Arkansas HVACR NewsMagazine January 2025

HVACR NewsMagazine January 2025

Tech News

joints during this process. Only perform this method if there is extra tubing length and the coil moves very easily. This is to avoid causing any refrigerant leaks due to a cracked joint. The drain line may need to be temporarily moved or cut as well. Make sure to wear proper PPE for safety.

line with non corrosive bubble leak detector. If the condensate line was cut, make sure to glue it back together with a coupling. Method 5: Measure the Static Pressure Drop Across the Coil For this method, a single port or dual port manometer and static pressure tips are used to take the readings.

In a similar manner, if the furnace has a gas flex line or a union on the gas line, and a metal exhaust, you may be able to slide the whole furnace forward, exposing the underside of the evaporator coil. Be sure to have the gas and power turned off when using this method.

Take the first measurement from the point above the blower motor but before the coil. In our case, we are using the thermal limit switch hole and inserting the static pressure tip into the air stream at this location. Turn the power off to the system and place the switch and wires away from any metal where it may short out, when the power is turned back on during testing. The outdoor disconnect can be turned off during this test so the outdoor unit does not turn on. Turn power back on to the furnace and set the thermostat to air conditioning mode for the highest fan speed. The picture below shows a measurement of 0.85” WC.

An advantage to using this method is that if you are able to get enough of the evaporator coil exposed, you could potentially clean the coil while keeping the majority of the system in place. Once you’re done, return everything into its place and seal it all back up. Be sure to check that your gas line and exhaust are all secure before you’re complete. Leak check the gas