Air Source Heat Pumps

Grants and Tariffs - For an Air source heat pump installation there are grants available of £850.00 for private dwellings if applied for before the end of March 2012, plus phase two of the renewable heating incentive which is due to start in October 2012, as yet we have no details of the tariff to be offered. For more information please contact us for a free quotation and energy assessment.

These units extract heat from the air outside; it will work successfully down to temperatures of minus 20 degrees centigrade. The flexibility of these units enables us to install multiples of configurations of units that will work in conjunction with solar to heat your house, domestic hot water, office and swimming pools. Later this year there will be a unit that will reach a temperature of 80c with no deficiency, ideal for the less insulated properties and making this type of heat pump a direct boiler replacement.

  View short video of how air source works.

Advantages

• Easy to install
• Will fit most properties
• In most cases will work on existing wet radiator systems
• Depending on type will do cooling as well as heating and domestic hot water
• Minimum amount of pipe work
• Works just the same as any other heat pump
• There is an outdoor unit that can be fitted up to 70m from the house, this unit looks similar to an air conditioning unit, if the unit is a split type the inside unit is about the same size as a boiler
• At maximum output the unit produces 46 decibel (as an example this is less than the noise of a modern boiler flue)
• The size of the unit is limited but can be made up of multiples

The co efficiency of performance or COP of a heat pump is the ratio of the output heat to the input supplied, example, one kilowatt of energy used produces 4 kilowatts. The air unit is more efficient in the summer than the winter, but on average it works out at a COP rating of 3.2 to 4.5. Below is an average cost per kWh for the main fuels, when calculating the heat pump one needs to divide the kWh by the COP example 10p per kWh peak divided by a COP off 4 equals 2.5p per kWh; off peak is 1.4p per kWh.

Natural Gas	3.4p per kWh	Electric off peak	5.6p per kWh
Coal	13.p per kWh	Oil	6.9p per kWh
LPG bulk	8.8p per kWh	Wood logs	1.0p per kWh
LPG cylinder	9.2p per kWh	Wood chippings	1.5p per kWh
Electric	10.p per kWh	Wood pellet	3.0p per kWh

These units are becoming more and more popular, more so on oil and LPG boiler replacements as they are four times cheaper to run than oil and LPG, working in conjunction with solar photovoltaic panels you could have a situation where you are heating and lighting you r house free of charge!

Below are some of our installations along with a brief description of the application:-

This is a complete renovation of a 1930's house that is approximately 900 square metres, it has a ground, first and second floor with a swimming pool and conservatory. The ground floor has under floor heating throughout, with the conservatory having the benefits of heating and cooling. The first and second floor have fan coil units (picture below), which will in this instance do heating and cooling. The swimming pool is also heated from the air to water heat pumps and there is no supplementary heat source. There is 600 litres of domestic hot water serving five bathrooms; again they are heated via the heat pumps.

The main units we fit are either Daikin Altherma or Mitsubishi Ecodan, the reason why we have chosen these two units is because they have the benefit of being extremely quiet and reliable, with the added benefit of an inverter driven compressor making these systems extremely cheap to run with a start up of only 5amps.

DAIKIN - ALTHERMA System

This is a split system i.e., it has both inside and outside units. The outdoor unit extracts low temperature energy from the environment; it upgrades the temperature then via a refrigerant circuit transfers it to the indoor unit, giving a typical COP range from 3 to 5, which means extracting heat from renewable sources requires only 1 kW of electric input to produce 3 to 5kW of heating, making this unit more than capable of warming a house completely even during our coldest winter days.

The indoor unit is known as a "hydro box", which can be connected to existing radiators, under floor heating or convector heaters. There are two options of this box; one that does heating only and the other does heating and cooling. Inbuilt to this unit is a standby electrical booster heater so that heat can be maintained should the pump malfunction. A domestic hot water tank is required which is constructed of stainless steel to maintain the highest standard of energy efficiency. With the combination of electric booster heaters and heat pump exchanger ensures rapid water heating with the lowest possible energy consumption.

The system controls are user friendly and gives you flexibility throughout the year for your heating and cooling functions.

This unit is very flexible as far as positioning is concerned, the outside unit having the ability to be up to 70 meters from the hydro box, it can also be installed on walls. The noise level is comparable to the exhaust of a modern condensing boiler whilst working. The hydro box is wall mounted and can be positioned anywhere within the property. The hot water cylinder has the option of mains pressure or vented versions and again can be positioned anywhere within the property, including the loft area, solar thermal can also be added on installation or at a later date, and comes with a 3 year parts and labour warranty.

Mitsubishishi Ecodan air to water heat pump

The Ecodan will heat your home and supply your hot water just like a traditional boiler with the benefits of being more energy efficient, reducing your bills and CO2. It will work with traditional radiators and under floor heating, hot water cylinders either vented or unvented and S plan controls. How does it work?

The Ecodan is an air source heat pump and the technology inside it is very similar to a domestic fridge. It basically transfers heat from one place to another- the back of your fridge is warm because it is removing heat from inside the storage space to the room. A heat pump removes warmth from the air outside and transfers it inside the home to heat radiators or water. The unit runs at a lower temperature but unlike a boiler which works with on-off bursts of heat to maintain the desired room temperature, heat pumps are different because they supply water to the radiators at a lower constant temperature. You still set the temperature of your home using a normal thermostat but you will enjoy constant and more controlled warmth. You will not notice any difference in the supply of your hot water – Ecodan can supply water up to 55c.

The unit sits outside either on a wall or on a solid level base up to 30m away from the distribution point in the house. In addition to the outside unit there will be a flow temperature controller which is specifically designed to ensure that space heating operates at optimum efficiency. Its noise level is equivalent to the exhaust of a modern condensing boiler (49dBA).

Below are a few pictures of our Mitsubishi installations:-