One thing you cannot take for granted in a home is that it will have sufficient heat sources. In older houses the situation could be as basic as a space heater that is being used to heat too many rooms. I have inspected newer houses where, for one reason or another, one room had no heat duct. And with brand new homes, at least 30% of the time, I find heat ducts that DO NOT WORK. You might ask why. Well, almost always, the flex heat duct is not connected into the system or it has come loose or someone has crushed it so it is flat as a pancake and no heat can pass through. A device that is really handy for checking all the ducts, when the furnace is running, is a laser thermometer. I use one at almost every inspection and it saves bending down to feel for heat. You can walk through a room and point it several feet and still get a reading that lets you know if anything is happening. It makes for a good photo too, that shows the true situation. For example, if I have the photo below showing one duct at 125F and another duct pictured beside it putting out 58F, both when the furnace is running, the point is made! Personally, I like the red dot that shows up too. It makes it clear what you are measuring.
Thanks for looking.
bellingham home inspector
Steven L. Smith
Steven,
A basic inspectors tool for all the reasons you stated. It's also good for those ducts way up high in the ceiling. I always check every duct or baseboard in a home for heat. Like you said some don't always work.
James,
I never dreamed how handy it would be when I first got it. It is great for all things warm or cold. It is useful, in the summer, for determining just how hot an attic is too. I put it right up there with a moisture meter, a basic means of testing circuit polarity and wiring and a rot probe. As you say, it is basic to essential for doing a thorough job.
Yes,
Although we inspectors do not check the balancing of the heating or A/C system, as that is exhaustive, when I find something like this 58 vs 125 I will mention it. Usually there is a need for service of the furnace anyway so I call for the HVAC pro to make necessary adjustments at that time. Also, often the duct closest to the furnace will be quite a bit warmer than others far away.
David,
I believe it is physical impossibility for all registers to read the same temperature. Close would be fine. As Steve said the closer to the furnace the warmer the temperature. This would be especially true with older uninsulated duct work.
For those reading this, who are not inspectors, the whole thing of balancing ducts, and why it is exhaustive, has to do with people who live in homes adjusting heat supply registers. Someone finds a room they like too hang out in most of the time and opens the register, and closes one elsewhere. Then someone else in the house, like the kid, gets too hot at night and turns off all ducts in his or her roomf. These changes affect the different registers and unbalance the system compared to how it was put in. However, another factor is that sometimes flex ducts have come loose or been crushed below. Or metal ducts have come loose. As James says, insulation on ducts is a factor too. As and inspector, I check ducts for warm air but do not adjust the air flow. If I did, I might irritate the resident who spent lots of time messing up the balancing of the system! I picked up these simple tips at a consumer hot to do it yourself site. Some of this is beyond the capabilities of the average user.
http://www.allabouthome.com/tips/mechanical/forced_warm_air_heat.html
Balancing the Heat