We use a blower door, pressure pan, and thermal imaging camera to find out what’s wrong with the home. Moisture-related issues not only affect the structure but also may negatively impact customer comfort and health. We use the Testo 440IAQ to measure the relative humidity in the home, which actually isn’t as high as we thought it would be. While we’re at the house, we also test all of the HVAC equipment to make sure it’s running as it should.
On a blower door test, we try to bring the house down to -50 Pascals to get the ACH50, but this house is so massive that it’s impossible to do that with just one blower. However, because we’re only diagnosing leakage, we don’t need a true ACH50 number. With the conditions we have, we manage to determine that the house is relatively tight, which explains the somewhat unexpectedly normal relative humidity. We determine that the hole in the house is 9 sq feet.
When doing a blower door test for diagnostics, we set the pressure to 50, acquire the readings, read the percentage, and then set the speed accordingly to keep the fan running at a constant speed instead of matching the pressure.
After doing the blower door test, we use the thermal imaging camera to test see what the temperatures are in areas with cracks and in corners. Granular, fuzzy areas indicate possible areas of air leakage.
When checking the pressure of possible leak points, we determine that there are indirect paths to the outside behind outlets, where the pressure is close to that of the outdoors according to the blower door test.
Afterward, we use the pressure pan to see where the largest holes are; our thermal imaging cameras already located them for the most part, and the vents weren’t too bad.
When we investigated further, we found a failed bypass damper, a disconnected bath fan duct, missing or displaced insulation, and unsealed areas around light fixtures. The crown molding also wasn’t mechanically fastened at the top. Some of the issues were owed to air intrusion through the front wall and between floors. Most of the issues didn’t have to do with HVAC; they were design issues, so it’s critical to make sure those issues don’t pop up later BEFORE a house is built.
Mitsubishi Cooling & Heating: https://www.mitsubishicomfort.com/
Carrier: https://www.carrier.com/carrier/en/worldwide/
Retrotec: https://retrotec.com/
Hayward Score: https://www.haywardscore.com/
Testo: https://www.testo.com/en/
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