How is Thermal Scanning integrated into my home inspection?

Preparation for the thermal scan:
    Before I begin a thermal scan, there must be a variance in temperature established between indoors and outdoors.  This is no problem during the winter, but during the other seasons, it often requires the aid of the HVAC system.  Ideally, the heat / AC would be on prior to the start of the inspection, but in most cases, I can achieve the difference I need as long as I am free to operate the furnce / air-conditioner.  If this temperature difference cannot be achieved, the thermal scan will be cancelled.

There are 3 primary issues that we can find with thermal scanning:

#1 The first is wetness behind finished walls and ceilings.  During this portion of the thermal scan, water is run through all of the fixtures for approximately 30 minutes.  The hope is that if there is a drip / leak anywhere, it will have had time to dampen the back side of the finished wall / ceiling areas prior to scanning.



This example shows a dining room ceiling area that appears fine.  There are no moisture stains.



but the thermal image clearly shows that there is active wetness at this location.  In this case, the utility room was located above this area and it was determined that the water softener was leaking.
 


This image shows a normal looking exterior wall.  A basement bathroom exists on the opposite side.



After running the shower for approximately 15 minutes, a small amount of moisture was detected at the exterior stucco wall - exiting one of the wall cracks.



The thermal image of this location revealed a very large dark / cold area directly behind the shower wall, which suggested that moisture had been leaking through the shower walls for a long period of time.  This is a situation where mold and mildew will likely be found.

#3

Attic spaces are also great for thermal scanning.  The primary thing we are looking for in the attic is evidence of thermal bypasses, or air leaks into the attic.  Thermal bypasses are the number one source of ice dams. so sealing any existing gaps is recommended.  With the use of our infrared camera, we can help locate the air leaks and can also provide recommendations for properly sealing them.



This image clearly shows heat loss at the base of this exhaust flue.



When the insulation was pulled back, I could see the large gap, which allows warm house air to leak into the attic.



Bath vents are also leakage sources - both at the fan housing and also where the vent passes through the roof.



Gaps are very common at the base of plumbing vents.



Here you can see the heat loss at the base of the pipe.



Recessed light are a major contributor to heat loss into the attic.  Some types are more problematic than others.



Here you can see the heat loss from the back side of the fixture.



If air ducts pass through the attic level ceiling, they should be properly sealed at their penetrations.



This image shows heat loss at a masonry chimney location.

In older homes, gaps often exist at the tops of the walls (referred to as "balloon framing").  Wood, plywood, rigid board insulation, or gypsum board can be cut to fit over these openings and then caulked into place.

What else can thermal scanning find?

We look for overheating switches, outlets and circuits.



These images show hot wires behind a finished wall.  This is a condition that needs to be repaired by an electrician and it would go completely undetected without the aid of a thermal imaging camera.



The draft fan on this furnace was overheating, and may not have been noticed without the use of infrared.

Air leakage is difficult to locate without performing a blower door test (this is used during an energy audit), so we do not claim to find air leaks.  However, some leaks may still be detectable during our evaluation, like this one - at a window.

Proper placement of structural members (i.e. headers) can be identified.

Air ducts can be located.  This can be useful in older homes, or newer homes when there is no air flow to a particular register.

Locate proper, or improper placement of radiant floor, or ceiling heating coils







Radiant floor heat should spaced at least 2".  This particular example is a potential overheating concern.



Radiant floor heat should be at least 6" away from toilet wax seals to prevent the seal from melting.



These coils were not spaced consistently - a sure sign of an amateur install.



This client did not know how this condo was heated.  We found heating coils covering almost every square inch of the ceiling.

Infrared can also check for leakage at covered radiators (helpful if the covers are difficult to remove)