Passivhaus with PVT collectors, a thermal store and a pellet boiler to provide backup hot water and to meet peak space heating demand

Crossways is built to Passivhaus standards and was featured on Grand Designs in 2009.

 

Heat and power is provided by a PVT array linked to a 500 litre thermal store with occasional backup from a Rika Evo Aqua pellet boiler. Space heating distribution is via a duct heater in the MVHR system linked to the thermal store. Whilst we were not involved in the original installation, we were asked to reconfigure the PVT array and to install a new thermal store to improve its performance.

 

The PVT array has four distinct angles of inclination and shading. By dividing it thermally into 4 separate sub-arrays using a header manifold and balancing between the sub-arrays using flow regulator valves, we were able to achieve a more even distribution of heat across the array.

 

Also by changing the inverter to a modular StecaGrid 300/500 we have been able to ensure that each panel within the array is controlled by its own MPPT and performs optimally.