16, 3.2-16 VDC

0-20*, 4-20 mA

0-5, 1-5, 0-10, 2-10, 0-

16, 3.2-16 VDC

0-20, 4-20 mA

N/A

MHB

0-10 VDC

On/Off

On/Off Control**

On/Off Safety**

24 VAC Dry Point 24 VAC Dry Point

* Transducer controls which have a possible 0 input are not recommended.

** All On/Off controls must be wired in series and connected to terminal 2 of the control terminal strip.


Note: Regardless of selecting On/Off or modulating control method, Nortec humidifiers must have a closed circuit across their On/Off security loop control terminal to operate.

Nortec highly recommends the use of a high limit humidistat and an air proving switch in series for this function.

Nortec Controls

Nortec provides optional On/Off controls, modulating humidistats, or humidity transducers as shown in Figure 22, Figure 23, and Figure 24. Controls are available either wall mounted with integrated sensor, wall mounted with a remote sensor, or duct mounted with integral sensor.

On/Off Controls

On/Off controls are used in all Nortec humidifier security loops. The digital humidistat can also be used as a space humidity controller, duct humidity controller, or duct high limit. These controls include:

 Air Proving Switch – duct mounted, pressure differential switch, adjustable set point from

0.07 IWC to 12.0 IWC, good for positive, negative or differential pressure applications, stops

MH if duct air pressure is not sensed. Turns MH off if air handler fails.

 Duct Mounted Digital Humidistat – On/Off control based on setpoint, adjustable set point from 15-90% RH with accuracy fixed at ±3% at 25°C, operating range of 0-95% RH, closes on humidity drop and opens on rise.

 Wall Mounted Digital Humidistat – On/Off control based on setpoint, adjustable set point from 15-90% RH with accuracy fixed at ±3% at 25°C, operating range of 0-95% RH, closes on humidity drop and opens on rise.

 On/Off Controls Supplied by Others – Can be used as long as they have a dry set of contacts capable of passing a 24-VAC, 2-A maximum signal.

2548731 - On/Off Wall Humidistat 2548732 - On/Off Duct Humidistat 1329203 - Air Proving Switch

Figure 22: Nortec On/Off Controls

Modulating Humidistats

Modulating Controls are used to send a modulating demand signal to the MHTC. MHTC models can accept different signals (see Table 7: Humidifier Control Configurations) Nortec supplied controllers send a 0-10 VDC demand signal. The MH stages its output to follow the signal. These controls include:


 Wall Mounted Digital Humidistat with Integrated Sensor – control of output, adjustable set point from 15-90% RH with accuracy fixed at ±3% at 25°C, outputs a 0-10 VDC signal.

 Wall Mounted Digital Humidistat Without Sensor – control of output, adjustable set point from 15-90% RH with accuracy fixed at ±3% at 25°C, outputs a 0-10 VDC signal. Requires a remote transducer sensor supplying a 2-10 VDC signal.

 Duct Mounted Digital Humidistat With Sensor – This package comes with both a remote sensor and a wall mounted controller without sensor. Control of output, adjustable set point from 15-90% RH with accuracy fixed at ±3% at 25°C, outputs a 0-10 VDC signal.

1510142 - Digital Wall Humidistat

2520261 - Digital Wall W/O Sensor

1509858 - Wall Sensor

2520266 - Digital Duct Humidistat Package

Figure 23: Nortec Modulating Humidistats

Humidity Transducers

Transducer send RH signals back to either a controller or back to the MH. The MHTC not the

MHB can accept a direct transducer signal. The sensors include:

 Wall Mounted Humidity Transducer – Sensor, output of 2-10 VDC, range of 0 to 95% RH.

 Duct Mounted Humidity Transducer – Sensor, output of 2-10 VDC, range of 0 to 95% RH.

 Transducer Sensor By Others – Humidity sensors that rise linearly with the sensed RH in the room.

1509858 - 2-10V Wall Humidity Transducer 1509857 - 2-10V Duct Humidity Transducer

Figure 24: Nortec Humidity Transducers


Outdoor Temperature Reset

The outdoor temperature sensor is used to prevent condensation on windows or other surfaces that are adjacent to outdoor air. This sensor can be used in conjunction with the Nortec digital

On/Off and modulating controllers. The sensor allows the controller to override the set point to prevent the humidifier from humidifying when condensation could be possible (see Figure 25).

Install the temperature sensor near the fresh air intake.

Figure 25: Outdoor Temperature Reset

2520263 - Outdoor Temperature Sensor

Figure 26: Outdoor Temperature Sensor

Control Acceptance Configured at Factory

Nortec offers factory configuration of controls to match those that will be used at site. Factory configuration eliminates the need to configure the MHTC in the field and makes it plug and play with respect to software configuration

Table 8: Factory Configured Control Acceptance Part Numbers

Signal

0-5 VDC

0-20mA

4-20 mA

0-10 VDC

0-16 VDC

1-5 VDC

2-10 VDC

0-20 VDC

Single Channel Single Channel

Demand Transducer

2523060

2523062

2523064

2523066

2523090

2523092

2523094

2523096

2523100

2523102

2523105

2523110

2523112

2523114

2523116

2523118


Control Location

The humidity controls, whether controller or transducer, must be installed in a location which best represents the space that is being humidified. The preferred location for the humidity control is in the return air duct.

Caution:

Failure to wire the MH in accordance with the wiring instructions could cause permanent damage. Such errors will void the warranty.

1

Air

Proving

Switch

2

Humidity/

Temperature

Control

(return air duct or in room)

Figure 27: Control Location

1 Air Proving Switch

 Locate so that it can sense air flow or lack of it.

2 Humidity / Temperature Control

 MHTC can be Modulating, On/Off, or a Humidity Sensor. MHB can be On/Off.

 Can be located either in return air duct (preferred) or in room being humidified / cooled.

 Mount in area representative of room humidity / temperature (draft, doorways, sunlight, or overhang such as a shelf can affect reading). Avoid placing near discharge diffuser of humidified / cooled air.

Note: Regardless of selecting on/off or modulating control method, The MH must have a closed circuit across its On/Off security loop control terminal to operate.

Nortec highly recommends the use of an air proving switch for this function.


Control wiring

The MHTC control terminal strip is shown in Figure 28 along with a brief description of each of the inputs/outputs. The figure also shows the MHTC remote relay board. For wiring use minimum of 18 AWG and keep as short as possible.

24 VAC power output for safety loop and On/Off controls

On/Off input - safety loop and On/Off controls

Ground reference for control signals

Control input - demand or transducer

Not used

5 VDC reference voltage

Ground

Activates staging valve 1



Ground for staging valves

24 VDC power

Level sensor input

Activates fill valve

Activates drain valve

Ground

Activates UV light

Ground

Activates pump

Ground

24 VAC Power

Ground

Input from conductivity sensor

Ground

Remote Relay Board

(Not present with Links XPS)

MHTC Control Terminal Strip

17

18

19

20

21

22

23

24

M

H

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

13

14

15

16

8

9

10

11

E

X

T

E

X

T

12

24 VAC

On/Off Loop

Ground

Control Signal

N/A

+5 VDC

Ground

Stage 1

Stage 2

Stage 3

Ground

24 VDC

Level Sensor

Fill Valve

Drain Valve

Ground

UV Light

Ground

Pump

Ground

24 VAC Power

Ground

Conductivity Sensor

Ground

Figure 28: MH Humidifier Control Terminal Strip


Nortec Links XPS (Optional MHTC Only)

Nortec LINKS XPS is an option that can be integrated with the MHTC. It allows a Building

Management System to monitor and / or control the humidifier.

See Nortec publication Links XPS MHTC Installation and Operation Manual for detailed information about Nortec LINKS XPS and its operation and configuration.

Table 9: Nortec Links XPS Recommended Wire Types and Lengths

Protocol Signal Type Polarity

A B

Recmended Cable

BACnet /MSTP

Johnson N2

EIA-485,

2-wire

Net + Net -

18-24 AWG

Shielded, Twisted

Pair

BACnet /IP

LAN Standard N/A N/A

Lonworks EIA-232,

2-wire

Tx Rx

CAT. 5E cable with

RJ-45 termination

18-24 AWG

Twisted Pair

Max. Recommended Distance from Nortec Module

2000 ft at 9,600 bps

2000 ft at 38,400 kbps

Depends on cable manufacturer

Should not exceed 50 ft

Figure 29: Sample Network with Nortec Links XPS



43 | Warranty

Warranty

Walter Meier Inc. and/or Walter Meier Ltd. (hereinafter collectively referred to as THE

COMPANY), warrant for a period of two years after installation or 30 months from manufacturer’s ship date, whichever date is earlier, that THE COMPANY’s manufactured and assembled products, not otherwise expressly warranted (with the exception of the media), are free from defects in material and workmanship. No warranty is made against corrosion, deterioration, or suitability of substituted materials used as a result of compliance with government regulations.

THE COMPANY’s obligations and liabilities under this warranty are limited to furnishing replacement parts to the customer, F.O.B. THE COMPANY’s factory, providing the defective part(s) is returned freight prepaid by the customer. Parts used for repairs are warranted for the balance of the term of the warranty on the original humidifier or 90 days, whichever is longer.

The warranties set forth herein are in lieu of all other warranties expressed or implied by law. No liability whatsoever shall be attached to THE COMPANY until said products have been paid for in full and then said liability shall be limited to the original purchase price for the product. Any further warranty must be in writing, signed by an officer of THE COMPANY.

THE COMPANY’s limited warranty on accessories, not of the companies manufacture, such as controls, humidistats, pumps, etc. is limited to the warranty of the original equipment manufacturer from date of original shipment of humidifier.

THE COMPANY makes no warranty and assumes no liability unless the equipment is installed in strict accordance with a copy of the catalog and installation manual in effect at the date of purchase and by a contractor approved by THE COMPANY to install such equipment.

THE COMPANY makes no warranty and assumes no liability whatsoever for consequential damage or damage resulting directly from misapplication, incorrect sizing or lack of proper maintenance of the equipment.

THE COMPANY makes no warranty and assumes no liability whatsoever for damage resulting from freezing of the humidifier, supply lines, or drain lines.

THE COMPANY retains the right to change the design, specification and performance criteria of its products without notice or obligation.

Warranty | 44

U.S.A.

Walter Meier (Climate USA) Inc.

826 Proctor Avenue

Ogdensburg, NY 13669

CANADA

Walter Meier (Climate Canada) Ltd.

2740 Fenton Road

Ottawa, Ontario K1T 3T7

TEL: 1.866.NORTEC1

FAX: 613.822.7964

EMAIL: [email protected]

WEBSITE: www.humidity.com

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