An efficient NZEB solution by Astron

All EU member states are responsible for defining their individual national nearly zero-energy building standards themselves. However, NZEBs must be very energy efficient and their very low energy demand has to be covered to a very significant extent by energy from renewable sources.

An example of an efficient NZEB solution by Astron is shown in the top figure. A well insulated and air-tight building envelope with optimized thermal bridges is the basis for a NZEB concept. In addition, the building´s heat energy demand is reduced by a high usage of free sources, such as passive solar energy and internal gains. Surplus energy from these sources is stored in the ground under the large slab to be returned in winter. The residual energy demand is provided by a heat pump, which uses electricity, produced by PV solar cells on the large LMR600 roof.

A low-temperature floor heating system in combination with free ground energy ensures a high efficiency of the heat pump (high COP). Alternatively an air heating or radiant heating can be used in combination with a cost-optimized perimeter insulation (see picture).” In combination with a Lindab ventilation and heat recovery system also the comfort is ensured at low operating costs. “In practice NZEB solutions will always have to be designed case by case to respect the individual conditions”, says Dr. Pascal Brinks, Building Physics Manager at Astron Buildings. “The design can be executed by Astron, using complete building energy simulation including the ground interaction. Such transient modelling ensures to meet the highest performance on lowest operating and investment costs.”