General FAQ
| What is a gas absorption heat pump? | A gas absorption heat pump (GAHP) provides warm, comfortable heating with exceptionally high efficiencies. Instead of burning natural gas or propane to heat air or water directly, a GAHP uses the combustion heat to drive a thermodynamic cycle that extracts additional heat from the ambient outdoor air and adds it to the heat created from the natural gas/propane. This “free” heat from the ambient air increases the efficiency of a GAHP, and less fuel is used to provide the heat. |
| What are the benefits of a gas heat pump? | A gas heat pump uses less fuel, so less CO2 is emitted for heating. Using less fuel also saves you money. Like traditional gas furnaces and boilers, a GAHP provides warm, comfortable heating even when extremely cold outside. And because a GAHP uses very little electricity, a small backup generator can keep your heating system running during a power outage. A GAHP provides additional safety benefits since all combustion, refrigerant, and venting remain outside the house. |
| Are gas heat pumps safe? | Gas heat pumps have been safely used in residential and commercial applications for over 50 years. All of the combustion and refrigerant are located outdoors. |
| Why should I consider a gas heat pump? | If you are currently heating using natural gas or propane, a gas heat pump is a great way to lower your gas bills while maintaining or increasing the comfort you are used to. Additionally, using less fuel emits less CO2 – a win-win for you and the environment. |
| Where is a gas heat pump installed? | The heat pump unit is located outside your home or commercial building and is connected by standard PEX or copper piping to the indoor air handler and/or water heater. A mixture of water and food-grade propylene glycol (for freeze protection) is transported within the piping. |
System FAQ
| Why is ammonia used as a refrigerant? | The American Society of Heating, Refrigerating, and Air-Conditioning Engineering (ASHRAE) provides a uniform system for classifying refrigerants. When ammonia is used as a refrigerant, it is known as R717 and classified within Inorganic Compounds. Ammonia is a common and preferred refrigerant in industrial applications because it is highly energy efficient, has a smaller heat transfer area requirement than chemical refrigerants, and is environmentally friendly with zero ozone depletion potential (ODP) and zero global warming potential (GWP). Ammonia-water absorption heat pumps have been widely and safely used in multiple residential and commercial applications for over 70 years. The most common uses include space heating and cooling, water heating, and inside refrigerators for RVs and motel rooms. |
| How is ammonia used in the Anesi Comfort System? | The Anesi Gas Absorption Heat Pump (GAHP) is the heating appliance in the Anesi Comfort System. It contains a sealed ammonia-water absorption system designed for a low-refrigerant charge, with approximately 12 lb. of ammonia and an equivalent amount of water. During the heat pump cycle, ammonia is separated from the water through a thermally driven process. The purified ammonia gas circulates through an evaporator coil to capture additional heat from the ambient air. Subsequently, the ammonia is recombined with the water in an exothermic reaction, releasing heat captured by the GAHP heat exchanger system and combined with the heat of fuel combustion. This absorption cycle continuously repeats within the sealed system, producing heat transferred indoors via a water- and food-grade propylene glycol heat exchange fluid. The building is warmed by a separate hydronic loop that does not contain ammonia. |
| What are the HVAC industry standards that guide the use of ammonia in appliances? | IIAR Standard 2 guides the safe usage of ammonia within residential and commercial HVAC systems. An important requirement within this standard stipulates the ammonia charge within a piece of equipment should not exceed 22 lb. when located in an adjacent outdoor location. The Anesi GAHP has a 12 lb. ammonia charge within the sealed system. |
| What fuels can be used by the Anesi gas absorption heat pump? | GAHPs can use any gaseous fuel utility companies provide, including lower carbon solutions like renewable propane, renewable natural gas blends, and hydrogen blends. |
| Can propane be used with the Anesi gas absorption heat pump? | Propane is the ideal companion fuel for the Anesi GAHP. Other heating appliances require special accommodations, component changes, or conversion equipment for LP fuel but not the Anesi GAHP. The installation contractor dials in the combustion during the initial installation. The high-efficiency Anesi HP80 uses up to 50% less propane to achieve the desired level of comfort in the household, resulting in 50% fewer emissions and a faster payback of the initial heating system investment. The development of renewable propane adds to the decarbonization efforts. The amount of carbon dioxide (CO2) generated for every unit of energy used is known as carbon intensity and is measured from low to high in grams of CO2 equivalent per megajoule. According to the California Air Resources Board, renewable propane has a carbon intensity as low as 20.5, impressive when compared to the average carbon intensity of the US electric grid at 130. |