Temperature differential test?

(Frank Rotte, , CPI, San Diego Home Inspector) #1

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.

(Dave Fetty, CMI) #2

Welcome back Frank!

(Frank Rotte, , CPI, San Diego Home Inspector) #3

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

(Roy Lewis, CMI - North Florida Inspector) #4

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

(Jeffrey R. Jonas) #5

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!

(Roy Lewis, CMI - North Florida Inspector) #6

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

(Jeffrey R. Jonas) #7

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

(Frank Rotte, , CPI, San Diego Home Inspector) #8

An HVAC tech would laugh at this.

(Frank Rotte, , CPI, San Diego Home Inspector) #9

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

(Roy Lewis, CMI - North Florida Inspector) #10

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.

(Emmanuel J. Scanlan, TREC# 7593) #11

What State?

(Frank Rotte, , CPI, San Diego Home Inspector) #12

Not Texas :slight_smile: it’s Arizona.

(John Olson) #13

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

(Frank Rotte, , CPI, San Diego Home Inspector) #14

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.

(Roy Lewis, CMI - North Florida Inspector) #15

How is that any better than what I do?

(Roy Lewis, CMI - North Florida Inspector) #16

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

How is that any better than what I do ?

(Frank Rotte, , CPI, San Diego Home Inspector) #17

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

(Roy Lewis, CMI - North Florida Inspector) #18

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.

(Frank Rotte, , CPI, San Diego Home Inspector) #19

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

(Frank Rotte, , CPI, San Diego Home Inspector) #20

And then plug the hole.