Temperature differential test?

I was involved in the sale of a home recently as the seller. And I thought this was an interesting observation by the buyer’s home inspector. I didn’t know you could test temperature differential like this.

Welcome back Frank!

Thanks Dave. I couldn’t resist this.
The inspection was in a “licensed” State, not California. I thought I should note that.

I do that, it gives me a general idea of how the system is operating.

I can’t, but uneducated inspectors do it that way every day. They are also the ones that will eventually be dealing with upset clients because of their improper testing methods.

Good seeing ya again Frank!

You don’t have a flippin’ clue as to what you are talking about…

No problem. You go right on testing the surface temp of those register grates. I’m sure your clients appreciate the diligence! :roll:

An HVAC tech would laugh at this.

I should also mention that this inspector is a Nachi member.

No they wouldn’t.
I’m no HVAC tech.
I could insert my thermometer in the supply and return duct at the AH, but that doesn’t tell me everything I want to know.
I hit every supply and if there is a large temp difference at one or more, I know the duct is loose and/or damaged.
I wouldn’t call it a delta-t, but it tells me alot about the system.

I have found many loose and/or damaged duct doing it this way.

What State?

Not Texas :slight_smile: it’s Arizona.

Nice to hear from you Frank, How do you test the AC unit?

Very basic using thermal imaging. I just say that it blows hot, and blows cold. I don’t make any claims about delta T. If they want to know more than that, call an HVAC tech.

How is that any better than what I do?

"An HVAC tech would laugh at this. " :smiley:

How is that any better than what I do ?

It’s not. It’s laughable when you’re using it to determine delta T however. IMO.

I agree.
How would you determine the delta-t?
I do tell the client the supply temp and the return temp with both cooling and heating.

You’re supposed to drill a hole in the duct and insert a thermometer.

And then plug the hole.