Common problems with Heat Pumps
An Air Source Heat Pump is generally a less efficient system than its ground source cousin.
An air source heat pump is best suited to houses that do not have sufficient room for ground collectors or generally have a smaller heating requirement. Well installed systems will happily run away, offering quiet, unobtrusive and consistent heating and hot water to a property.
This does not mean, however, that the equipment, or the people installing it, are infallible. Here is a list of the challenges faced by heat pumps that has resulted in a large number of Irelands installed heat pumps costing more to run than the homeowner expected.
Defrosting
The vast majority of air source heat pumps are designed for climates radically different to that of Ireland, Consequently, the equipment inside the machine is less well equipped to deal with the high levels of water in the Irish climate. A practical example of this can be seen in most air source heat pumps in winter. The water in the air gathers around the heat pump’s heat exchanger and freezes. This causes the heat pump to go into a “defrost cycle”, where the machine stops heating the house and has to take some heat from the house in order to defrost the heat exchanger. The more expensive air source heat pumps feature much larger heat exchangers with larger gaps between the fins and as a result have much longer running times between defrosting periods and better efficiencies at lower temperatures. This keeps more heating going into the property and keeps everyone happier. Even at 7 degrees outdoor air temperature the refrigerant inside the heat pump evaporator is cold enough to freeze moisture in the air that is passing through the machine.
Life expectancy and system costs
Many installers focus only on one type of heat pump and sell it as the solution to every problem. This is far from the case. Making the distinction between and air source and a ground source heat pump is an important first step. In general an air source heat pump should be a last resort for any new build or retrofit especially when compared to the running costs and life expectancy of ground source heat pumps.
In general air source heat pumps have much less capital outlay on day one but when you look at running costs over the lifespan of the unit being considered and add the replacment costs then most people will find that the system will end up costing them a lot more over 20 years when compared to the extra cost of the ground source heat pump on day one.
Siting
Knowing where to site an air source heat pump is essential to maximising efficiency and minimising noise generated. Poorly sited machines will cause undue noise, bother neighbours and run inefficiently by consistently recycling their own cooled air and decreasing efficiency.
Lack of installer knowledge
As with ground source heat pumps, air source heat pumps are only as good as the company that installs them. Despite the comparative simplicity of an air source heat pump system, it is not a plug-and-play solution and it still requires experienced and specialised engineers to maximise the system’s potential. Poor system controls and a general misunderstanding of how the system works will only serve to frustrate owners.
Look for installers with a proven track record.
An Air Source Heat Pump is generally a less efficient system than its ground source cousin.
An air source heat pump is best suited to houses that do not have sufficient room for ground collectors or generally have a smaller heating requirement. Well installed systems will happily run away, offering quiet, unobtrusive and consistent heating and hot water to a property.
This does not mean, however, that the equipment, or the people installing it, are infallible. Here is a list of the challenges faced by heat pumps that has resulted in a large number of Irelands installed heat pumps costing more to run than the homeowner expected.
Defrosting
The vast majority of air source heat pumps are designed for climates radically different to that of Ireland, Consequently, the equipment inside the machine is less well equipped to deal with the high levels of water in the Irish climate. A practical example of this can be seen in most air source heat pumps in winter. The water in the air gathers around the heat pump’s heat exchanger and freezes. This causes the heat pump to go into a “defrost cycle”, where the machine stops heating the house and has to take some heat from the house in order to defrost the heat exchanger. The more expensive air source heat pumps feature much larger heat exchangers with larger gaps between the fins and as a result have much longer running times between defrosting periods and better efficiencies at lower temperatures. This keeps more heating going into the property and keeps everyone happier. Even at 7 degrees outdoor air temperature the refrigerant inside the heat pump evaporator is cold enough to freeze moisture in the air that is passing through the machine.
Life expectancy and system costs
Many installers focus only on one type of heat pump and sell it as the solution to every problem. This is far from the case. Making the distinction between and air source and a ground source heat pump is an important first step. In general an air source heat pump should be a last resort for any new build or retrofit especially when compared to the running costs and life expectancy of ground source heat pumps.
In general air source heat pumps have much less capital outlay on day one but when you look at running costs over the lifespan of the unit being considered and add the replacment costs then most people will find that the system will end up costing them a lot more over 20 years when compared to the extra cost of the ground source heat pump on day one.
Siting
Knowing where to site an air source heat pump is essential to maximising efficiency and minimising noise generated. Poorly sited machines will cause undue noise, bother neighbours and run inefficiently by consistently recycling their own cooled air and decreasing efficiency.
Lack of installer knowledge
As with ground source heat pumps, air source heat pumps are only as good as the company that installs them. Despite the comparative simplicity of an air source heat pump system, it is not a plug-and-play solution and it still requires experienced and specialised engineers to maximise the system’s potential. Poor system controls and a general misunderstanding of how the system works will only serve to frustrate owners.
Look for installers with a proven track record.
Sizing of Equipment
When sizing an air source heat pump for your installation, your installation company should size your heat pump to compensate for drops in outside temperature resulting in higher heat demands from the dwelling, this is not a problem for ground source heat pumps as they have a stable source temperature, Many units rely on electrical backups for when these periods of low temperature occur,
Obviously this results in higher running costs and carbon emissions.
A properly designed system will generate 5kws of heating for every kw taken to run the machine. Coefficient of Performance (COP), basically the amount of kilowatts (kW) in heat produced to the amount of kWs of electricity to run the machine.
When sizing an air source heat pump for your installation, your installation company should size your heat pump to compensate for drops in outside temperature resulting in higher heat demands from the dwelling, this is not a problem for ground source heat pumps as they have a stable source temperature, Many units rely on electrical backups for when these periods of low temperature occur,
Obviously this results in higher running costs and carbon emissions.
A properly designed system will generate 5kws of heating for every kw taken to run the machine. Coefficient of Performance (COP), basically the amount of kilowatts (kW) in heat produced to the amount of kWs of electricity to run the machine.