Delta T of 26 degrees

What would cause this? How would you write it up?

No picture, no other information?

Please, tell me you are kidding around…:shock:

It’s caused by the difference in temperature between 2 different points.:wink:

What are you measuring?

How are you measuring?

Where are you measuring?

What did you inspect?

Such a great community of sarcasm and belittling. I was naive enough to think HIs were on here to help each other.

This is a Carrier
Model Number: FB4CNF060
Serial Number: 1113A87546
Year Built: 2013

I was taught Delta T should be between 15 and 22, unless it’s a high velocity unit.

Hay Snowflake, STFU and answer the questions asked of you, or just go away.

You are being rude.

If you want an answer, ask a question with facts, and answer questions posed to you for clarity. Otherwise don’t wast out time.

Seriously, how in the world can we help you if you post a cryptic question with no real info?

So you have a 5 ton Carrier that’s 4 years old with a “perceived” dry-bulb temp split of 26 degrees?

What were the other measurements and variables? Humidity?
What’s the coil condition, filter, ductwork, etc?

A delta T by itself is almost meaningless.


Low fan speed would be my guess.

“Observed high temperature differential readings of approximately 26 degrees F between the return and the supply (pic included). Recommend that this condition be corrected by a Qualified HVAC Contractor.”

Who cares…as a home inspector our job is not to diagnose, it is to observe defects and to report them so someone in that field can repair it. HVAC has a lot of things that cause the system to act a certain way. Without proper equipment and training no way to know for sure. You will get yourself in big trouble. How about this narrative " HVAC system did not appear to function as designed at the time of the inspection. Inspector observed a rather high temperature differential of 26°F. Recommend further evaluation by a qualified HVAC technician and repaired as necessary. "

Well said thanks …Roy

So how do you know it’s high?

You can’t look for a dirty filter, but you can quote Old Wives Tales taught by HI Trainers?

No one said you have to diagnose the equipment. You can look at stuff (that you should be looking at anyway).

You see ice.

You can know it’s air flow or refrigerant charge.

Can you look at the filter, duct, feel air flow? No tools required. Just a brain.

a brain ?

I have been told high T Deltas can be a result of low freon, or maybe air in the freon. Don’t know if this is true, just what I have heard.

That would produce a **low **Delta-T.

The indoor air would not be properly treated so the air coming out would be closer to the air temp going in.

Delta-T has everything to do with sensible heat ratios. It has nothing to do with unit performance/capacity as taught. If you don’t know how the unit was set up and the Delta-T when working properly, you don’t know anything from it (as a home inspector).

Your measuring only dry bulb temperatures. That is only part of what the equipment is doing (thus Sensible heat ratios).

Delta-T could explain why a house is too humid or dry. But again, it’s just about airflow through the coils (less the by-pass factors of the equipment).

Ask an intelligent question, receive an intelligent response. Pretty simple really.