Air source heat pump is an affordable investment, easy to buy and fast to install. It is the most common method to utilize renewable energy in a detached or semi-detached house and at the summer cottage. The system consists of an outdoor unit and an indoor unit that blows warm air into the rooms. The outdoor unit can be covered by grating for aesthetic reasons but that will make it lose some of the power. Right beside the bedroom window is not an ideal placement for the unit because it makes a humming noise.
In Finland, an air source heat pump alone does not usually suffice as heating, but particularly in electrically heated buildings it will reduce the need to buy energy by 50–60% and respectively the cost of and emissions from heating. When temperature is below –20 degrees Celsius, the pump’s power is significantly reduced. During mild winters, an air source heat pump may produce nearly all necessary heating for a detached or semi-detached house in southern Finland, but its heat will not reach the bathroom, toilet or all rooms in a closed-concept house.
The design and installation of the pump system must be ordered from a professional expert including a warranty period. Electricity consumption may increase if the pump is not installed correctly. Return on the investment can be expected in just 2–7 years, but there is great variation.
Its carbon footprint is approximately 50–60 g CO2/kWh.