Heat pumps are a much more energy efficient solution that a traditional gas boiler. However, the only way to get the most out of a heat pump is with a properly insulated home. Today we’re exploring the relationship between heat pumps and insulation, and how we can all reap the benefits they offer.
What is a Heat Pump & How Does it Work?
A heat pump is a renewable energy system that transfers heat from an external source (ground, air or water) into the home. Heat pumps come in several forms, and each one works a little differently.
Air Source Heat Pumps
An air source heat pump generates heat by transferring the heat of the outside air into water. This then heats your home through your heating system, be it radiators or underfloor heating. The heat pump will extract heat from the air using a refrigerant, which then passes into the pump via a heat exchanger.
Air source heat pumps are usually cheaper to install than ground source heat pumps, as they only require the standalone unit without any groundwork. However, they typically use more electricity in winter, as the outside air is colder and requires more work to heat the property.
Ground Source Heat Pumps
A ground source heat pump utilises a network of underground pipework to collect solar heat.
Since the average UK ground temperature is around 8 to 12 degrees, the heat pump will extract this heat and upgrade to a higher temperature.
As the seasons change, air temperature tends to change the most, while ground temperature is fairly consistent. This means that ground source heat pumps can have a higher coefficient of performance (CoP) than an ASHP, where the air temperature is more changeable. They are generally more expensive than air source heat pumps, but can be more efficient, meaning you could save money on electricity in the long run.
Water Source Heat Pumps
A water source heat pump uses pipework submerged in water to collect its heat. It works in much the same way as a ground source heat pump, by compressing the heat it collects into a higher temperature. This is called a closed loop water collector – there are also open loop collectors, where the water is physically sucked into the heat pump, heat extracted, and then water let out downstream. Nu-Heat do not provide either type of water source heat pump, and careful consultation with environment agency rules are required to install one.
Extracting heat from water is more efficient than from the ground, because the heat transfer rate is higher. They also tend to be cheaper to install, as no ground excavation is needed. However, an open water source close to the building in question will be required, and the extracted water would need to be clean enough not to cause silt to build up in the heat pump.
Do Heat Pumps Require Insulation?
Heat pumps work at lower temperatures than a traditional heating system, therefore insulation is key to getting the most out of the system. A poorly insulated home will not reap the benefits of a heat pump, so this should be addressed before installing one.
If a home is insulated to the right standard, then the fact that a heat pump works at a lower temperature will not be an issue. If you can stop heat from leaving your home, a heat pump will be able to maintain a comfortable temperature all year round.
What Insulation is Best for Heat Pumps?
The best insulation for heat pumps is whatever is most effective at helping your home retain its heat. Here are the best ways of insulating your home in general.
1) Loft Insulation
Perhaps the most effective method of home insulation is in the loft. Just as humans lose most of their heat through their head, a house loses more heat from its roof than anywhere else. Insulating your loft is a relatively easy and cost-effective method of keeping your home warm and getting the most out of your heat pump.
Ideally, you should insulate your loft with at least 270mm of mineral wool insulation. This will ensure that the bulk of your home’s heat is retained. Installing loft insulation is a job that most homeowners should be able to complete themselves. It will cost you around £6 per square metre, or £11 – £15 PSM if you use an outside company to do it for you.
The insulation can either be installed between the joists of the loft or in the rafters. Installing it between the joists will keep the living space below the loft warm, and the loft cool. Installing insulation on the rafters will keep the loft warm, and allow you to use it as a living space, not just for storage.
2) Wall Insulation
Cavity wall insulation is insulation which is put into the cavity of the wall. Most homes built after 1935 will have a cavity wall. This method of insulation does need to be installed by a professional, as it involves drilling directly into the cavity of the wall. If your home has solid walls, this means that insulating it will have to be done on the inside or the outside, which is slightly more costly than within the cavity.
Most homes built since the 1990s will have more than adequate insulation within their walls. These homes will retain their heat better than older houses, and will reap the benefits of a heat pump more easily. Insulating your walls also means that while your property retains heat in the colder months, it will stay a little cooler in the summer.
3) Double Glazing
Ensuring your windows are double glazed is another great way of ensuring your home retains heat, and gets the most out of a heat pump. Windows are a common escape method for heat, so ensuring they are built to retain heat will avoid this. The Energy Saving Trust said double glazing can help an average household save around £100 a year in heating costs!
Double glazed windows will also keep the fiercer heat of summer out. What’s more, they are harder to break, and reduce condensation. The cost of installing double glazed windows can vary depending on a range of factors. Style of windows, materials and size can all contribute to the price of double glazing.
Ventillation is also very important, as the balance between retaining heat in a building, while providing clean air, needs to be right.
While insulating your home does come at a cost (some methods more costly than others) they all contribute towards greater energy efficiency. Better energy efficiency means lower bills, and a better functioning heat pump.
Here at Nu-Heat we provide heat pumps for homes across the country. We supply both air source and ground source heat pumps, so whichever method is best for you, we can help. If you are unsure which type of heat pump is best for you, take a look at our free guide for choosing the right heat pump!