Humidity in my house

[Bozo_Casanova 26188]

So at least for the last few days it's been pretty humid in my house. My AC is cooling the place just fine, but the humidity is running in the mid 60's. I''ve checked around the dryer vent in the laundry room and althought it's more humid in there than the rest of the house, the dryer looks to be venting to the outside. I don't see anything else that could be an issue. 

 

Thoughts on what to do or check?

[Dewey 3279]

If you're not a stay at home worker, you might just be experiencing it for the first time, its starting to get warm outside, things feel different,  or it could be your attic, the turbines on your roof finally rusted enough not to turn, sofit vents arent doing their job, etc

[TwiceHorn 31087]

"Freon" level.  Compressor or coil leak?

Increased humidity tends to come from a higher heat exchanger temperature.  It can still cool, but a fast cooling rate is required to condense humidity out.  Fast cooling rate equates with higher DeltaT, so if your coil temp isn't as low as it should be, that can cause it.

[bluto 4861]

Not an expert but isn’t there something where if your AC system is too powerful for your home then it cools the air without taking care of humidity too? So it’s actually over efficient resulting in inefficiency.

[TwiceHorn 31087]

5 minutes ago, bluto said:

Not an expert but isn’t there something where if your AC system is too powerful for your home then it cools the air without taking care of humidity too? So it’s actually over efficient resulting in inefficiency.

Also true.  High deltaT for a given flow rate.  If the air's not flowing enough (compressor running) that can cause humidity problems, also.

Since it isn't a new unit or new coil and presumably worked fine before, and assuming the fan is working properly (especially if a multispeed fan), it would seem to come down to coil temp.  Which could also be a dirty coil in addition to refrigerant problems.

[Bozo_Casanova 26188]

13 minutes ago, Dewey said:

If you're not a stay at home worker, you might just be experiencing it for the first time, its starting to get warm outside, things feel different,  or it could be your attic, the turbines on your roof finally rusted enough not to turn, sofit vents arent doing their job, etc

I work at home a lot, so this is new. 

4 minutes ago, TwiceHorn said:

Also true.  High deltaT for a given flow rate.  If the air's not flowing enough (compressor running) that can cause humidity problems, also.

Since it isn't a new unit or new coil and presumably worked fine before, and assuming the fan is working properly (especially if a multispeed fan), it would seem to come down to coil temp.  Which could also be a dirty coil in addition to refrigerant problems.

Air is flowing, and it's an old unit (about 10 years). The fan is blowing. 

For what it's worth, it does seem more humid in the attic, but I'm not sure how relevant that is, because cooled air isn't blowing into the attic.  

Edited March 27, 2020 by Bozo_Casanova

[TwiceHorn 31087]

Just now, Bozo_Casanova said:

I work at home a lot, so this is new. 

Air is flowing, and it's an old unit (about 10 years). The fan is blowing. 

For what it's worth, it does seem more humid in the attic, but I'm not sure how relevant that is, because cooled air isn't blowing into the attic. 

Check the sight glass near the compressor and see if it has bubbles in it.  I might assume that you aren't over or under capacity and it's just an efficiency issue.  If there's a small leak, the first thing to go would be humidity, along with longer compressor runtimes, and eventually loss of cooling capacity, and then compressor lock up.

[Bozo_Casanova 26188]

14 minutes ago, TwiceHorn said:

Check the sight glass near the compressor and see if it has bubbles in it.  I might assume that you aren't over or under capacity and it's just an efficiency issue.  If there's a small leak, the first thing to go would be humidity, along with longer compressor runtimes, and eventually loss of cooling capacity, and then compressor lock up.

I'm pretty handy but HVAC is completely foreign to me. Would the bubbles indicate a leak?  Also, how would i be able to tell if the coil was dirty? 

[TwiceHorn 31087]

Yes, bubbles indicate a leak, or at least not enough refrigerant.  There should be a "fixture" in the refrigerant line going into the house near the compressor outside with a viewing port.  If it's transparent (no bubbles) you're ok on that front.  If it's frothy or bubbly, you've lost refrigerant somehow.

The coil is in the air handler, usually inside, and is also usually enclosed in a "box."  Sometimes you can get a look up at it from below or down at it from above.  Sometimes there's a panel you can remove to see it "vertically."  It's usually got fins on it like an automotive radiator.  If that's all kludged up with dustbunnies and crud, it needs cleaning.

[Bozo_Casanova 26188]

Thanks, I'll start there. WOuld it be a good idea to flush the drains and change the filter too?

[TwiceHorn 31087]

13 minutes ago, Bozo_Casanova said:

Thanks, I'll start there. WOuld it be a good idea to flush the drains and change the filter too?

Probably so yes.  Both of those could cause such problems.

 

I can't claim to be a complete expert in this stuff as my practical knowledge is somewhat lacking.  But as an ME, I feel like I have to know what's up with HVAC and have kind of taken an interest in the problems that have arisen over the years in my dwelling and those of friends and family.  @Jkwellborn I believe, is pretty expert on A/C matters in the real world.

All that said, it could be something like excess moisture in your crawlspace if you have one.  Dallas I know has had record rains in terms of consecutive days of rain and the ground is really saturated.

Edited March 27, 2020 by TwiceHorn

[Bozo_Casanova 26188]

I'm not sure I have a sight glass. My system was installed in 2009, but I'm not seeing anything. I'll keep looking. 

[TwiceHorn 31087]

4 minutes ago, Bozo_Casanova said:

I'm not sure I have a sight glass. My system was installed in 2009, but I'm not seeing anything. I'll keep looking. 

I'll be damned.  We have one unit original to the house, 2011, and it has a sight glass.  One was replaced in September and it doesn't.

[SHOOTER12 8783]

Humidity is up, but a/c is running and cooling?  Quit pissing on the carpet.

[TwiceHorn 31087]

Looks like they are increasingly uncommon on residential systems.  Maybe the "new" freon?  It appears that they are not foolproof, either.

So, as I said, sometimes my practical knowledge sucks.

[RPM 26168]

Step 1, is it blowing cold air? If yes, open the unit and look at the drain pan (the pan/tray under the condenser). Is there condensation in the pan and is it draining? If yes, button everything back up and quit bitching until the answer to Step 1 is no.

[bernorange 8345]

3 hours ago, Bozo_Casanova said:

So at least for the last few days it's been pretty humid in my house. My AC is cooling the place just fine, but the humidity is running in the mid 60's. I''ve checked around the dryer vent in the laundry room and althought it's more humid in there than the rest of the house, the dryer looks to be venting to the outside. I don't see anything else that could be an issue. 

 

Thoughts on what to do or check?

Close your damn windows.

[Bozo_Casanova 26188]

2 hours ago, RPM said:

Step 1, is it blowing cold air? If yes, open the unit and look at the drain pan (the pan/tray under the condenser). Is there condensation in the pan and is it draining? If yes, button everything back up and quit bitching until the answer to Step 1 is no.

So, uh, is that inside or out?

[RPM 26168]

17 minutes ago, Bozo_Casanova said:

So, uh, is that inside or out?

Inside. If the inside coil is getting cold and dripping, it's working. If it's a block of ice or warm and bone dry it's borked. Probably just high humidity and warmer weather.

Edited March 27, 2020 by RPM

[bernorange 8345]

I had an issue once where the drain pan line was clogged because of insects/critters trying to make a home in it.  You can try pouring a little water in there (from the drain pan obviously) to make sure it's draining.  If it isn't you can try unclogging it with a snake where it exits the wall near your foundation. 

[Updawg 2254]

Turn it down a few degrees and that should do it. right now the temp in and outside is the same so it doesn't run enough.

[bluto 4861]

You turn it off and back on again? Maybe jiggle the plug? Or if it’s really borked, a couple taps on the side?

[ROFL BOX 6644]

If you're not a stay at home worker, you might just be experiencing it for the first time, its starting to get warm outside, things feel different,  or it could be your attic, the turbines on your roof finally rusted enough not to turn, sofit vents arent doing their job, etc

Assuming he has adequate insulation for the attic void, intake / exhaust ventilation is not going to be the issue as those components do zero for his living space.

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[ROFL BOX 6644]

FYI & slightly related, homes with an attic based air handler will commonly have 2 drain ports for the condenser collection pan ("drain pan") that TwiceHorn was mantioning.

One is inconspicuous, usually near the AC compressor (that's the outside component). The 2nd drain line is placed over a window. The idea is if the primary gets backed up, the secondary will start to work & they want it dripping over a window so it might get noticed.

To clear the line, 1st try some compressed air. For the 2nd step, make a bleach solution, maybe 5% bleach with 90% H20 & pour that through the drain line as the follow up.

If you don't have any equipment available to blast air, straighten out a coat hanger & maybe poke down the line a bit however be careful to not get anything stuck.

Either way, do the water / bleach solution.




*5% Aggy tears

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[3adays 454]

I was experiencing the same thing this week. Had my AC guy come out and the condenser was bad. He replace it and it’s made a huge difference in how it feels. 

[CrownKing 55]

A real simple test (for folks with little to no knowledge) to see if your outside condenser is working properly is to see if it moving hot air out of the house.  To do this you would turn you AC On inside and set your thermostat to a temp slightly lower than you normally keep it. Once you believe the AC is blowing cold air into the house go back outside and feel the temp of the air being blown off the condenser. If the air is not warm to hot, then you are not moving heat or humidity. 
 

A simple first step would be to clean your coils on your condenser with a a high pressure water hose. Secondly it may be a sign that you are low on Freon. 
 

This will not work today since cool weather has come back but once the heat and humidity move back in try that first. 
 

You can also inspect the outside copper tubing during a hot humid day and you should see sweat coming off one of the pipes. 
 

Also don’t forget to change your filters regularly. 

Edited March 29, 2020 by CrownKing

[Bozo_Casanova 26188]

With the lower humidity and cooler weather I’m on hold but I’ll try that when the humidity returns tomorrow 

[Gil Bang 25843]

On 3/27/2020 at 10:57 AM, TwiceHorn said:

Probably so yes.  Both of those could cause such problems.

 

I can't claim to be a complete expert in this stuff as my practical knowledge is somewhat lacking.  But as an ME, I feel like I have to know what's up with HVAC and have kind of taken an interest in the problems that have arisen over the years in my dwelling and those of friends and family.  @Jkwellborn I believe, is pretty expert on A/C matters in the real world.

All that said, it could be something like excess moisture in your crawlspace if you have one.  Dallas I know has had record rains in terms of consecutive days of rain and the ground is really saturated.

I always assumed that you were a lawyer.  Mind blown. 

[Catpfish 618]

When I built my house, we had it foam insulated. We were having a hard time getting the humidity down due to the efficiency of the house and lack of AC runtime. My AC guy suggested that we turn down the speed on the AC to force it to run longer to reach the desired temp. That helped, but to supplement I bought a dehumidifier. It's just a smallish portable unit that'll fill up at 8 quarts. Some days it'll fill up 3 to 4 times depending on how diligent I am at emptying.

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[ROFL BOX 6644]

5 hours ago, Gil Bang said:

I always assumed that you were a lawyer.  Mind blown. 

 

That's what I was thinking!!

[TwiceHorn 31087]

6 hours ago, Gil Bang said:

I always assumed that you were a lawyer.  Mind blown. 

Lawyers have undergraduate degrees.  Also a patent lawyer.

[Parliament 14086]

That helped, but to supplement I bought a dehumidifier. It's just a smallish portable unit that'll fill up at 8 quarts. Some days it'll fill up 3 to 4 times depending on how diligent I am at emptying.

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Good Lord, Man. Where do you live, Thailand?

And you can buy a "lift pump" for your dehumidifier than will pump your condensate to your sink drain or whatever. Saves the hassle of dumping your tank every 6-8 hours.

[Catpfish 618]

On a septic system so don't want to put water there. Just dump it on the yard. Live in Central Texas, so it's humidity central
right now

[Gil Bang 25843]

11 hours ago, TwiceHorn said:

Lawyers have undergraduate degrees.  Also a patent lawyer.

[Lat22 3976]

Close your fireplace damper. 

[High Plains Drifter 10961]

12 hours ago, Parliament said:

 

 

Good Lord, Man. Where do you live, Thailand?

And you can buy a "lift pump" for your dehumidifier than will pump your condensate to your sink drain or whatever. Saves the hassle of dumping your tank every 6-8 hours.
 

 

 

Houston, even Central Texas humidity is no bullshit. South Texas humidity probably rivals Thailand.

[horn4life 3749]

Either your AC isn't running long enough to take the humidity out of the air before it hits temp. Or you have some other problem with heat transfer, that is hurting the efficiency. 

We eliminated #1 since you stay at home , so it's an efficiency heat transfer problem. The odds are that you are gonna find yourself sweating when it's humid and the temps start to rise. This may be an early warning for you.  First thing I do is the next time the unit kicks on I run it down 5-7 degrees more to make sure  the unit keeps running 15 minutes or more. Then I go look at the drain, the lines exiting the compressor, and the  two lines inside the air handler/evaporator.  You need the unit to run for a while to see if it's really working or not.  

AFTER THEN UNIT HAS RUN FOR 3-4 MINUTES FIRST CHECK

- I am looking at the drain line initially after it runs for a few minutes just to get a "baseline" to see if the dripping flow seems to remain the same as the unit continues to run.  When I come back later I check to see if the flow is reduced.  If that flow reduces or stops, then that means your evaporator coil is freezing up.   This could be because of low freon or dirty evap coil.

-Outside lines  ---- There are two lines at both ends of the system.  An insulated (cold) line and an uninsulated (hot) line.  The insulated line carries freon from compressor/condenser outside  into the air handler/evaporator coil inside. The cold line should be extremely cold at the compressor, and the other line should be hot if functioning properly. The temps outside are another sort of "baseline" to compare the inside temps on same lines. The temperature DIFFERENCE between the lines will provide your best clues. Basically an AC is just two places to exchange heat on both ends.

- Inside lines- Check the lines after then unit runs 3-4 minutes and make a mental note of the temps. The cold line should be very cold.  And the hot line should be at least reasonably warm.  IF both the inside lines are close to the same temp at the first check 3-4 minutes in you likely have a freon problem. 

SECOND CHECK 15-20 MINUTES OF RUN TIME

- IS drip the same? If flow is decreased then your evaporator coil is freezing to some degree.

- Lines- Inside -Do they feel the same temp as they did at the first check? I doubt they do. IS the cold line frozen? (coated with ice) and the hot line just warm?   Outside  - Do they feel the same or is the hot line not as hot and only warm? 

IF the cold line outside is frozen, the cold inside line is cool, but NOT frozen or still very cold, THEN you likely are low on freon.  Hot lines will be warm on both ends, but not hot. Call the tech and hope it's freon.  Cleaning a dirty evaporator coil is nasty and if you have been changing your air filters religiously then it's more likely freon than a dirty coil.

IF your unit is UNDER 10 years old you may still be under warranty, call the tech ASAP. 

 

Edited April 9, 2020 by horn4life

[horn4life 3749]

PS -  GOOD NEWS IS IF no lines feel different, no drip change, and house is just cold and no longer humid, THEN you simply are not letting the unit run long enough, but you have no underlying problem!

[Nivek 16772]

I started having humidity issues at the tail end of the life of my old ac unit. Replaced it with a variable speed, quiet, trane unit that was smaller and nicer with the option to set humidity levels.

[Jkwellborn 6616]

Make sure your filters are clean. Kill the power to the condenser. There should be a disconnect outside by it. Clean the condenser coil. You can either pull the top off of the unit and clean it from the inside out properly with some foaming cleaning and a water hose (that’s the correct way) or wash it out from the outside. If you pull the top off, be careful and don’t get shocked. Make sure the power is off and you hook everything back up properly.

I’m betting you’ve got a dirty coil since this just started happening but low refrigerant is something else to check.

Someone mentioned checking the high side and suction side line temps. The smaller line should be pretty damn warm if everything is working right. The line that’s insulated should be pretty chilly and sweating.

Being dirty will make it freeze up like being low on refrigerant.

Have you checked to make sure all of the duct work is hooked up and not leaking?

[Jkwellborn 6616]

PS -  GOOD NEWS IS IF no lines feel different, no drip change, and house is just cold and no longer humid, THEN you simply are not letting the unit run long enough, but you have no underlying problem!

Yeah, but it should be running long enough to remove the humidity regularly. Especially since this hasn’t been a problem previously. I know I’ll occasionally run my ac down a little lower than normal because of how humid it is. That could be ops problem. Just an increase in the humidity around the house and the unit is doing what it’s always done.

[Bozo_Casanova 26188]

Looks like everything obvious is in working order. I think the problem is just a combination of temps in the 60s-70s morning in combination with my family leaving the windows and back door open all the time when it’s humid.

Edited April 11, 2020 by Bozo_Casanova

[Jkwellborn 6616]

Your dad mode should have kicked in and made them keep that shit closed. And turn off the lights when they’re through.

[smuggs 9318]

On 4/11/2020 at 8:11 AM, Bozo_Casanova said:

Looks like everything obvious is in working order. I think the problem is just a combination of temps in the 60s-70s morning in combination with my family leaving the windows and back door open all the time when it’s humid.

You should probably stop burning pressure treated lumber inside the house as well.

[Bozo_Casanova 26188]

Well I can't do it with the windows closed. 

[Onboard 2.0 9083]

On 4/11/2020 at 9:11 AM, Bozo_Casanova said:

Looks like everything obvious is in working order. I think the problem is just a combination of temps in the 60s-70s morning in combination with my family leaving the windows and back door open all the time when it’s humid.

Familes suck !!

[RPM 26168]

On 4/11/2020 at 8:11 AM, Bozo_Casanova said:

I think the problem is just a combination of temps in the 60s-70s morning in combination with my family leaving the windows and back door open all the time when it’s humid.

CaptainObvious.jpg