|
H110Hawk posted:https://nordicpure.com/ probably has yours, though they are expensive and don't sell cookie dough anymore. Yea, that's where I got my current filters from. I just remembered that I had disabled the fresh air intake on my whole house dehumidifier because we were having issues with one room being much hotter then the rest. While this probably isn't the cause of the odor, I imagine it's definitely not helping. So, new goal is to find something that can control this based on CO2 levels. I had cobbled together something based on a raspberry pi + some relays, but it's probably a good time for a commercial product.
|
#
?
Aug 5, 2020 01:35
|
|
|
|
| # ? May 16, 2024 23:23 |
|
|
HVAC folks, I've got a bit of an issue. I live in coastal MA, and we've got a bit of a mold/moisture issue in several Mini-split systems in my house, shop, and elsewhere. House: Fijitsu Halcyon 36k outdoor, 9k in basement, 18k in living room, 9k in bedroom. Shop: Mitsubishi Hyper Heat, 12k, IIRC. All 3 units in the house run 24/7 (fan speed on low/medium, no auto) all summer long. There's a dehumidifier in the bedroom, and one in the basement. Both units are set to 50%. The unit in the shop runs 24/7 in the summer and winter, as it's the main source of heat in the space. The shop space is a room within a warehouse, and the warehouse is climate controlled (55°-60°F in the winter, and 75°-80° in the summer). The shop is concrete floors, and nearly zero soft surfaces. All units are growing mold on the blower blades and louvers. The bedroom is the worst, followed by the living room. Basement is less, but still growing. The shop is on it's 2nd year, and it's pretty bad. 2 years ago, I removed the entire blower from all the units in the house, pressure washed the blower blades, sterilized them with StarSan, and reinstalled everything. Last summer there were no issues. The house is well insulated, we run a Panasonic humidity-sensing fan in the bathroom with the shower, and there are minimal air leaks in the house. How common is this, and how the gently caress do we deal with this? I see lots of messages on HVACR Talk, but everyone blames the users for short cycling the units, shutting them off when they're still cold, or poor drainage. I've verified that the pans are draining, the units NEVER turn off, and the fan speeds are all on manual, so the fans never stop. We're good about cleaning the filters (not that the Minisplit filters are very good). The dehumidifier pulls a ton of moisture out of the air, and forces the AC to work harder, which should make things better. But here we are... Help?
|
|
#
?
Aug 6, 2020 01:26
|
|
|
Put the fans on auto.
|
|
#
?
Aug 6, 2020 01:40
|
|
|
angryrobots posted:Put the fans on auto. We tried that the first two years at the house. No difference. The installer suggested we set the speed manually to avoid the blades sitting stationary and giving moisture time to condense on the fan blades.
|
|
#
?
Aug 6, 2020 02:08
|
|
|
Well, I know that running the blower fan for a bit after the tstat is satisfied is pretty common for efficiency reasons (controlled automatically on newer units), but it's generally inadvisable to run the fan all the time because you will pull moisture out of the drain pan and back into the air circulating in your home. It would seem like this is happening? I'm no expert on troubleshooting mini splits in particular, but I know that the interior unit needs to be leveled properly and has a small drain pan. I'm guessing you checked that the drain pan was cleaned out with no blockage on the outlet?
|
|
#
?
Aug 6, 2020 02:37
|
|
|
angryrobots posted:Well, I know that running the blower fan for a bit after the tstat is satisfied is pretty common for efficiency reasons (controlled automatically on newer units), but it's generally inadvisable to run the fan all the time because you will pull moisture out of the drain pan and back into the air circulating in your home. It would seem like this is happening? That's what we thought too, and left everything on auto at first. I'll switch them back to auto at the house, and investigate what's the setting at the shop. The Mitsubishi is much more complicated than the Fuji's. They are pitched correctly and the drains are open. I check every spring to make sure nothing has blocked them, and they are all draining. Not so much in the basement because the dehumidifier seems to be taking care of all the available moisture. I forgot to mention that if left on auto, they'd spit water when the fan spooled up. More fuel for the fire, I guess. Anyone ever install UV tubes in a mini split? sharkytm fucked around with this message at 02:43 on Aug 6, 2020 |
|
#
?
Aug 6, 2020 02:40
|
|
|
Are the drains just gravity fed or going to a condensate pump? Do they have traps?sharkytm posted:I forgot to mention that if left on auto, they'd spit water when the fan spooled up. More fuel for the fire, I guess. That is definitely not normal and an indication that you have a drain issue IMO. I found this video where this guy talks at length about various mini split installation issues, some of which may be very relevant to your problems. https://www.youtube.com/watch?v=YBppLRT5gAs angryrobots fucked around with this message at 03:05 on Aug 6, 2020 |
|
#
?
Aug 6, 2020 02:43
|
|
|
Two of the units in the house are direct drain, the basement has a pump. The shop is direct drain. None have traps. I opened the unit in the living room and watched it on auto mode. You can hear the refrigerant enter the unit and expand, the coil gets cold, water condenses on it, and the fan sucks the water off and spits it out. This doesn't happen on sharkytm fucked around with this message at 13:46 on Aug 6, 2020 |
|
#
?
Aug 6, 2020 03:23
|
|
|
sharkytm posted:Two of the units in the house are direct drain, the basement has a pump. The shop is direct drain. None have traps. I'm not an hvac person but try setting your humidifiers a little lower? Are they actually keeping up? Your Fujitsu has a dry mode, maybe draw yourself down to 40% and see if there is an improvement?
|
|
#
?
Aug 6, 2020 03:32
|
|
|
H110Hawk posted:I'm not an hvac person but try setting your humidifiers a little lower? Are they actually keeping up? Your Fujitsu has a dry mode, maybe draw yourself down to 40% and see if there is an improvement? The dry mode can't cool enough to keep the set point of 72°, not is it supposed to. We can certainly drop the dehumidifier lower, but it's maintaining 48-50% RH, as measured by a data logger in our bedroom. The basement is very dry, thankfully. 40% is going to be pushing it, but I'll crank it down. The only downside is that there's nothing to be done except a full disassemble and clean at the end of cooling season. Mostly, this is a cry for help for next year once we're starting fresh again. When asked, the contractor (a big local company that does hundreds of these systems every year) said the mold is a constant problem in this area, and they do the "bag and spray" cleaning, which sure as poo poo can't get everything clean. We opted for these over ducted for easier maintenance and slightly lower install cost. It turns out that was a mistake. They're much louder than ducted, the added dehumidifier is wicked loud, and they're a nightmare to disassemble and clean. I can kind of understand the house, but my shop is very clean, has very little air exchange, and still has issues.
|
|
#
?
Aug 6, 2020 03:41
|
|
|
sharkytm posted:The dry mode can't cool enough to keep the set point of 72°, not is it supposed to. We can certainly drop the dehumidifier lower, but it's maintaining 48-50% RH, as measured by a data logger in our bedroom. The basement is very dry, thankfully. 40% is going to be pushing it, but I'll crank it down. The only downside is that there's nothing to be done except a full disassemble and clean at the end of cooling season. Mostly, this is a cry for help for next year once we're starting fresh again. That may just be an issue living that close to the ocean. I wouldn't listen too closely to me.
|
|
#
?
Aug 6, 2020 04:31
|
|
|
sharkytm posted:Two of the units in the house are direct drain, the basement has a pump. The shop is direct drain. None have traps. That seems nuts to me at 50% RH. I rarely get our living space that low in summertime with the outdoor humidity here in the deep south. How often are the units cycling, and how long would you say they run for on average?
|
|
#
?
Aug 6, 2020 05:05
|
|
|
The AC units? First floor and bedroom probably are actively cooling 20-40% of the time, depending on the time of day. Basement is probably 20% of the time. Shop is around that, I'd guess. Setpoints are 68 across the board. Cooler than average, but they're all cooling more than one room, plus fighting the dehumidifiers. It's my understanding that they're designed to run low and long for energy reasons.
sharkytm fucked around with this message at 13:44 on Aug 6, 2020 |
|
#
?
Aug 6, 2020 12:56
|
|
|
Air conditioning is a dehumidifier (both are removing moisture from the air via condensation), so running them together is fine, they're not fighting one another. A humidifier would be going in the opposite direction, but that's a thing for people in the desert mostly. If you're talking about the heat released by the dehumidifier, generally that's pretty negligible, especially in a basement I would think? I was hoping someone else who is a professional would chime in, but my gut is that if it isn't some other installation issue, something in the refrigerant charge/metering/airflow is not matched properly. You shouldn't have condensate being drawn out of the unit like that. As a stopgap, I would recommend raising your tstat setpoint at least during the day, cause 68 is pretty low in the summer, and using some floor fans to move air between the conditioned and unconditioned spaces. In the video I posted above, he implies that annual maintenance to clean the louvers and scroll cage is normal.
|
|
#
?
Aug 6, 2020 17:04
|
|
|
angryrobots posted:Air conditioning is a dehumidifier (both are removing moisture from the air via condensation), so running them together is fine, they're not fighting one another. A humidifier would be going in the opposite direction, but that's a thing for people in the desert mostly. If you're talking about the heat released by the dehumidifier, generally that's pretty negligible, especially in a basement I would think? I meant the heat. It's negligible in the basement, but not in the bedroom. Cleaning is normal, but mold growth (supposedly) isn't. Then again, I've looked at minisplits in lots of other places locally, and they all seem to have some growth on the blades. I was hoping someone who had some direct mini-split experience would chime in. Maybe this is just something that people ignore until it causes a big problem. The charge has been checked, and the calcs said this was slightly undersized for the house. I really didn't want to oversize the system so it short-cycled like crazy, and there wasn't a slightly higher output setup available. It was 36k btu or 45k.
|
|
#
?
Aug 6, 2020 19:23
|
|
|
Do you have a regular fan? Maybe toss that in the basement, and see if the dehumidifier still reads the same with a bunch of air movement. The fans on every dehumidifier I've seen are pretty anemic... I wonder if only part of the basement is that dry.
|
|
#
?
Aug 7, 2020 00:54
|
|
|
The fan on the mini split runs all the time, so there's plenty of sure movement, and the basement is actually dry. Amazingly, the basement unit is the least moldy. I checked the unit at the shop today. It's on auto mode, and has been from Day 1. I thought I set it on a set fan speed, but nope, it's on Mitsubishi's auto setting.
|
|
#
?
Aug 7, 2020 01:10
|
|
|
So today I am the idiot(also most days). I was looking to make my AC run efficiently during this heat wave. I have central AC, a 3-ton unit with a condenser installed about 4 years ago, I bought the house 3 years ago. First time owning a house and having AC in my life. Because of that I didn't think to change the filter on the AC in the last 3 years. At which point I realized I don't have a filter on the AC system. The house seller didn't put one in. How bad have I hosed my air conditioner?
|
|
#
?
Aug 17, 2020 17:35
|
|
|
There's a good chance your evaporator coil is caked with dust, meaning it's going to perform like poo poo. It can also cause your coil to freeze, but my guess is you would have noticed that if it happened. Best bet is to call someone and have them come out to clean it. Do you have a place to install a filter, and one was just never installed, or do you not even have a place for a filter?
|
|
#
?
Aug 17, 2020 17:51
|
|
|
Bird in a Blender posted:There's a good chance your evaporator coil is caked with dust, meaning it's going to perform like poo poo. It can also cause your coil to freeze, but my guess is you would have noticed that if it happened. Best bet is to call someone and have them come out to clean it. Looks like I have one on the big return in the center of the house:  Which has this behind it:  Looks to be about 22" x 32" and has a little space I suspect a filter goes into. The system does appear to push out cool air and it's been nearly 100 here the past few days, and it's kept our place at 80. However it doesn't ever seem to turn off and I hear an odd noise form a fan in the attic. I'm guessing that's the thing covered in dust. Or is that the thing outside the house? I don't love the idea of having someone out here with COVID and all, but I'm not sure I have a choice.
|
|
#
?
Aug 17, 2020 18:58
|
|
|
You should have a person clean both of the units, the inside one and outside one. and get a filter installed, and check out the noise.
|
|
#
?
Aug 17, 2020 19:39
|
|
|
Additional question.....does closing the registers in rooms that I dont use often help the AC? I have 2 rooms I barely use. Edit: looking around it seems the answer is "dont do that" Jaxyon fucked around with this message at 05:19 on Aug 18, 2020 |
|
#
?
Aug 18, 2020 04:35
|
|
|
There’s no issues closing registers in rooms you don’t use, unless we’re talking like 3/4 of your rooms or something. It will push air to areas you are actually using.
|
|
#
?
Aug 19, 2020 02:30
|
|
|
I recently moved into a townhouse (rental) in the upper midwest that has central A/C and heat. For context, the bottom level is the garage where the A/C and furnace units are, the second level is the living room/kitchen/dining area and the third level is two bedrooms. The return air vent is in the floor of the second floor as is covered by a 10x18 grate that has no filter I can identify. In the garage, I can see the return air duct that goes from the floor of the second level down to the A/C and furnace; there's no slot or opening where a filter should go. My question is: should I do something about this? Common sense says that having a filter on the unit is a good idea so a ton of poo poo (like the excess hair from our cat) doesn't eventually gum up the works somehow. While I don't own the unit and thus would not be responsible for paying to fix or replace anything, I'd rather not deal with something breaking. Especially during the winter when heat is going to be A Thing™. Assuming I should do something about this, how should I go about that? I can get 10x18 filters but I don't have a way to install them outside of constructing some sort of contraption to hold the filter in place over the return air vent on the second level. Any ideas would be appreciated.
|
|
#
?
Aug 19, 2020 18:21
|
|
|
Mackieman posted:I recently moved into a townhouse (rental) in the upper midwest that has central A/C and heat. For context, the bottom level is the garage where the A/C and furnace units are, the second level is the living room/kitchen/dining area and the third level is two bedrooms. The return air vent is in the floor of the second floor as is covered by a 10x18 grate that has no filter I can identify. In the garage, I can see the return air duct that goes from the floor of the second level down to the A/C and furnace; there's no slot or opening where a filter should go. Call your landlord and ask. Say you're trying to replace the air filter and can't seem to find it, do you know where it is? This should help get your relationship off to a good start, it's their responsibility anyways to know, and in theory should help you out in the long run with lower heating and cooling bills.
|
|
#
?
Aug 19, 2020 19:44
|
|
|
I need to promote airflow to a basement storage area (supply in main area -> return in supply area), but the storage is back by the utility plant and noisy due to air handler, powered water heater, etc. Normally I would just cut a jump duct between above the door, but I have insulated for sound between the rest of the wall and here. Do they make jump ducts with offsets or baffles to cut down on sound transmission? I can probably MacGuyver something but wanted to check if there's a standard solution.
|
|
#
?
Aug 21, 2020 02:01
|
|
|
You could just use two short-way 90s and some cleats if all else fails. I've never seen that as a standard fitting in any catalog or supply house I've been to, but I'm certainly no expert.
|
|
#
?
Aug 21, 2020 04:47
|
|
|
Could you get two oversized caps and essentially create a box the width of the wall? Then cut in a register on either side, and offset them. It’s the only thing I can think of if you’re trying to fit in inside of a wall.
|
|
#
?
Aug 21, 2020 12:17
|
|
|
Insulating the inside of the duct bits will help a bit too. This will accumulate dirt and gross crap. It's a difficult problem. You're basically making a tube between the two spaces, so sound is going to find its way down that tube no matter what you do.
|
|
#
?
Aug 21, 2020 21:07
|
|
|
Argh, got a A/C problem. - Noticed that my outside unit (the condenser) was running way more than it should. Smart thermostat said air conditioning only ran 45 minutes total all day Friday, but the condenser seemed to be running for the entire day. - Turned air conditioning off at the thermostat. An hour later, condenser was still running. - Switched off condenser at the outside 220 breaker and relied on fans inside while I looked it over. - Initially assumed the contactor inside the unit had gone bad, since it failed (open) a few years ago when (according to the HVAC guy I called in), a bunch of ants crawled inside it and physically obstructed it from closing. Was hoping it has just failed closed this time. - Not the case this time, as with the 220 voltage off, connecting and disconnecting the thermostat wire from the contactor, I could hear it mechanically switching. - I next suspected the wiring going to the contactor, since the internet says that any worn insulation can cause shorting that leaves the contactor always in the closed position. However, while turning off the thermostat did not turn off the condenser, physically disconnecting the thermostat from the wall caused the condenser to immediately shut off. I'm assuming that if the problem was a wire short, disconnecting the thermostat would do nothing. I now suspect that the problem is either the thermostat itself (which would suck, as it's one of those fancy smart ones that I got as a gift) or something electronic wrong with the interior unit. My plan was to swap the smart thermostat for the basic thermostat that was there when I moved in and see if that solves the problem. If everything works as intended, the problem is the thermostat. If the condenser keeps running continuously, it might be a problem with the interior HVAC unit. Does that sound right? Bobulus fucked around with this message at 17:35 on Aug 23, 2020 |
|
#
?
Aug 23, 2020 17:33
|
|
|
A solid plan.
|
|
#
?
Aug 23, 2020 17:45
|
|
|
Excellent troubleshooting. It really sounds like the thermostat since disconnecting it stopped the issue.
|
|
#
?
Aug 23, 2020 18:13
|
|
|
A voltmeter would give you an immediate answer.
|
|
#
?
Aug 23, 2020 18:26
|
|
|
And better yet you can put that fancy smart thermostat in the trash or RMA it and sell it when it gets back. Win win. 
|
|
#
?
Aug 23, 2020 18:48
|
|
|
Bobulus posted:Argh, got a A/C problem. It's a nest, isn't it? This is a known failure mode, but it's typically the solid state relays that at least used to live in the base, not the stat itself.
|
|
#
?
Aug 23, 2020 21:01
|
|
|
Motronic posted:It's a nest, isn't it? Yeah, Nest, 3rd generation. I disconnected the nest from the base to disable it, and then reseated it, and it's working fine ever since. Weird. Thanks for all the quick responses!
|
|
#
?
Aug 24, 2020 01:46
|
|
|
Nope, spoke too soon. Now the compressor refuses to turn on. And the contactor is making a loud buzzing noise. How the heck? Did the thermostat and the contactor both break at the same time? Or is the buzzing a sign of low signal voltage where it's incompletely switching? edit: Replaced the contactor, and that solved the problem. So weird that one failed immediately after the other. Bobulus fucked around with this message at 16:58 on Aug 24, 2020 |
|
#
?
Aug 24, 2020 14:15
|
|
|
Bobulus posted:So weird that one failed immediately after the other. Maybe not. When my nest failed and left the compressor running I wasn't getting 24v, I was getting more like 10-14, just enough to barely draw the contactor in, sometimes breaking and snapping back on. Your broken iot junk probably put 10 years of cycling on the contactor in the last week or however long it was broken.
|
|
#
?
Aug 24, 2020 18:10
|
|
|
MRC48B posted:You should have a person clean both of the units, the inside one and outside one. and get a filter installed, and check out the noise. Local quote from one reputable business says they can fix most issues for flat $350. Is that reasonable or high? This is Los Angeles during a heat wave. That may be reasonable, I just don't have a frame for reference. Online says AC maintenance is generally 75-200. This is a relatively recent unit, installed 2016.
|
|
#
?
Aug 24, 2020 19:28
|
|
|
|
| # ? May 16, 2024 23:23 |
|
|
Thanks with the previous issue... solved simply by adjusting my AC schedule, now I’m cool all day. But now a new issue has arisen: I noticed that a small dark line had appeared near the edge of the air diffuser/register in one of the bedrooms. When I took off the diffuser, it was wet with pooled condensation on the inside edge/frame (pic 1 bottom left). The ceiling drywall was also wet/crumbling near where the water had pooled (pic 2 top left):   I checked out the other diffuser/registers and returns and didn’t see any additional darkness or wetness... so at this point I’m feeling like I shouldn’t be that worried about mold since it looks like it’s isolated? That said, what would have caused this (incorrectly installed/insulated diffuser?) and what should I do to keep it from happening again? testtubebaby fucked around with this message at 22:05 on Aug 24, 2020 |
|
#
?
Aug 24, 2020 21:42
|
|
