design temperature

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We Are the 99% — AND the 1%

Design temperatures, load calculations, and oversized HVAC systems

Posted on May 16 2012 by Allison A. Bailes III, PhD

We're making progress! With the all the emphasis on energy codes and energy efficiency programs like Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. New Homes, more homes are getting Manual J heating and cooling load calculations these days. The intent is for the heating and cooling systems to be sized properly because oversized systems have problems (poor dehumidification, short cycling...).


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Image Credits:

  1. Steve 2.0, from flickr.com, used under a Creative Commons license
  2. Energy Vanguard

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How to Perform a Heat-Loss Calculation — Part 2

Simple ways to calculate transmission losses and exfiltration losses

Posted on Apr 27 2012 by Martin Holladay

To continue last week’s discussion of heat-loss calculation methods, let’s consider a simple rectangular building, 20 feet by 30 feet, with 8-foot ceilings. Let’s assume it has an 8-foot-high basement with uninsulated concrete walls; the below-grade portion of the basement is 7 feet high, with 1 foot above grade.

To keep things simple, we’ll assume that the house has a flat roof, and that each side of the house has two windows (each 3 ft. by 4 ft.) and one door (3 ft. by 7 ft.). The house doesn’t have a chimney.


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Image Credits:

  1. IBACOS

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