![]() ![]() In northern climates, 90% or greater efficiency gas furnaces are used at least 70% of the time in the market (see Table 1) and this usage increases in colder climates to more than 90% of the time ( view source). But, the federal minimum has stagnated at 80% efficient equipment (old technology). In some significant cases, the federal equipment efficiency requirements are extremely out-dated and do not represent the common technology used in the market. Unfortunately, this trade is not neutral in its consequences. One particularly problematic trade-off that some would like to use to weaken the building envelope (reduce insulation levels) is the use of HVAC equipment that is more efficient than that minimally required by the federal government. The kilowatt-hours of energy wasted by weakening building envelope insulation are being justified by using a more efficient HVAC system that uses less kilowatt-hours of energy. Now you might ask, how then does someone hit a “foul ball” in applying the energy code to a building such that an envelope backstop is needed?Įver heard of “trade-offs”? Example 1: Equipment Efficiency Trade-offs In the realm of energy code compliance, a building envelope backstop is needed for similar reasons. It keeps the building envelope thermal performance levels in the “playing field” and it prevents buildings from becoming “foul balls” that stray into unintended consequences. In baseball, a backstop is defined as a wall or fence behind home plate that keeps the ball on the playing field. One baseball backstop supplier notes that it protects fans from stray or foul balls. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |