Abstract: Apparatus for expelling air from a liquid storage tank, such as a hot water storage tank includes a bleed line coupled between a water circulating pump discharge conduit and a hot water discharge line emanating from tank 10. The bleed line is connected to the hot water discharge line at a location which is elevated with respect to a location where the bleed line is connected to the pump discharge conduit. The pump is operable to draw hot water from the top part of the tank and discharge it into a cold water fill line extending into the tank to enhance water circulation in the tank. Air and other gas released when water is heated in the top part of the tank are drawn from the top part of the tank and expelled via the bleed line, to prevent accumulation of air and other gas in the tank. In accordance with another aspect of the invention, an elongated tubular member is inserted into the cold water fill line.

Abstract: A combination water heating and space heating apparatus includes a water heating unit and a space heating unit releasably coupled with the water heating unit. The water heating unit has a water storage tank and a helically wound tubular heat exchanger inside the tank for exhausting products of combustion from a combustion chamber located in a top part of the tank and for transferring heat from the products of combustion to the surrounding water. The space heating unit is an air handler with an hydronic heat exchanger coil and a blower for blowing air over the coil. Hot water is supplied from the tank to the coil and is returned to the tank by means of a water circulation pump located in the space heating unit. Air blown over the coil is heated by the hot water flowing over the coil.

Abstract: A heat exchanger comprises a clam shell having a first passage, a second passage and a third passage connected sequentially in a plane. A hot collector box made from metal, for example, aluminized steel, in connected to the third passage. A secondary heat exchanger coil is operatively connected to the hot collector box. A second collector box or cold collector box made from plastic is connected to the outlet of the secondary heat exchanger coil. Condensate from the flue and condensate from the cold collector box may be discharged in a common line from the furnace. The clam shell is constructed and arranged to remove about 90%-95% of the energy from the flue products flowing therethrough. The heat exchanger is disposed in a passage between the inlet and the outlet in the housing of a furnace. Air is forced over the heat exchanger, which is disposed in the passage, by a blower in the housing.

Abstract: The present invention relates generally to pulse combustion furnaces, and more particularly to an improved air flapper valve assembly for use in association therewith, such improved air flapper valve assembly having a valve body formed from an elastomeric material which results in significant reduction in air valve sound and vibration.