Arkansas HVACR NewsMagazine November 2019

S tate, National, Chapter News Tech News

f. Air moves to offset temperature difference against walls and windows g. No high velocity air flow with perpendicular surfaces h. No circulation short cuts between return and supply air A few guidelines to remember- When we diagnose air flow, it is common to validate performance by measuring deltas. Do not rely on infrared thermometer technology to validate performance. Infrared thermometer technology is dependent upon materials and finishes to give the proper readings. You can use infrared thermometer technology to validate a delta presence or for comparative measurements only. While moving away from infrared thermometers for measuring performance, they are extremely valuable for identifying mixed air infiltration in chases and return spaces. Simply move the device around inside the chase or return while viewing the reading and even a small crack will influence the reading up or down depending upon ambient conditions. Do not confuse infrared thermometers with infrared imaging. Infrared imaging is much more precise and is valuable in all aspects of investigating temperature differences. A quality imager will identify air flow patterns, diagnose blocked dryers and can be used to

identify defective evaporators and dirty condensers. I can take the place of an infrared thermometer with an electronic temperature probe, but my temperature probe will not identify infiltration or heat loss from windows across the street. Never install terminal devices in a coffered ceiling.

Attempt to make arrangements for high sidewall grilles in these applications. If you find high sidewall grilles in residences that adjust air down and into the occupied space, they are installed upside down.

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