Retrotec USACE - Manual (Page 357)

Appendix G G27
Take a copy from the plan maps for the scanning. ■
Confi rm that the operating conditions in the target do not differ from ■
normal.
Measure the pressure conditions in areas that will be monitored.
■
Determine the indoor air temperatures in areas that will be monitored. ■
Measure the outdoor temperature before the scanning and also take ■
into account the weather conditions of the last 48 hours; consider pos-
sible temperature changes, which may affect results.
Use a temperature criteria chosen in advance (thermal index value).
■
Scan all structures systematically, and the air supply units and radiators ■
as well—save the results, with comments and also visible-light images
(if possible) on videotape or a memory card.
Record the internal heat sources and other factors that may affect
■
results.
Do the new scanning, if needed, using different pressures established by
■
a blower door or ventilation system. Unusually little pressure difference
is necessary to document air leakage sites, and IR thermography can be
performed at the typical commercial test pressure of 75 Pa or lower.
Decide on the other supporting measurements, if needed.
■
Compare your fi ndings with other results (air fl ow measurements, etc.). ■
Analyze the results using image-processing software and write the ■
report, providing thermal images as an appendix.
Evaluate possible investments, savings, and payback.
■
Example of a work list before an energy audit (not all measurements need to
be carried out, depending on the case):
G.14 The Thermal Performance Survey
G.14.1 Thermal Scanner
Thermal and visible images should be saved to digital videotape or memory
card (PCMCIA or SD card) for later analysis.
IR thermal images will be analyzed by thermal image processing software.
In thermal training, it is learned that the air temperatures can be deter-
mined using IR.