Arkansas HVACR NewsMagazine November 2021

HVACR NewsMagazine November 2021

Tech News

After the airflow and ductwork have been tested, it’s possible that balancing may need to be done. You can balance a system by carefully and incrementally dampening up or down a duct in order to increase or decrease the amount of air supplied to a zone. We won’t get too technical with the information involved with air balancing a space here, but it’s important to realize that there are simple balancing practices that can and should be done when commissioning a system.

temperature probes to the system and let it run for at least 15-20 minutes. For R410a systems especially, it’s important to allow time for the refrigerant to stabilize before attempting to make any kind of assessment. Once the system has stabilized, the readings to be taken are superheat, subcooling, line temps, saturation temps, pressures, and air temperature split (Delta T = Return Temp – Supply Temp). Remember, there are ways to determine what these readings should be. To revisit this, here is the LINK.

Refrigerant

The refrigerant charge is the next area of the system to check during commissioning. The first thing to do on a startup is to weigh in the charge. Take the length of the line set and calculate how much more refrigerant should be added to the charge of the system (for most residential split heat pumps, the standard calculation for weighing in the correct charge is as follows: 0.6 oz/ft of line set after 15ft. Refrigerant Charge Calculators can help in other applications.) If you’re not on a startup, then all yo u’ve got to do is hook up your refrigerant gauges/probes and