An Investigation onOptimal Personal Heaters

UBC Social Ecological Economic Development Studies (SEEDS) Student Report
An Investigation on
Optimal Personal Heaters
Amar Manj, Dong Lin Xuan, William Geng, Ziqian Wang
University of British Columbia
APSC 262
April 09, 2015
1071
1796
Disclaimer: “UBC SEEDS Program provides students with the opportunity to share the findings of their studies, as well
as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this
is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these
reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned
in a report or a SEEDS team representative about the current status of the subject matter of a project/report”.
The University of British Columbia
APSC 262 - Technology and Society II
Tutorial Instructor: Dr. Naoko Ellis
An Investigation on
Optimal Personal Heaters
Submitted by:
William Geng
Amar Manj
Ziqian Wang
Dong Lin Xuan
April 9, 2015
i
ABSTRACT
This report provides an in-depth analysis on the selection of an optimal office
space heater to serve as a replacement for the current 1500W convection heaters
that are used by the UBC staff. Available models currently on the market are
investigated using the triple bottom line analysis.
The methods of investigation for this project consisted of gathering both primary
and secondary data. Primary data consists of only user reports and company
datasheets. Secondary sources include peer-reviewed journal articles and online
articles. Within the economic aspect of the triple bottom line, the purchase cost,
payback period and energy cost savings were evaluated with the assumption that
the heater was used for a fixed number of hours per year. This analysis
determined that the Lifesmart/LS-IQH-DMICRO-IN is the best economical choice.
The environmental aspect compared energy savings and greenhouse gas
emissions during the manufacturing process. For the social aspect, user
experience and safety are taking into consideration along with manufacturer
background. The final recommendation for UBC is to only offer the Lifesmart/LSIQH-DMICRO-IN heater to staff members requiring additional heat during the
winter.
ii
Table of Contents
ABSTRACT ....................................................................................................................................................................... i
List of Equations ........................................................................................................................................................... iv
List of Figures ................................................................................................................................................................ iv
List of Tables ................................................................................................................................................................. iv
GLOSSARY ...................................................................................................................................................................... v
LIST OF ABBREVIATIONS ............................................................................................................................................... vi
1.0 INTRODUCTION........................................................................................................................................................1
2.0 METHODS OF INVESTIGATION .................................................................................................................................2
2.1 PRIMARY SOURCES ..............................................................................................................................................2
2.2 SECONDARY SOURCES .........................................................................................................................................2
3.0 COMPARISON OF DIFFERENT TYPES OF HEATERS ...................................................................................................3
3.1 FAN-FORCED HEATERS .........................................................................................................................................3
3.1.1 BACKGROUND...............................................................................................................................................3
3.1.2 ADVANTAGES AND DISADVANTAGES ...........................................................................................................4
3.2 OIL-FILLED HEATER ..............................................................................................................................................4
3.2.1 BACKGROUND...............................................................................................................................................4
3.2.2 ADVANTAGES AND DISADVANTAGES ...........................................................................................................5
3.3 CERAMIC HEATER ................................................................................................................................................5
3.3.1 BACKGROUND...............................................................................................................................................6
3.3.2 ADVANTAGES AND DISADVANTAGES ...........................................................................................................6
3.4 INFRARED HEATER ...............................................................................................................................................7
3.4.1 BACKGROUND...............................................................................................................................................7
3.4.2 ADVANTAGES AND DISADVANTAGES ...........................................................................................................7
3.5 CONCLUSION OF THE COMPARISONS .................................................................................................................8
4.0 TBL ASSESSMENT OF INFRARED HEATER MODELS ..................................................................................................8
4.1 ECONOMIC ASPECTS ............................................................................................................................................9
4.1.1 Product Price: ...............................................................................................................................................9
4.1.2 Electricity Savings .......................................................................................................................................10
4.1.2 Payback Period ...........................................................................................................................................11
4.2 ENVIRONMENTAL ASPECTS ...............................................................................................................................12
4.2.1 Carbon Emission .........................................................................................................................................12
4.2.2 Energy Efficiency Settings and Controllability ............................................................................................12
4.3 SOCIAL ASPECTS.................................................................................................................................................13
iii
4.3.1 Manufacturer Background ..........................................................................................................................13
4.3.2 Safety ..........................................................................................................................................................14
4.3.3 Comfort-Related Features ..........................................................................................................................15
5.0 CONCLUSION AND RECOMMENDATIONS .............................................................................................................16
References ...................................................................................................................................................................18
iv
List of Equations
Equation 1: Calculating Electricity Cost per Year .........................................................................................................10
List of Figures
Figure 1: Typical Fan Forced Heater ..............................................................................................................................3
Figure 2: TYPICAL Oil-Filled HEATER ..............................................................................................................................5
Figure 3: A Typical Portable Ceramic Heater .................................................................................................................6
Figure 4: Portable Infrared Heater ................................................................................................................................7
Figure 5: LifeSmart New Infrared Technology .............................................................................................................15
List of Tables
Table 1: Purchase cost of selected models ....................................................................................................................9
Table 2: Power of selected models ..............................................................................................................................10
Table 3: Electricity Savings Comparison between chosen Models and the Standard 1500W Personal Heater ..........11
Table 4: Payback Period of Selected Models ...............................................................................................................11
Table 5: Energy Efficiency Settings and Controllability Features of Selected Models .................................................13
Table 6: Safety Feature of Chosen Models ..................................................................................................................14
Table 7: Additional Comfort Related Feature of Four Models ....................................................................................15
Table 8: Summary of Triple Bottom Line Assessment .................................................................................................16
v
GLOSSARY
Ventilator
a device that blows fresh air into the room and
expels dirty air
Payback Period
the period of time required to recover the cost
of an investment.
vi
LIST OF ABBREVIATIONS
TBL
Triple Bottom Line
HVAC
Heating, ventilating, and air conditioning
1
1.0 INTRODUCTION
During the long cold winter months in Vancouver, faculty and staff of UBC
rely on the old HVAC systems to keep them warm and cozy throughout the day.
The HVAC system, however, is inefficient as many staff members have purchased
their own personal heaters for their offices. As more space heaters are purchased
and used, there is a great increase in the energy demand.
Assuming that the staff members utilize a standard 1500W air convection
heater, there would be a large burden on UBC’s power consumption. Even though
such a model could be cheaper and provide an adequate level of comfort, it
would be wasteful. Each 1500W air convection heater could take up to 1% of the
building’s power when in full cycle, and the heated air could still escape through
opened office doors or any other free air-flowing area. This “escaped” heat
confuses the temperature sensor of the HVAC system -- triggering unnecessary
cooling during the winter time.
To address the issue, UBC SEEDS is working to create a trade-in program for
employees in which they could trade-in their old heaters for a more sustainable
heater for free. The purchase cost as well as the trade-in cost would be recouped
from later electricity cost savings.
This report explores the four major types of heaters available on the
market: Fan-Forced air convection heater, Ceramic heaters, Oil-filled heaters, and
Infrared radiant heaters. By evaluating the advantages and disadvantages of each
type of heater, an optimal heater type is selected to replace the standard air
convection heaters. Based on the type of heater selected, different models of the
chosen type are compared and contrasted using the triple bottom line
assessment.
2
2.0 METHODS OF INVESTIGATION
As shown in the subsections below, the investigation began with an
extensive literary review of primary and secondary sources. A general consensus
is achieved upon analyzing the collected data, thus revealing the generic features
of each of the space heater models.
2.1 PRIMARY SOURCES
Primary sources include consumer reports and customer reviews found on
popular retail store websites such as Best Buy and Home Depot. These reports not
only detail the functionalities of specific heater models but also reveal their
defects. Also, by analyzing the consumers’ review on the space heater, a list of
social, environmental, and economic aspects are compiled. The main aspects
found in consumer reviews were then utilized as indicated for the TBL assessment.
For example, factors such as comfort and safety are evaluated under social
indicators. Other factors such as purchase cost and expected lifespace are used as
economic indicators.
2.2 SECONDARY SOURCES
The secondary sources consulted include product specifications, user
manuals on websites, peer-reviewed academic journal articles about personal
space heaters, and previous TBL assessment reports relevant to this project. The
reason for choosing similar (past) TBL reports is because they provide a broad
idea about how the project objective can be achieved, and what part of the
project can be better conducted. Moreover, quantitative reviews of peerreviewed academic journal articles provide indispensable background information
and knowledge of this project.
3
3.0 COMPARISON OF DIFFERENT TYPES OF HEATERS
The space heaters can be divided into two broad categories: Gas heaters
and Electric heaters. Since the heaters are to be used in UBC workspaces, safety,
portability and ease of use are major aspects of consideration. Gas heaters are
hard to install and using gas can be dangerous due to the risk of fire and gas leaks.
As a result the investigation is focused on the four popular types of electric
heaters: Fan-forced air convection heaters, Oil-filled heaters, Ceramic heaters,
and Infrared Radiant heaters.
3.1 FAN-FORCED HEATERS
Fan-forced heaters (Figure 1) are a popular type of heater with a price range
from $10 to $600 (Home Depot, 2015). It is widely used in the home places.
3.1.1 BACKGROUND
Fan-forced heaters are heated by passing electric current through the coil
elements, thus heating the coils inside the heater. A built-in ventilator blows the
air through the heated coils while heating the air in the process.
F IGURE 1: TYPICAL FAN F ORCED H EATER
Source: http://www.worldmkting.com/sites/default/files/HB211T.jpg
4
This process then forces the hot air to circulate the room, thus raising the
temperature in the room.
3.1.2 ADVANTAGES AND DISADVANTAGES
Fan forced heaters are relatively cheap to purchase since the design is
extremely simple. The use of ventilator not only speeds up the heating process
but also evenly distributes the heat throughout the room.
As the fan operates, an audible noise is generated which would be
disruptive for users requiring a quiet workspace. The heated air reduces the
humidity of the office creating a dry environment for the user. Moreover, the
heated air tends to escape the room from window leakages and opened doors,
further extending the “On” cycles and wasting energy.
3.2 OIL-FILLED HEATER
The price range of the Oil-filled heater (see Figure 2) varies greatly: $30 to $300
(Home Depot, 2015)
3.2.1 BACKGROUND
The Oil-filled heater consists of metal columns with cavities. It contains oil
acting as a heat reservoir which circulates the heater and heats up the fins of the
heater.
5
F IGURE 2: TYPICAL O IL -FILLED HEATER
Source: http://www.homedepot.ca/wcsstore/HomeDepotCanada/images/catalog/17124.CYAA45-7T 4.jpg
The surface of these fins is in contact with air and thus heats up the room through
the process of convection.
3.2.2 ADVANTAGES AND DISADVANTAGES
Oil-filled heaters uses natural air circulation to heat the room (heated air
rises while cooler, more dense air sinks to be heated by the metal columns), and
operates silently.
The natural circulation, however, results in a much slower temperature
increase when turned on. This effect is not desirable especially when staff
members arrive in the morning while the office is very cold. Similar to the Fanforced heaters, the heated air will escape the room through opened doors and
window leakages, hence reducing its effectiveness in heating.
3.3 CERAMIC HEATER
The Ceramic heater’s (Figure 3) price ranges from $15 to $250 (Home
Depot, 2015)
6
3.3.1 BACKGROUND
The working principle of the ceramic heater is similar to the fan-forced
heater.
F IGURE 3: A TYPICAL P ORTABLE C ERAMIC HEATER
Source: http://www.veotag.com/images/delonghidch1030safeheat-1.jpg
It generates heat by passing electric current through the electrically heated
ceramic and aluminum plates, while relying on a blower fan to distribute heat.
3.3.2 ADVANTAGES AND DISADVANTAGES
Ceramic heater has the lowest price among the electric heaters. Fans and
thermostats inside the heater prevent it from overheating. Moreover, many
ceramic heaters have the oscillating feature which allows them to heat the room
faster and more effectively.
The ceramic heater does, however, operate loudly and produces dry heat.
Dust could potentially accumulate on the ceramic plates while the heater is not
in-use and be blown into the air when turned on. This would pose as a safety
concern, if not hazard, to people with respiratory problems and allergies.
7
3.4 INFRARED HEATER
The price range of the infrared heater varies between $25 to $600 (Home
Depot, 2015).
3.4.1 BACKGROUND
Infrared heaters, as seen in Figure 4, use a built-in infrared lamp to emit invisible
infrared light at an adjustable intensity. This light increases the temperature of
the object it makes contact with, without heating the air.
F IGURE 4: P ORTABLE I NFRARED H EATER
Source: http://www.o-digital.com/uploads/2179/2196-3/Infrared Heater IH a 115.jpg
3.4.2 ADVANTAGES AND DISADVANTAGES
Similar to the sunlight’s warmth, the infrared heater operates without
heating the air and provides comfortable heat to the user. It is energy efficient
since it only heats objects covered by the infrared light. In addition, it operates
silently and requires minimal maintenance.
Since the infrared heater’s surface operates at a high temperature, it
carries a potential burn hazard. Additionally, turning the power off causes the
8
heat to turn off immediately. Another flaw for this heater is that it heats in certain
directions, and therefore, limits the user’s movement around the room.
3.5 CONCLUSION OF THE COMPARISONS
The four types of heaters, each have their own advantages and
disadvantages. Ceramic heater and Fan-forced heater are relatively cheaper and
they heat the room fast and evenly. Unfortunately, they both operate with an
audible noise, reduce air humidity, and blow dust and other allergens into the air.
The oil-filled heater is relatively safer, but it heats slowly and is hard to maintain a
consistent, desirable temperature. The infrared heater is preferred because of its
silent and comfortable heat. Additionally, it will not trigger HVAC cooling as the
air in the office would not be directly heated. The general temperature of the
building will still be controlled by the HVAC system while infrared heaters can
provide additional heat directly to the user as needed. Since there are not many
children or pets around the office areas, the burning hazard of accidentally
touching the inner components of the heaters can be viewed as a small risk.
Based on the advantages and disadvantages listed for each type of heater,
it is safe to recommend Infrared heater. The UBC SEEDS project coordinator
explained that social aspects are to be considered, before environmental, and
finally economic. Therefore, as the conclusion of this section, infrared heater is
selected as a favorable type of heater for use in the UBC workspaces.
4.0 TBL ASSESSMENT OF INFRARED HEATER MODELS
In the previous section, we concluded that the infrared heater is the
recommended heater type. In order to recommend a specific heater model,
different infrared heaters are compared in economic, environmental, and social
aspects. As mentioned previously, priority is given to social aspects first, then
environmental, and finally economic. The four heater models are from Home
Depot, each with a limiting heated area between 0 to 400 sq.ft and a consumer
rating above three stars. These factors were used to apply the TBL assessment.
9
The following models were chosen and analyzed using the triple bottom
line assessment:
1. Optimus H-4438 14 in. Oscillating Radiant Dish Heater with Remote
Control H4438
2. 250-Watt to 500-Watt Electric Parabolic Heater with Oscillation
JHS500G
3. Optimus 22 in 500 Watt 1000 Watt Oscillating Carbon Barrel Heater
with Remote Control H84001
4. Life Pro Series 400-Watt Plug-in Micro Infrared Heater with Digital
Display LS-IQH-DMICRO-IN
4.1 ECONOMIC ASPECTS
The four infrared heater models are evaluated with respect to their
economic aspects. The product price, payback period and electricity savings are
chosen as indicators.
4.1.1 Product Price:
The prices of the selected models can be seen in Table 1. Note that UBC plans on
purchasing 750 units for the staff members.
T ABLE 1: C OST OF SELECTED M ODELS
Model No.
Product Price(CAD)
Optimus/H4438
$64.97
Unbranded/JHS500G
$24.99
Optimus/H84001
$69.97
Lifesmart/LS-IQH-DMICRO-IN
$39.97
10
As the data shown on the table, the unit price of our models ranges from $24.99
to $69.97, which is an affordable range for UBC.
4.1.2 Electricity Savings
The electricity savings is a direct index showing how much a recommended
heater saves in the economic aspect. To calculate the electricity savings (per year),
simply multiply the power of a heater by its time of use, and then analyze the
difference with the electricity cost of a standard 1500W space heater. Table 2
shows the four infrared models and the corresponding power produced.
T ABLE 2: P OWER OF SELECTED MODELS
Model#
Power(Watt)
Optimus/H4438
800
Unbranded/JHS500G
250
Optimus/H84001
1000
Lifesmart/LS-IQH-DMICRO-IN
400
According to the stakeholder, the heater is assumed to run for 5 hours a
day for every five days a week. This is expected to continue for a total of 20 weeks.
The electricity rate on UBC campus is estimated at $0.0539/kWh.
E QUATION 1: CALCULATING E LECTRICITY COST PER YEAR
/ =  × ℎ/ × / × /
×  
Using the aforementioned formula (Equation 1), the electricity cost per
year of each of the infrared heaters is calculated and compared with the 1500W
Convection Heater to determine the yearly electricity savings (as shown in Table 3)
for each model.
11
T ABLE 3: ELECTRICITY SAVINGS C OMPARISON BETWEEN CHOSEN M ODELS AND THE STANDARD 1500W PERSONAL HEATER
Model #
Electricity Savings(CAD/yr)
Optimus/H4438
$18.87/year
Unbranded/JHS500G
$33.69/year
Optimus/H84001
$13.48/year
Lifesmart/LS-IQH-DMICRO-IN
$29.65/year
Note that the above numbers are representative of a single unit and that
the stakeholder plans on purchasing 750 units of space heaters.
4.1.2 Payback Period
For further analysis on the economic aspects, comparisons were made with
the payback period of the chosen models, to indicate the length of time required
for the investment to recover its initial outlay in terms of profits or savings. To
calculate the payback period, simply divide the product price of a specific model
by its calculated savings per year compared to a standard 1500W personal heater.
The resultant payback period of each model can be found in Table 4.
T ABLE 4: PAYBACK P ERIOD OF SELECTED MODELS
Model#
Payback Period (years)
Optimus/H4438
3.44
Unbranded/JHS500G
0.74
Optimus/H84001
5.19
Lifesmart/LS-IQH-DMICRO-IN
1.35
12
4.2 ENVIRONMENTAL ASPECTS
Although prioritized second, the environment plays a big role when
evaluating the triple bottom line assessment. The manufacturing companies are
often neglected when examining the impact on the environment. Another
important indicator for the environmental aspects includes the energy efficiency.
4.2.1 Carbon Emission
To analyze the carbon emission of a specific product, generally, the
emission during manufacturing and using process should be considered. The
carbon emission during the manufacturing process is hard to be determined
because there is no relative data found on the supplier’s website or even on the
manufacturers’ webpage. Since all the chosen models are infrared heaters that
consume electricity, only the carbon emissions produced during the production of
electricity need to be considered. For example, greenhouse gasses are released
during the combustion of fossil fuels, such as coal, oil and natural gas, to produce
electricity. Under this condition, the amount of carbon emission during the using
process is in direct proportion to a infrared heater’s power, meaning that low
power heaters are a product of less carbon emissions. Therefore, in order to
reduce the carbon emission of heating, a lower powered heater should be chosen.
4.2.2 Energy Efficiency Settings and Controllability
As shown in the Table 5, the selected models all have energy efficient
settings allowing the user to choose between the different heating levels. Also,
the last model is noteworthy because it has a built-in thermostat control which
can be preset with a desired temperature to automatically power the unit on and
off by detecting the room temperature.
13
T ABLE 5: ENERGY EFFICIENCY S ETTINGS AND C ONTROLLABILITY FEATURES OF SELECTED MODELS
Model#
Energy Efficiency Settings and
Controllability
Optimus/H4438
❖ 2 heat settings: 800 and 1200Watt
❖ Remote control
Unbranded/JHS500G
❖ 2 heat settings: 250 and 500-Watt
❖ Remote control
Optimus/H84001
❖ Adjustable settings
❖ Timer
Lifesmart/LS-IQH-DMICRO-IN
❖ Digital thermostat control
❖ Timer
4.3 SOCIAL ASPECTS
The stakeholder for this project emphasized the importance of the social
aspects. As mentioned in the previous sections, the key indicators for social
aspects includes topics such as safety and the overall comfort of the user.
4.3.1 Manufacturer Background
LifeSmart Corporation is a newly founded tech company, formerly Source
Network Sales and Marketing that brings new infrared heating products featuring
luxury, state-of-the-art designs and much-needed safety enhancements, all of
which received critical acclaim and recognition at the 2014 International Home +
Housewares Show in Chicago, Illinois. This Chinese based company develops
smart home solutions that are environmentally friendly and also easy to afford
(Factiva, 2015).
As the company is relative new to the industry very few third party reviews
have been found throughout the internet. Our investigation includes a 30 minute
phone interview with the customer service representative and gathered
14
information on employee welfare and environmental precautions during
production.
At LifeSmart the company is fully in compliance with the Chinese Labour
Law. Employees are ensured with fair pay, regular working hours and holidays.
Assembling factories are located in Shenzhen, Guangzhou and Shanghai with
necessary components shipped in from mostly local suppliers. The manufacturing
process of the heaters are half automated and half manual. Little carbon emission
is present during the production apart from generating electricity at local power
plants as source of power for automated production lines. The manual production
line generates no carbon emission.
The company provides heater products that are both economically and
environmentally friendly for users around the globe.
4.3.2 Safety
As shown in Table 6, all of our selected models have special features to help
improve user safety. Note that the fourth model, Lifesmart, is the only one with
the ETL listed mark, which is proof that the product is compliant with North
American safety standards.
T ABLE 6: SAFETY FEATURE OF C HOSEN M ODELS
Model #
Safety Features
Optimus/H4438
❖ Safety tip over switch
❖ Overload thermal protector
Unbranded/JHS500G
❖ Safety tip over switch
Optimus/H84001
❖ Safety tip over switch
Lifesmart/LS-IQH-DMICRO-IN
❖ Over heat safety switch
❖ ETL listed
15
4.3.3 Comfort-Related Features
The four infrared models each have special comfort-related features which
have been listed below in Table 7.
T ABLE 7: ADDITIONAL COMFORT RELATED FEATURE OF F OUR MODELS
Model #
Additional Features
Optimus/H4438
❖ 75˚ oscillation
Unbranded/JHS500G
❖ Wide angle oscillation
Optimus/H84001
❖ Ultra quiet operation
❖ Timer
Lifesmart/LS-IQH-DMICRO-IN
❖ Digital thermostat control
❖ Timer
The oscillation function of the first two models make the heater more
efficient. The last two models use timers which makes the heater easier to use.
Additionally, the Optimus H84001 contains an “ultra quiet operation”
functionality allowing its users to work without being disturbed.
F IGURE 5: LIFE SMART NEW INFRARED TECHNOLOGY
Source: http://i.ytimg.com/vi/0nyuFtxf0hc/maxresdefault.jpg
16
The Lifesmart heaters contains a digital thermostat which allows the user to
set a desired temperature while the built-in thermostat powers the heater on and
off by detecting room temperature. Lifesmart also features Wrapped Infrared
Quartz Element (see Figure 5) to provide efficient and natural warmth.
5.0 CONCLUSION AND RECOMMENDATIONS
As the triple bottom line assessment applied in the previous section, the
four infrared heater models were analyzed in all three, economic, environmental
and social aspects. The triple bottom line assessment of the four heaters is
summarized in Table 8.
T ABLE 8: SUMMARY OF TRIPLE BOTTOM L INE ASSESSMENT
As shown on the table, the last two heaters, Optimus/H84001 and
Lifesmart, have a greater advantage in the economical aspect. Considering that
social aspects such as safety and comfort are more important, recommendation is
given to the last model, Lifesmart LS-IQH-DMICRO-IN Infrared Heater. Its digital
17
thermostat control function provides the users with a major convenience.
Additionally, it’s ETL listed mark makes it more reliable in terms of safety.
The Lifesmart Life Pro Series Micro Heater provides infrared warmth in
small areas. Users can simply plug the unit into the wall and set the digital
thermostat for gentle warming infrared heat. This heater is ideal for small spaces
like under a desk, small dorm room, laundry room or bathroom. The built in
thermostat control automatically powers the unit on and off. This micro heater
also includes a timer feature as well for ease of operation.
18
References
Ali, A. H., H., & Gaber Morsy, M. (2010). Energy efficiency and indoor thermal perception: A comparative study
between radiant panel and portable convective heaters. Energy Efficiency, 3(4), 283-301.
http://dx.doi.org/10.1007/s12053-010-9077-3
BC Hydro. (n.d.). What you need to know about portable electric space heaters. BC Hydro. Retrieved from:
http://www.bchydro.com/content/dam/hydro/medialib/internet/documents/Power_Smart_FACT_sheets
/Portable_Electric_Space_Heaters.pdf
Factiva. (2015, March 31). LifeSmart; LifeSmart, New Choice to Automate Your Home. Retrieved from
https://global-factiva-com.ezproxy.library.ubc.ca/ga/default.aspx
HomeDepot(2015) H4438 Product Information. Retrieved From: http://www.homedepot.com/p/Optimus-14-inOscillating-Pedestal-Digital-Dish-Heater-with-Remote-ControlH4438/205495061?N=5yc1vZc8oeZ2bctm5Z2bctm6Z2bcu02Z2bcu04Z2bcu05
HomeDepot(2015) JHS500G Product Information. Retrieved From:http://www.homedepot.com/p/Unbranded250-Watt-to-500-Watt-Electric-Parabolic-Heater-with-OscillationJHS500G/205743593?N=5yc1vZc8oeZ2bctm5Z2bctm6Z2bcu02Z2bcu04Z2bcu05
HomeDepot(2015) H84001 Product Information. Retrieved From:http://www.homedepot.com/p/Optimus-500Watt-1000-Watt-22-in-Oscillating-Carbon-Barrel-Heater-with-Remote-ControlH84001/205433937?N=5yc1vZc8oeZ2bctm5Z2bctm6Z2bcu02Z2bcu04Z2bcu05
HomeDepot(2015) LS-IQH-DMICRO-IN Product Information. Retrieved
From:http://www.homedepot.com/p/Lifesmart-Life-Pro-Series-400-Watt-Plug-in-Micro-Infrared-Heaterwith-Digital-Display-LS-IQH-DMICROIN/205422939?N=5yc1vZc8oeZ2bctm5Z2bctm6Z2bcu02Z2bcu04Z2bcu05 Previous Seeds Project
LifeSmart Corp. (2015, March 15). Infrared Quartz Heater User Manual. Retrieved from
http://lifesmartproducts.com/wp-content/uploads/2014/06/LS-IQH-DMICRO-OM-Rev1-052914.pdf
Marina Oster, ( 2010, March) Space Heaters vs. Central Heating: Essential Question Retrieved from:
https://alumni.stanford.edu/get/page/magazine/article/?article_id=29533
Will, Henry, (2015, January 6) Which is the Most Energy Efficient Space Heater? 6 Reviews & Some Tips Retrieved
from: http://gadgetboy.hubpages.com/hub/Which-is-the-Most-Energy-Efficient-Space-Heater-5-ReviewsSome-Tips
Williams, K. (2004). Selecting space heaters. Plant Engineering, 58(4), 52-54. Retrieved from
http://search.proquest.com.ezproxy.library.ubc.ca/docview/221012713?accountid=14656
Download PDF