Combined solar and gas heater

In a solar collector assembly of the type which includes a solar heat pipe formed as a sealed enclosure, with one wall of the solar heat pipe being a solar collector which has a solar evaporator wick on the surface of the solar collector wall within the solar heat pipe;

• a heat utilization device acting as the condenser of the solar heat pipe;
• capillary means delivering condensed liquid from the condenser to the solar evaporator wick;
• a fuel burning heater to furnish auxiliary heat to the solar heat pipe;
• a combustion chamber enclosing the fuel burning heater;
• a fuel delivery means supplying fuel and air to the heater;
• and an exhaust means open to the interior of the combustion chamber to exhaust combustion products from the burner;
• the improvement comprising:
• the combustion chamber including at least one surface which is heated by the fuel burning heater, with the heated surface including a first side within the combustion chamber and a second side outside the combustion chamber;
• a burner evaporator wick attached to the second side of the heated surface;
• and
• a heat pipe enclosing the burner evaporator wick on the second side of the surface, with the heat pipe removing heat from the combustion chamber and with the heat pipe including a condenser section to condense evaporated vapor and a delivery means to supply liquid condensed within the condenser section to the burner evaporator wick further including:
• at least one cavity formed in a wall of the solar heat pipe enclosure other than the solar collector wall, with the cavity forming the combustion chamber and having at least one surface exposed within the solar heat pipe;
• and
• the burner evaporator wick being located within the solar heat pipe and covering a surface of the cavity which is exposed within the solar heat pipe, so that the solar heat pipe is the heat pipe enclosing the burner evaporator wick.