PV Gap

Hilda Said:

what are the major considerations in designing a solar home?

We Answered:

the roof area. the larger the surface area the more solar panel that can be installed on the roof. In Queensland, Australia;you would ensure the greater surface area of the roof had a northerly aspect as that surface will have the most daily sun. Ensure the use of solar hot water; same considerations as solar panels. If not grid connected then consider a way of storing the electricity generated by the panels; eg a battery bank of some type.consider the safe storage of the battery bank in a seperate storage area.Consider an alternate source or electricity in the even of several days on little or no sun.
now the important stuff. You need to consider the average home and the amount of electricity used per day. then allow for the approproiate size solar array. If in a grid area then it would be best to export directly to the grid as the need for back up batterys is redundant lessening the cost.
consider objects like skylights; which will help reduce the need for lighting during the day thus reducing the amount of electricity required. consider also the material used to build the home.Using materials like double brick give good insulation characteristics; if you allow for metal foil between the layers of brick then it will be even better . Allow for insulation in the roof cavity . If considering metal foil then allow for possible dramas with electrical wiring. good luck

Javier Said:

How is thermal mass related to the heating and cooling of a solar home?

We Answered:

Thermal mass is used for storing the heat. Since the sun is only shining for part of the day, you need to capture that heat and slowly release it through the night. Water is an excellent storage medium, so you will often heat up a tank of water from the sun during the day, and then draw off that heat at night. Concrete or stone is also used as thermal mass to store the heat and slowly release it.

A trombe wall is a good example in a passive solar home of thermal mass. It is designed so that the sun hits it when it is low in the sky in the winter, but eaves are positioned so that when the sun is high in the sky in the summer, it is shaded. That way it captures heat and heats the room in the winter, but does not in the summer.

Radiant floors in concrete are another great example of thermal mass. The water runs through the pipes in the floors, and the heat is slowly released throughout the house. This helps prevent against wild temperature swings that you may have with a heater turning on and off throughout the day. This is more of a steady, even heat.