boiler backup
Air-to-water air-source heat pumps for use with a boiler
An air-to-water heat pump can also be adapted to an existing central heating installation (gas or fuel). In this case we talk about heat pumps for use in addition to a boiler. They reduce energy consumption and limit emissions which are harmful to the atmosphere.
During the winter months, the heat pump is the primary energy supplier so long as its output is adequate, i.e. providing that the outside temperature remains above a certain limit. In fact, for all outside temperatures between 0 and about 5°C (balancing point), the heat pump operates independently. If the outdoor temperature drops below this point, the oil-fired boiler is switched on and acts as a back up to the heat pump by supplying the additional energy. As a result, fuel is used only during the coldest periods of the year.
This constitutes a simple and efficient way to save fuel by 70% and to cut annual energy bills by 40% to 50% without compromising on comfort. Another advantage is that the client constantly benefits from two completely independent energy sources.
Constraints
For a heat pump to be incorporated into an existing installation, certain conditions must be met. It is important to know the heating water supply temperature in order to ensure that the radiators are able to discharge all the energy that the heat pump can provide. This condition is often met as old installations are often equipped with "oversized" radiators.
The adaptation of a heat pump to an existing installation requires a certain number of measures to be taken. If the average annual heating consumption exceeds 33 litres of fuel per m2 of living space or if the heating water supply temperature is higher than 70°C, the structure must be adapted. Moreover, contrary to a fuel boiler which can provide hot water to a temperature of almost 90°C, the upper limit reached by a heat pump is closer to 55°C.
Today, the new ?high temperature? range of heat pumps can supply water to a temperature of 65°C, even when the outdoor temperature is low. It is therefore essential that the heat pump be connected where the water temperature of the installation is at its lowest.
Nevertheless, it is also important to check another point: the temperature difference between the inlet and outlet water for the heat pump. The heat pump is designed to operate with a temperature difference of 5 to 7°C, while an existing system operates with a difference of between 15 to 20°C. It is therefore necessary to install a buffer tank so that the water circuits may be separated.
The installation of a heat pump can result in an alteration of the electrical power subscribed to, or a change in the connection (3-phase instead of 1-phase).
Energy savings for existing homes
The installation of an AQUALIS 2 heat pump practically cuts annual energy bills in half without compromising on comfort when used alongside a boiler.
Thanks to an efficient control system, the installation automatically switches between the heat pump and the boiler, depending on the outdoor temperature.
The dual-energy system can be installed with any type of conventional gas or fuel-oil heating system.
