Home Humidity at 80%

Posted by Sudden-Impact-8216@reddit | Dallas | View on Reddit | 41 comments

My Homes humidity is at 80%, I have purifiers and dehumidifiers in every room (the expensive ones about $1,100 each) they are reading humidity levels at 80% the home is 5,800 sq ft I have 3 ac units

Inside units

4 ton

2 ton

Exterior/condensor Units

3 ton

1.5 ton

Many ac companies have come to take a look at it. I was told that the humidity is coming from the condenser units not matching the interior systems.

Can the humidity at this rate cause mold issues in the long term?! My air seems to work fine just not sure what the priority should be on changing the condensers to match and if it would help with the humidity by a substantial amount

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Any-Tennis4658@reddit

80%?

You have a massive leak of air. Even a poorly sized system will get you to 60.

Run your smallest unit to minimum temp. If your house doesn't get to 60%, you've got a hole in a wall, or a hot tub full of water in the house.

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FormulaKimi@reddit

Dew point is currently 43F, if it was an air leak letting outside air in that would actually help right now.

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Any-Tennis4658@reddit

He's got a boiling hot tub then, 80% humidity indoors is wild even if you had a 5ton strapped to a 1400 sqft insulated house.

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FormulaKimi@reddit

Wouldn’t surprise me he got a slab leak, roof leak, or similar. Then maybe because it’s been colder turned on heat making it worse

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Sudden-Impact-8216@reddit (OP)

I have 4 ton (2) and 2 ton (1) indoor unit 3 ton (2) and 1,5 ton outdoor all the hvac said i should have (2) 5 ton vs a 4 ton die this make sense?

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Any-Tennis4658@reddit

Dude. 80% humidity is so insane it's basically raining inside your house.

The WORST AC balance will get it below that. A 5 ton unit on a 600 sqft apartment will get it below 80%.

You have a fucking hot tub in your house, or a humidifier, or a massive gaping hole in your roof or are your ducts torn?

This isn't magic; what you're saying is impossible.

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USMCLee@reddit

After reading all your comments, you might have a water leak somewhere in your house.

Make sure no water is running in your house (dishwasher, washing machine, water heater,etc).

Go to each toilet,close the door and listen. Do you hear water running thru your pipes?

If you do you have a water leak 'somewhere'.

Good luck & God speed if you do. They can be very time consuming and expensive to remedy.

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freedommachine1776@reddit

Your HVAC units are probably oversized and cooling the house too quickly, which in turn doesn't allow them to bring down the humidity levels. Set the fans to "On" instead of "auto". This won't cure it, but it should help somewhat. Ask your HVAC company to run a Manual J calculation and install correctly sized units.

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Powerballs@reddit

Eighty percent is definitely too high. If your fan is already set to Auto, I would also look at whether the condensate drain is partially clogged or the system is oversized and short cycling. In Dallas, the house should usually settle a lot lower than that once the AC has been running. If you are seeing condensation on vents or windows too, I would get an HVAC tech out sooner rather than later.

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peskyavs@reddit

Do you have a fresh air vent? They usually run on a cycle, turning on the fan and opening the vent letting in humid air from outside. There's debate on whether to turn it off or not, but after I turned ours off our issues with high humidity got much better. I bought an air quality monitor from Amazon to keep an eye on things with the fresh air shut. No issues.

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radarksu@reddit

If you want an HVAC engineer to take a look at it, I'm in the Dallas area.

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No_Bend8@reddit

Where in Dallas are you at?

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SimpleVegetable5715@reddit

Using your central air conditioner is way more efficient than those portable dehumidifiers. I do know it’s better to slightly undersize the air conditioner’s BTUs for your needs, so that it runs longer. That’s what’s important to have plenty of that humid air going over the condenser coils, more time to remove all that humidity from the air.

We have a 2 story house, 30-ish years old. Our upstairs air conditioner went out a couple of years ago. The downstairs one is the original that came with the house. That upstairs air conditioner can have a 30-45 minute cycle, while the downstairs one only runs 15 minutes max. But that upstairs one actually is doing a better job removing the humidity. Texas was more arid when this house was built in the 90’s. Now we’re like what Houston used to be, and Houston’s a swamp. The Gulf of Mexico is heating up and creating all this extra humid air.

Humidity over 60% will make your house more prone to mold. My house is still frequently above 60%, especially in the spring, when it’s not quite warm enough for the ac to be on all day. We have to be on top of bleaching and cleaning to keep the mold under control. I also got plenty of fans, I like the Vornado air circulators that just make a slight breeze, and run a few 24-7 to keep the air moving. That helps things not get stagnant.

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H0lyH4ndGr3nade@reddit

Are your units even running? To my knowledge, the sizing only impacts the ability to cool your house as it gets hotter, and shouldn't impact its ability to remove moisture from the air.

You might need to temporarily reduce the set point to force the AC to run a bit. Try to keep track of how long it is running each cycle/day... Over sizing the units can actually impact humidity since it cools the air too fast and doesn't have a chance to pull much moisture out.

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insta-kip@reddit

The ability to cool the house is directly related to the humidity level. AC air is dry. If it cools too quickly, it doesn’t have time to replace the moist air with dry air.

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Sudden-Impact-8216@reddit (OP)

The home is almost 6k ft so I don’t think the system would be oversized with matching the current inside units

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sadisticamichaels@reddit

It seems like on days when its like 60ish outside my ac never runs because the house tends to stay around 70 on its own. When doesnt run then it isnt pulling any humidity out of the air. I can kinda feel it getting humid in the house so I kick the ac sown by 1 degree just to get some humidity out if the air.

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improbablyatthegame@reddit

What thermostat do you have and are your furnace running all the time?

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masterjsa003@reddit

You have a 6k sq ft house and your asking reddit for help? Save your time and sanity and call a reputable company. I use always there air, out of keller. Incredibly knowledgeable and honest. Ive had them work on several of my homes

https://alwaysthereairtx.com/

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masterjsa003@reddit

Use caleb at always there air, out of keller. Incredibly knowledgeable and honest. Ive had him work work on several of my homes

https://alwaysthereairtx.com/

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CaptainBlase@reddit

Set your temperature lower. It's because it's humid outside and the temperature is mild so the AC doesn't run long enough to de-humidify. So, have your AC run longer by setting the thermostat lower.

This function might also be built-in to your thermostat if it's the "smart" type and you just need to set it on.

I had the same problem with my house, and I installed a nest thermostat that has this dehumidify function. Now my house never goes above 60%.

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Synthline109@reddit

Might be a better question for an HVAC or Building Science sub reddit if you're looking for a good technical answer

But short answer, yes you should work on getting the humidity lower

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FormulaKimi@reddit

Keep your windows open the next few days, dew point is so low outside it will lower the humidity. Do not turn on the heat, will make it worse.

Call Greentech Engineering Heating & Air Conditioning, one of the few HVAC companies in the area that actually do the required Manual J,S,D calculations. They will be able to tell you if the units are oversized or not. I would also ask them about having a whole house dehumidifier installed. If you can afford only one, tie it into your upstairs unit.

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Aaliyah-coli@reddit

That’s so weird

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Catullus13@reddit

I had a very similar situation. Yes 80% is too high. 60% is too high. The number one thing the AC recommended to me was turn off the auto fan. You AC acts like a dehumidifier anyway. When these units are this big, they are so efficient at cooling that they don't stay on long enough to dehumidify your house. When you use the fan with the condenser coming on, you're basically blowing moist air through your system and raising your humidity. Set it to zero auto fan run time and see what happens

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4ofheartz@reddit

What do you mean, Turn off the auto Fan? Thx.

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texastyphoon77@reddit

There are two settings for your fan on hvac. “On” or “Auto”. You should set it to Auto. Leaving the fan setting to “on” will cause the humidity to rise

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4ofheartz@reddit

Thx. Good to know!

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Ok-Nose29@reddit

I think I have a similar situation. Did they basically recommend to turn it on/off manually? Or any specific advice about temperatures or how long to keep on?

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improbablyatthegame@reddit

What…

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electricgotswitched@reddit

Around 11am tomorrow I'd open all your windows and run the fans non-stop to try and dry things out. Humidity is going to be pretty low outside.

What is telling you it's 80%? My thermostat shows 8-10% higher than two other devices I have. I'm betting it's not 20% off unless it is just straight broken.

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codysdad89@reddit

I had a similar issue, we dealt with high humidity and inefficient cooling for about 4 years! Multiple a/c companies came out and found nothing was wrong. Finally a tech came over and said "I can tell you with absolute certainty you have a bad compressor" while standing next to the outside unit and hearing it kick on. It was covered under warranty and all our issues were fixed when he came back and replaced the compressor & filter dryer.

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locodfw@reddit

You ac units might be oversized. Causing them to run short cycles. Longer cycles not only heat and cool but also removed humidity from the air.

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Bardfinn@reddit

Anything over 60% relative humidity and you start to get condensation.

Worth deploying calcium chloride dehumidifier kits for sure.

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ForeverOk7505@reddit

I think it’s best you have a professional come out. To measure for mold. That percentage is very high. I had a Nanit that gauges humidity and unfortunately it reads within the range that’s acceptable however I know there’s mold where there shouldn’t be and I can smell the damp - it’s likely in the walls.

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A14245@reddit

Yeah that's pretty high. I would look at getting some smart humidity monitors and having them record the humidity over the next month or so, just to get a different data point than the dehumidifier. (If AC guys were reading the same humidity numbers as the dehumidifier, you can skip this).

For this point in the year it's not that crazy for it to be higher since the rain increases humidity but it's not cool enough yet for the AC to be running and reducing humidity, but 80% is well above where it should be anytime.

As for AC stuff, I think you generally want matching sizes but I think there are some configurations that work, no idea if that applies to your setup. You can run into humidity issues if the system is oversized though. AC not only cools, but it also dehumidifies, and that de humidification process takes time. If you have a super big system that can quickly cool your house, you may not be giving it enough time to dehumidify. If you wanted to get this checked you need to ask specifically for a "Manual J Load Calculation". That will tell you the actual tonnage of systems you need.

I would also look into videos from a youtuber called Technology Connections. He has a number of pretty informative and digestible videos about a number of things including dehumidifiers and HVAC systems. You're getting into very expensive repairs territory so it's probably worth it to familiarize yourself with what is actually going on in these systems.

https://youtu.be/j_QfX0SYCE8

https://youtu.be/DTsQjiPlksA

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Art-Vandelazy@reddit

Bosch units? If so turn off dipswitch sw4-3 and turn on sw4-4. Idk if other manufacturers have similar settings, I just know from experience this is the default setting for Bosch units and it improved my issues drastically changing this.

Also try setting your indoor handler speeds to a lower setting so the A/C is running longer to cool the house, therefore dehumidifying more in the process.

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Sudden-Impact-8216@reddit (OP)

Can you elaborate? Does this affect the humidity? Home came from a builder and there was only 1 owner before me it was built in 2019