Solar Air Space Heater

We constructed an Solar Space heater by going in-series of the thermal closed liquid loop tying in on the hot side from the collector before it gets to the hot water tank.
Heat Exchanger Parts: 110 volt AC blower 150cfm, 12inch by 10inch  liquid to air heat exchanger, sheet metal, 6 inch collarHeat Exchanger Parts: 110 volt AC blower 150cfm, 12inch by 10inch liquid to air heat exchanger, sheet metal, 6 inch collarSolar Heat Exchanger Parts: Visible is the blower starter, angle iron used to bend the sheet metalSolar Heat Exchanger Parts: Visible is the blower starter, angle iron used to bend the sheet metalSolar Air Heat Exchanger: View of end Collar and tabsSolar Air Heat Exchanger: View of end Collar and tabs


We had added a 3 valve assembly when first rigging up the hot water loop and here we tied in. Found a new 150cfm squirrel cage 110ACVolt fan on ebay for $50. Found heat exchanger that could hold 100psi and had pipe thread fittings to easily connect to our copper pipes. The dimensions of the aluminum heat exchanger core is 10" by 12" and 2" thick. We built a box from Lowes sheet metal. With screws and duct tape assembled the unit on the ground. When locating the box we added fiberglass insulation with a R of 4.
Solar Heat Exchanger: View of air flowing twards the exchanger coreSolar Heat Exchanger: View of air flowing twards the exchanger coreSolar Squirrel Cage Fan: Heat exchanger with fan in bottom rightSolar Squirrel Cage Fan: Heat exchanger with fan in bottom rightSolar Heat Exchanger with duct tape: Case assembled and ready to locate before attaching copper tubes and insulation and electrical supply.Solar Heat Exchanger with duct tape: Case assembled and ready to locate before attaching copper tubes and insulation and electrical supply.


We decided to not connect into the auxiliary central unit. One reason was if the gas heater was on and putting out 135°F air and the solar heat exchanger was a nice warm 120°F, it would not be helping but rather hindering the heating of the office. Also it would restrict air flow. It would be in the way in the summer via air flow and temperature.

Solar Heat Exchanger in place: Assembly in location with insulation installedSolar Heat Exchanger in place: Assembly in location with insulation installedSolar Heat Exchanger Insulated: Installed the first copper lineSolar Heat Exchanger Insulated: Installed the first copper lineSolar Air Heat Exchanger: Another view with both lines installedSolar Air Heat Exchanger: Another view with both lines installed



If the solar office heater had it's own duct work it would assist the heating of the air space. So we drew in and expelled heated air out through 2 ceiling 6" openings. We ran the air through the Lowe's flexable preinsulated Standex ADP 6" x 25' Black Insulated Flex Duct . We added a filter (will improve that in the future) and wired it through a added on/off light switch operated in the office. We added a fourth sensor (controller is now maxed out with sensors) to record the temperature of the pipe coming out of the space heat exchanger and it is labeled T4.

The air heater tank was connected into the liquid loop with sweated copper tubes. The added lines and exchanger tank held about a quart of liquid.
Had to bleed out the air with the rigged purge-bleeder valves explained earlier with hot water tank. This took about an hour.

After 2 weeks of adding the space heater

The solar office air space heater does assist the main gas heater on sunny days.

All the following temperatures are in ° Fahrenheit
For example: --3:35 pm-- T1(collector)=172, T4 (heat exchanger)=152, T2(tank bottom coil)=156. T3(tank top hot water)=134, pump is on, space fan is on. The output of the heated air is 110 and input of office air is 79. Outside is 58.

The space heater does not work well in the early morning, but can start warming space around 9:00 am when the collector is above 130°F. Have not had any real cold sunny days since the collector was full of the 30 tubes.