In the middle of November 2008, we had two Sunmate solar heating panels from Environmental Solar Systems installed on the south facing wall of our new addition. The photo taken in January 2008 shows the two panels. To the right, part of our solar greenhouse can be seen. The solar greenhouse has been on our home for nearly 30 years and it supplies between 30% and 50% of our heating on the original house. Thes Sunmate panels are about three feet wide by just over six feet tall and have a small muffin fan to circulate heat into the house.

Here one of the panels is being installed. The photograph on the left shows where siding has been removed with the panel's bottom bracket already installed. The photograph on the top right provides a closer view of the bottom bracket with the two holes for the panel vents. Notice that the bottom bracket has a ledge on which the panel sits. The panel is held to the bottom and top brackets by screws. Flashing is provided that fits over the top of the panel to keep out water. The photograph on the bottom left shows one of the carpenters cutting an interior hole for the outlet vent. Even though directions for installing the panels indicate that the interior holes should be cut first, it was easier in this case to cut the exterior holes first using the bracket holes as a template. Paul, the owner of Environmental Solar Systems, suggested that we install the panels this way. It is interesting to note that the exterior walls of our addition used double 2X4 walls to allow for additional insulation.
Second Panel installation
How to Pages
Having lived with these panels now for over a year, we have a good idea of how they perform. To provide some background, we live in St. Louis MO. Our south wall actually faces about 15 degrees east of south. Our new addition has roughly R-27 insulation in the walls and R-50 in the ceiling, and all windows are double pane. Only two small windows in the addition are not on the south wall. The panels are heating an area of over 900 square feet. There are trees that shade the panels before 9:00 am at the beginning of winter in December. As the sun rises higher in the sky later in the winter, the sun hits the panels a bit earlier in the morning and later in the day.

In mid January on a day with full sun, the panels will begin providing heat about 9:00 am and will run until 2:30 or 3:00 pm. There is a period in the day of about 40 minutes when the panels will stop providing heat due to a shadow cast by a tree in our neighbor's yard. The exact time when the panels come on and shut off depends in part on the outside temperature. Even when the temperature is in the single digits, the panels will provide heat from about 9:20 am until after 2:00 pm. With the outside temperatures in the mid twenties or above, our furnace will not come on at all during the hours in which the panels are operating on days with full sun. Even when the sun is partially obscured by clouds the panels will provide some heat. Our large solar greenhouse does not provide heat until about 10:00 am, but continues to provide heat later in the day. It will heat the old part of the house a bit more than the panels heat the new addition. The old section of our house has only about R-7 insulation in the walls and has more north facing windows. With its large expanse of glazing, nearly 250 square feet, the solar greenhouse easily provides more heat than the small panels. But considering their size the Sunmate solar panels do an amazing job of providing heat.

Overall these panels provide a significant amount of heat reducing the time that our furnace runs. In addition, we have put insulated shades on many of our windows to further reduce our use of natural gas. These shades are described on the window_insulation page. Our main motivation in using solar heat is to reduce our use of non-renewable energy sources. A side benefit is any monetary savings from the reduced use of natural gas. Based on our current cost of natural gas, I estimate that it will take over twenty years before the panels save us enough to cover their cost. Of course, as the price of fuel goes up, the payback period will be shortened. During the heating season we have full or partial sun only about half of the time in our area. Thus, a location with more sun would see a shorter payback period. My only regret is not installing three panels, two for the family room and one for the bed room. This would have provided more heat on partially sunny days and days with temperatures in the teens or lower.

Check out the photovoltaic system that was completed in February of 2010

photographs by bernard

Solar Heating Panels

Solar Panels and Greenhouse
Sunmate Solar Panel Vents Sunmate Vent
The two photographs above show the vents from one panel inside of the house. The vent on the left is the return and the one on the right delivers warm air to the house. In the photo on the left, you can see the wire going from an electrical outlet to the low voltage muffin fan. Between the right vent and the electrical outlet is a thermostat that may be set to turn the fan off when the room reaches the temperature set on it. There is a small disc thermostat inside the panel that is wired in series with the external thermostat. This turns the fan on when the temperature inside the solar panel reaches 110 F and turns the blower off when the temperature goes below 90 F. Output temperature varies between 80 and 125 F.
Sunmate Bottom Bracket
Installing Sunmate Panel
Cutting Vent Holes
View of Panel Installation
Two Sunmate Panels
Close View of Sunmate Panels
Two more views showing both panels
Installation of a panel
Interior View
This shows another view of the bottom bracket for the second panel installed on the bedroom wall. The first panel is shown next to the patio door of our new family room. On the far right our back door and the solar greenhouse are shown. This photo was taken about 2:00 in the afternoon. You can see the shadow of the addition on one of the greenhouse windows. These windows are are double pane acrylic. As they age they become more fragile and may have to be replaced.

Two solar heating panels from Environmental solar Systems