Keeping It Cool
Summer has officially arrived and brought with it the HOTTEST DAYS OF THE YEAR! I personally LOVE this weather, but reality hits home when my 1970’s built home starts accumulating heat radiating in through windows, walls and the ceiling. Yes, as previously stated in my post Strategic Landscape Shading, my home is one of those built when energy was cheap and consideration for insulation was not a priority. I should state that it was insulated to the building code standards in place at the time. Those standards just don’t match what we do today. Running the A/C mean running up my electrical bill. So what is a man to do? Move my office into the basement… it’s much cooler down there!
So, what is it about basements that make them cooler? What is it about any underground structure made of concrete that provides relief when it’s scorching hot outside? Let’s take a look:
First, let’s examine the properties and effects of Thermal Mass, specifically of Concrete:
Thermal Mass: Thermal mass is a property that enables building materials to absorb, store, and later release significant amounts of heat. Thermal mass is effective in improving building comfort in any place that experiences these types of daily temperature fluctuations—both in winter as well as in summer. When used well and combined with passive solar design, thermal mass can play an important role in major reductions to energy use in active heating and cooling systems. The terms heavy-weight and light-weight are often used to describe buildings with different thermal mass strategies, and affects the choice of numerical factors used in subsequent calculations to describe their thermal response to heating and cooling. (Source: Wikipedia)
Thermal Mass of Concrete: Buildings constructed of concrete and masonry have a unique energy-saving advantage because of their inherent thermal mass. These materials absorb energy slowly and hold it for much longer periods of time than do less massive materials. This delays and reduces heat transfer through a thermal mass building component.
(Source: Concrete Thinker)
Great, concrete has thermal mass, and it absorbs energy and releases energy. But what does this mean? My basement is cool but what is really at work here? How about:
At a depth of 4.5 to 5 feet, the temperature of the ground in constant all year around, and since the building envelope is in contact with the earth, conduction through the building elements (primarily walls and floor) regulates the interior temperature. The normal temperature of the earth 5-10 feet below grade is about 50 degrees Fahrenheit all year round so in the summer there is a natural cooling effect from the earth in relation to the air. (Source: Fine Space Design)
A combination of Mother Nature and Concrete providing all the cooling I need. Long Live Summer!