Energy Supply Systems for Buildings
Profile of Market Area
New residential buildings are built to be increasingly energy efficient and have a low heating demand. The building envelope is airtight to a large extent and therefore a ventilation system, preferably with waste heat recovery, is generally necessary. In residential buildings that are especially energy efficient, e.g. passive houses, the heating demand for the hot water can be greater than the demand for the space heating. Comparable goals in energy efficiency can be attained, when building renovation is carried out using the state-of-the-art technology available today.
For these high efficiency buildings, a suitable building technology system (HVAC) is required. Ventilation units having a high degree of heat recovery, low energy consumption and low noise level are important assets for achieving efficient buildings. Particularly interesting for these low energy yields is a mono-energetic energy supply provided only by electricity and an efficient heat supply provided by a heat pump. In buildings which are especially efficient, the co-generation of electricity and heat by means of small Stirling motors, gas turbines or fuel cells often can take place without the use of a costly back-up heating unit. Using biomass for the heating supply greatly increases the CO2 balance of the building. The integration of the heating supply unit and the ventilation unit into one saves costs. Within the scope of an integral building planning strategy, an HVAC system in combination with a thermal solar system further increases the efficiency.
Projects and References
Frequently Asked Questions
What is a passive house?
A passive house is characterised by a very high insulation standard in the thermal building envelope, a very good glazing which as a rule consists of triple pane insulating glazing and often insulated window frames, a building envelope which is nearly airtight and a ventilation unit with exhaust heat recovery. As a result the building has such a low heating demand of less than 10 W/m² that this can be alloted to the inlet of the ventilation system. The typical annual heating demand of a passive house is under 15 kWh/m²a. An active supplementary heating supply to ensure the thermal comfort of the residents is not necessary.
What is a 3-litre house?
As compared to a passive house, the 3-litre house has somewhat less insulation or there is no exhaust air recovery in the ventilation system. The heating demand is greater than in the passive house so that it can not be met solely by heating the inlet air. However, a large fraction of the heat can be distributed by heating air, which can be met by installing a few radiators or a small floor heating system. The annual heating demand is less than 30 kWh/m² a, which is equivalent to a consumption of 3 l/m² when using heating oil.
What is a heat pump?
A heat pump is an ordinary device that is found in every refrigerator. This device functions as follows: Heat is taken out of the environment at one place. High-grade energy like electricity is used to further increase the temperature, and it is released at another point into the environment. In a refrigerator, the inside volume should be cooled. For a heat pump used for heating, the process is reversed whereby the heat from the environment is transported to the building interior in order to heat it.
What is a Stirling engine?
In a Stirling engine, the change in volume of an enclosed working gas is matched to the heat supply and heat removal so that mechanical or electrical energy can be supplied using an external heat source. In contrast to the usual combustion engine where internal combustion takes place according to the Otto Principle, no combustion takes place within the engine. Thus, less maintenance is required and particularly good biogene energy sources or even solar energy can be used to power it.
Does Fraunhofer ISE sell this product?
No, the role of Fraunhofer ISE is to support our industrial customers in the development and optimisation of these and other products. As a rule the products are sold by our partners and industrial customers.
Does Fraunhofer ISE advise building owners in the planning?
Fraunhofer ISE must finance its work almost completely from the project budget paid by our customers. Therefore we can offer our services only within the framework of a financial compensation. We would be glad to provide you with an estimate for a specific proposed task you describe.
Who can help building owners in the planning phase?
Qualified consulting companies like solares bauen GmbH in Freiburg are happy to assist you. For further information contact Mr. Ufheil at ++49-761-45688-30.