AC Splits Yea or Nay

[Brian E. Kelly]

Do you take AC splits as part of your inspection protocol?

[Dale Duffy]

Originally Posted by bkelly2

Do you take AC splits as part of your inspection protocol?

Nope....

[Mark A. Timpani]

yes..

[Brian E. Kelly]

Dale do you bring an AC guy?

[Joe D. Funderburk]

How do you take a split?

[David P. Valley]

Originally Posted by jfunderburk

How do you take a split?

Simply obtain a temperature reading of the return register and the supply register. You want to see a 12 to 15 degree difference.

[Dale Duffy]

Originally Posted by bkelly2

Dale do you bring an AC guy?

Hi Brian,

No, every technician which has either serviced mine or customers has said it really has no bearing on how the equipment might really be functioning unless a temp reading is taken at the unit, and I have never seen a technician even take a reading from a register.

I do check the supply temp for readings in the 50's which tells me it is operating correctly.

You know the way they build here, there could be ducts separated, uninsulated, or nobody has had the equipment serviced in years, which is generally the reason one is not producing the correct temps.

I have found the systems just designed poorly, under sized, two story homes with 12 foot ceilings with both returns on the second floor, the second floor very cool and you cannot bring the temp down normally on the first because of the design.

As a matter of fact, an entire subdivision is suing a builder here in Chandler for that very reason...wrong conditioning design of every home.

So a temperature split of 14-22 degrees makes no difference if the equipment is producing 65 degree air and returning 80 something degrees, it's just not working or designed right.

[David A. Andersen]

If you are using a thermometer to take your split, it is worthless.

[Brian E. Kelly]

Dale interesting, so if it is 115 F outside you look for 50's F? Seems like the unit would be working prettty hard.

[Doug Edwards, CMI]

There are so many reasons why this method DOES NOT do what so many inspectors think it does I can't even begin to list them. There are literally a hundred variables that come into play. Like David said, if you are taking a dry bulb temperature you are wasting your time trying to determine if the system is working properly. I know this is what a lot of the HI books out there all say is the method for checking an HVAC , but it is just plain wrong.

[Brian E. Kelly]

Doug even more interesting. I am in the temp split camp, as that is how I was taught, and that was a question on the NHIE. I was taught that if he splits are not correct (taken at the inlet and outlet of the unit) then the system should be evaluated by a HVAC technician.

As a generalist HI I am all ears if there is a better way to test the AC. But if it involves specialized equipment, psychometric charts, and/or engineering, I will pass.

[Blaine Wiley]

I take them across the coil and look for 14 to 22 degrees. It gives an indication of how the system is working. In and of itself, it is not an accurate measurement, but it can be used with other visual clues to give the inspector a better idea about the condition of the system.

[Joe D. Funderburk]

Originally Posted by jfunderburk

How do you take a split?

I was only kidding. Should have used a different smiley.

[Dale Duffy]

Originally Posted by bkelly2

Dale interesting, so if it is 115 F outside you look for 50's F? Seems like the unit would be working prettty hard.

Like others said....to many variables.

The only way to really test them is with gauges and instruments like the techs use.

If it's 115 outside and the unit is producing 62 degree air from a duct system numerous feet long in a attic 155 degrees, chances are it's doing the best it can.

Very seldom have I run across anyone who said the system was serviced in the last 12 months like the manufacturers recommend...so I naturally recommend it before the close of escrow, if the buyers disregard my advice...oh well.....

[jmichalski]

I have seen many say that splits are worthless but no explanation of the position.

Anyone?

For what it's worth, I also take the temps at several registers (clients like to see the data relative to the other rooms). If it takes me only 3 minutes to do - and the clients like to play with the laser thermometer, then so be it.