Masonry Magazine June 1974 Page. 33
Which building material will you use?
You've got energy shortages to think about. Air-conditioning costs. Heat gain through the long, hot summers. Heat loss in the winter months. Heating equipment costs. The whole set of energy-use factors suddenly has become critically important. The building material you use affects all of them.
Compare the energy conserving capability of masonry, for instance, with double-plate glass walls. At 4:00 P.M. on a hot August day in Washington, D.C., the heat gain through a square foot of west-facing insulated brick and concrete block wall will be 2.2 Btus an hour. The heat gain through a double-plate glass wall in the same location will be 173 Btus a square foot in an hour. A big difference.
Project this differential over 10,000 square feet of wall. You come up with a heat gain through masonry of 22,000 Btuh, while the heat gain through double-plate glass is 1,730,000 Btuh. In the case of the masonry wall, cooling equipment with a two-ton capacity can handle the heat gain. But with the double-plate glass wall, about 143 tons of cooling capacity will be needed.
An analysis of a typical 10-story building shows that over its useful life, the air-conditioning cost for a square foot of our masonry wall will be about 23 cents. For the double-plate glass wall, it will be $7.60. It takes a lot of money to buy, install and create space for all the extra air-conditioning equipment
YOU DIDN'T PLAN ON AN ENERGY CRISIS, BUT NOW YOU'RE PLANNING YOUR NEXT BUILDING.
required by the double-plate glass wall. A lot of money and a lot of energy to run that equipment. Compare the heat loss in winter. It has a dramatic effect on energy consumption and building operation costs.
Our masonry wall, for example, has a "U-value" of 12. The double-plate glass wall has a "U-value" of 55. (U-values are used to determine heat loss through one square foot of wall area in Btuh per degree Farenheit differential across the wall.) This means that the masonry wall is about 450% more efficient, on the average, than the glass wall in reducing heat loss.
Over the useful life of the building, the heating cost per square foot of wall area for masonry will be about 30 cents. For double-plate glass, about $1.38.
In a time of one energy crisis after another, masonry makes eminently good sense as a good citizen. The masonry industry believes that the thermal insulating qualities of masonry are an important economic consideration to building designers, owners and investors, and all citizens.
Masonry walls save on air-conditioning and heating costs. And just as important, they are less expensive to build. The masonry wall we've described would have a 38% lower initial cost than the double-plate glass wall.
If you'd like to find out more, write to us and we'll send you a booklet comparing the thermal insulating qualities of masonry walls with double-plate glass walls, metal panel walls and pre-cast concrete walls.
IMI
International Masonry Institute
823 15th Street, N.W., Washington, D.C. 20005
Please send the booklet comparing insulating qualities of masonry with other building materials.
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