Warm Feet, Cold Reality

Matt Schwoegler, Infrared Training Center

It can take being uncomfortable for some homeowners to really start thinking about the efficiency of their house. Certainly, the bill from the electric company or that propane truck *once again* backing into the driveway all serve as painful reminders that your home uses (too much) energy. However, when air leakage across the floor leaves you with cold feet, or you find yourself always shivering from a draft on a windy day, it starts to get old...fast. Experiences like this can help motivate one to consider putting energy efficiency improvements on the fast track.

This assumes, of course, that the occupants are *feeling* cold in the first place. How about when it might not be as obvious, such as the case here? Sometimes thermal imaging can help a homeowner understand why what they are experiencing (feeling) is very different from what is actually happening.

These infrared images (above) were taken near the rim joist in the basement of a contemporary-style home built in 1984.  The residence has wood floors, fiberglass insulation and, not surprisingly, a decent amount of air leakage (3550 CFM 50).

As expected, one of the larger areas of air infiltration in the structure is located around the rim joist. What you will notice too is that the home also has a radiant floor heating system (images below):

Inspecting Steam Valves with Thermography

by Ron Lucier, ASNT NDT Level III
They are several types of steam valves:

• Isolation Valves
• Control Valves
• Non-Return Valves
• Safety Relief Valves

How you inspect them is different, but first, a little bit about steam. When you boil water at atmosphere it will reach 212˚F (100˚C).  Put it in a pressure vessel and continue heating, adding another 960 or so BTU’s and it becomes steam, but still at 212˚F (100˚C).  Pretty useless, though.  Keep heating it and the pressure goes up.  That heat is called enthalpy.  That’s the energy steam turbine blades extract via pressure drop to make power and it’s an important concept in steam valve leakage diagnosis.

Isolation Valves
Steam is hot and many valves and lines are insulated.  This is a problem for inspection.  I used to have holes in insulation cut anywhere from 10 to 16 “pipe diameters” away from the valve, on the bottom of the pipe and use high temp black paint.  I would also cut a hole in a convenient location upstream of the valve and within a day of startup establish a baseline.