An Air Source Heat Pump is a type of heat pump that extracts the heat directly from the surrounding air and transfers this heat to a usable heat for heating your home and water.
The air source heat pump is therefore relatively simple to install as it only requires connection to a single flow and return similar to standard heating systems.
By design, an air source pump is most suited to an external location, where it can have access to free-flowing air with which to interact, though systems can be designed to use air ducted from external sources or air recovery systems.
Due to the air outside constantly being moved around by natural effects and interactions, there is always a fresh supply of air which can be processed by the air source heat pump to provide adequate heating for the property. Similar to ground source heat pumps, air source heat pumps operate very much like a fridge/freezer in reverse, taking the heat out of one area and depositing it in another. This allows heat to be extracted from relatively cold temperatures (-3°C, -7°C, -10°C) and still be able to produce a usable temperature of heating water to heat your property.
This is because even at 0°C, the energy contained in a cubic metre of air is substantial, remembering that the absolute zero (for zero energy) is -273°C (or 0°K) hence 0°C is actually 273°K and 5°C would be 278°K and even -7°C is 266°K….
An air source heat pump can be installed anywhere where there is sufficient flow or air and where it won’t cause any acoustic problems. Whilst the majority will be situated on a simple concrete base, they can easily be wall mounted to keep gardens and exterior space uncluttered.
As with all heat pumps, the means by which the heat produced by the heat pump is delivered is critical. The default hydraulic system will use radiators to emit the heat, and whilst this type of system is perfectly compliant with an air source heat pump, it will affect the flow temperatures that you use and thus the efficiency of the heat pump. Radiators are usually sized to operate at around a 70°C flow temperature, delivered by a boiler or similar. This gives a very high temperature difference between the room temperature (18°C/21°C) and the flow temperature (70°C) of around 50°, known as the delta T (ΔT).
As heat pumps work differently from boilers, their ability to produce high temperatures is limited, and their efficiency is therefore much better at lower flow temperatures. To compensate for the lower temperatures at which they work, you will need larger heat emitters to transfer the equivalent amount of heat into the room. This is most easily and efficiently done when using an underfloor heating system, which has a network of buried pipes that use the entire floor to emit the heat to the room. Radiators can also be used but due to the lower amount of heat in the system (because of the lower temperatures and therefore lower ΔT), they require larger or more efficient versions to provide adequate heat. This is known as “oversizing” and can be achieved by physically increasing the size of the radiators or using double or triple convector type radiators.
Hot water is produced as a by-product of the heating system and normally done using a special heat pump compatible water cylinder. Heat can be programmed to charge the cylinders when the pump is least likely to be used for heating purposes and are specifically designed to need lower temperatures to enable adequate heating of the water. A known factor in heat pump design is the re-heat time needed to recharge the cylinder, as this often takes longer for a heat pump to achieve than a conventional boiler, hence the size and design of the cylinder can compensate for this.
Modern heat pumps offer very reliable and offer controllable and efficient heating solutions for almost any property. They are suitable for almost any home, though work at their best when coupled with highly efficient properties using modern heat emitters.
Unlike a ground source heat pump, an air source system does not require collector loops, and due to being designed for external use neither does it require any internal space to be sited.
An air source pump has the ability to lower your heating bills, as it offers relatively low costs per kWh for the heat in your home due to the efficiencies at which they operate. For any off-grid property, where common alternatives would be solid fuel, oil or LPG-fired systems or electric heating, you could make significant savings. Again, the costs and efficiency will depend on the type of system you connect to and a variety of other factors but we try and design a system that achieves a cost effective efficiency in excess of 370% – 400% efficiency where possible.
Air source heat pumps also offer relatively maintenance free operation with minimal inspections and servicing required. It also isolates you from the need to top up and manage your fuel stores which can be surprisingly refreshing if you are used to checking and monitoring fuel stocks & prices.
By virtue of the fact that the heat extracted from the air is produced from energy taken directly from the Sun’s light, an air source heat pump is rightly classed as a renewable form of heating energy. Whilst it still uses a small amount of electrical energy to run the compressor, you can run a completely green air source system if you combine the pump with a Solar PV system or similar.
With all renewable heating systems, by far the biggest factor in deciding to opt for them is the financial gain that is offered from the government. The RHI (or renewable heat incentive) scheme offers guaranteed quarterly payments to anyone who has installed a suitably accredited and operational air source heat pump. You get paid for the amount of renewable heat that is generated using the heat pump so the efficiency of the pump will affect how much percentage of the overall heat provided is through renewable means.
For example, if you heat pump achieves an efficiency of 300% (3 kW of heat for every 1kW of electricity input) then 2 out of every 3 kW of heat is renewable (66% or 2/3). Similarly, if you can achieve an efficiency of 400% you can now have 75% of your heat (3/4) as renewable. The bottom line is that the more efficient the heat pump is, the more your RHI payments will be, so it is a good idea to consult your heat pump installer or technician when designing your emitter system as this can affect the performance.
There is a cap on the amount of renewable heat that you can claim for on the RHI scheme, which currently stands at 20,000 kWh for an air source heat pump. Nevertheless, a reasonably sized family home with a well-designed system can easily achieve payments in excess of £1300 per year, though the right property with the right system could potentially achieve over £1500 per annum.
We have extensive experience in the design and installation of air source heat pump systems. Our experience has enabled us to offer a very productive and comprehensive service. We support and advise our clients throughout the process including designing and choosing the right system the installation process and support to claim your RHI payments and the ongoing care of your system.
We have installed a variety of heat pumps and regularly offer products from worldwide manufacturers and leaders in the field such as Samsung, Mitsubishi and Stiebel Eltron. The product you choose will reflect the type of system you require and your budgetary requirements but it is important to stress that all will provide you with a safe, environmentally friendly and reliable heating source for your home if installed and designed properly.
Speak with us to find out how an air source system can help heat your home and how it can help lower your heating costs substantially. We are qualified installer to MCS standards and operate under the RECC code of conduct which protects customers and gives additional protection to our clients. We have a 100% success rate in our installations achieving RHI approval and are confident that we offer the most comprehensive and technically astute service available.
In conclusion, an Air Source Heat Pump is a very practical and efficient way of heating your home and should be at the top of many people list if they are looking at replacing or swapping their current heating or indeed looking at options for new build properties. It will be critical to the performance of the pump and the efficiency of the system that the full design of any such system is done carefully and precisely to maximise the benefits and ensure the system operates effectively and reliably for the customer. With our experience and knowledge we can make the whole process as simple as possible for you, the customer, and ensure that you get the full benefit of your investment.
Speak with us to find out the full benefits and suitability of a heat pump system in your home.