Is this reasonable?

[Sean Fogarty]

Originally Posted by fnewman

No, only 2 deg. more than the room temp. It was a digital thermostat, so I should have seen an indication in the display if the aux was on. I guess it could have been on if the the thermostat wiring was incorrect at the unit. Given that the house is essentially new, such a problem could have gone unnoticed by the previous occupants.

Frank,
At 55 deg outside I don't think it is unreasonable for that size unit to produce 115, but I what do I know. I have found a few that put out the heat but they are usualy new or close to it. The rest when working pump out between 90 to 105 in testing both sides.

Here are the facts for you..
First, if you grab the line set and its hot you know the heat pump is working.


Second if the aux heat is pushing 90 or better you know the heat strips are working.

Thats really all you need to worry about because the system is working and your functional part of inspectiing the heat pump is now complete..

I understand your wonder though, I had the same thought before to.

[RAY THOROMAN]

Originally Posted by cbottger

Frank I quit posting for over a year until just recently all I can say they are in the archives.

Ok lets see if I can bring the SOP nuts out of the woodwork.

The only true way to determine if the aux is on and how many of the aux's because there will normally be more than one strip is to use a amp meter.

The strips are staged on by the stat each strip will draw approximately 20 amps.

One has to take the excess panel off the furnace to expose the strips then you can count the # of strips if there are 3 strips if all are operating you should have 60 amps or close

Whoops have to go carry Grocery's get back to this later

Good info Charley


Frank, I'd say sure that's reasonable. But I'd not concern myself or report on issues outside the iNACHI sop if that is what you inspect to. You can evaluate systems above the sop, just do not report over the sop.

Just sayin' I inspect in your State GA and same general area.

[Frank P. Newman]

I do try to stay close to SOP, but sometimes, when I run across something out of the ordinary, I like to dig a little deeper just to satisfy my own curiosity, if nothing else. The problem, in most cases, is that time is limited and you can spend a lot of time in the name of learning a bit more. That's really why I asked the question in the first place - to see if some of the experts could shed a little light on the situation.

[Sean Fogarty]

Originally Posted by fnewman

I do try to stay close to SOP, but sometimes, when I run across something out of the ordinary, I like to dig a little deeper just to satisfy my own curiosity, if nothing else. The problem, in most cases, is that time is limited and you can spend a lot of time in the name of learning a bit more. That's really why I asked the question in the first place - to see if some of the experts could shed a little light on the situation.

I would like to know myself.. Is it unusaual to have a heat pump put out that much or is the thermostat wired wrong where both sides are running?

[Charley L. Bottger]

Originally Posted by fnewman

I understand how the strips work and how to use the clamp-on amp meter I carry in my case, but what I really was oringally asking was whether a supply temp of about 115 is likely without strips for the situation I described. It just seemed so high that I suspected at least one strip was on - if so, the question would be why? With the old analog thermostats I coudl always tell if the Aux had been turned on, but with the digitals, it is not as easily determined.

At 55 degrees outside ambient a 115 degrees on the supply side is possible on some HP's very close to the max I have ever seen. I still would have used the amp meter to see if one of the elements was activated the unit could have been wired to bring one element on with normal heat. It should not be wired that way but I don't trust contractors to do what is right.

[Charley L. Bottger]

Originally Posted by jfunderburk

Of course Charley, you are right. And if they wanted a technically exhaustive inspection, I'd do it your way.

So basically you don't care if the unit is performing as the MFG intended. Technically Exhaustive Should have nothing to do with the operation of this piece of equipment it either operates as the MFG intended or it does not. How does one know AMP meter. Just because some desk jocky that wrote the SOP did not have enough knowledge about proper operation of a heat HP does not make it right

Joe you have been doing HI's for a long time now and I believe you know the SOP is just the minimum required to perform just as building Codes are the minimum requirements for a builder. I see HI's slamming builders all the time for constructing homes to minimum codes and then they turn around and inspect to SOP the minimum standards for HI's.

[Charley L. Bottger]

Originally Posted by sfogarty

I would like to know myself.. Is it unusaual to have a heat pump put out that much or is the thermostat wired wrong where both sides are running?

Yes and don't you think your client would like to know the same thing being they are the ones going to be paying the utility bills

[Bruce A. King]

Originally Posted by fnewman

Just finished an inspection on a 2 year old home, 2800 sq. ft. with a 5 ton Lennox heat pump. Outside air was about 55 F this morning. Supply / return differential was approx. 32 degrees. I've never seen one that high, so am wondering if that is reasonable without the aux. heat being on? TIA

Sounds like you have R410 units since the house is only two years old and those temps are typical.

I have lots of testing experience with these.

I have owned two heat pumps with R410 for 9 years now, one is a 3 ton and the other a 3.5 ton. Both have the same type variable speed air handlers with 10kw strips in each. Also have the outside temperature sensor option so I can program the aux heat strips to stay off unless its really cold out. The defrost mode still kicks on the aux heat during the 1-2 minute cycle to knock off the chilled air.

These R410 units are awesome, the supply air will vary depending on the outside temperature. Properly sized, they will heat a properly insulated house with no aux strips running down to the low 20's or even below in some cases.

I can see where a miswired unit could be overlooked and you could have aux heat running when it should not (costs 3 times more to heat with electric strips than R410 system). With outside temp at 55 and heat pump and aux heat running you could see supply air above 130 easy, but depends on the size of the aux strips installed.

Since my variable speed units were a new thing in 2001, the installer wired them wrong. They worked ok but made some weird very high speed fan cycles during defrost mode. The airhandlers have several jumper settings for comfort modes and efficiency modes etc so I eventually took the 4 pages of system wiring options up there and figured it out. They were wired as basic air handlers instead of variable speed types.

One of the things I write up on new homes is the lack of labeling on the airhandler cabinet to indicate which size aux heat kit is installed.

Another difference with R410 is the presence of a little more ice on the outside unit before the defrost kicks in than you might be used to seeing on the old R22 systems, not a problem. The outside units typically have a jumper adjustment to choose the total run time between defrost cycles.
I think mine came set for 45 minutes and I changed it to defrost a little sooner.

[Joe Funderburk, CMI]

Originally Posted by cbottger

So basically you don't care if the unit is performing as the MFG intended. Technically Exhaustive Should have nothing to do with the operation of this piece of equipment it either operates as the MFG intended or it does not. How does one know AMP meter. Just because some desk jocky that wrote the SOP did not have enough knowledge about proper operation of a heat HP does not make it right

Joe you have been doing HI's for a long time now and I believe you know the SOP is just the minimum required to perform just as building Codes are the minimum requirements for a builder. I see HI's slamming builders all the time for constructing homes to minimum codes and then they turn around and inspect to SOP the minimum standards for HI's.

Charley, I know about how a heat pump ought to feel because I have one. If it's blowing hot air, I'm not too concerned and will let the HVAC guy pick the system apart with a fine tooth comb during his annual inspection (I recommend a full HVAC eval. prior to closing also). If the system is blowing air below 80 deg. in aux. mode with the outdoor coil off, I question the functionality of the heat strip(s) and refer it out. But if it's blowing warm air, I'm not taking the cabinet apart (especially not in a hot attic).

I don't check refrigerant pressure either and I'm sure the MFG has a standard for what that out to be. If they want a technically exhaustive inspection, I offer one for $10,000 and allow them to pay at closing also.

[Charley L. Bottger]

Originally Posted by jfunderburk

Charley, I know about how a heat pump ought to feel because I have one. If it's blowing hot air, I'm not too concerned and will let the HVAC guy pick the system apart with a fine tooth comb during his annual inspection (I recommend a full HVAC eval. prior to closing also). If the system is blowing air below 80 deg. in aux. mode with the outdoor coil off, I question the functionality of the heat strip(s) and refer it out. But if it's blowing warm air, I'm not taking the cabinet apart (especially not in a hot attic).

I don't check refrigerant pressure either and I'm sure the MFG has a standard for what that out to be. If they want a technically exhaustive inspection, I offer one for $10,000 and allow them to pay at closing also.

Don't get your panties in a wad Joe Cain't you tell by now when I am ragging someone just having fun with you. Your just to easy

[Scott Donnelly]

There are a number of things that can cause the temp. to be this high but with out the heat strips working none of them are good. I suspect your thermostate is miss wired. I find some heat strips come on with just 2 degree change at the thermostate. Try turning it up 1 degree and see what happens.

[Brian E. Kelly]

The Unit probably has a Gas Furnace.

Charley would be there all day with his Clamp Meter.

[David A. Andersen]

Hay Scott; quit trying to resurect the "dead".

This post was started Dec 2010!

If you perport to know anything about HVAC you know that under "any" test conditions that a dry bulb temperature differential can tell you "nothing" about how the equipment is operating!

The unit was "starving" because of the low ambient conditions.
Simple "matter-of-fact".

[Jay Bucklew]

Don't know if 1st reply was sent. So.. I am a cunsumer. I am looking to replace a heat pump system. My question re: the air handler. Today's options include a multi- or variable speed handler. This was not a choice available 30 yrs ago when current handler was installed. Single speed handler is either on/off depending on whether compressor is running. My understanding is the multi or variable speed motor will run continuously (although at varying speeds), & thus use varying amounts of electricity. Is the multi/variable speed handler less efficient in the use of electricity? I know when single speed is on, it will run at higher speed, but by being off at times may actually cost less. I am told the variable/multi speed handler makes the HVAC experience more comfortable. Am I worrying about pennies or nickles here, or is it a reasonable question and concern in my purhcase decision? I am new to the group. Power company could give me no help on this. I hope you all can. Thanx
Jay