Heat Pumps

SUPPLY AND INSTALLATION

Air Source Heat Pumps

An air source heat pump (ASHP) is a highly efficient device that harnesses the free low-grade energy from its surroundings and delivers this as useful heat energy. Air source heat pumps also provides cooling in the summer months.

Solwat Air Source Heat Pumps offer the most cost effective and eco-friendly way of heating your home. With this heating solution there is no need for the costly replacement of boilers, pipework or tanks. The heat pump installation is a relatively speedy procedure involving minimal disruption yet offering maximum benefits.

Key benefits of an air source heat pump

An Air Source Heat pump could substantially reduce your heating energy bills. Typically, the most impressive gains are realised when swapping out obsolete oil-fired boilers and other outdated energy sources, like LPG or natural gas, for newer technologies such as a heat pump system.
Installing an Air Source Heat Pump can help reduce the carbon footprint of your home. Not only do they not require any additional fuel other than electricity, but switching to this efficient heating option is a wise move as it can drastically cut down your emissions.
Minimal maintenance is needed; a single yearly inspection is required in order to ensure the heat pump is operating effectively and safely and to maintain the relevant manufacturers’ guarantees. The units are designed to be low maintenance and usually last twice as long as a conventional boiler.
No groundworks required during installation
Ideal for smaller properties as minimal space is required for installation
Can be used for both heating and hot water production similar to a combi boiler

For more information on the many advantages of owning a heat pump, see our Benefits page.

Why should I choose an air source heat pump?

The most efficient gas boilers claim efficiency of up to 99%. This is for the combustion of gasses only, not for the usable heat delivered – which is considered to be around 70%. Conventional electric heating, though more efficient (in the region of 98%), is perhaps the most expensive and creates huge amounts of greenhouse gasses during production.

In comparison, heat pumps operate with coefficients of performance in excess of 4:1. This means that for each unit of energy used, FOUR times as much is delivered in heat – keeping your home warm for a whole lot less! You can even combine your heat pump with a Solar PV system and heat your house for FREE!

How does an air source heat pump work?

An Air Source Heat Pump works like a fridge in reverse. It takes energy from the air around you and, using a system of heat exchangers and compressors with a refrigerant, it multiplies this up to heat enough hot water for your heating systems and hot water taps.

Step by step process

Air is pulled over a series of fine coils by a finely balanced fan unit. The coils contain a liquid refrigerant which absorbs the heat from the air. The refrigerant boils at -24°C so, even if the air outside has dropped below -10°C during a cold snap, it will still be warm enough to make the refrigerant boil.

The vaporised refrigerant is compacted using a compressor. This creates hot gas, up to 100°C, which is used to heat the water contained in the thermal store via a heat exchanger.

The air source heat pump continues to work in this way until the water in the thermal store hits the temperature required for the radiators and hot water required. The fan unit then switches off until the temperature of the thermal store falls and needs recharging again.

The efficiency of an air source heat pump varies as the outside temperature changes. Overall, we would expect most systems to generate 3.5kW of heat for every 1kW of electricity used, creating an average Coefficient of Performance (COP) of 3.5. indicating that they deliver 3.5 times more thermal energy than they consume in terms of electrical energy. Coefficient of Performance measures the ratio of heat to electricity and is the standard measure used to describe the efficiency of a heat pump.

Ground Source Heat Pumps

Solwat ground source heat pumps extract heat from the ground using pipes that are buried underground, typically in your garden. The pump circulates a mixture of water and antifreeze around a loop of pipe, called a ground loop. Heat from the ground is absorbed into the fluid and then passes through a heat exchanger into the heat pump.

Even in winter the ground stays at a constant temperature under the surface, so the heat pump can be used throughout the year. The length of the ground loop depends on the size of your plot and the amount of heat required to heat your home.

This heat can be used to heat radiators, underfloor or warm air heating systems and the hot water in your home all year round.

How does a ground source heat pump work?

A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe, called a ground loop, which is buried in your garden.

The heat from the ground is absorbed into the fluid and then passes through a heat exchanger into the heat pump.
The ground stays at a fairly constant temperature under the surface, so the heat pump can be used all year round.

A Ground Source Heat Pump (GSHP) consists of four elements:

1. The collector loop is placed under the ground in a parallel array, similar to an underfloor heating system, or via a vertical bore (also known as a borehole). A mixture of water and antifreeze is pumped through this. As the liquid flows through the underground pipes, it picks up the temperature of the earth around it, typically returning to the heat pump at about 6°C. This temperature remains fairly constant throughout the year, which is why ground source heat pumps provide such an efficient means of heating, even during very cold winter conditions.

2. Once back at the heat pump, the liquid is passed against a heat exchanger. On the other side of the heat exchanger is a refrigerant. This refrigerant boils at -24°C, so 6°C is plenty to make it boil rigorously.

3. The now gaseous refrigerant is squashed back down using a compressor. Whenever you squash a gas you force it to release energy.

4. The released energy is passed into a thermal store (a large body of stored water), causing the water to get hotter. The cycle of collector loop, heat exchange, compression and energy release continues until the water in the thermal store hits the temperature required to heat your radiators and hot water. The cycle then stops until the temperature of the thermal store falls and needs recharging again.

Key benefits of a ground source heat pump

It could lower your fuel bills, especially if you replace conventional electric heating
Can be used in the production of both heating and hot water
Provides good levels of efficiency all year round, even in the depth of winter
Lasts up to three times longer than a conventional boiler installation
Designed to be incredibly low maintenance
Nothing visible from the outside of your property

For more information on the many advantages of owning a heat pump, see our Benefits page.

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We pride ourselves on delivering the best heating and hot water systems available today - providing our customers with cost effective, green solutions and great customer service.

The installation process
We want to ensure that your experience with us is easy and enjoyable. We use our own highly skilled, certified engineers to install and commission our systems. We are also happy to work closely with any third party plumbers or other contractors involved.