Technical Info

Thermal Mass

One of the benefits of the Octaform™ System is the thermal mass of the concrete.

Thermal mass is the ability of a material to absorb heat energy. A lot of heat energy is required to change the temperature of high-density material like concrete, bricks and tiles. They are, therefore, said to have a high thermal mass. Lightweight materials such as timber have low thermal mass. Appropriate use of thermal mass in buildings can make a big difference to comfort and heating and cooling costs.

"Appropriate use of thermal mass in buildings can make a big difference to comfort and heating and cooling costs."

Thermal mass acts as a "thermal battery". During summer, it absorbs heat, keeping the building comfortable. In winter, the same thermal mass can store the heat from the sun to release at night, helping the building to stay warm. Thermal mass is particularly beneficial where there is a big difference between day and night outdoor temperatures. Correct use of thermal mass can delay heat flow through the building envelope by as much as 10 to 12 hours producing a warmer building at night in winter and cooler building during the day in summer.

It is important to understand that thermal mass is not a substitute for insulation. Thermal mass stores and re-radiates heat. Insulation stops heat flowing into or out of the building. As a rule of thumb, the best place for thermal mass is inside the insulated building envelope. Insulation levels required will depend on the climate. A better-insulated envelope will mean more effective thermal mass.

For more information on thermal mass, please click on the following links:

http://www.greenhouse.gov.au/yourhome/technical/pdf/fs17.pdf

http://www.buildinggreen.com/features/tm/thermal.html

http://greenbuildings.santa-monica.org/envelope/envthermalmass.html

http://www.concretenetwork.com/concrete/radiantfloorheating/thermalmass.html

http://www.cpca.ca/cement.nsf/internet/A7443DB6354F810785256AA4005A7CC0?OpenDocument

http://www.cibse.org/pdfs/Embedded%20Hydronic%20Pipe%20Sys.pdf

http://www.concretehomesmagazine.com/99con1wi/walpower/walpower.htm