Heat pumps in new and older buildings

A heat pump makes use of natural energy in a particularly effective and environmentally responsible way: energy is drawn from the ambient air, ground or groundwater by means of a heat exchanger and, in a heat pump circuit, raised to a temperature level that is useful for heating. Using this free energy from nature means you are no longer reliant upon oil or gas. Plus your investment pays for itself in just a few years.

When it comes to the right heating system for new build, house builders are increasingly turning to heat pumps. According to the Federal Statistical Office, 32 percent of all residential buildings completed in 2016 were equipped with a heat pump. This development reinforces the misunderstanding that heat pumps are only suitable for new buildings, which is not entirely correct. Under certain conditions, the use of a heat pump in an older building can also be worthwhile. 

Heat pumps in older buildings

The new Vitocal  250-A and Vitocal  252-A air source heat pumps make it easy to modernise heating systems even in older houses. Innovations include the particularly climate friendly refrigerant, patented hydraulic system and the new electronic platform with Viessmann Energy Management.

Existing radiators can still be used

The Vitocal  250-A is designed as a particularly space saving wall mounted appliance, while the Vitocal  252-A is a compact floorstanding appliance with an integral 190  litre DHW cylinder. The units, which have been specially developed for heating system modernisation in detached and two-family houses, are conventionally operated with the refrigerant R290 (propane), which is extremely climate friendly when compared to the refrigerants used in other heat pumps.

This refrigerant also enables the new heat pumps to achieve high flow temperatures of up to 70  degrees Celsius, even when it is minus 15  degrees Celsius outside. Generally speaking, it is therefore possible to simply continue using the existing radiators. It is not essential that underfloor heating is installed, which helps to keep the costs of the modernisation project within limits.

Cost saving installation through innovative hydraulics

Cost savings are also ensured if an existing heat pump is replaced with one of the new ones that has the patented Hydro AutoControl hydraulic system. This adapts to virtually all existing heating systems during modernisation and significantly reduces installation time compared to other heat pumps. In addition, the hydraulic system helps to reduce the space requirement of the system by two thirds.

Heat pumps in new build

New buildings usually have good energy values and a correspondingly low heat demand. Generally speaking, modern condensing boilers are used for central heating, operating with high efficiency in the temperature range of 35 to 50 degrees Celsius. Heat pumps are also one of the most widely used heating systems in new build. The reasons for this are obvious – heat pumps achieve the highest efficiency levels in new buildings. Furthermore, some of the primary energy demand in new buildings must be covered by renewable energies, which is easily achieved with a heat pump.

By far the quietest outdoor unit of its kind

The new Vitocal outdoor unit has excellent workmanship and product quality. It impresses with its quiet operation thanks to advanced acoustic design. These units are particularly suitable for densely built-up areas.

Operating heat pumps with a photovoltaic system

A photovoltaic system is also a good way to make use of free environmental energy. Photovoltaics absorb solar radiation with the aid of an absorber, before converting the solar energy into electricity. Depending on the orientation, collector type and global radiation, a photovoltaic system can cover a large part of a home's electricity demand. When combined with a heat pump, the solar electricity can be used for the refrigerant circuit process. This helps to make system users a little more independent of their electricity providers. In addition, this combination means almost entirely carbon free heat, which is great for the environment. The heat pump itself has an intelligent PV optimisation function, which makes best possible use of the self-generated solar power.

The combination of heat pump and photovoltaics can also be useful for homeowners who want to achieve the standard of a low energy house. This is because the German Energy Saving Ordinance (EnEV) allows self-generated power to be deducted from the calculation of the final energy demand. This reduces the annual primary energy demand and makes homeowners eligible for attractive government subsidies for heat pumps in new build.

Regardless of whether the heat pump is used in a new or older building, in order to ensure reliable and economical operation in the long term, the heating system must match the heat demand as closely as possible. The section entitled Purchasing a heat pump explains what homeowners should look out for when considering such a purchase.

Mechanical ventilation with heat recovery

For those living and working in closed indoor spaces, controlled air exchange is essential. Controlled mechanical ventilation ensures a comfortable room climate, reduces ventilation heat loss and lowers heating costs. Ventilation units recover up to 98 percent of the latent heat in extract air, using it to heat the incoming outdoor air. When combined with a Vitocal heat pump, this becomes a complete air conditioning system.