Bill B. Chehalis, Washington
Your install is exceeding my expectations. You may remember that we have a timer on the water heater. At present, the timer connects the tank elements to the grid for a couple of hours in the evening. We took a chance the other day and turned the timer off. The next day was fairly sunny. Ambient temp never got above about 40 deg. The loop ran for about 3 hours, taking the tank from 60 degrees at the lower probe up to about 110 degrees, which is the same temp that the AC elements achieve. I’m a little bit nervous about what’s gonna happen in August. We might have to put some shadecloth over the panel!
Basic Solar Passive Design keeps a house warmer in the winter and cooler in the summer, decreasing heating and air conditioning bills by as much as 40%.
The first rule of design is to exceed building codes. Remember, building codes are the minimum requirement. Do not go for the cheapest or the least acceptable, do better. Maximize your insulation and minimize the air infiltration. Install an air to air heat exchanger to ensure fresh air and minimum heat loss.
In the northern hemisphere, the sun is in the south. Glazing should be maximized on the south side of a structure. Glazing (windows) should be minimized on the North and West. Here’s why. On the North side, glazing only leaks heat to the outside. “Cold north winds” in the winter time will penetrate the structure and make it colder. On the West side, remember the sun rises in the East and sets in the West. In warm summer weather, the hottest sun is in the afternoon. Western facing windows absorb all of the solar energy in July and August and soon the house – on its own – can reach 80 or 90 F! Carefully plan western facing windows. They need to have shading, coverings, or special low UV glass to minimize overheating in the summer.