Arkansas HVACR NewsMagazine January 2025

News Magazine January 2024

FEATURE STORY

IWC which is double the minimum. If you use all the static pressure available (.5 IWC) on filters, the air will stop moving with enough velocity to deliver the BTU’s required. Pay attention to static pressure requirements and air flow speeds necessary to deliver both BTU and CFM. Once you find a combination that works, stick with the same set up. (Hint- April Aire) Providing filters with an unimpeded quantity of air Most often, there is nowhere near enough return air. Half the cfm requirement for the equipment and convert to square inches. Three tons require 1200 CFM, divided by 2 = 600 square inches gross grill area required. In many instances, commercial return air grills (high AK factors) will be necessary to meet the requirement for low static and high air flow. Once the installation is complete be sure to adjust for all the connected components. Set dip switches or taps as required. Remember, gas furnaces come set from the factory at either 1200 CFM or 1800-2000 CFM. Three- or five-tons nominal air flow. Adjust proper settings to match other components Design or adjust existing duct work and terminal devices Most often small adjustment on existing duct work can provide major

improvements to air flow and BTU delivery.

Weigh in refrigerant and validate start up performance After evacuating the system and checking for leaks, adjust the charge computation to account for line length and weigh in the charge. Start the system and run while cleaning up your work site, review operation criteria. If the system runs long enough for you to clean up the site and invoice the customer, it will run reliably for years. Walk away with confidence Take the time to double-check your workspace and make sure nothing has been left behind. Thank the customer for their time and trust. Ask if they have any questions and leave confident you have installed a system at an address that you will not have to return to until required maintenance is due. If you just left a home where the customer has a system financed, you can rest assured you have done everything possible to limit your risk on an unscheduled return visit.

On the other hand, why would you install any system in a different manner?

To Finance Or Not to Finance That is the Question