Is there any excuse for a heatpump not keeping up other than improper sizing?

[Tom Chambers]

I recently had a new Trane GEO heat pump installed on my second floor and it runs 24x7 and when temp exceeds 80 it can no longer keep up... Its well insulated and etc... but no matter how bad the system is isn't it the job of the installer to analyze just how bad or poorly insulated a property is and size the unit accordingly..
Of course this assumes a new unit that has been tweeked to run as efficiently as it can..

 

[Stuff]

Could be many things but the installer should stand behind it. Call them and ask to speak with the owner. If already there then ask them to get the regional Trane rep involved.

 

[Sponsor]

 

[Jacobsond]

Did you insist on a heat load calculation and an inspection of your ducts? If not and the system is not sized properly its on you then for not insisting on that. A lot of heat/AC guys just size by whats in there already or a just silly rule of thumb. Of course the low bidder will probably not do the calculation. Anyway got to make sure the system is working correctly so get a tech out. You may even have (or want) to pay another company to check it out if you don't get satisfactory results.

 

[Tom Chambers]

In regard to your duct cleaning as a possibility.. its an entire new system top to bottom all new everything including ducting.. and thanks for your input.

I have beat all those drums..and they have spend many hours trying to make it better.. and they believe its doing the best it can.. So i am trying to convince them its undersize as the heat load has never been done.. and apparently they are not willing to do that as it may be embarrasing to them. Before i get mean i am trying to gather support in regard as to whether this is normal... some techs say things like well 24x7 is fine as long as it can keep up... (easy for you to say you are not paying the electric bill or replacing the pump twice as often as normal..) so i am looking for general opinions is it normal for 24x7 especially when it does not keep up when the temp passes 80 degrees outside...
I am hesitant to get the mfg and BBB and State Board involved unless I have a strong case.. Maybe I should hire a 3rd party company to do the load calculation and if it says i need a 3 ton.. then go in with both barrels blazing... Problem with that is the new tech can see that it appears not to be keeping up and may automatically say need 3 ton when the facts may only barely suggest that... My 800 square feet should be ok with 2 ton.. and i do have good insulation and good windows.. but had they done a load they may have given me a 3 ton to start.. they did do 3 ton down stairs and its working great... and takes out the moisture too just fine.. so its not oversize. Maybe i should try to contact the regional rep myself.. but my experience with factory guys is they tend to not say anything for fear of pissing off their bread and butter.. any thoughts or idea on the best way to proceed would be greatly appreciated..

 

[Jacobsond]

At design temp (hottest it gets outside) a properly designed system will likely run all the time to maintain set temp. Someone that does a heat load calculation will know that temperature. Thats what needs to be done. Also a manual D ( I think that's what its called) to determine if your ducts are correct.With an entire new system that would (should) have been the 1st step. Not the last step which you are in right now. IMHO you got a hack. You might as well cut your losses with them and find a new guy that will do the load tests and measure the airflow. No ducts are leaking are they? Did they use flex and maybe its crushed somewhere? The good HVAC guys will ask(and do) a commissioning report.Do they have that? That will contain all the information on how the system is working. You need stuff like sub-cool,superheat delta T and so forth. The manufacture will need that if you go to them. If you dont have that from your guy with this issue you have a hack.

 

[Jacobsond]

http://hvac-talk.com/aop/. Maybe you can find one of these guys to help. I dont think there are any hacks in this group.

 

[Tom Chambers]

So far the contractor who did the install has called in 2 other 3rd party Water to Air so called specialists... and neither one have been able to solve the problem... So far they all think you measure the water flow with temp drop. So that should tell you something about the quality of tech support in my neighborhood. But then that is because it not waterflow its undersize.. but with 800 sqft.. 2 ton should be enough but will only know for sure with good load calculation..

 

[Stuff]

You still don't know that it is undersized. For 800 sqft most would guess that it is oversized.

Did they verify that it is actually providing 24K BTU of cooling? They need to take some measurements and pull out a calculator.

With water flow the temp should rise when the unit is cooling as it is absorbing all of those BTUs.

How much do you want to do their job? Tell the dealer to pull in the Trane rep. Since I assume you already paid then you need to come up with something else to threaten them with. State that you are not going away until the system works.

 

[Tom Chambers]

I talked to Trane yesterday they said for them to send a rep i had to make a formal complaint before they could investigate..
So i went back and give the installer an ultimatum .. to go get the Trane Rep and and they both come out together or i get the Trane rep without them. and DONOT arbitrarily install a 3 ton since I too believe a 2 ton is sufficient.. if you jump up a 3 ton and it is oversize i will be on your ass again.. so the ultimatume is to provide with me a manual J and Manual D since they put in all new ducts.. and explain to me what it says i need... PERIOD and they have till close of business today to satisfy me or a formal Complaint will be lodged with TRANE asking for a letter that say TRANE cant keep up as your contractor is claiming.. doubt Trane will say that...
As far as I can tell it was all done from the seat of the pants and now the pants is to hot to sit in..
In regard to some of your questions:
The temp rise in inlet and outlet water is 6-8 degrees which is in book ball park.
The outlet air is 59 degrees 24x7 and never stops
The inlet air is around 75-76 degrees 24x7
Temp is set for 73 degrees.. on thermostat.. and every now and again it hits actually 73 like 3:00 am and may shut down for a few minutes..
The condensate is 5 gallons each 12 hours while the condensate for my down unit is a pint in 24 hours .. bottom unit runs maybe 10-15 min per hour and keeps nice and cool..
So its working big time but just not keeping up at peak and killing my electric..
Water flow has been tampered with to no end with no help... back pressure remains around 25-30 psi but should not be a problem as long as the temp rise is there and it does not become so great that it slows the mfg recommended water flow..
The small copper line is around room temp... which i find odd.. i am used to the small copper begin very warm to hot when doing its job.. on the air to air.. but a geo guy told me should be ok as long as the small copper is warmer than the outgoing water temp and it is.... wow i thought a hot line indicated hard work on the compress and doing a good job..
Does that sound right ok for small copper to not be hot.. especially while pulling out 10 gallons a day of moisture in the condensate line..
When i grabbed the small copper line and found it barely lukewarm i immediately thought "Crap this sucker is very in efficient and not sucking up much heat... what do you think.. does anyone have access to a GEO to feel the line and let me know if that is normal for a well functioning unit when it is doing lots of work removing moisture to be just lukewarm and not hot?

 

[Jacobsond]

5 gal of condensate? You got to be pulling in a lot of humid outside air from somewhere. Must be trying to cool the whole state down.

 

[Tom Chambers]

not 5 gallons but 10 gallons... i am not sure we think of condensate as gallons per day but i never dreamed that a steady drip from condensate 24x7 would equate to 5 gallons per day and 5 gallons per night 10 gallons in 24 hours... but it sure does... and we all know that on a hot day condensate will be dripping most all of the hot day.. and trust me a steady drop is 10 gallons in 24 hours.. so my guess is many homes are dumping 10 gallons per day and many more. But i plan to check very close to see if i can detect any holes that heat may be getting sucked thru the walls or from the attic.. even a small hole would be a killer and my pull down door for the attic has no insulation... on the door so i will try taping the tiny cracks where the door closes.. every little bit help.. looks like it might be a chore to try to put insulation on the door due to the folded stairs in the way.. but will look for more ideas.
But i would have thought if the upstaris had 10 gallons a day the down would be at least a gallon.. NOPE .. never more that a pint to a quart per 24 hour period. Actually the 5 gallons will be a little more since we know that some at least a quart of so might evaporate as the 5 gallon bucket of waters sits outside in the heat under the condensate discharge line all day.

I may go out and buy a humidity monitor to see what is there.. but it feels ok like humidity is not bad but it just won't keep up above 80 degrees....

 

[Reach4]

Its well insulated and etc...

I am wondering if a blower door test would be useful. If you pressurized the space, maybe you would hear or feel air escaping an air duct somewhere. Is the AC unit in the attic?

A calibrated test would show how tight things were, but presuming jacobsond's thought of pulling in outside air, maybe the test could not only see a problem but help locate it.

Even if the test finds an air leak that is not part of the AC system, it could still be useful.

 

[Tom Chambers]

Yes the air handler is in the attic the compressor is in the garage.. and hoping to get the Trane Rep to look soon and see what he recommends.. my guess is a pressure test of the room will be very expensive.. so will hold that to the end.. but plan to take some streamers (or maybe toilet paper) and move them around the room to see if they move away from any wall suggesting the fans are pulling attic air in.. maybe i will for it into 2nd stage and turn the blower to max so as to get as much air as possible moving which may pull more air in.. (actually that my hurt as it will force more air into the room and add press ure vice a vacuum as i need... but one negative is that upstairs i have a 2 bedroom only.. with a hall between them and the air intake is in the hall between them so that it can pull air from both bedrooms.. equally and has worked well in the past.. another think is the stairwell is in the center of the hadd so the intake would be pulling some air from down stairs.. but I have tried dropping the down temp to 72 just to make sure its not pulling any warm air from below.... So now i have an idea while going on and on.... I think I may put a heavy drape over the stairwell to reduce its impact then close the vents in one bedroom and close the door so that it no longer gets cold air or is able to return air.. and see if it can easily hold say the left bedroom as it should and maybe even shut down a little... Then after 24 hours switch rooms and see what the difference is.. can it do well when handing one room at a time if not we have a real problem.. since that will be only 400 sqft for the 2 ton...
It could give valuable info since only one room has the huge wall with the hot attic.. both rooms and the hall way have the hot attic over head but only one room has an attic on its entire wall... that way i can evealuate the impact of the extra attic heat... will let you know the results.. anyone have any thoughts about this brain fart?

 

[Jacobsond]

If the air handler is in the attic and its 100++ degrees and the return is disconnected or not connected properly that could be a big problem. Plus if its all flex and run poorly another problem. I would start in the attic and inspect all the duct work I can see. Can you take a few pictures of the air handler and the ducts.

 

[Tom Chambers]

Ducting looks good and is all brand new.. i have not noticed any breaks... but there could be some and its all new mastic not duct tape.. so looks to be sealed really good.. intake is pretty long but i know its not supposed to be straight or very super short due to noise and vibration will take some snapshots tonight once it cools down... possible leaks maybe ... disconnected intake no.. its almost doing its job.. and right now i am testing one room at at time as i mention above.. and the air has dropped from 59 to 48 and inlet air has dropped form 77 to 68 so that is and the air flow to the room has doubled.. but its been running now for 30 min and still has not shut down..with the new readings hope it shuts down pretty quick now.. Don't wnat to keep those ducts shut down too long i am sure the air handler is hating all the restrictions.. but it definitely jacked the outlet and inlet temps down so i do expect satisfaction shortly.. and hopefully it will stay satisfied for at least 30 min... hope hope.. more to come..

 

[WorthFlorida]

I had a two story home on S Florida. Two ton units on both floors. The second floor could never get cool enough unit I replaced the second floor with. 2.5 ton and during the heat of the day it might make it down to 75 but it would run most of the day until the evening. I had the home for 26 years.

The best trick is you need to balance the thermostats. The first floor unit needs to be set 2 or 3 degrees cooler. What happens is we all know that hot air rises. At certain temps the second floor can actually cool the entire home and if both thermostats are set the same temp the first floor ac shuts off. Now all the heat from the first floor continues to rise and the second floor unit now tries to cool the entire home thus run all day.

Set the first floor thermostat, to start at 3 degrees cooler. Now the first floor will do it’s fair share on the heat load. The second floor will always be warmer and yes it will run most of the time when the sun is up.

You mention 800 sq ft. I’m assuming that’s the second floor only. What’s the entire home?

Another problem I had was after I had the roof replaced, the ridge vent did not work as well as the original ridge vent. On the summer days I could actually feel the heat radiating down from the attic space. Better ventilation and or attic insulation will help big time.

I sold the home and the first thing the new owner complained was the second floor ac wasn’t working, it was a brand new unit. He set the first floor thermostat too high thus the first floor ac would hardly run and not take it fair share of the heat load b

Your problem is not the Trane unit. Air temps you mention are good but there is not enough volume of cool air. It the unit was not performing the gauges would show incorrect pressures.

Right now the entire east coast is high in humidity and it takes more energy to wring the air of water.

I now have a different two story home on Orlando with one 3.5 AC heat pump on the second floor. Seer 16. A well insulated home, windows tinted, the south facing front porch shades 72 sqft of windows. No problem keeping the both floors cool but the second floor is always warmer and will always be warmer.

I have a Honeywell smart thermostat and it has a fan setting “circulate”. At a minimum the fan will run 35 minutes per hour just circulating the air. It allows the air from the first floor and warmer air from the second floor to mix thereby keeping the temp of both floors more even.

My son lives down the street in a two story home with two heat pumps. 3200 sq ft. 2 ton first floor, 3 ton second floor. No problem keeping the temp down but summer time the ac will run a lot. The home has the same insulation and same builder built in 2007.

You mentioned compressor in the garage? What?
What’s the temp of the first floor, second floor and where is the thermostat.
How old it the home?
Attic and walls well insulated?
How many windows (sw ft of glass$ faces south.
Is this your first central air for this home?

 

[Tom Chambers]

Will answer the rest of your questions when i get a little more time.. thanks for the suggestions but this one sorta has me wondering how this is possible.. I understand hot air rises and can surely understand that a down unit can definitely heat the upstairs with very little problem.. maybe not make it cozy up there but for sure make it livable warm as all your hot air will try to float upstairs.. but unless i flunk my physics the cold air down will be a far cry from floating up stairs.. so I can go for keeping it cool down will ensure that NO hot air remains to be sucked up stairs.. but trust me NONE of the cool ain't going up my stairs... matter of fact when its hot up and cool down all the hot comes down the stairs and messes with my down unit and makes it kick on more frequently... am I wrong is my physics all messed up...

Here is how I know for sure.. when the upstairs is OFF.. you can go down the stairs and feel very cold air about half way down the stairs.. and from there on up its hot as hades... NO cool air ever made it all the way up my stairs.. so not sure the cool below will have anything more than a very negligible effect on the up cool... but will have a drastic effect on my upstairs heat when in the heat mode... heat rises and cool falls in my book.

So I am in the process of testing your suggestion running the down 3 degrees cooler than what i am trying to achieve above.. but I am not holding my breath but will let you know how the experiment comes out..

Has anyone else tested this theory that running cooler down stairs can have a measurable effect on the up temp.. of course it will have a tiny effect but it will be miniscule in my mind but willing to test anything to make it work..

Some Questions... you asked...

You mentioned compressor in the garage? What?
The upstairs compressor used to be under the stairwell on the first floor for 30 years and did fine but the contractor failing to have a yard stick brought one that did not have enough room to fit there so they were forced to move it to the garage.. OH WELL! not in a controlled environment but has to be better than in the yard.

What’s the temp of the first floor, second floor and where is the thermostat.
Thermostat is in the hall way between the only two bedrooms along with the air inlet.. temp in each room is within 1 degree of the hall thermometer. seem pretty close
Temp down set for 73 and maintains it rock solid 24x7 by kicking in maybe 15-20 min each hour and dumps about a pint of condensate water each 24 hours.
Temp up set for 73 and maintains that with 24x7 run until temp outside exceeds 80 degrees and then it slowly climbs reaching maybe 82 when outside is 95...


How old it the home?
1989 bout 30 years...
Attic and walls well insulated?
Insulated all around based on reqmts back in 1989 code.. not great but ok.. besides ain't it the installer job to make sure if the insulation is below par or house not as tight as possible he should recommend a fix or jack up the BTU to meet what the Manual J calls... oh he did not do a J sorry.
Not sure he knows what a J is and not about to ask if he has heard of a D before as he did new vents all around too.

How many windows (sw ft of glass$ faces south.
Have no idea but a lot.. will measure... but they are all double pane and a top of the line MFG but are now 30 years old.

Is this your first central air for this home?
It has has Florida Heat Pumps since day one back in 02.. i mean 1989.. and have never had either unit run 24x7... however it used to have real freon back in the old FHP days... LOL. now they all have simulated Freon.

But very interested if you reverse physics works or not will let you know...
Still trying to get a Trane Rep out to tell me "Sorry but our systems will not save any energy.. our product has to run 24x7 to keep up and will double your electric bill on 5 of the 12 hot months... wonder if that will be true for the coldest months too... GEEZ. If he is willing to say that I will ask if its ok if i use his words in my Review of his systems.. i could deal with 60% on and 40% off on hot days but 24x7 is a little much for 80 degrees... maybe i will be ok for 24x7 at 95 degrees.. but that is not where i am right now.. lets get past 77 first...

 

[WorthFlorida]

Just to clear it up a little. When both units were 2 ton each the upstairs still had trouble keeping the temp down with the thermostat difference but usually livable during the hottest part of the day and the ac would run most of the time. When I replaced both units I upped the second floor to 2.5 ton and that was a big difference. Even my son would check the the thermostat and raise it bit since it felt cold.

From your temp experience just sounds like the second floor unit is too small. What was the tonnage of the old units?
When you say compressor was under the stairs do you mean the air handler is now in the garage?

Where is the second floor air handler and the location of the return (inlet)?

 

[Tom Chambers]

Not absolutely sure what the 30 year upstairs FHP was but pretty sure the tech crossed the numbers and gave me what he thought those units were..and he installed 2 ton Trane up and 3 ton Trane down.. both GEO..but the 2 ton up and 3 ton down was using real FREON.. not make believe.. so doesn't that make the old unit a 2 ton + Real Freon = 2.5 ton equivalent.. a little joke... so Yes i think the originals were 2 ton up and 3 ton down.. but not sure.. (I miss the real freon and so does my car.)

Nope just what i said the compressor was under the stairwell and with the huge TRANE 3 ton under the stairs.. no room for the split upstairs compressor to remmain in the controlled environment to the garage it went....

No way the air handler in the garage that would be monster trunk.. piping and would act like that crazy gaspack outside going up the outside walls to the upstairs .. not talk about inefficient. So the normal split half (compressor) is in the garage and the air handler is in the 2nd story attic at about 100 degrees. Did you really mean to ask me if the air handler was in the garage? I wish the compressor was back in the 1st floor under the stairwell along side my new bosch but when the old tram lived there there was not room... Now there is room but if i ordered my contractor to put the up compressor back under the stair well where it lived for 30 years he would pull the rest of his hair out... and that would put him even more in the hole on this job. As he has lost his ass big time on this job... my guess he went to zero profit and is now in the red out of pocket to tune of maybe 3+ grand..
Second floor air handler is on third floor.. ( that is a joke its the 2nd floor attic) and the air inlet is in the hall at the top of the stairs centered in the hall between two bedrooms.. maybe one 450 square feet and the other 350 square feet.

I am hesitant to get on the band wagon and demand an upsize due to the fact that 2 ton should easily handle 800 sq ft.. unless its not running right.. and if i force the issue and now it does not run 24x7 but i am humid as heck that would be worse.. so what i am suggesting is bringing in a super Manual J Super Manual D guy and see what he thinks from the numbers...
Course based on my results so far my contractor might say.. "What's Dat? Man j and Man d? LOL

My understanding is with geo there is no 1/2 values.. so i cannot go to 2.5 have to go to 3.. does the fact that you did a 2.5 prove me wrong.. if so i need to go back to the nummie that told me there was no .5 in the geo business.. you get a 1 up or 1 one down.. nothing else.. so please clarifiy if you did a 2.5 geo i will twist some folks neck off for lying to me.. Thanks

 

[WorthFlorida]

Yes there is 1/2 ton increments. Your dealer may not want to deal with them.

The 3 ton must be the upstairs and the 2 ton down stairs. No arguments about sq ft. 800 sq ft second floor in a home is not the same as the first floor. The air handlers may also need to be switched. The 2 ton air handler unit may be too small for a 3 ton compressor.

If you can please take pictures of the labels for the air handlers and compressors. Please take pics of these units. I just cannot understand your issue with the locations.

If you do not swap out the units, any two ton will not keep up with the second floor heat load.