Dear Jim: I want to try to heat my house partially with solar to lower my utility bills and to protect the environment for my kids. What simple options do I have and is solar only effective in cold climates? – Ken F.

Dear Ken: It is a common misconception that solar heating is suited only to cold, northern climates. Using solar can also be effective in warmer climates. In many cases, it can actually be more effective in the South because winter days are longer and the outdoor temperatures are higher.

There are many simple methods to incorporate solar heating into your home with minimal expense in materials and labor. If you are an average do-it-yourselfer, you should be able to build many solar projects for less than $100 in materials. It would be a good idea to have your children help.

Passive solar projects are the simplest to design and build yourself. These solar projects don’t include pumps or motors, yet they are effective and efficient. The simplest of all passive solar concepts is just making sure curtains on south-facing windows are open during the day and closing them at night.

A room heater is a very simple passive solar project. There are several different designs, but any of them can keep a room toasty warm on a sunny winter day. These designs use a thermosiphoning principle. This means hot air is less dense and rises naturally without the need for a fan.

A very shallow solar heater can be built and mounted vertically flush against an outside wall. Cut one small hole through the wall near the bottom of the heater and another one near the top. Seal the perimeters of the holes with caulk. The solar heated air will naturally flow out the top hole and draw cool room air in the bottom.

Another similar design is mounted, on an angle facing the sun, on the outside of a window. The window closes on the inlet and outlet openings so no holes need to cut through the wall. By insulating a baffle between the cool room air and the solar heated air, the thermosiphoning action is created.

These solar heaters can also be used to cool the house during warmer weather with natural ventilation. Open an outdoor vent in the top of the solar heater, block off the outlet into the house and open some windows. As the heated air exhausts out the top, it draws room air in the bottom, creating a breeze throughout your house.

If you are energetic or doing some remodeling, consider building a Trombe wall. This is an indoor brick or stone wall built close to a south-facing window. When the sun shines on the wall and warms it, natural warm air circulation is created in the room. Since the wall has a high thermal mass, it continues to heat the room well into the evening.