Abstract: A grey water heat recovery apparatus has first and second passes in counter-flow orientation. The hot side is grey water. The cold side is fresh water. It extracts heat from the grey water. The fresh water is carried in tubing bundles in series immersed in grey water sumps in cylindrical plastic, mild steel, or stainless steel pipe. Both ends of the fresh water bundle assembly extend from the same upper end pipe closure, without a pressurized line wall penetration in the walls of the pipe. There is a non-electrically conductive barrier between the fresh water and grey water flow paths. The apparatus has a leak detection circuit and co-operable bypass valves. The tube bundle is wider at the top than at the bottom. The lower manifold has grey water passages between the centering ears. The entire assembly is enclosed in a unitary external housing with easily accessible connection fittings.

Abstract: A grey water heat recovery apparatus has first and second passes arranged in counter-flow orientation. It has a hot side for grey water, and a cold side for fresh water supplied under pressure. It extracts heat from the grey water drains of a building. The fresh water is carried in tubing modules in series immersed in a grey water sump in a cylindrical plastic or stainless steel pipe. The coils have a return leg such that both ends of the fresh water coil are carried out through the same upper end pipe closure, without a pressurized line wall penetration in the walls of the pipe. There is a non-electrically conductive barrier between the fresh water and grey water flow paths. The apparatus has a leak detection circuit and co-operable bypass valves. The entire assembly may be enclosed in a unitary external housing with easily accessible connection fittings.

Abstract: A grey water heat recovery apparatus has first and second passes arranged in counter-flow orientation. The heat recovery apparatus is made from commonly available materials. It has a hot side for grey water, and a cold side for fresh water under pressure. The heat recovery apparatus extracts heat from grey water to pre-heat water for a water heater. The fresh water is carried in passes in series, each pass being immersed in a grey water sump in a plastic pipe. The water level in the sump is high enough to immerse the dominant portion of the fresh water pass in grey water. Both ends of the fresh water coil are carried out through the same upper end pipe closure, without a penetration in the pipe wall. The entire assembly may be enclosed in a unitary external housing with easily accessible connection fittings.