WSI is an authorized dealer for the SOLARSHEAT System            WSI built solar home in Bellingham, WA               WSI built solar home in Blaine, WA               

Space heating accounts for about 60% of all residential energy costs.  Solar energy can meet 60 to 70% of that demand in the Pacific Northwest.  We can design the best approach for your new home or business.  Options include:  direct or indirect passive solar heating utilizing south glazing and interior thermal mass, liquid thermal collectors with interior radiant heating,  hot air collectors, attic space collectors, sun room or trombe wall additions, and ground-source heat pumps. 

Key Benefits

How does it work?

Solar space heating can be achieved in many ways.  However, the two general approaches are called passive or active solar heating.  Passive systems rely on direct solar gain through south windows and do not have "active" systems to circulate the collected heat.  Active systems use collectors to concentrate solar thermal energy and then pumps or fans to circulate that energy through the building. 

                         WSI solar home heating requirement                                                                   Performance of WSI passive solar home

Passive Solar Space Heating

In most areas, including the Pacific Northwest, passive solar heating is the simplest and most cost-effective approach.  However, it works best when integrated into the initial design of new construction.  Western Washington Solar has designed and built passive solar homes in the Pacific Northwest since 1979  (see "Green Building").  Passive solar homes include a number of essential elements:

Active Solar Space Heating

Active solar space heating, using solar heat collectors and circulating pumps or fans, can be used in new or often in existing homes.  It is especially useful, where sunlight falling on south facing windows is not practical.  Western Washington Solar can design and install the system best suited to meet your needs including the SOLARSHEAT space heating system.

Roof mounted air collector                Wall air collector                                Attic Collector                            Solar-Assisted Hydronic Radiant

How Much Does It Cost?

Features such as internal thermal mass, extra insulation, additional glass, or active solar collectors can add 3 to 5% to the cost of new construction.  However, these features will pay for themselves in a few years of added energy savings and re-sale value.  For example, with good design heating costs (gas) for a 2000 sq ft home in Western Washington can be reduced from about $852 per year to $148 per year, an initial savings of $704 per year.  Natural gas costs are predicted to increase about 14% per year.  At that rate a solar home will save more than $35,000 in heating costs over 15 years.  Energy efficient mortgages can provide up to an additional 4% borrowing limit and discounts on closing costs and fees.  Finally, the selling price of homes increases $20.73 for every $1 decrease in annual fuel bills (The Appraisal Journal, Oct. 1988).  Using the above example, a solar home would have an added value of $14,593 compared to a traditional home.  

More Information

Passive Solar Design Article - DOE

Chiras, Daniel D. 2002.  The Solar House: Passive Heating and Cooling.  Chelsea Green Publishing Company. 274 pp. ISBN 1-931498-12-1

Kachadorian, James. 1997.  The Passive Solar House.  Chelsea Green Publishing Company. 210 pp. ISBN 0-930031-97-0

Watson, Donald & Labs, Kenneth. 1983. Climatic Design. McGraw Hill.  288 pp.  ISBN 0-07-068488-X