More people are considering installing an air source heat pump (ASHP) than ever before as they are one of the most efficient ways of heating your home all year round.
How Do Air Source Heat Pumps Work?
The air source heat pump (ASHP) uses a fan that rotates to bring in the outside air and is installed outside. Once the fan brings in the air the heating process begins which includes the following stages:
- Outdoor air passes over an exchanger coil which contains a refrigerant fluid
- The refrigerant fluid boils and evaporates, turning into a vapour
- That vapour is then compressed at high temperatures to produce heat
How is Heat Pump Efficiency Measured?
Heat pump efficiency is measured using Coefficient of Performance (CoP) which is calculated by comparing the amount of input to the amount of output.
For example, if an air source heat pump uses one kW of electricity to produce 3 kW of heat, the CoP is three. The higher the CoP, the better as it indicates that the heat pump is more efficient. Air Source Heat Pumps are at least three times more efficient than gas boilers, all year round.
Homeowners planning to install air source heat pumps often ask whether their heat pump will keep them warm during the winter because they work by drawing warmth from the air outside your house.
Although an air source heat pump is unlikely to be as efficient in winter as it is in warmer weather, they can continue to heat a property even in temperatures as low as -25 degrees Celsius in some cases. They can perform all year round though more electricity may be required to remove the heat form the air which can result in a lower efficiency.
How do get the most out of your air source heat pump during winter
There are a few things that need to be borne in mind in order to get the most out of your air source heat pump during the winter months:
Make Sure Your Heat Pump Is Serviced Before The Winter
To ensure your heat pump is ready for the colder months it is recommended that you have an annual maintenance service by a trained installer to make sure that it is running efficiently and to improve its lifespan.
Over time your heat pump can lose some efficiency so a properly maintained pump could save you money too. The service will include simple checks such as air and system filters, anti-freeze levels, leaks, loose electrical connections and tightening any vibrating components.
The installer will also check that the compressor starts and the run times of the heat pump. The fan blades will be cleaned as well as any filters that are blocked or dirty. If the filters are too blocked, they may need to be replaced.
Booking in a service will give you peace of mind that your heating system will stay fully operational during the winter.
Maintain a Constant Temperature
A considerable amount of electricity is required for a heat pump to fully heat a property from cold. They take longer to warm up from cold than either gas or oil central heating systems. This is because heat pumps are sized to match the continuous heat loss of a building whereas an oil or gas boiler are typically three-times oversized related to the property, meaning they have excess power to heat a property from cold.
To get the most from your heat pump and to reduce the amount of electricity required to keep your property warm it’s best to leave your thermostat on constantly at a set temperature (approximately 18-21 degrees) during the winter months. This way you will avoid heating the system from the cold and use a lot less electricity which will save you money.
Systems that are inverter driven units have a considerable advantage over other units that have a fixed temperature output. The sophisticated on-board controller will speed up or slow down the heat output to match the exact amount of heat a property needs. Your heat pump will operate at maximum efficiency if you keep your property at a constant temperature.
Only Fully Heat The Space You Need
One of the most frequent ways that heat can be lost in your home is by warm air escaping into unused rooms such as studies or spare rooms.
Though you may be tempted to turn off the heat in a room that isn’t being used very much, it’s best to have the heating system continuously running but to set the thermostat at approximately 14-16 degrees. Otherwise, a cold space will act as a vortex for the heat you’re generating in the rest of the house.
It’s also important to bear in mind that when you want to use one of the less frequently used rooms, if left unheated, it will take a lot longer to feel the warmth of heating from a heat pump than a traditional boiler.
By keeping your spare rooms on a low heat, you will reduce the chance of losing warm air and less energy will be required to heat the space when it comes time to use it.
Have a Smart Thermostat Installed
A smart thermostat is a worthwhile and beneficial addition to any central heating system including a heat pump system. If you automate the way you heat your home and make heat control remotely accessible, you can always adjust the temperature of your house without even needing to be in it.
Having a smart thermostat will give you greater and more convenient control over the central heating which will help in keeping your energy bills down.
Don’t Let The Warm Air Escape
A well-insulated home can make a big difference in getting the most out of your heat pump. A heat pump can be efficiently heating your home but if there isn’t adequate insulation then the heat will escape. This means having to heat the property for longer which will increase your energy bills.
For best results and maximum cost-saving, make sure that all windows and doors are closed, and curtains are drawn at night to avoid letting the heat out.
Don’t Cover Your Heat Pump
You might think that covering the heat pump will prevent it from freezing over but this is something you shouldn’t do under any circumstances.
If you cover an air source heat pump, the airflow is being blocked which will reduce efficiency and could even lead to mould. The defrost mode will help to keep the heat pump from freezing.
Clear Leaves, Snow and Other Debris
It’s important to clear the area around your heat pump of any debris as often as possible. If you don’t do this, you run the risk of the airflow being blocked and the efficiency of the heat pump beginning to drop.
Consider Installing Larger Radiators
The water heated for circulation around the heating system by an air source heat pump doesn’t reach temperatures as high as water heated by a boiler. For this reason, radiators with a larger surface area or underfloor heating are the best heating systems when using an air source heat pump.
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You should have no problem with your air source heat pump operating in cold weather. However, you will most likely receive higher energy bills when the temperature drops, as your pump works harder to bring you the same amount of heat.
The great thing to remember about the air source heat pump is that it is at least 3 times more efficient than gas boilers, all year round.
Written by Zachary Marley for Towy Valley Heating.
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