A review of air-to-air heat pumps, how to select, how it works, advantages and disadvantages, how to select the right type (split, packaged, ducted or ductless…), efficiency, the main components and top manufacturers.
Air-to-air heat pump is one of the most efficient electric HVAC devices designed for home heating and cooling. Models that are built as the Energy Star are able to save up to 20 percent than standard models, reduce the greenhouse gases emission and increase the comfort. The energy cost of the air-source heat pumps is lower than gas, oil heating systems or geothermal HP.
One of the greatest advantages of heat pumps is that there are no burners to generate heat, no fume gases, fire and smoke. The heat is not made; it is just moved from one place to another – making heat pumps more efficient while heating the room gradually and uniformly. Only in a case of the northern cold regions, the homeowner should select the heat pump with the supplemental heat (gas or electric) while in warmer regions electric heat pumps are sufficient.
Making the right decision about an air-to-air heat pump is very important as the home heating and cooling depends on it and because it is a great deal of an investment. No matter are you buying a new or used heat pump, three factors have to be considered for an efficient, comfortable and trouble-free heating and cooling.
The best heat pumps are high efficient (high SEER and HSPF) that use variable- or two-speed scroll or advanced reciprocating compressors, thermostatic expansion valves and insulated tubes instead ductwork. On the other side, lower level and less efficient models come with the single-speed reciprocating compressors. Looking for more info? Check out this article - selecting tips.
Split heat pumps systems utilize one outdoor and one indoor unit both containing a heat exchanger coil, connected together with the refrigerant lines, usually made of copper and ducted system for heat distribution. The split systems, thanks to the advanced features, can be used in all climates, from mild to freezing regions, and it is the most favorable type installed in residential housings.
Air-source heat pumps that are designed as mini-split are mainly used for local, room heating/cooling, where the ductwork does not exist or cannot be installed. These are known as ductless heat pumps and due to its small size are easy to handle and install –on the wall or ceiling. Mini-splits are recommended for retrofit in homes with hydronic and electric baseboard heating. They usually have one outdoor unit and one or more indoor for the multizone climate control.
Ducted vs. ductless
Ducted heat pumps utilize the vents or ducts to distribute the heated or cooled air inside the house – from the source to the rooms, while ductless units don’t and there is no energy loss through the ducts.
As opposed to the above split-systems, there is also a packaged system which combines all the components into one system located outdoor, while the cooled or heated air is transferred to the house using the ventilation ducts. The main advantages of these systems is that the unit is installed outside (rooftop for example) which helps in noise reduction, it can serve different zones and allows quick installation and servicing.
Air-to-air heat pump works very simple where most of the models incorporate three cycles; heating, cooling and defrost cycle. The heat pump draws heat from the air and delivers it to the residential home (heating) or outdoor (cooling). Its ability to heat and cool, depending on the weather, makes it very economical and efficient HVAC system. Check out this article to see in details how does the heat pump work.
One of the most important features that should be considered when buying an air-to-air heat pump is the efficiency. The seasonal heating (HSPF) and cooling (SEER) ratings should be check before buying the unit. Some manufacturers also provide COP and EER ratings for efficiency check.
Note that the ability of the heat pump to transfer heat from the outside to the house depends on the outdoor temperature. Also if the heat pump is operating without any supplementary heat, the air temperature from the heat pump is cooler than heated by any other heating device, such as furnace. Check out other differences in this comparison heat pump vs. furnace.
Air-to-air heat pumps, due to its complexity and warranty requirements, must be designed and installed by professionals for the valid warranty and ensure efficient and reliable operation. The cost can be up to twice the cost of a gas or electric furnace.
Keep in mind that the supplementary (backup) heating might be required if you live in the area of cold weather.
According to some studies, the payback period could be somewhere between two to seven years. The service life is between 15 and 20 years, but depends on the region; shorter in colder areas, longer in southern climates. The warranties also vary; it goes from 5 to 12 years on the compressor and coils and less for labor.