Final Report of Research and Development of a Diagnostic Procedure to Measure Changes in Thermal Integrity of Building Envelopes: Phase 2, BTR (Building Thermal Resistance) Meter Development.

摘要

Previous work (''Application of Building Thermal Resistance Techniques'' by J. E. Janssen, ''Comparison of BTR Measurements'' by J. E. Janssen and A. N. J. Pearman) has shown that the overall Building Thermal Resistance (BTR) of a typical home can be measured by observing the rate of temperature fall when the furnace is off and the rate of temperature rise when the furnace is turned on for 90 minutes. An instrument, based on an Epson Notebook computer, was built, and the computer was programmed to record the measured temperatures and compute the BTR value. An interactive program guides the user in the operation of the instrument. BTR measurements on three test houses agreed with ASHRAE heat loss calculations within /minus/6% and +9%. The BTR meter offers a simple and convenient way to assess the condition of the thermal insulation in an existing residential structure. No other method is available for such an overall measurement with relatively unskilled labor. The meter should be useful to building inspectors, builders, real estate people and sales people. For example, it has been shown that the method can discriminate between the presence and absence of storm windows. The instrument can also be used to make gross measurements of infiltration. While the BTR meter works best with warm air heating systems, its use is limited only by the ability to measure a representative indoor air temperature and the knowledge of the true heat input to the building when the heating system is operating at steady state. Further wide-scale testing of the meter is needed to establish its credibility. 3 refs., 12 figs., 12 tabs. (ERA citation 14:024551)