Building Envelope consists of the overall building materials inside and out. It also consist of how the building operates, the efficiency or non efficient it is. It also includes health and safety. Having said that, lets review what this means. A buildings structural components, insulation, thermal and air barriers, solar loading, pressures, duct systems, air leakage, gas and oil fired appliances, lighting and ventilation.
Testing. Involves utilizing scientific equipment and knowledge to place buildings under loads to see and measure how well the structure performs. These tests will provide a set of numbers we use to conduct calculations. Each structure has an existing set of numbers to compare to depending on sq footage, air volume, insulation, windows and mechanical equipment.
We can actually pinpoint how leaky a building is, how leaky duct systems are, heat and or cooling loads, all by measuring pressures. Of course visual inspections play a big part. We can even test room by room in order to discover which room is more leaky that the other. To provide a better idea how much experience we have, in 2012 we tested 165 residential structures ranging from 1200 sq ft to 6000 sq ft. Commercial buildings ranging from 20,000 sq ft to 150,000 st ft.
We are asked very often how come the HVAC company we use didn't tell us how leaky our ducts were or the about the pressures. A short answer is, they must take additional classes and education courses. A very small percentage of HVAC companies will invest the time or resources.