LG Heat Pump frustration
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No, that’s just something odd about the photo. The vent is completely free of any obstruction.
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No. Opposite wall of the room.
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contractor coming in the morning.Can he weigh the charge without losing the charge?
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This could be a big help.Are you saying that instead of resistive electric coils added to the existing system there exists coils that are heated with a propane boiler that can be inserted into the existing air handler? That sounds like a fabulous solution. Especially if there is smart communication and coordination that controls when the boiler heats the water that flows through the coils.
Is this a thing for my lg air handler?
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I have been trying to find any air leaks. I think I found that at the base of the baseboard molding on the first floor is a leak.As for the humidity, it in indeed quite low. I don’t have a whole house humidifier. I was led to believe that with a tight house such as mine, the concern was a tendency to have too much humidity.
But the low humidity making people feel as if it is too cold is fascinating — and an explanation that fits perfectly.
Given all the dangerous described everywhere about high humidity, should I add humidity? If so, what is the best way?
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consider blower door testing for each apartment to find the leaks, or the building as a whole,
sounds like you already suspect the baseboard to floor, I had same and caulked everything, window trim including top and bottom, ceiling fixtures(bathroom fans) are horrible holes in the envelope,
and if the bathroom and kitchen exhaust to the outdoors, I turned mine on and went around barefoot and with the back of my hand, feel the hurricane coming thru your light switches and electrical outlets, my toes felt the baseboard leaks,
where the hvac vents poke thru the floor and walls, make sure the boots are sealed to sheetrock and flooring,
tapes, expanding foams, caulks, and patience and determination
known to beat dead horses0 -
I don't know where I got apartments from , , ,
you could add whole house to the the hvac, or I use a free standing evaporative humidifier, a little noisey, but it stays in an little used dining room, close to a return,
I shoot for 40, but bitter cold and I may turn down to 35%, I watch for condensation on windows, 2 pane double hung, pretty air tight, and adjust down if I need to
known to beat dead horses0 -
@SuperTech These are not the heat pumps of yore. Cold climate heat pumps don't need backup in climates much colder than the OP, I'm using one to heat a cottage in zone 6 without issues. That is real winter up there.
@josephny Your thermostat has a big offset, the reason for the low supply temps in your earlier post is that the thermostat was satisfied. Before going to much further, crank the thermostat and see what the temps are. Do this for all zones. If the issue is the offset, your HVAC tech can adjust it. The thermostats can also be programmed to use either the thermostat sensor the the air handler sensor for room temperature sensing. It could be it is configured for the wrong sensor. You generally want to use the thermostat sensor for most installs.
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Isn't a thermostat offset just a way to adjust the thermostat to correct for it's inaccuracy? How do you know that my thermostats are programmed with any offset? Can you tell from the screen I showed?
I remember learning how to enter the deep set up functions of the tstat and that there was a setting for which location to read the temp from. I think the conclusion then was that the tstat reading is different from the sensor used by the remote LG data collection system whose API is used to gather the data that shows the temp drops. That's a long way of say I don't think the short term temp drops have anything do with keeping the house warm enough.
I have had the tstat set to 82 for the past 2 hours and the room has not risen above 76. And the air temp coming out of the supply is still around 80.
I put my portable thermometer right on top of the tstat. It reads 75.6. The tstat reads 76.
The reason I was excited about a gas fueled coil added to the existing system is because I have LP at the house and I've been fighting with this failed, $50k heat pump for going on 4 years now.
Here is what my hot water system looks like. The IBC is just for hot water — I was hoping it was a combi.
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Your previous shot showed the thermostat setpoint of 76 with room temp at 76.
Since cranking the thermostat did not increase supply temps, there is an issue with your unit. 99% of the time there is a small leak and it is low on refrigerant. The only proper way to re-fill these modulating units is by reclaiming the refrigerant and fill it back to spec weight. They also find where the leak is as this problem will keep on happening.
Your hotwater setup is a boiler and indirect so it can easily supply a hydro coil, but that isn't the issue here.
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Are you sure your house is really that tight? Low winter humidity is a sign of a leaky house.
If you haven't done blower door testing you're just guessing.
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I have not had a blower test done. I would like that but this is not something I can’t take on myself and it is very very difficult to find competent people in my area.
And tomorrow when I tell the contractor that there is a leak and he needs to fix it I am quite confident he will tell me all sorts of reasons why I am wrong.1 -
4am update:
1st floor tstat set to 82 for past 6 hours.
Room temp is 71 — on both tstat and separate thermometer.
LG Thinq app (which uses same data source as provided via API and feeds my graph) shows temp as "LOW" —- I believe this further confirms the source of that data is NOT the tstat (probably inside the air handler).
Am I correct that this indicates that the heat pump is absolutely unable to bring (incapable of bringing) the house up to the set point temperature?
And one reason for this is low refridgerant due to a leak (which is the reason 99% of the time)?
And the only way to know if the refrigerant is low is to empty the system and reload the proper amount?
Is there any other explanation that could be reasonable?
BTW, keeping the tstat well above the temp setting that the system can provide uses about 11kw/h (which costs me about $2.20/hr or $53/day). This is maddening.
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I understand that these aren't just an old fashioned single stage heat pump and that these inverter systems should be able to heat the home in the extreme cold. I suggested Hydro air because when these heat pumps fail to do the job or need repair, the boiler and hydro air coils are a lot more efficient than resistance heat strips and offer a very reliable form of heating. I'm sure that those LG units could easily be converted to use hydro air coils. I've seen many inverter systems setup this way
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It gets recovered into a clean recovery tank, weighed and returned to the system.
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A small hot water coil can be installed in the return duct to supplement during defrost. A larger coil can be used if you want 100% backup heat.
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Is this hot water coil an LG part, or a 3rd party (or custom) device fitting to the duct.
Out of curiousity, why the return and not the supply duct?
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HVAC guy was here this morning.
Said there was no problem whatsoever, and that it was cold outside.
I told him that I had the setpoint at 82 all night and the inside temp never rose above 73.
I told him the delta T was about 10*. He again blamed it on the weather — said the heat pump could not do any better.
He said that is normal — a heat pump will never get the temp up to 82.
We then opened the unit and (shockingly) there is no electric coil installed.
He checked the thermostat and the temp reading on the tstat is coming from the tstat's location — not the air handler (the temp reported to LG Thinq comes from the air handler), and that defrosting every 3 hrs or so is normal in this weather.
I told him about the humidity being low, he confirmed, and will price a humidifer add-on to the ductwork to keep the humitidy up.
So the state of the art, non-stop loud and hard working heat pumps that fail to keep my house comfortable (perhaps because of the humidity, but I'm not 100% convinced) are working exactly as they should. That is, I have no problem. Except being uncomfortable.
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Third party and might require a third party control as well. Do you know the model of the indoor units? are they the full size air handlers (look like a furnace) or the little fan coil units? What temp is it outside when they won't keep up? what room temperature do you want to achieve? Have you changed your filters?
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Looking through this whole thread with some bemusement.
Has anyone actually verified — with hard data from the manufacturer — just what this system is capable of given the actual outside (source) air temperatures? I don't see that information being put forward, and the actual output will drop off at low source temperatures. Mother nature is a b___h, and you can't beat thermodynamics even with the best technology. Is there any chance that the poor thing is doing the best it can?
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England1 -
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Here is a link to the submittal sheet:
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Sounds like fitting a water coil in the unit with control integration would be a substantial job. Combined with having to install another boiler just for that (I think the IBC is just potable water heater), not sure it makes sense vs. electric coils.
I don' t know exaclty what temp, but I would guess that right around freezing (32F) the system starts to struggle.
Yes, filters are changed (and the replaced ones were pretty clean looking).
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Fair enough. And I presume it has been verified that the rated net output from the air handlers should be enough to counteract the heat loss from the house? Just askin'…
Perhaps not in this situation — I'm probably being unfair — but I've noticed around my area an odd inversion on the old problem with steam: with steam, we get boilers which are oversized. With heat pumps, I'm seeing installations which are undersized, sometimes rather seriously, at the temperature extremes, or undersized systems depending on electric resistance auxiliary heat at temperature extremes. The one gets chilly and annoyed clients, the other gets warm enough clients — but electricity bills which are truly astounding.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England1 -
So the state of the art, non-stop loud and hard working heat pumps that fail to keep my house comfortable (perhaps because of the humidity, but I'm not 100% convinced) are working exactly as they should. That is, I have no problem. Except being uncomfortable.
The system maintained 73° overnight with an ambient around 10°.
My opinion is that the only problem with the system is your expectations for it.
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I hear you, and I really do respect your analysis and appreciate your help.
Nonetheless, my expectation is that my hands, feet and ankles (wearing socks) are not painfully cold. I am wearing long underwear (top and bottom), t shirt, sweatpants and sweatshirt, and socks, and I am cold. I understand that there subjectivity involved.
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AIr handler submittal:
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I will provide some anecdotal evidence of why you feel cold:
The current house is FHA.
If I set the 'stat to 69, I will absolutely feel cold, just like you. I'd need 72 for this system if I want to be comfortable.
BUT, when it is 10F outside, the humidity is 23%.
So, I say…………self…………what if I boil water on the stove with the LP and get that value up to 45% (I have a gauge that lives on the mantle).
In this weather, it takes about three gallons evaporated to bring it to 45% and the pot has to run continuously (at moderate level) to maintain it.
BUT, I am completely comfortable at 69F and the furnace doesn't need to run as long (still burns 12 G per day at these ambients).
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Nothing wrong with your expectations. Nothing at all. You expected that you would get a heating system which would keep you warm and comfortable in very cold weather. Quite reasonable. And, to give the installer credit, they looked at what the system was advertised to do and did what they thought was correct. And no real fault to the manufacturers…
The fault, if any, is that the advocates for heat pump only systems don't take into account climate extremes in their advocacy, and people like you are unhappy. I see this quite frequently around where my cousins live, in northern Scotland…
EDIT: before someone enquires or screams, let me point out that I do have a heat pump for auxiliary/shoulder season heat in one apartment in Cedric's home. It's very nice to have, since that tenant likes things toasty. It's also 0 outside this morning, and the heat pump is turned off. Cedric is cheaper to run by quite a good margin and is happily doing his thing.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England1 -
aftermarket coils
So during defrost the coil can absorb that heat giving you a shorter defrost.0 -
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That is a great story and explanation with specifics.
I am hopeful that adding humidity will help. No idea what this will cost.
Thank you.
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hold on you have ceiling cassette units?
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Thank you so much!
I had a similar conversation with my wife this morning, althought my side of it was (1) far less informed than you are, (2) somewhat more emotional, and (3) railed more against the condemnation of fossil fuel systems (something about this all being millenials and gen-z's fault).
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Can't say I understand, but I know you do — and I trust that.
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The hvac tech is wrong, plain and simple. The unit is not running as it should. Most likely low on refrigerant, very rare to be another issue. Did the tech at least measure coil delta and check pressures on the outdoor unit?
Your system is under warrantee. Call LG and have them talk to the contractor, this needs to be fixed and not your problem.
Unless the temps have dipped bellow -20F there, the issue isn't that it is "too cold".
@Jamie Hall The unit the OP has will put out near rated output at 0F. Even at -13F the 3 ton unit will put out about 2.5tons of heat. 3tons of heat with a roughly 1000CFM air handler means the supply temp of at least 110F. The OP is not seeing anywhere near that, thus the system is not running properly. This is not a technology issue, this is an install issue.
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@pecmsg made a good comment about the need for someone to measure static pressure in the ducts.
I am not a heating pro, just a homeowner who is a mechanical engineer, and I got a very painful education in HVAC installation failures when I had to troubleshoot our church's forced air furnace. Long story short, it turned out the installer hadn't figured the duct sizes correctly, and as a result the static pressure in the ducts was way too high, causing the furnace to overheat.
The HVAC installer had never bothered to measure static pressure in the ducts, and I subsequently learned this is a common failing with HVAC installers. Many do not even bother to measure static pressure after their installs, even though this is a critical parameter for proper operation of the equipment.
Since your installer seems to be giving you the runaround about system performance, I would have little faith that he has checked static pressure in the ducts either.
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One and all. Please note that I am not faulting the technology — heat pumps properly designed can, and do, move heat at very low source temperatures (although delta Ts source/sink much over 100 F become problematic). Heat pumps, properly sized and installed, can meet the heating requirements of pretty much any normal space, from an elderly building to the latest airtight structure.
What I am saying is that overly optimistic assumptions as to heat pump performance, coupled with overly optimistic assumptions as to heat loss demands at weather extremes, can and will result in unsatisfactory results. The problem is not unique to heat pumps — it could apply to any heating or air conditioning system. The solution also applies to any heating or air conditioning system: use conservative assumptions, not optimistic ones. That's just good engineering.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
When I repeated what you said to the contract his response is:
"The system is designed for 70 degrees at 2 degrees. That is what your system is designed to maintain. It will never get to 82. It isn't designed to do that."
I then told him that 3 tons of heat with 1000cfm handler should make a supply temp of 110.
His response:
"The supply temp coming out will be about 110 yes. But it will never get the room up to 82. It was deisgned to get the room to 70 at 3 degrees. Those are the indoor and outdoor temperatures set by NYSERDA. If we look at the manual J that is what is designed for. If it was log on refrigerant you wouldn't have gotten the room over 60 last night. It was -3 when I got in my truck this morning. Did you measure the temperature out of the register? Or on the ternostat is never got above 80"
I then said: "The supply temp never got above 80. Doesn't that sounds like a problem?"
I then confirmed: "At the supply register."
No more conversation after that.
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