20230120INT to Staff Attachment - Response to No. 31_48520 Attch 6_ASHRAE_ESC-GHP_Guide 2022 IGC.pdf

Table of Contents:
Efficient &
Affordable
Natural Gas
Heat Pumps
1
What is a Heat Pump / How It Works
Introduction to Gas Heat Pumps
Why are Gas Heat Pumps Important
Types of Heat Pumps
Heat Sources
Efficiency
Economics
Environmental Benefits
Comfort
Applications
Markets
Supporting Grid Reliability by Reducing Electric Demand
GHP Product Status
Applicable Codes and Standards
GHP Resources
Disclaimer
This guide is intended to provide an overview of natural gas fired heat pumps, benefits associated with such
systems, and market opportunities. The guide includes some background and provides an understanding of gas
heat pump (GHP) technologies and applications.
This Guide: a) Makes no warranty or representation, express or implied, with respect to the accuracy,
completeness, or usefulness of the information contained within, or b) Assumes any liability with respect to the
use of or for damages resulting from the use of any information disclosed in this guide.
© December 2021 Energy Solutions Center Inc. – All Rights Reserved

2
What is a heat pump? / How does it work?

Heat pumps are systems that transfer thermal energy from a heat source to a heat sink. Thermal energy is moved
in the opposite direction of spontaneous heat flow. Heat pumps use energy to accomplish the desired transfer of
thermal energy from heat source to heat sink. In short, a heat pump running in heating mode functions in the
same way as a standard air conditioner running in reverse, so instead of rejecting heat to the outdoors when
cooling, it is extracting heat from outdoor air or another source and transferring that heat to the indoor space.

Heat pumps come in a variety of configurations such as air source, water source, and ground source. In this
guide we will discuss natural gas fired heat pumps along with their economic, environmental, and resiliency
advantages & benefits.

Introduction to Gas Heat Pumps

Natural Gas Heat Pumps (GHP) are heat pumps that utilize the
combustion of natural gas to drive the heat pump system. All heat
pumps require a source of heat which can be from the surrounding air,
a water source or the ground. Gas fired heat pumps have an advantage
as they can capture additional heat off the combustion process to
improve
overall
efficiency and
work much
better in
colder
climates. The
graph to the left
shows how gas
heat pumps
maintain high
heating
effectiveness as the temperature drops. Electric Heat
Pumps (EHP) require a back-up heating system to
provide heat when no more heat can efficiently be
extracted from the air or another source. GHPs maintain greater heating capacity across various source
temperatures.

Why Gas Heat Pumps Are Important

Natural gas heat pumps have system efficiencies that exceed the traditional 100% barrier and offer pathways to
substantially reduce greenhouse gas emissions across various climates for both residential and commercial
space and water heating sectors. With new North American Greenhouse Gas (GHG) reduction targets on the
horizon, governments will demand more efficient HVAC technologies, to meet standards not currently met by
traditional boilers and furnaces. Several gas heat pumps are commercially available today and more

Sources:
https://www.energy.gov/sites/default/files/2014/01/f6/4_3a_ba_
innov_buildingscienceclimatemaps_011713.pdf
https://www.energyvanguard.com/blog/do-you-know-your-
building-science-climate-zone/

(Graph courtesy of Stone Mountain Technologies)

3
manufacturers will enter this market in the near future. Continued advancements in the development of gas heat
pumps provides a viable and effective option for reaching aggressive climate action targets such as net-zero
emissions by 2050. With the ability to operate on renewable natural gas today and hydrogen tomorrow, natural
gas heat pumps will be an attractive solution to meet future emission reduction goals.

In addition, natural gas heat pumps offer the following advantages:
• Ability to operate on RNG and hydrogen to reduce emissions
• Ability for some models to operate without the use of harmful refrigerants (No Global Warming
Potential)
• Ability to reduce electricity grid constraints by not having to upgrade electrical infrastructure
• Higher performance in cold climates because GHPs use gas combustion to deliver the majority of the
system’s heating load
• Technical feasibility to overcome retrofit barriers compared to alternatives
• Lower operating costs as compared to existing gas heating equipment or EHPs

Heat Sources

Heat pumps extract heat
from a heat source and
deliver that heat to a heat
sink. Air, water and the
ground can all act as heat
sources for heat pumps.
Both gas and electric heat
pumps can be configured to
extract heat from an air
source, water source or
ground source and move
that heat to a home or
business to heat it.

Types of Gas Heat Pumps

Heat pumps extract heat from outdoor air, a water source or a ground source and moves to the inside of a home
or business. Before discussing how gas heat pumps work, it is helpful understand the basic principles of the
vapor compression cycle used in typical air conditioners to provide cooling. In cooling mode, refrigerant is
compressed and the hot gas is moved to the condenser (outside coil) where it is condensed into a high pressure,
high temperature liquid. This liquid moves through an expansion devise device lowering the temperature and
pressure before it enters the evaporator (inside coil) where air is circulated around this coil to cool the space. In
heating mode, a reversing valve is added to the system to allow the system to run in reverse to provide heating.

4

Engine Driven Heat Pumps
Engine-driven gas heat pump air conditioning systems
utilize an efficient reciprocating engine running on
natural gas to produce the shaft horsepower to turn a
vapor compressor. Gas engine driven heat pumps use the
same vapor compression cycle as electric heat pumps
with the electric motor being replaced with an engine that
runs on natural gas. The primary advantage of a natural
gas engine-driven heat pump is the operating cost. This
image shows the system in heat mode.

Commercially Available Engine Driven Heat Pumps:
Company Website
Aisin World Corp. of America www.aisinworld.com
Blue Mountain Energy www.bluemountainenergy.com
Gridiron https://www.gridironenergy.com/
Tecogen https://www.tecogen.com/heat-pumps
Yanmar America https://www.yanmarenergysystems.com/vrf/

5

Absorption Heat Pumps
Natural gas absorption heat pumps differ from
traditional electrical heat pumps. Instead of
consuming electric energy to operate a vapor
compression cycle, absorption heat pumps
consume gas to heat a solution of water and
ammonia or Lithium Bromide in a completely
sealed absorption circuit.

Absorption heat pumps are hydronic type
systems, as they heat and/or cool water in order
to heat and/or cool the air. The system is similar
to a vapor compression cycle, but instead of a
motor and compressor, absorption systems use a
generator, pump and absorber. There are
multiple absorption heat pump configurations available. This image shows an absorption-based heat pump in
heating mode.

Commercially Available Absorption Heat Pumps:
Company Website
Broad USA https://broadusa.com/broad/
Energy Concepts www.energy-concepts.com
Homy / Vicot www.homybuild.ca
Robur www.roburcorp.com

Thermal Compressors
Thermal Compression heat pumps represent a new emerging category of efficient heating,
cooling, and hot water appliances. Thermal energy provided by the combustion of natural gas
powers a unique thermodynamic cycle. Helium is heated, increasing its pressure, and this heat is
removed and sent to a home or building for space heating or for hot water. As heat is removed,
the pressure of the helium drops, causing a cooling effect that can be removed and used for
cooling in a home or building. A pressure wave is established that “pumps” recovered heat from
the cold end of the unit into the warm end, causing a “heat pump” effect that increases
efficiency. This process does not employ phase change for heat transfer. The system offers a
broad temperature range up to 165⁰F and down below freezing. This type of system utilizes no
ozone depleting refrigerants.
Courtesy of ThermoLift

6

Adsorption
Adsorption systems achieve their heat pumping effect by boiling a refrigerant and extracting heat from ambient
air. The refrigerant is made to boil by letting a salt absorb the refrigerant vapor. The refrigerant absorption
process delivers heat to the space. In the second step of this batch process, the saturated salt is dried, or
desorbed, by supplying heat and increasing the temperature of the salt. The released ammonia vapor condenses
and delivers additional heat to the space.

Efficiency

The efficiency of a heat pump (electric or gas) is defined by a term called the Coefficient of Performance
(COP). The COP is a ratio of the energy produced and the energy consumed by a heat pump.

COP (cooling)=Cooling Produced
Work or Heat Input

COP (heating)=Heating Produced
Work or Heat Input

The COP can be calculated on an instantaneous, hourly, daily, or seasonal basis. Seasonal COP is calculated as
follows:

Seasonal COP (heating)= (Heat produced during a heating season)/
(Heating gas energy consumed during the heating season)

Another term called Gas Utilization Efficiency (GUE) is also used to define GHP performance:

GUE=Heat produced
Heating gas energy consumed

Here are some average COP values for different types of GHPs:

Gas Heat Pump Type Average Heating COP Average Cooling COP
Absorption 1.3 0.7 – 1.4
Engine Driven 1.4 1.3
Thermal Compression 1.6 1.4

7

How GHPs Achieve Greater than 100% Efficiency

GHPs use natural gas as their primary source of
energy. They also capture additional renewable
energy from the air or other source and deliver it to
the heating load. This diagram on the right shows
how GHPs achieve greater than 100% efficiency by
combining the two energy sources. To explain the
concept, let us assume 100 units of energy are
supplied by burning natural gas, with 5 to 10 units of
this energy lost through the exhaust, just like in a
furnace. Depending upon the type of GHP, 30 -70
units can be captured from the outside air, delivering
about 120 - 160 units of energy to load, yielding a
GHP efficiency of 120% -160%.

Comparing COP of Electric and Gas Heat Pumps

Published COPs for electric heat
pumps (EHP) are higher than those
for GHPs. The reason for this
discrepancy is attributed to the fact
that the COPs of EHPs are
reported based only on the amount
of electrical energy consumed on
site, without considering the
amount of energy consumed to
produce electricity at the source of
generation and transmission losses
to supply electricity from the
source to the site. (Source to site
efficiency is covered further in the
Environmental section of this
guide.) For gas heat pumps,
conversion efficiency is included
in COP calculations. The diagram
below helps to explain this
concept.

8
The COP of an EHP (red line) changes when electricity generation efficiency is considered in COP calculations
(gray line). This example assumes 36% electricity generation efficiency and 91% natural gas extraction and
distribution efficiency.

Economics

The local cost of gas and electric is the largest factor that impacts the payback and/or life cycle cost of a
GHP. On average, electric costs 3 or more times the cost of natural gas on an BTU for BTU basis, ranging from
around 3 to as high as 7 Energy Price Ratio (EPR). This chart shows the average expected retail cost of gas and
electric from the Energy Information Administration’s Annual Energy Outlook 2021. The EPR will vary across
different states and provinces and vary at the local level as well.

Note that electric rates are
complex, and a detailed analysis
should look at additional electric
charges beyond the simple cost per
kWh such as electric demand
charges and time of use rates and
as these tend to impact the true
electric cost.

It is important to choose the right
equipment to best meet the desired
application. For heat and hot water
only applications or in regions
where heating is far more
prevalent than cooling, absorption
GHPs might provide the best
economics. For applications requiring heating and cooling, an engine driven GHP might be the best solution. If
heating and cooling are to be utilized simultaneously, overall system efficiency increases and can reach as high
as 3.0 COP. This chart summarizes the average cost reduction for commercial buildings in four climate regions
compared to traditional rooftop HVAC systems that has gas heating and electric cooling.
0.5
1.5
2.5
3.5
10 15 20 25 30 35 40
CO
P
Outside Temperature (⁰F)
COP Comparison of GHP and Electric HP
GHP COP Standard EHP - Site Standard EHP - Source
Courtesy of Enbridge Gas Distribution
$0.00
$10.00
$20.00
$30.00
$40.00
Residential Commercial
$10.34 $7.89
$36.45 $31.60
2022 Average Retail Energy Prices ($/MMBTU)
Natural Gas Electric
Source: Comparison of Operational Costs and Carbon Emissions for Gas and Electric Heat Pumps at Commercial Buildings,
ICF, August 2021

9

When comparing GHPs to conventional systems it is best to perform a Life Cycle Cost calculation that
considers installed costs amortized over the life of the equipment, as well as energy and maintenance costs with
appropriate inflation over time. The technology with the lowest life cycle cost should be selected. The following
results are derived using an online tool at: https://gasairconditioning.com/general-resources/tools/. This
calculation is for a 20-ton system amortized over 20 years at 5% interest with $.17/kWh, $10/kW, and
$.65/Therm energy rates, with 2% energy & maintenance inflation rates.

Environmental Benefits

Calculating greenhouse gas (GHG) emissions for a gas heat pump is straightforward. Simply multiply the
amount of natural gas consumed by the GHG emission factor for natural gas. For an electric heat pump,
however, calculating GHG emissions is somewhat complex, since it involves estimating associated marginal
fuel of generation, called marginal emission factor (MEF). The generation mix for the electricity consumed by
an EHP varies by region, time of day, and season. Therefore, it is important to apply MEFs on an hourly basis
for better accuracy. For certain jurisdictions, MEFs may be constant because the majority of electricity is
generated from fossil fuels. For example, the MEF will be about 0.493 ton/MWh if the marginal electricity is
produced from combined cycle gas plants. However, for some other jurisdictions where the non-

10
base load generation is provided by a combination of emitting and non-emitting sources such as hydro, wind
and combined cycle plants, the MEF could vary from 0 – 0.493 ton/MWh, depending on the hour of the day.
Approximately 62% of electricity was generated with fossil fuels in 2019. There has been a clear shift away
from coal to more renewable sources of electricity and more natural gas generation plants. New natural gas
generators are combined cycle plants that are much more efficient that older gas plants. You can see below that
the shift away from coal fired power has had a profound impact on overall CO2 emissions for power systems
and that CO2 emissions from natural gas plants has improved over time as well.

The Energy Information Administration (EIA) of the U.S.
Department of Energy forecasts that coal will continue to be
replaced into the future, but even with aggressive policies, it is
projected that almost ½ our power will come from fossil fueled
generators in 2050 (figure right).

Electric generation and distribution is inherently energy
inefficient. Only around 36% of the energy that goes into
generating electricity makes it to end users.
The graphic below highlights energy losses from source to site for
natural gas and electricity. When you take into account the
emissions resulting from power production and distribution, the
direct use of natural gas at homes and businesses is the clear
choice for lowering greenhouse gas emissions.

-
200
400
600
800
1,000
1,200
1,400
1,600
-
500,000,000
1,000,000,000
1,500,000,000
2,000,000,000
2,500,000,000
3,000,000,000
3,500,000,000
4,000,000,000
4,500,000,000
2000 2004 2007 2010 2014 2016 2018 2019
U.S. Sources of Net Power Generation in MWh vs. Emissions from
Power Generation
Nuclear Power (MWh)Coal Power (MWh)
Natural Gas Power (MWh)Renewables Power (MWh)
Other Generation (MWh)Natural Gas CO2 Emissions (lb/MWh)
Total Output CO2 Emissions (lb/MWh)Source: eGRID data
Source: https://www.eia.gov/outlooks/aeo/pdf/04%20AEO2021%20Electricity.pdf

11

A study by the ICF in August
2021 titled ‘Comparison of
Operational Costs and Lifetime
Emissions for Gas and Electric
Heat Pumps at Commercial
Buildings’ found that gas heat
pumps provided lower
emissions than standard HVAC
equipment and electric heat
pumps. The study looked at two
commercial building types in
four different climate zones and
compared heat pumps to a
standard RTU with gas heat.
The lowest emissions for
heating only applications came
from a gas fired absorption heat
pump. When it came to heating
and cooling, the engine driven
heat pump provided the lowest
overall CO2 emissions.
28%19%
-33%-34%
24%
15%
-40%
-30%
-20%
-10%
0%
10%
20%
30%
40%
50%
Absorption GHP Engine-driven GHP EHPPe
r
c
e
n
t
a
g
e

E
m
i
s
s
i
o
n
s

R
e
d
u
c
t
i
o
n
,

%
Average CO2 Emissions Reduction vs. Typical HVAC
System
Heating Cooling
Source: Natural Gas Our Clean Energy Future- 2020 AGA Playbook
Source: https://consortia.myescenter.com/GHP/ESC_GHP_Operating_Costs-Emissions-Study-ICF-August2021-Full.pdf

12

The following table shows CO2 emissions for a standalone retail store in four climates. GHPs have lower
heating CO2 emissions than incumbent HVAC system and well as EHPs in all climate zones

All heat pumps use some sort of refrigerant. The primary refrigerant used for many years for vapor
compression-based heat pumps was a Chlorofluorocarbon (CFC) known as R-12 or a Hydrochlorofluorocarbon
(HFC) such as R-22. Both R-12 & R22 CFCs are known to damage our ozone layer and production has been
phased out. Gas heat pumps use more environmentally friendly refrigerants that are non-ozone depleting and
have lower Global Warming Potential (GWP). Engine driven GHPs use either HFCs such as R-134a or R-410a,
or a Hydrofluoro-olefinan (HFO) such as R-513a, which has a low GWP. Absorption heat pumps use either R-
717 Ammonia (NH3) or Lithium bromide (LiBr) and water. Both of these are natural refrigerants with zero
ozone depletion potential and zero GWP. Thermal compressors use R-704 Helium as the refrigerant which is
non-toxic and has a GWP of 0.

(Tons of CO2)
Incumbent
System Absorption GHP Engine-Driven GHP EHP
Ba
l
t
i
m
o
r
e
Heating Emissions 834 562 665 834
Cooling Emissions 769 994 567 631
Total Emissions 1,603 1,556 1,232 1,465
Ho
u
s
t
o
n
Heating Emissions 283 186 212 240
Cooling Emissions 1,459 2,060 1,183 1,198
Total Emissions 1,742 2,245 1,395 1,438
La
s

V
e
g
a
s
Heating Emissions 338 216 260 285
Cooling Emissions 1,318 1,802 1,056 1,104
Total Emissions 1,655 2,018 1,316 1,389
Mi
n
n
e
a
p
o
l
i
s
Heating Emissions 1,775 1,365 1,506 2,975
Cooling Emissions 481 489 271 394
Total Emissions 2,255 1,854 1,777 3,369
Refrigerant Global Warming Potential (GWP)
Carbon dioxide equivalents, CO2e
R-134A 1430
R-410A 2088
R-513A 631
R-704 (Helium, He) 0
R-717 (Ammonia, NH3) 0
Liutium Bromide (LiBr) 0
GWP source: https://ww2.arb.ca.gov/resources/documents/high-gwp-refrigerants

13
Comfort

A study titled ‘Technical, Economic, and Market Analysis of Gas Heating Equipment in Comparison to Electric
Heat,’ by ERC at the University of Chicago found that electric heat pumps typically deliver 90-95⁰F air
temperature to a space while natural gas furnaces deliver hot air at approximately 120 ⁰F. GHPs typically
deliver hot air at 100°F to 120°F. Delivered air temperatures for electric heat pumps tend to be lower compared
to gas heating options. As a result, electric heat pumps need to circulate more air to warm a space, making the
space feel cold and drafty compared to natural gas heating options. Ultimately, electric heat pumps work twice
as hard to achieve the same heating level as a standard efficiency gas furnace. The air being moved is cooler,
which tends to be noted by the occupants as lukewarm or even cold and drafty.

Applications

There is no need to reinvent
the wheel. Gas heat pumps
offer all the same capabilities
as traditional equipment plus
increased efficiency and
added features. GHPs can be
used in all market segments –
residential, commercial,
institutional and industrial.

Typical Applications:
• Space Heating Only
• Space Heating & Domestic Hot Water Heating
• Domestic Hot Water Heating Only
• Alternating Heating & Cooling

Special Applications:
• Simultaneous Heating & Cooling
• Process Applications
• District Heating or Cooling

Installation flexibility and the ability to utilize multiple zones allows for a variety of terminal units:
• Air Handlers
• Fan Coils
• Ceiling Cassettes
• High Wall Units
• Radiant Floors & Panels
• Small Duct High Velocity Systems

14

GHP Markets

Although natural gas is widely utilized
across the electric power sector for
electricity generation and in the
transportation sector as fuel for mobility
and operating machinery, we will limit
our market review to GHP applications
in the residential, commercial and
industrial sectors.
Traditionally, GHPs were limited to
large scale industrial and commercial
applications. Today, due to research,
technical advancements, system level
improvements and the increased
popularity of Combined Heat & Power
(CHP), smaller products have been
brought to market, offering a more
compact footprint and modular
configuration. This has led to more
market exposure extending to the
residential and light-commercial
markets.

With a need and urgency to capture waste heat, stakeholders can now make efficiency decisions at both the
equipment level and overall system level to compare competing products.

Residential:
About half the homes in the United States
(and North America) use natural gas as the
main energy source for space heating,
domestic hot water, cooking and drying
purposes. According to the U.S. Energy
Information Administration (EIA), the
residential sector in 2020 accounted for
15% of total natural gas consumption and
23% of total energy consumption.
Due to the reliability, availability and
lower energy cost, gas heat pumps have the
potential for promising applications in
various single/multi-family homes,
apartments and condominiums.

Source: 2015 Residential Energy Consumption Survey, released Feb 2017
Transportation
3%Commercial
10%
Residential
15%
Industrial
33%
Electric Power38%
U.S. Natural Gas Consumption by Sector, 2020
Total= 30.48 trillion cubic feet
transportation commercial residential industrial electric power
Source: https://www.eia.gov/energyexplained/natural-gas/use-of-natural-gas.php
Natural Gas
47%Electric
36%
Oil/Kero
5%
Propane
5%Wood
2%
Other
1%
No Heat
4%
U.S. Residential Main Heating Fuel
Natural Gas Electric Oil/Kero Propane Wood Other No Heat

15
Residents with an existing natural
gas connection have the highest
incentive to add a GHP to meet their
home energy needs. Absorption or
thermal compression heat pumps
are typically best for residential
applications.

Commercial:
The commercial sector typically
uses natural gas as its energy source
for space heating and hot water
heating. Commercial buildings
seeking energy savings and
reductions in electric demand have
also been using natural gas air
conditioning systems for many
years.

In order to provide a robust, reliable
and efficient infrastructure, the past
few decades have seen increased
usage and popularity of combined
cooling, heating and power systems
(CCHP or CHP) as a single package
unit. The commercial sector
accounted for 10% of total natural
gas consumption and 19% of total
energy consumption. GHPs offer
commercial buildings significant
efficiency improvements for heating, water
heating and cooling spaces, while reducing
electric demand. Standard efficiency gas
heating systems are approximately 80% efficient, while high efficiency furnaces, boilers or roof top units are
92%+ efficient. GHPs typically offer heating efficiencies of approximately 140%. Commercial buildings
usually require both heating and cooling applications, which lend themselves more towards engine driven GHPs
due to their higher cooling COPs.

Space Heating
67%
Water Heating
18%
Cooking
12%Other
3%
Natural Gas Consumption for
Total Commercial Market
Space Heating Water Heating Cooking Other
Source: CBECS 2012 released 3/18/16, EIA CBECS
Natural Gas, 48%
Electric, 27%
Heating Oil, 5%
Wood, 18%Other, 2%
Space Heating Energy Use in Canada
Natural Gas Electric Heating Oil Wood Other
Source: Natural Resources Canada – Energy Fact Book 2020-2021

16
Industrial:
The industrial sector remains the highest consumer of natural gas which accounts for 33% of total natural gas
consumption and 34% of total energy consumption. This sector typically uses natural gas for process
applications that require heating, cooling or dehumidification. Gas heat pumps save industrial customers money
on heating and cooling while reducing electric demand and reducing greenhouse gas emissions on a source
basis.
Supporting Grid Reliability
The reliability of the electric grid that we benefit from depends on an array of factors. The figure below shows
how various energy resources support the 8 key reliability attributes for grid system health. Natural gas comes
to the forefront in these various energy resources.
Reliability Attributes and Technology
17
GHPs reduce electric demand and therefore help improve grid reliability and resiliency. The negligible
electricity consumption in this technology can help decrease overall demand at the national grid level for
meeting the consumer’s cooling and heating needs.
Electric demand varies greatly throughout the day across different climate zones. The grid is made up of a mix
of baseload, intermediate power and peaking power plants. The following graph shows the electric grid dispatch
order and load duration curve for a Combined Heat and Power (CHP) System running up to 8,760 hours per
year. A gas heat pump will have similar characteristics to the CHP in helping to reduce peak and intermediate
loads on the grid, thus helping to stabilize the grid while reducing congestion and constraints. This helps the
grid maintain its reserve margins and become more reliable and resilient during critical hours.
GHPs are very efficient based on a source energy basis. GHPs help to limit power consumption during times of
high electric demand (peak hours).
Source: Combined Heat and Power Potential for Carbon Emission Reductions, National Assessment, 2020-2050. ICF, July 2020

18
GHP Product Status

There are multiple gas heat pump systems in various stages of development that are available in a wide range of
sizes for use in different applications. The following table summarizes the various products as of the writing of
this guide. Please note that this is an evolving landscape that is subject to change.

Company Type Technology Best
Applications Status Heat Sizes Cooling Sizes
Aisin IC Engine

Commercially
available
103,000 to 410,000
BTU/h
8, 15, and 30
Tons
Blue Mountain
Energy IC Engine

Commercially
available, 5 &
11 Ton, field
testing others
91,000 to 410,000
BTU/h
5, 8, 11, 15, and
30 Tons
boostHEAT
Thermal
Compressor
Field test
2022 68,000 BTU/h n/a
Broad USA Absorption
Commercially
available
962,000 BTU to
57,800,000 BTU/h 30 to 3,968 Tons
Energy Concepts Absorption
Commercially
available
396,000 to
40,000,000 BTU/h
20 Tons to 2,000
Tons, down to -
50⁰F
Gridiron IC Engine
Commercially
available 70,000 BTH/h 5 Tons
HeatAmp
Adsorption
(Chemisorption)
Field test
2023 Up to 50,000 BTU/h n/a
Robur Absorption

Commercially
available 120,000 BTU/h 5 Tons
Stone Mountain
Technologies Absorption
Commercially
available
2022
10,000 to 140,000
BTU/h
Future cooling 1-
4 tons
Tecogen IC Engine
Commercially
available 527,500 Btu/h 22 Tons
ThermoLift
Thermal
Compressor
Field demos 55,000 to 75,000
BTU/h 3 Tons
Yanmar IC Engine

Commercially
available
108,000 to 198,000
BTU/h
8, 10, 12, and 14
tons
Vicot Absorption

Commercially
available.
Resid. units:
Field Trial
68,000 BTU to
290,000 BTU/h n/a
Key: Residential Commercial Industrial Heating Cooling Water Heating

Note that many of these manufacturers offer modular design solutions that package more than one unit together
to meet larger heating and cooling needs.
19
Contacts:
Company Name Email Web Site
Aisin World Corp. of
America Yoshi Sekihisa [e-mail] www.aisinworld.com
Blue Mountain
Energy Tom Young [e-mail] www.bluemountainenergy.com
Broad USA Kevin Fu [e-mail] https://broadusa.com/broad/
Energy Concepts Ellen Makar [e-mail] www.energy-concepts.com
Gridiron Dan
Giampetroni [e-mail] https://www.gridironenergy.com/
HeatAmp Ekblad
Magnus [e-mail] www.heatamp.com
Homy / Vicot Houman
Ameri [e-mail] www.homybuild.ca
Robur Bert Warner [e-mail] www.roburcorp.com
Stone Mountain
Technologies Scott Reed [e-mail] www.stonemtntechnologies.com
Tecogen Jeff Glick [e-mail] https://www.tecogen.com/heat-
pumps
Thermolift Paul Schwartz [e-mail] www.tm-lift.com
Yanmar America Taihei
Yamashita [e-mail] www.yanmar.com
GHP Codes and Standards
ANSI Z21.40.1- CGA 2.91 is the standard for safe operation, substantial and durable construction, and
acceptable performance of gas fired, heat activated air conditioning and heat pump appliances. There is also a
similar safety standard for work activated heat pumps (Internal Combustion) which is ANSI Z21.40.2. These
standards cover two sections 1) the constructions, and 2) the performance.
The provisions in this standard are intended to help reduce injury risks to a person while retaining the normal
operation of the appliance. This standard was initially published by the American National Standard (ANSI) and
Canadian Gas Association Standard (CGA) in 1996 and reaffirmed in 2017. It is currently being updated by
CSA.
Along with this standard, for performance testing there is ANSI Z21.40.4 – CGA 2.94 which proposes test
methods to cover a wide range of unitary gas‐fired technologies, including engine‐driven, desiccant/adsorption‐
driven, and absorption‐driven cycles. This ANSI test is comprised of a series of steady state rating points under
static conditions, at full and partial loading, including considerations for defrost modes and cycling degradation.
Data from these rating points will be used to generate performance curves and to calculate seasonal
performance metrics, including seasonal efficiency (AFUE, Seasonal COP) and estimated electric power
consumption.
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GHP Resources
Visit gasheatpumps.com to learn more about GHPs. You can also find a variety of case studies, a video that
provides an overview of GHPs and a magazine highlighting success stories. If you would like to perform a
simple life cycle cost calculation for a GHP compared to conventional HVAC and EHPs, you can find a tool at
gasairconditioning.com/general-resources/tools/.
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Visit www.intgas.com/saveenergy for
more information and updates on gas
heat pump technology.