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Heat Pump FAQ

An air to water heat pump extracts low temperature energy from the environment and increases its temperature for heating purposes. Heat pump efficiencies are normally quoted as the coefficient of performance of the system, these are typically in the range 3 to 5. In other words, extracting heat from renewable sources requires just 1kW of electrical input to generate 3kW to 5kW of heating output. Heat pump systems, therefore, are 3 to 5 times more efficient than fossil fuel boilers and are more than capable of warming a house completely, even during the lowest winter temperatures.

Air passes through the heat exchanger outside called the evaporator and the refrigerant gas absorbs heat from the outside air and evaporates. The vapour passes into the compressor and by compression increases its temperature and pressure. Hot vapour is condensed in the 2nd heat exchanger, the heat is being passed by water onto heating or domestic hot water system. The liquid refrigerant passes back through the expansion valve, reducing its pressure ready to start the cycle again.

A heat pump’s efficiency is often referred to as a “Coefficient of Performance” (COP) and all heat pump manufacturers are giving this value for nominal conditions of 7°C outdoor temperature and 35°C flow temperature.

The Coefficient of Performance (or COP) describes the ratio of electrical power used to heating power produced under fixed input and output conditions by the heat pump unit only. A COP is used for examining the performance of a heat pump unit at ideal test conditions, usually in a laboratory.

COP of 4 means for every 1kW of electrical energy used, 4kW of useful energy is produced – a net 3kW of useful energy will be ‘free’ generated by the heat pump.
Air to water heat pump – can be used in conjunction with underfloor heating and low temperature radiators, aluminium or steel panel or fan coils which require flow temperatures up to 55 °C

A heat pump can heat an indoor space and heat up a DHW (Domestic Hot Water) cylinder by the means of a refrigerant gas that can evaporate even at -25 °C. The refrigerant inside the piping helps in transporting this energy between the inside and outside of your home. This is the reason why there is an indoor and outdoor unit. The substances used have such properties that the process is the most energy efficient and achievable with technology, which is safe to use. There are a few types of refrigerants that Daikin has invented and still owns the patent on them, such as : R410 and the most environmental friendly & energy efficient R32.

SEAI are offering a grant incentive of up to €6,500 for air to water heat pump installations.

Apartment (Any) €4,500

Semi-Detached/End of Terrace/Detached/Mid Terrace €6,500

There is also an SEAI incentive of €200 for a technical assessment and €50 for a BER assessment.

In order to qualify for the air to water heat pump grant your home must be built and occupied prior to 2021 and have a heat loss indicator of 2 W/K/m2or lower.

Finally in order to be eligible, you must not have been in receipt of the air to water heat pump grant in the past.

Generally, air to water heat pumps can cost between €13,000-€17,000 but to determine an exact cost, we would have to conduct a technical assessment which is a detailed heat loss survey of your home.

This step is also required by the SEAI who is offering a grant for air to water heat pumps of €6,500.

The annual average consumption ranges from 3,000 to 5,000 kWh, depending on factors such as the size of the system, the size of the home, and its efficiency, as well as the running settings configured. The cost will vary depending on these factors and on your unit rate. Checking with your electricity supplier about favourable rates for heat pumps is recommended, as many of them offer discounts or reduced day/night rates.