Solar Heated Brick Floors

Thermal Mass

• Materials with high thermal mass, such as brick, concrete and stone, have the capacity to store heat. This stored heat is valuable energy that radiates back into the space, heating the air. In cold weather, the presence of a warm surface also enhances thermal comfort. In winter, a room with a solar-heated floor is usually more comfortable than a room with the same air temperature that has no warm surfaces. This is because warm surfaces radiate heat directly to people in the room.

Solar Gain

• For solar-heated brick floors to be effective, they must receive solar gain, which refers to solar energy entering the room that the floor material can absorb. Ideally, sunlight should strike at least part of the floor itself. However, sunlight can also heat the interior air and the brick floor will absorb some of this heat. South-facing windows and glass doors are ideal for letting sunlight penetrate far into rooms in winter.

Solar Control

• Although daylight is desirable in winter for heating brick floors, in summer it is not. Window overhangs or blinds can reduce or prevent overheating by blocking excess sunlight from entering a space. Windows on the south are preferable to the east and west because it is much easier to control the daylight coming through them. Even in winter, solar gain coupled with thermal mass can cause overheating on sunny days, making window shading or coverings important.

Advantages & Disadvantages

• High mass floors such as brick offer advantages over low mass floors such as wood. They provide a low-tech, low cost way to reduce heating costs by storing thermal energy for release throughout the day and overnight. A disadvantage is that they must be exposed to the air, so area rugs interfere with their function. Additionally, brick floors are sometimes uneven and rough, making them more difficult to clean than other floors. However, sealants are available to make them more resistant to chipping and staining.