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How does a heat pump work?

How heat pumps can work for you

See how a heat pump can benefit you and if you have any more questions send a direct message, or pick up the phone and call us on 01798 307000.

The areas we cover are West Sussex, East Sussex, Surrey, Hampshire, Cambridge and Norfolk

Air source heat pump standing


See below how our heat pumps can work for all types of properties

Air heat pump

How do heat pumps work?

An air source heat pump utilises external air temperatures and ground temperatures for ground source heat pumps.  It's what the heat pump does with this energy that is so beneficial to our energy consumption.  

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The science

The chemical in the heat pump, refrigerant, reacts to the absorbed energy from the ground or air,  making it boil and expand then compresses it and in doing so causes it to react and create a super heat, thus the energy used to compress, the now excited refrigerant, creates 3 to 4 times the energy in heat.  The cost is for 1 KWh to power the compressor and the result is 3 -4 KWh of heat for your home. Simple!  Pay for 1 KWh and get 3-4 KWh.

Radiators and underfloor heating

Underfloor heating is the most suitable partner for a heat pump, but it doesn't mean that radiators don't work, they do.  Part of our service is to provide you with full heat loss calculations, which will include the required radiator sizing at the lower flow temperatures that heat pumps work with. 

Radiator thermostat set optimal

New building and old buildings

Yes, new buildings are a perfect fit for heat pumps. New buildings are now so well insulated they need very little heat, so the low and steady high efficiency of heat pumps are most suitable.  However, older buildings can and do have heat pumps, even castles, which are quite drafty and have very little insulation.  It is all a matter of understanding the building's requirements, what you want to achieve, and what design best suits those factors.  If you look at our case studies and customer stories, you can see we have a mix of old and new and even very old properties, where heat pumps are keeping these homes very cosy.


Air Source Heat Pumps 

Air Source Heat Pumps (ASHP) have proved to be super-efficient heating systems for home owners. 

Heat pumps are efficient by producing more heat than power used.  For example a Mitsubishi Ecodan 8.5 KWh can produce 4.1 KWh (SCoP) of heat for every 1 KWh of electricity used and paid for, 3.1 KWh of free heating.  So, why doesn't everyone simply change to heat pumps?  But like most great ideas and things, it's never quite that simple.

Most homes can be heated with an air source heat pump, but there are a few important things to get right, and in some cases a few things that need changing in your home.

If your home is heated via radiators these may need to be increased in size or number.  The heat pump heats your home at a lower temperature than gas, oil or LPG, and so you need more surface area for the heat to transfer to your home.  

If you don't have a DHW cylinder designed for a heat pump  you may need to replace this, as the coil inside the cylinder needs to be larger than that of a standard cylinder.

Electrics will need to be checked.  You are installing quite a large appliance, and with so many electrical gadgets, including electric cars, we have to make sure your home is OK.

Don't worry, we provide full reports from our surveys that can tell you everything you need to know.

Air source heat pumps

Ground Source Heat Pumps

Ground source heat pumps (GSHP) are one of the most efficient systems to heat your home.

This heat pump utilises stored energy from the ground and converts into usable heat for your home.  It does this via a system very similar to your fridge.  When these systems are designed properly, they can generate 75%* of your heat free from the ground, the heat pump then converts this and provides you with the 100% of your heating needs.  Smart, efficient and financially pleasing.

Ground source heat pump systems gather the ground energy via two main systems, a horizontal collector and boreholes.

A horizontal collector array is a pipe system laid 1-1.5m below the surface; very much like underfloor heating looks like, but simply outside.  The heat pump then pumps water around this array gathering the energy as it goes and delivers it on its return to the heat pump.

A borehole collector works exactly the same as a horizontal, but there are boreholes drilled deep down into the ground with the pipes running down and up, gathering energy to delivery to the heat  pump.

Why are heat pumps so good?

Heat pump systems, when designed properly, provide all your heating and hot water needs, without costing the earth.  The heat pump operates by converting the energy stored in the ground into useful energy for your home.  The ground doesn’t charge you, so the heat pump gives it to you for free.  Which means that you can heat your home and only pay 25% of the cost of a 100% heating.

Our comprehensive approach to heating your home ensures our customers have the most efficient systems available.  Check out our customer comments and projects.

Ground Source heat pumps


We continually research new technologies and equipment to ensure we can offer the most up-to-date and efficient systems. 

We do not align ourselves with any one manufacturer, which allows us to pick and choose the best equipment most suitable for your home.  Not all heat pumps are made equal.

Listed below are some of the manufactures we work with at the moment, but we do update this, and it can change.

  • Mitsubishi

  • MasterTherm

  • Stiebel Eltron

  • Vaillant

  • Viessmann


Snugg Systems only design systems that suit your needs, the heating, efficiency and carbon reduction. 


BUS - Boiler Upgrade Scheme - £7500 from the Government

The Government launched the new grant, BUS, in April 2022. 


The grant was originally for £5000, but as of the 23 October 2023 homeowner's can apply for the new Boiler Upgrade Scheme value of £7500(Ofgem's website:


The grant changes are shown below:

•              Air source heat pump: original grant level £5,000, new grant level as of Oct 2023 is £7,500.

•              Ground source heat pump: original grant level £6,000, new grant level as of Oct 2023 is £7,500.


 There are certain criteria homeowners must meet, such as having an EPC no older than 10 years, and not have any recommendations for roof or cavity wall insulation.  The homeowner must use an MCS approved installer, of which we are one and use MCS and BUS approved equipment.  For further information regarding the scheme go to

Efficient heating systems

We only design heating and hot water systems for homes, after we have fully assessed their suitability for the technology; not all homes are suitable, and we openly tell clients why they won’t work and what would be involved to make one work. In some cases, a little updating of radiators is needed and in others re-insulation plans are required. When we design a system, tailored to your home, we outline how much it will cost to run and how much you will save both financially and carbon. 

HVAC heating and air conditioning residential units

Reduce carbon emissions

Probably the most important factor in today’s environmental crises; how do we reduce our carbon and use less of the planets precious resources?  Heat pumps are one of the most efficient home heating systems available, and with the correct design, air and ground source heat pumps can achieve averages of 300-400% efficiency, they not only can save you money, but can help towards saving our planet.

Planting a Tree
heat pump

Government Grant - Boiler Upgrade Scheme (BUS)

The Government launched the new grant, BUS, in April 2022.  BUS gives a one off payment of £7500 to those installing a new heat pump system.  There are certain criteria homeowners must meet, such as roof insulation and cavity wall insulation, having an EPC no older than 10 years, and not have any recommendations for roof or cavity wall insulation.  The homeowner must use an MCS approved installer, of which we are one and use MCS and BUS approved equipment.  For further information regarding the scheme go to

Plant Growing In Savings Coins -

VAT 0% on all our air and ground source heat pumps

As of the 1st of April 2022, the government has reduced the VAT on heat pump installations to 0%.  Which means that now our clients can save even more money on their installations as well as receiving the government BUS grant.

For full information regarding the boiler upgrade scheme either call or email us with any questions, or follow this link to Ofgem, who are managing the new grant,


Taking care of the planet

One of the most pressing issues of our time is global warming.  We are all responsible for helping to reduce the load on our planet, we have to reduce our demand on its resources.

Heat pumps can help with this, they still provide 100% of your heat demand but reduce the carbon output of your home. We are always looking at innovative ways to help reduce energy costs and carbon, and will happily advise our clients on the best way forward to achieve these essential goals. 

Now you know how a heat pump works, why not get in touch with Snugg Systems to arrange your design and installation?

01798 307000

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