This design uses a gas boiler and solar thermal collectors as heat inputs, and incorporates an HRV into the air handler.
The solar thermal collectors are expected to produce 40 percent of the yearly demand for heat and hot water.
The Munchkin boiler will fire whenever the collectors are unable to keep the water in the storage tank at or above 120 degrees.
Aluminum cladding protects the insulation on the two pipes that carry fluid to the solar collectors. Slightly lower and to the right are the PVC flue and air intake for the condensing boiler. The hood by the door is the HRV’s air intake.
Further down the wall are the HRV exhaust hood and, to the left of the exhaust, a small pipe that serves as the outflow for the boiler condensate.
A circulator pumps heat transfer fluid between the storage tank and the solar collectors in response to a set-point control.
The set-point control (the white box with the screen) is programmed to activate the pump when the fluid in the collectors is 15°F hotter than the water in the tank. The gray box beneath the set-point control houses the zone controller, which activates the zone dampers and air handler when a thermostat calls for heat.
The air handler — a Lifebreath Clean Air Furnace — has a blower below, an HRV in the middle, and a pump and water-to-air heat exchanger coil above.