How expensive is a domestic ventilation system?

Depending on the level of interest, there are all kinds of results and information on this issue that are increasingly difficult to read and understand, even for experts.

The book “Welche Heizung braucht das Haus? A comparison of heating and ventilation technology systems” by Rolf Schmidt, January 2010.

The above-mentioned paper takes a pragmatic approach. She looks at the systems using the example of a newly built detached house, which serves as a reference house. The standards of the Energy Saving Ordinance (EnEV) and the funding criteria of the Kreditanstalt für Wiederaufbau (KfW) are taken into account and then the individual system variants are compared with each other using the most up-to-date prices possible (as of 2010).

The publication also provides information on modernization measures in existing housing stock, showing how the current energy requirements of the EnEV and KfW can be achieved through measures based on the standards of the 1960s, 1970s and 1980s.

The calculation results, the investment costs and the consumption costs of the alternatives are summarized clearly in tables, diagrams and comparative illustrations. They should enable architects, planners and building owners to compare the various heating and ventilation technology options and find the most sensible solution for each individual case.

The annual heating requirement of the reference building is 64.29 kWh/m²*a. With an output of H=0.38 W/m²*a, the reference house achieves a system effort factor (ratio between primary energy expenditure and energy demand of the building) of ep=1.17 and a primary energy demand of 89.72 kWh/a. According to the state of the art, taking into account DIN 1946-6, a measure to ensure the air volume flow for moisture protection is essential. The system comparison therefore shows that a ventilation system is required in all cases.

The investment costs for the complete heat generation system, i.e. appliances including installation and air duct systems, are shown in the following table.

The reference house, which should not be confused with the reference building according to EnEV 2009 because it was built in 2001, has two storeys, no basement and 150 m² of living space with a room volume of 575 m³. This is based on the energy standard of EnEV 2002. The systems used for the calculations are a selection of current combinations with domestic ventilation and solar collectors based on gas condensing boilers, heat pumps and pellet systems. The results of the comparative calculations are based on the EPASS-Helena calculation program, version 4.8, with the boundary conditions according to EnEV 2009.