Arkansas HVACR NewsMagazine January 2026

HVACR NewsMagazine January 2026

Energy Talk

the space, temperatures will spike one way or the other, once again, depending on the season.

proper documentation. Be sure you have sufficient air into the appliance with unrestricted flow. Assume all doors closed when calculating required air flow. Never forget a static return from even the smallest room separated by a door should be a minimum ten-inch duct. The size of the bottom of the air handler has little relationship to fulfilling the requirement for low velocity low pressure filtering. In some instances, three times the surface area of the filter rack is required for efficient operation. Learn what general grill sizes translate to actual cfm. The popular one square foot per ton is leftovers from 30 years ago. (See Arkansas HVACR Magazine May 2021 page 53). What is behind the grill? Are there restrictions? Are raw wood or drywall edges, gaps or cracks present? Is the return lined with plywood or other solid material that is sealed? And if you use duct board to seal a return, put the shiny side facing air flow. If you can’t see the entire return path , and suspect air infiltration, record the temperature in the room where the return is located, and in the blower compartment with the fan running and blower door closed. Be sure to use the same instrument for both temperatures. If there is a temp rise or fall (depending on the season) over a degree you generally have air from outside the envlope influencing performance. This simple test validates air tightness. We have discussed the point repeatedly that infrared temperature guns are only for compairative temperatures readings. Never use a temp gun to analysze refrigerant flow through components or calculate actual deltas. Colors and material texture can give false temperatures reading. The infrared temperature gun excels at locating air infiltration . Point the gun toward seams in the return. If there is any outside air invading

Raw edges, open chases, and concealed return space may lead to unidentified loading.

Protocol objectives When establishing objectives, never assume the last person working on the system understood what they were doing. Your job is to provide real-time competence. We sometime identify issues that are based upon geography bias. In the south you will seldom see equipment undersized on the cooling side. In the north the same goes for heating. Contractors in general never want to be short on design capacity and we forget load calculations have fudge factors built in.