An air source heat pump makes use of the external air to either heat or cool your home for you. This pump draws the heat from the air outside and moves that around to heat your home. This can be done even if the temperature is very low.
The reverse is possible as the warm air is moved from inside the home to the outside to cool it down. It works on the same principle as the refrigerator, that extracts warm air from its inside to cool it down on the inside. In some instances, these air heat pumps could also be used to turn stale outgoing air into heat and return it to the home as fresh warm air. Most of these pumps have three cycles, which is the:
- Heating cycle for the colder winter days
- Cooling cycle for the warmer summer days
- This operates opposite to the heating cycle and is easy to switch over as you have reversing valves for this purpose.
- What is great about this cooing cycle as well is that it also dehumidifies at the same time.
- This happens as part of the cooling as the air moves out water is collected in a pan below the coil and runs away into the normal drain.
- Defrost cycle that would make sure that there is free flow in the pipes at all times
- This is when vapor passes over the outside coils and creates frost. The defrost cycle is then used to get rid of this build up of frost.
- This is necessary as the frost build up will decrease the efficiency of the air heat pumps.
How Air Heat Pumps Work
The air source heat pump requires certain components for it to perform the tasks assigned to it (that is, the cooling and the heating of the home). These components include:
- The expansion device
- The piping
- A compressor
- The fans
- An indoors coil made of copper tubing
- An outside coil made of copper tubing
- Aluminum fins to aid heat transfer
- Thermostatic expansion valves for better control over the flow of the refrigerant to the indoor coil or outdoor coil (depending on which time of year it is). The thermostat should be set at the comfort level which is usually at twenty degrees.
- The reversing valves that would turn the air heat pumps into cooling or heating systems.
The process occurs when the air is absorbed into the liquid at low or high temperature. The compressor increases the temperature or lowers the temperature as your need it at the time. The heated liquid, especially, is transferred to the heating circuits as well as the hot water circuits as a vapor.
Thus, the above components are employed to work together to create a vapor, which is what is heated, compressed and let into the home to the various an as many applications as you prefer. The downside of it is that you might loose some or most of your heating efficiency if the heat is directed at, for example, the heating of your water supply as well.
One of the specifications of most air heat pumps is the annual cooling efficiency (SEER) and heating efficiency (HSPF) by which a model or unit is identified. This is what makes it perform at a certain level. The air heat pumps are usually between ten and seventeen SEER and its HSPF ranges between 5.9 to a maximum of 8.6.
When you do purchase an air source heat pump, these numbers would usually indicate what you are able to utilize in the size home you have. However, the contractor would be the best person to advise you on what your requirements are.
It is also vital that you again look at the area in which you live and then, with the help of the contractor decide what it is that you need for your specific needs. The seasonal as well as the temperatures normal for your area could be a guideline as well. You might just live in an area that would require a much harder working system, especially for the colder areas.
Some Benefits of Air Heat Pumps
One of the major benefits would be the fact that there is a larger savings on your electricity bill. It does this as it does not operate in the same way as any of the other heating systems – whether gas or electrical. The reason for this is that:
- The heat generated in this way, by an air source heat pump (ASHP), keeps the area heated for much longer than with any of the other heating systems.
- By using this pump, you are able to benefit from the Renewable Heat Incentive (RHI) the government has in place.
- You are living in and providing a greener environment for yourself and everyone else.
- This includes the fact that you would not need to participate in fuel deliveries to your home.
- This is a dual facility in that you are able to heat your home and at the same time have hot water as well.
- Another part of this is that you could also use it in conjunction with other heating sources. The problem with this is that you might not obtain the benefits you want from as you would with a standalone unit.
- It is easier to install and it also needs very little maintenance.
The only slight difficulty is that during the winter, the air heat pumps need to be on constantly in order for it to keep your home warm for longer. The reason is that it provides heat at lower temperatures over longer periods than conventional heating systems.
The Suitability of Air Heat Pumps
The suitability of an air source heat pump for your home will depend on a few requirements, such as:
- You do need a large enough area where the unit can be placed and installed.
- It needs to be mounted on the inside as well as on the outside especially I terms of the piping and the outside coils.
- This does mean that you do need a reasonably sized home.
- It is also for the reason that you need to justify the purchasing of such a unit as it would function best in a larger home.
- It also needs free space around for free airflow for it to operate at its best.
- The home you are in would also need to be well insulated. It would serve no purpose to circulate air for heat or cold if there is not in a suitably sealed in space. This is especially to make sure that the temperature you are after is achieved.
- You would find that you are able to replace your current heating or cooling gas or electrical system and save on cost in the long run. If you use gas as your mains, though, air heat pumps would not be suitable for your home. If you have any doubts about this, you should speak to a professional for assistance.
- The best way to utilize the air source heat pump is to make use of under-floor heating or to make use of a radiator system with it. This is possible as you use very low temperatures. It is therefore not a good idea to use air heat pumps in places where temperatures reaches sub-zero over long periods as you will not be able to achieve the necessary comfortable warm temperatures.
- When you are building a new home, it would be most cost-effective if the system is installed with the home. It might not give you the same result with later installation, but it will save you on cost in the long run.
The best way to find out what type of air source heat pump you would like to install is to find a good contractor to assist you with the evaluation and also the installation if you should go ahead with it. You should also keep in mind that the efficiency of these heat pumps are constantly improving as new developments are made and new components are developed as a result.
The Costs, Savings and Earnings of Air Heat Pumps
There are many different types of air heat pumps available in terms of makes and models. This is what would also determine the cost of the unit as well as the installation. The installation could cost between 6,000 to £10,000. This will exclude the running costs, which would be far less than that of conventional heat pumps. It would depend on:
- The size of your home
- How well it is insulated as well as
- What you would like your room temperatures to be
If you want to have a look at what you would be saving, you would look at:
- The heat distribution system, which means you could use under-floor heating or use a radiator for your heating purposes.
- The fact that you are replacing fuel, such as coal or gas, can mean great savings in the long run.
- Your new system (the air source heat pump) would give you lower running costs and might be more efficient than your previous system.
Some drawbacks on the system, which is minor, is the fact that:
- Air heat pumps might not be as efficient if you are including your water heating as well. You might want to consider using an alternative source (such as solar heating) for your water heating, so that your pump can be focused on heating your home.
- It is also important to be well acquainted with the controls of the air source heat pump, so that you can gain the maximum benefit from it.
It is important to note that you would be able to earn some money by simply installing Air heat pumps in your new home or by replacing your old heating system with one of these. Most governments are getting onto the Renewable Heat Incentive (RHI) schemes as a means of encouraging their citizens to go green. You would therefore be able to receive some payment for the use of one of these pumps for your heat generation.
The Maintenance of Air Heat Pumps
There is not a heat pump in the world that would not offer you a warranty on its parts, its compressor and other aspects of it, such as for labor for example. Most Air heat pumps will carry a warranty of ten years, but the sturdy and durability of these units could last you for more than twenty years. This does come with the necessity of regular maintenance and servicing.
You should have your air source heat pump checked and serviced regularly. Each unit would come with instructions as to when you should do your servicing and check-ups. The contractor installing your unit for you would also be able to tell you when you need to do this.
Some of the things you might want him or her to look at are:
- The air inlet grill
- That the evaporator is free from any debris or leaves
- The unit needs free air flow around it and any plants that started to grow nearby after the installation needs to be removed
- To make sure that the anti-freeze levels are in order. The professional will know what the concentration of the substance should be will top it up when he or she comes around for the check-up.
When you do install air heat pumps you need to make sure what the requirements are in your area. For example some areas may require planning permissions and other areas might require permitted permissions. It is also important that employ the best contractor as the best installation will give you the best efficient heating or cooling.