Step-by-step explanation:
It typically should take less than five minutes to measure a residential system’s static pressure. Here are sample instructions for a furnace and an external coil:
STEP 1: Locate the appropriate locations to drill the test ports on the supply side (+) between the furnace and the coil, and on the return side (-) between the filter and the furnace. Center the test ports for neat appearance. Stay away from any coils, cap tubes, condensate pans, or circuit boards to avoid damage. Always look before you drill.