R-value (insulation) as ASHRAE 90.1 and the IECC prescribe U-values. However, R-value is widely used in practice to describe the thermal resistance of insulation products, layers, and most other parts of the building enclosure (walls, floors, roofs). Other areas of the world more commonly use U-value/U-factor for elements of the entire building enclosure including windows, doors, walls, roof, and ground slabs. The SI (metric) unit of R-value is whereas the I-P (inch-pound) unit is For R-values there is no difference between US customary units and imperial units, so the same I-P unit is used in both. Some sources use ″RSI″ when referring
Air Quality Egg different versions; depending on what customers choose, the egg can measure Particulates (PM10, PM2.5 and PM1.0), CO2, NO2, SO2, ozone, carbon monoxide and/or Volatile Organic Compounds. The Particulate version detects particles as small as 0.3µm (microns), using two Plantower PMS5003 sensors. The PM2.5 measurements of the Air Quality Egg version 2 had an R² correlation factor of 0.79 to 0.85 with a professional reference sensor, in a field test run by the Sout Coast Air Quality Management District (an R² approaching the value of 1 reflects a near perfect correlation, whereas a value of 0 indicates a complete lack of