Simulation of a convective loop for the Nested Thermal Envelope Design™ low-energy house

The Nested Thermal Envelope Design™ is an innovative low-energy house design that incorporates two thermal envelopes to create a core and perimeter zone. The perimeter acts as a thermal buffer zone, where heat loss from the core and solar gain in the perimeter are recovered to the core via an inter-zone heat pump. To optimize heat recovery from the perimeter and minimize temperature stratification, a complete loop is formed around the core living space, through which air may flow in a convective loop. A simplified convective loop was modelled with a commercial computational fluid dynamics software package. The results show that the convective loop distributes solar gains and reduces temperature stratification in the perimeter. The location of the heat pump in the convective loop was found to affect the heat pump’s coefficient of performance by up to 21%.