Heat recovery VRF through a building with no risers

A stone mill with 600 mm walls, single-glazed north lights and no vertical service route left in it. A water system would have needed a plant room the building did not have and a riser we would have had to cut.

Heat-recovery VRF moved the plant to the roof and the distribution into the disused lift shaft. Twenty-two indoor units, four branch controllers, and studios on the north side heating while the south side cools — which on a March afternoon in this building is exactly what happens.

The pressure test ran for 24 hours at 41 bar before a gram of refrigerant went in. That is not optional and it is the step people skip.