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new bryant evolution system unable to control humidity
Our family lives in a 2 zone, 4 floor townhouse. We’re experiencing tremendous humidity in the top zone, on the third floor which did not occur with the previous, elderly but now much missed HVAC system. We used to have an approximately 28-29 year old 1.5 ton Carrier heat pump. It worked fine, but it seemed to strain (turned on and off very noisily, was loud) when the blowers came on in both the summer and winter. Still it maintained a reasonable temperature and expected humidity /dryness levels (nothing unusual) in either of the two major seasons. In particular it was quite efficient in the summer.As the Carrier system seemed to be around its rated lifetime , thinking it’d be best to avoid an unplanned replacement if it should fail unexpectedly, last November we replaced it with a new, (and to us, very expensive) Bryant evolution 2 stage system for the top zone.
The installation environment (vents, ducts, equipment location) has not changed. As was the case with the Carrier, the Bryant system’s fan coil unit/heating element are behind a knee wall on the topmost (4th)floor. The family bedrooms are on the floor below (3rd) and the thermostat is on the 3rd floor stair landing between the bedrooms. The return for this zone is high up in the stairwell near the landing between 3rd and 4th floors.
One 3rd floor bedroom has ceiling vents almost directly under the fan coil unit; the other has one ceiling vent and one floor vent that may be fed from the hvac unit from the lower zone. The new condenser is located 2 floors downstairs, outside under the deck.
Configuration details-
A. The model numbers for the new Bryant system’s fan coil unit, condenser, thermostat and heating element (top zone)are
1) FV4CNF002L00---1.5 - 3 Ton Residential Fan Coil Variable Speed Multipoise (Aluminum Coil)
2) 286BNA024000---Bryant® Evolution® - 2 Ton 16 SEER Residential Heat Pump Condensing Unit, 2-Stage
3) The thermostat is a Housewise T6-WEM01-A. We keep this in manual mode, aiming for a fixed temperature; no wifi control.
4) To complete the configuration list the heating element situated with the fan coil is an FC-2601C10 Tutco - 81-0460-00 10 Kw Circuit Breaker Single Phase Unit Heater for Carrier Air Handlers
The upper zone’s thermostat shows humidity between 72-77%.- we have had to set it between 71 to 75 F. We are running it with a dehumidification profile as follows- set point of 59 % humidity and a 3 degree Fahrenheit drop to dehumidify. So the temps range between 68 and 72 F. The temperatures are colder than we’ve ever had them with the older system but the humidity experienced and indicated on both thermostat and bedside hygrometers is much higher. These show a range of 68-75% humidity, a bit lower than the thermostat which shows upto 77% humidity.
B. The lower zone has a 4 year old system. Its configuration is:
1) Bryant preferred unit- Part number bryant 126bna036000, a 3 Ton 16.5 Seer Bryant Air Conditioner Condenser also under the deck,situated about 8 inches apart from the newer condenser which also happens to be taller
2) This zone also has a Bryant gas furnace in a closet in the garage, and another Home wise thermostat on the 2nd floor in the living room. This is also in Manual mode, no wifi access enabled.
3) Its returns are in the living room and in the staircase going down to the walkout basement/garage level (first floor) and vents are in the basement ceiling and living , dining and kitchen floors on the 2nd floor.
4) The humidity levels in the lower zone are never over 63%; the dehumidification profile used is the same as for upstairs.
We also mostly keep the fans on always in both systems.
The installers haven’t been able to debug what to do to get the humidity down to at least 65 % upstairs. So if anyone here might have some insights it'd be greatly appreciated.
Incidentally all winter the upstairs system had a different problem- it kept overheating way over what the thermostat setting said. We were told it was going unexpectedly into defrost. But then it became summer, and this oother humidity problem took over so they say they’ll revisit the overheating (upto 90 F, with thermostat at 74-74 f) later this year. They may have made some adjustment to the fan coil control boards but I do not have those details. thanks very much in advance for any help. Nalini
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ZIP _ _ _ _ _ ?
AGE OF RESIDENCE ___ ?
Total air flow rate each system ___ ?
Supply and Return Air Temperatures AT THE AIR HANDLERS ________ ?
Designer Dan __ It's Not Rocket Science, But
It is SCIENCE with
Some Art. _ _
KEEP
IT
SIMPLE &
SINCERE ___ __
www.mysimplifiedhvac.com ___ __ Define the Building Envelope & Perform a Detailed Load Calc: It's ALL About Windows & Make-up Air Requirements. Know Your Equipment Capabilities
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zip 20877
age of residence--30 years.
I do not have a way that i know of myself to measure the total air flow rate of each system; or the supply/return at the air handlers. The new system is behind a knee wall that's not got the easiest access into the enclosure. But if there are system indicators for these paramters on existing gauges already built in that dont need special equiment, i could try to get a look and log readings. Please advise.
Thanks
Nalini
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Seems like the system was not commissioned properly. Is the thermostat wired to control AC staging? Was airflow measured and adjusted to proper speed? With the Evolution outdoor, why not Evolution Air Handler and control?
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Comfortdoc, Thanks for your reply. to answer what I can-
1) as to the mix of system components, I didn't pick them- they were part of the quote from the installer- i trusted they would assemble a suitable system . The same company /engineer had speced the bryant preferred system downstairs. Which is four years old and so far (fingers crossed ) with fewer issues.
2) When you say not commissioned, do you mean initial set up was wrong? it is certainly possible as the install crew seemed awful and after it went in mid November the system had heating problems all winter.
3) About the thermostat and ac staging- The thermostat has been a factor, possibly the main one, in each season's problem. They started out with an ecobee which was apparently a known misfit . Why it was speced and installed even so is not clear. The heat kept going up to 90 F though set at about 73.THey then replaced the ecobee with homewise. Helped a bit but even so later in the winter this system , no matter what the thermostat was set at- would crank up the aux heat and the problem resolver team and their engineering expert said that the Aux had to go on in the defrost cycle. Because I had a lot of health issues i couldnt keep calling them in- as it was I’d had about ten appointments on this issue alone, so this problem is waiting to reappear this winter. I do not know if the House wise wiring was configured to allow for the stages. I thought they said they reduced the number of wires for some reason.
4) Do these systems have built in dehumidifiers?
5) Is there a time limit within which Bryant can be consulted ? The installer company is willing to work with me which is much appreciated, but the proffered solutions so far have not had much success. this has become a long running nightmare in the midst of much else.
Thanks, N.
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Originally Posted by
nalini
Comfortdoc, Thanks for your reply. to answer what I can-
1) as to the mix of system components, I didn't pick them- they were part of the quote from the installer- i trusted they would assemble a suitable system . The same company /engineer had speced the bryant preferred system downstairs. Which is four years old and so far (fingers crossed ) with fewer issues.
2)When you say not commissioned, do you mean initial set up was wrong? it is certainly possible as the install crew seemed awful and after it went in mid November the system had heating problems all winter.
3)About the thermostat and ac staging- The thermostat has been a factor, possibly the main one, in each season's problem. They started out with an ecobee which was apparently a known misfit . Why it was speced and installed even so is not clear. The heat kept going up to 90 F though set at about 73.THey then replaced the ecobee with homewise. Helped a bit but even so later in the winter this system , no matter what the thermostat was set at- would crank up the aux heat and the problem resolver team and their engineering expert said that the Aux had to go on in the defrost cycle. Because I had a lot of health issues i couldnt keep calling them in- as it was I’d had about ten appointments on this issue alone, so this problem is waiting to reappear this winter. I do not know if the House wise wiring was configured to allow for the stages. I thought they said they reduced the number of wires for some reason.
4)Do these systems have built in dehumidifiers?
5)Is there a time limit within which Bryant can be consulted ? The installer company is willing to work with me which is much appreciated, but the proffered solutions so far have not had much success. this has become a long running nightmare in the midst of much else.
Thanks, N.
3.) Why did they not install the correct Bryant communicating thermostat? They have crippled a very expensive unit by not using the factory communicating thermostat.
4.) No they do not have built in dehumidifiers.
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Originally Posted by
BALloyd
3.) Why did they not install the correct Bryant communicating thermostat? They have crippled a very expensive unit by not using the factory communicating thermostat.
4.) No they do not have built in dehumidifiers.
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BALloyd - it is not a communicating indoor unit.
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There is really no time limit for a Bryant tech rep to get involved.
Have you spoken to the Service Manager or Owner of the Installing company? It sounds like they need to send their best technician or call Bryant for assistance.
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Serving Northeast Philadelphia and Surrounding Areas
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Originally Posted by
comfortdoc
BALloyd - it is not a communicating indoor unit.
Oops.....missed that. You are correct.
Let me rephrase....why did they cripple the unit by not including the evolution series air handler and thermostat?
Last I checked the communicating Air handler was not that much more expensive than the performance series.
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If you figure out how to remove significant amounts of moisture during evenings/rainy day weather with high outdoor dew points plus the moisture from the occupant, post "How in broad print" so I do not miss it.
In green grass climates include a whole house dehumidifier sized for the latent load from the manual J calcs.
Regards Teddy Bear
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"
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BALloyd, Teddy Bear, comfortdoc- Thanks for the responses. The company that installed the system had scheduled another attempt to fix the system’s problems and their senior staff could only attempt it last week. They wanted to try out more options before possibly considering replacing some components- perhaps the fan coil and thermostat. I would be very grateful for perspectives on whether replacements might help and want to organize the information for easier reading.
A. System configuration is as listed in my first email. I didnt mention it then but the original proposal included a different , supposedly less capable condenser (Bryant’s "Preferred"line) than the one that got put in (one of the "Evolution" series) . The other components installed (fan coil, thermostat, heating element) were intended to match up with the Preferred condenser initially proposed. I’m wondering if the fan coil/thermostat combination just aren’t working or compatible with the Evolution condenser.
1. The fan coil installed is the FV4CNF002L00
2. The original design had as condenser the Bryant Preferred 2 Ton 16 SEER Residential Heat Pump Condensing Unit 2-StageNumber: 226ANA02400. This model wasn’t available in time for their install deadline back in 2019 so they substituted a different condenser – the Bryant® Evolution® - 2 Ton 16 SEER Residential Heat Pump Condensing Unit 2-Stage; Number: 286BNA024000
3. The heating element is the BRYANT HEATER KITS Tutco - 81-0460-00 10 Kw Circuit Breaker Single Phase Unit Heater for Carrier Air Handlers Model: FC-2601C10
4. The thermostat is the Bryant T6 Housewise.
B. System operation and Symptoms- In all seasons we set the thermostat to manual with no varying temperature schedule or wifi control. The fan varies from Auto to on. There have been severe problems in each season including the following. The operations expert seemed to think the problems are related (consistent cause).
1. Cooling Mode-(mid June to mid September) the humidity stayed at very high levels even with the de-humidification profile enabled to drop temperature a couple degrees with a lower humidity bound of 58% . Despite this profile setting the humidity levels in the summer ranged up to 77% indoors whereas the previous single stage 1.5 ton never went over 63-67 % in the same zone same room /vent configuration. And the previous 1.5 Ton carrier condenser and who knows what fancoil kept the humidity below 65%; so at least that level of dehumidification with the ancient less powerful Carrier was possible.
With the new system, the temperature would drop if this dehumidifier profile was enabled but It stayed very humid, so we could have say 68 F with 77 % humidity. Th e lower zone in the house, handed by a different system did not exceed 63% humidity.
2. Heating Mode- Over the 2019-2020 winter /spring and now early Fall, the heating element suddenly would/will go on, as does the blower, and severely overheat the bedrooms, though the system thermostat showed it had reached and remained at the temperature it was set for. All the T6 thermostat shows is ‘heating’ but one could smell the coil, feel the heat and the blower raging. As a recent examplea week ago, with the external temp at about 58 F, and the thermostat set at 71, one bedroom with vents directly under the fan coil and heating element went up to 79 F (as per the room thermometer located away from the vents) about 4 am and the temperature was still going up. Only way to stop it was to drop the thermostat temperature setting to 69F. On previous occasions the temperature has gone up to the 90s in the bedrooms, often overnight, leading to very disturbed sleep; but this has also happened at random in the daytime.
3. Thermostat issues: The thermostat even if it reaches set temperature doesn’t appear to fully control the system in terms of letting the heating carry on, or never stopping the fan.
a. In the winter, even if it’s set at and shows 70 for instance the heat comes on and ramps up as described;
b. in the summer, despite the dehumidification profile set, the humidity never changed; though the temperature dropped as per dehumidification setting
c. the fan stayed on in cool mode with Auto; and
d. The aux/heating2/ indications never show up on the stat; even though the coil smells like it’s on; and if cooling, the stat only shows cooling 2, so it seems one of the stages of the condenser or coil never communicates with the stat. I know one of the rotating series of techs changed the wiring, i asked if the senior staff checked it and they said they had
C. Fixes tried during attempted troubleshooting-
a. FRom what I was told it sounded like they've had several belated 'commissioning' sessions trying to configure the control boards with different options. The most recent modifications tried aimed to fix both seasonal problems included lowering the blower speed and turning off some heater elements. I was told there had been further jumpers set on the control boards in the attic enclosure containing the fancoil and element. They mentioned the housewise T6 Thermostat could not be used to control these features and the only way was on the control boards.
b. I got the impression that that some other fan coil model could be controlled from the thermostat.
c. One of the engineers also mentioned trying to fix something about the defrost cycle turning on the elements uncontrollably- defrost without aux is what I heard I think.something about why the element turns on without regard to the thermostat being the defrost cycles that periodically run on t he condenser
D. Questions
1) Could a fancoil /condenser incompatibility combined with a possible thermostat incompatibility cause the symptoms above?
2) If a system combination isn’t working out, and it is not the manufacturer’s fault the design was speced as it was, mixing incompatible pieces would good install practice include swapping out the systems till they get one that works?They say each house is different and they have installed such systems elsewhere but, obviously this isn’t working.
thank you,
Nalini
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There is a bug in there some place. These are complex systems. My experience has been good these units has been good. Your contractor/mfg. are working on the the unit. When they find the problem, expect that the unit will maintain 75^F, 50%RH during significant sensible cooling loads. During evening and rainy days, expect that you will need supplemental dehumidification during evenings and days of low sensible cooling and high outdoor dew points. Get the a/c working before going to the final fix of adding a whole dehumidifier. I use Carrier on my WI home. My brother uses a Carrier Green speed. We have good results but added a dehumidifier to the evenings and rainy days.
Keep us posted.
Regards Teddy
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"
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The combination is fine. There is a setup issue. If your 1.5 ton performed well, the system now should operate in 1st stage almost always. They need to measure airflow, then adjust refrigerant charge.
Do you know if the thermostat is wired for 2 stage cooling?
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Originally Posted by
comfortdoc
The combination is fine. There is a setup issue. If your 1.5 ton performed well, the system now should operate in 1st stage almost always. They need to measure airflow, then adjust refrigerant charge.
Do you know if the thermostat is wired for 2 stage cooling?
hi Comfortdoc
Unfortunatley I dont know how it's wired. I just know lots of techs came and went in the early days before the senior staff and i seem to recall someone saying something about wiring . When the experts stepped in and even before, I got the feeling that my hovering around would just bother them so i didnt watch what they were doing .The thermostat does sometimes show 'cooling 2'. In heating mode if this indicates anything as far as wiring, it never shows heating 2 or aux even when that toaster oven comes on and it smells like it is.
so you think the airhandler speced for the preferred should work with the Evolution?
I am not sure how to relay your suggestion re airflow and refrigerant charge. They did say they reduced blower speed.. which might affect airflow?
What would a refrigerant charge adjustment do to prevent the drastic and uncontrollable overheating that seems to occur at random, regardless of thermostat setting being met?
thank you
Nalini
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The Evolution series outdoor unit works just fine with your air handler. If the airflow and refrigerant charge are not correct humidity removal may suffer.
Airflow needs to be measured. Since you have electric heat it is very easy to calculate airflow accurately. Once airflow is set correctly, 350 cfm/ton since you are concerned with humidity, they can then properly adjust refrigerant charge to manufacturer’s specifications. If hey are not doing it in this order hey are guessing.
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IN the final adjustment, air flow +- to get the 30^F cooling coil below return air temperature for a 50%RH in the space. This surest way to get humidity control. During evenings and rainy days without sensible cooling loads and high outdoor dew points plus the moisture from the occupants, even a properly setup a/c will not remove significant moisture.
Tell me how to maintain 50%RH during this condition?? I suggest adding a small whole house dehumidifier.
Regards Teddy Bear
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"
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So you had a single stage 1.5 ton. And they replaced it with a 2 stage 2 ton. That in first stage is probably operating at 1.5 tons, but with a warmer coil than the old single stage did.
Unless they can lower the blower CFM down to 300 to 310 CFM while the humidity is high. It ain't gonna get any better without a dehumidifier being installed.
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the system with a poltergeist in the machine-
Originally Posted by
beenthere
So you had a single stage 1.5 ton. And they replaced it with a 2 stage 2 ton. That in first stage is probably operating at 1.5 tons, but with a warmer coil than the old single stage did.
Unless they can lower the blower CFM down to 300 to 310 CFM while the humidity is high. It ain't gonna get any better without a dehumidifier being installed.
Comfort doc + BeenThere-thanks to you and all the other respondents. despite everything tried the techs working on this havent made any progress. So I ve some followups-
1) Re Humidity-
a)is there anyway to measure and lower blower cfm that doesnt need a maintenance tech but can be controlled by those in the home? Any wiring to a more capable thermostat? I am told the people looking into this have years of expertise but if they tried anything like it Im not sure.
b) what does the charge have to do with this, and what adjustment is needed?
2) Re overheating-which was the first problem all winter and is the problem now.
a) the thermostat shows it's at the set temp but the heating system cranks up and heats very fast and very high-no obvious control to it. It did this all last winter and they said it was the defrost cycle. now they say they need to relocate the thermostat from the landing to one of the bedrooms under the fan coil. An example of what happens --The thermostat is set for and shows it's at 70 F, BUt says the system is 'heating' and the rooms go up to 77 and up.Its gone to 88 before. It doesnt stop heating till the setting on the thermostat is lowered and it often happens overnight which pretty much wrecks any hope of rest.
b) could the thermostat be wired wrong if one can smell the fan coil but the only state displayed by the thermostat is 'heating' , never 'aux' or 'heating 2'
3. Could the lack of humidity control in summer and uncontrolled heating in the winter be related? Could the techs have missed something in the system which causes both errant behaviors? This system has been a nightmare over the year it's been installed. Nver had these issues before. Is maintenance tech needed season to season to manage quirks? Or could one or more components in the installed system just be broken?
Thanks
Nalini
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They can lower the blower speed, to get a better handle on the humidity. And may be adjustable from that thermostat. But I don't have an install manual for it to see if it can.
Any chance there is a cold draft in the wall the thermostat is mounted on.
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Originally Posted by
beenthere
They can lower the blower speed, to get a better handle on the humidity. And may be adjustable from that thermostat. But I don't have an install manual for it to see if it can.
Any chance there is a cold draft in the wall the thermostat is mounted on.
did you mean is there a draft on the wall or stat in the heating season? No, I do not believe there is. I'm guessing you're wondering why it shows it 's reached set temp yet the system never stops heating (either that or it takes so long someone would either pass out due to the high temp if they were present if they waited for it to settle down or have not been in the room in the first place. as i t happens often in the small hours of the night, (but also in the day_ someone is usually there and woken up with the blower roaring and a desert style temp rise in the room, they try to fix it any way they can, soon.-by lowering the set temp ).The thing is if the thermostat exerted any control at all on the system, surely it'd be related to the temp it observes. except maybe from something the tech lead said maybe in defrost the thermostat doesnt control the system but even defrost should consider the impact on the inhabitants and not raise the temp to insane levels .
another reason there may be miswiring or malfunction- the system never indicates aux was on but we smell it, and it keeps on heating at random unpredictably, at any temp of 70 or above. It also never displays heating 2.So it seems the system or thermostat is defective. is it possible a system newly installed could be a lemon? How could this be tested? These guys have kept comign back for just under a year and that's exhausting for us and them, but we have to live with this and it's impossible. It's got some major flaw in both the longest seasons.
is it possible 2 ton systems are too high performing, that the upstairs just needs a 1.5 and they made a mistake dimensioning it then trying to force it to work?
I dont know for sure but i think they're implying there's a 1 year deadline to get this fixed and as that's coming up Nov 14 we are out of luck now. I thought their warranty was for 5. They say theyve talked with bryant.
thanks,
Nalini