UNI-T UT305A, User Manual, Page: 19 / 26

19
Scanning Walls for Air Leaks or Insulation
Deficiencies
1. Turn off heating, cooling, and blower.
2. Press
SET to select emissivity. Press / to select
emissivity relatively high for painted surfaces or
window surfaces.
3. Press
YELLOW button to select MIN when opposite
side of wall is at lower temperature and or select MAX
when opposite side of wall is at higher temperature.
4. Measure an interior partition wall surface temperature.
Do not release the trigger. Record this temperature
as your baseline (or benchmark) for a “perfectly”
insulated wall.
5. Face the wall to be scanned. Stand 1.2m away to
scan a 10cm spot on the wall.
6. Scan horizontal rows of wall from top to bottom, or
horizontal rows of ceiling from wall to wall. Look for
greatest deviations from baseline temperature to
identify problems. This completes the insulation test
scan.
Turn on the blower (no heat, no cooling) and retest. If
test results with the blower on are different than results
with the blower off, this may indicate air leaks in
conditioned envelope walls. The air leaks are caused
by duct leaks that create a pressure differential across
the conditioned space envelope.
Testing Bearings
Warning
To avoid injury when testing bearings:
l
Do not wear loose clothing, jewelry, or anything
around neck when working around moving parts
such as motors, belts, blower, and fans.
l
Make sure an electrical disconnect is within
reach and operating correctly and freely.
l
Do not work alone.