Unlike ground source heat pumps that require a plant room and either land for ground loops or the right conditions for boreholes, air source heat pumps require little in the way of space for installation. However, in certain locations there may be particular considerations to ensure that air source heat pumps continue to perform to their optimum levels – for example, air source heat pumps situated on the coast.
A ‘coastal’ installation refers to a property that is located within 4 kilometres of the sea ‒ and as Britain is an island, there are a large number of houses that fall into this category. When Nu-Heat specifies any heat pump, a coastal location will be flagged up by the estimators who always consider the property’s location in order to size the unit – in accordance with MCS. Properties on particularly exposed coastal locations such as a cliff top facing out to sea have a greater heat loss, so an increased ‘exposure’ figure is included in the heat loss calculations. The bonus for heat pumps situated on the coast is that the air temperature is generally warmer and there is less chance of frost.
The main issue for a seaside air source heat pump is that the salt in sea air may corrode the heat exchanger within the heat pump, although the solution to this is fairly straightforward. Every air source heat pump that Nu-Heat specifies for a coastal location is treated with Blygold anti-corrosive coating.
Blygold has traditionally been used to protect HVAC coils, and is ideal for air source heat pumps. The coating provides a long lasting corrosion protection without affecting heat transfer and pressure drop, protecting the surface from premature deterioration. The heat conductive pigmentation in the coating creates a very high chemical resistance at a low layer thickness.
One coating should last for five years and can last longer, depending on actual location. The customer is asked to wash the coating annually with soapy water and inform Blygold that they have done this. If the coating shows sign of wear, Blygold can supply a touch-up kit or there is an option of a refurbishment programme that will ensure performance and longevity, although this is unlikely to be required in most situations.
In coastal locations, as with any other location, an air source heat pump should not be contained it in a tight space, next to a high fence or against the wall of the house, as air may leave the unit and return straight back in the other side, reducing efficiency.
With many remote locations having no access to natural gas, the installation of an air source heat pump is an ideal solution, as long as insulation levels are sufficient. Although all new builds will achieve these levels, older properties are likely to require improvements through the installation of various combinations of loft, door and wall insulation and double glazing.