I know they do these in the States.
Maybe try searching the Home Time website for ventilation systems.
I think they have also popped up on the Renovation Nation program on Quest with Steve Thomas. I did see a system that basically took the stale air from the ceiling and roof spaces, then extracted the heat via a heat exchanger and pumped in fresh warm air. It also had a chiller/heating unit attached to it as well.
Have you looked on Ventaxia's website or Xpelair