Renewable Energy Success Stories

Solar Space Heating (Passive Solar)

The Laetz Home – Clean, Natural Solar Heating

This home belongs to Bob and Sandy Laetz near Traverse City, MI, in the northwester corner of the Lower Peninsula. This house was designed to capture and hold heat from the sun, which supplies about 85% of their home heating needs. Large windows on the south side of the house allow sunlight into the house, where it is absorbed by the floors and walls, converting it to heat. Since there are no moving parts (pumps or blowers), this is called "passive" solar heating.

In addition to capturing heat, all those windows eliminate the need to turn on electric lights during the day, saving electricity. The window system is also designed to provide summer ventilation. Sliding glass doors on the first floor of the house can be opened to allow fresh air into the house. The small windows at the top are opened to let the hot air out. This "convection current" of air cools the house and provides natural ventilation all summer.

The Laetz's passive solar envelope home:

* is over 20 years old

* is well insulated (R35 walls, R60 attic)

* gets about 85% of the home’s heating needs from the solar energy

* hasn’t needed a fix or service call
* was built for less than standard construction costs