Abstract: A gray water heat recovery apparatus has first and second passes in counter-flow orientation. The hot side is gray water. The cold side is fresh water. It extracts heat from the gray water. The fresh water is carried in tubing bundles in series immersed in gray water sumps in a unitary cylindrical plastic, mild steel, stainless steel or copper pipe section that defines multiple flow passages. 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 gray water flow paths. The apparatus has a leak detection circuit and co-operable bypass valves. The lower manifold has gray water passages between the centering ears. The entire assembly is enclosed in a unitary external housing with axially accessible connection fittings.

Abstract: A gray water heat recovery apparatus has first and second passes in counter-flow orientation. The hot side is gray water. The cold side is fresh water. It extracts heat from the gray water. The fresh water is carried in tubing bundles in series immersed in gray water sumps in a unitary cylindrical plastic, mild steel, stainless steel or copper pipe section that defines multiple flow passages. 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 gray water flow paths. The apparatus has a leak detection circuit and co-operable bypass valves. The lower manifold has gray water passages between the centering ears. The entire assembly is enclosed in a unitary external housing with axially accessible connection fittings.

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 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. 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.

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. The heat recovery apparatus has a hot side for grey water, and a cold side for fresh water supplied under pressure. The heat recovery apparatus is used to pre-heat water for a water heater, and extracts heat from the grey water drains of a building in which the grey water drains are segregated from the sewage drains. The fresh water is carried in copper or stainless steel coils or linear tubing modules in series, each coil or linear tubing module being immersed in a grey water sump in a cylindrical plastic pipe. The water level in the sump is determined by the drain outlet level, and is high enough to immerse at least the dominant portion of the fresh water coil in grey water.

Abstract: Device for closing and automatically opening a cover of a cooking instrument, such as a grill and griddle, which includes a timing unit to determine the time for which the cooking instrument will function. The device includes an electromagnet for keeping the cover in closed and one or more springs for actuating opening of the cover, i.e., the springs are biased to open the cover. In operation, the closing position of the cover is detected, e.g., by a microswitch, and the electromagnet is activated in order to keep the cover closed. The electromagnet is controlled by the timing unit such that, when the cover is closed, the electromagnet is activated and the cover remains closed, and the electromagnet is deactivated after the time preset by the timing unit so that the cover is automatically opened through the bias of the springs.