Question about air conditioning and humidity

[Grumpy218]

I recently purchased a home in the villages. The house was built in late 2017, so it's fairly new. I've noticed that it feels very humid in the house. The thermostat is set on 74 degrees and it maintains that temperature but it registers a humidity of 63%. The humidity would be great if I wanted to turn my home into a humidor!!! I don't think my wife would go along with that idea.

I moved here from Poinciana, FL so I'm familiar with the Florida humidity. My home A/C in Poinciana was set at 75 degrees and it was cool to the point we used blankets in the evening to watch TV.

Is there something I'm missing, e.g. have the freon checked in the A/C unit? Flush out the condensate line (although there doesn't seem to be much condensate exiting the house). Or could it be something else. Is a whole house de-humidifier the answer?

All feedback is welcome!:coolsmiley:

[Garywt]

We keep our AC at 72 usually and we set the humidity to below 50%. What is you thermostat set at for the humidity.

[kkingston57]

Check with an AC company. Too much humidity could be caused by having a Too Large AC. If you have too big of an AC it cools house down too quickly and does not remove the humidity.

[Fredster]

How often does your AC run?

“Keep the AC running
One of the best ways to dehumidify your home is to keep the AC running at all times. Yeah we know, it doesn’t sound cost effective. But when you’re not running it, it’s not doing its job of dehumidifying your home. Yes, duh. Thank you Captain Obvious! So let’s say it’s raining outside and your AC is set on Auto. It will shut off once the rain has cooled the house down, but if it’s muggy outside, it will eventually get that way inside too. And while the temperature inside might be fine, it’s still going to get muggy due to the excess moisture in the air. Keeping your AC running all day during muggy weather might not sound like the ideal solution when it comes to energy efficiency, but it helps.”

[Fredster]

Just checked....my thermostat is set at 75 and the humidity is 46%... house feels very cool.
Also have two ceiling fans running on low.

Found this....

“But if your air conditioner isn’t dehumidifying the air properly, it’s probably because of one of these issues:

Thermostat is set to “ON” instead of “AUTO”
Dirty evaporator coil
Leaky ductwork
Oversized air conditioning system

[retiredguy123]

Something doesn't sound right. My house is 78 degrees and the humidity is 45 percent, and I am not using any humidity control. The basic thermostat installed by the builder doesn't control the humidity on the normal setting. But, there is a special "dehumidify" setting that will allow the air conditioner to overcool the house by about 3 degrees when the humidity goes above the setpoint. So, if you set the thermostat for 75 degrees, and the humidity is higher than the setpoint, the air conditioner will cool the house down to about 72 degrees in an attempt to reduce the humidity. I don't use that feature because the house can get too cold. Most people in The Villages do not have a whole house dehumidifier and their houses stay pretty comfortable. I would suggest you buy a 10 dollar device from Home Depot that will measure the temperature and humidity in various locations in your house.

[Grumpy218]

Thanks to all of you for your feedback. I re-examined my thermostat and found that it does have a humidity control. I’m not used to that! All my previous controls were simple, set and forget.

I’ve adjusted the controls this afternoon and the humidity has already dropped from 63% to 58%. Remarkable! Thanks again.

[Topspinmo]

Humidistat - How to Set It - YouTube (https://www.youtube.com/watch?v=P1wsamQxpC0)

I was told when occupying the house set to on?

Anybody notice when it rains the A/c kicks on more? It feel it feels cooler due to all the moisture in the air?

[MandoMan]

Just checked....my thermostat is set at 75 and the humidity is 46%... house feels very cool.
Also have two ceiling fans running on low.

Found this....

“But if your air conditioner isn’t dehumidifying the air properly, it’s probably because of one of these issues:

Thermostat is set to “ON” instead of “AUTO”
Dirty evaporator coil
Leaky ductwork
Oversized air conditioning system

Yes, one possibility I’ve seen before is an air leak in the return vent in the attic, caused by some repair guy bumping it or stepping on it. That will let humid, hot attic air be sucked into the system. The system may cool it down, but the air may need to be recirculated a few times to remove the extra moisture, yet with the leak, it doesn’t get the chance.

A more common reason is leaving doors open when the temperature is pleasantly cool, but the humidity is high, such as early morning. Having an outdoor humidity gauge is a good idea. Another common reason is taking long showers without adequate ventilation. I have Panasonic ultra quiet exhaust fans in my bathrooms that draw about 100 cubic feet per minute and use them for a half hour after a shower. This helps towels dry, too, and makes mold less likely. A third reason is boiling water on the stove. Cooking can steam up a house quite quickly. A fourth reason is using a humidifier at night. That can add a gallon of water to the air overnight!

[toddsmig]

Also for maintenance...a 50/50 mix of bleach and water down the condensate tube twice a year to keep the mold/critters down and make sure it is draining out. There is a cap at the furnace that unscrews and just pour it in.

[richs631]

I recently purchased a home in the villages. The house was built in late 2017, so it's fairly new. I've noticed that it feels very humid in the house. The thermostat is set on 74 degrees and it maintains that temperature but it registers a humidity of 63%. The humidity would be great if I wanted to turn my home into a humidor!!! I don't think my wife would go along with that idea.

I moved here from Poinciana, FL so I'm familiar with the Florida humidity. My home A/C in Poinciana was set at 75 degrees and it was cool to the point we used blankets in the evening to watch TV.

Is there something I'm missing, e.g. have the freon checked in the A/C unit? Flush out the condensate line (although there doesn't seem to be much condensate exiting the house). Or could it be something else. Is a whole house de-humidifier the answer?

All feedback is welcome!:coolsmiley:

Along with the temp control you can also set the humidity if most likely you have the same thermostat as everyone else

[RICH1]

I recently purchased a home in the villages. The house was built in late 2017, so it's fairly new. I've noticed that it feels very humid in the house. The thermostat is set on 74 degrees and it maintains that temperature but it registers a humidity of 63%. The humidity would be great if I wanted to turn my home into a humidor!!! I don't think my wife would go along with that idea.

I moved here from Poinciana, FL so I'm familiar with the Florida humidity. My home A/C in Poinciana was set at 75 degrees and it was cool to the point we used blankets in the evening to watch TV.

Is there something I'm missing, e.g. have the freon checked in the A/C unit? Flush out the condensate line (although there doesn't seem to be much condensate exiting the house). Or could it be something else. Is a whole house de-humidifier the answer?

All feedback is welcome!:coolsmiley:
I purchased the Sensi Emerson WiFi Thermostat which has multiple functions to address your humidity/temp issue.. it has programs which you can set to set your AC on and off Duty cycle and drop your humidity level!
You still will need to do your AC basics , filter changes, clean evaporator, spray and clean your condenser... run a shop vac on your evap drain line, it might be partially clogged...therm was 110.00 on the Amazn

[graciegirl]

We keep our AC at 72 usually and we set the humidity to below 50%. What is you thermostat set at for the humidity.

We don't have a humidity setting on our wall thermostat but we do have a little gadget that we bought that monitors humidity and temperature that we can carry from room to room. We set our thermostat on 79 when it is set to cool and on 72 when it is set to heat. It feels comfortable at both settings and FEELS the same temperature although they are degrees apart. I think the cooling itself dehumidifies.

[Hiltongrizz11]

We keep our AC at 72 usually and we set the humidity to below 50%. What is you thermostat set at for the humidity.

Not everyone has the ability to set their humidity level on their indoor ac

[gmdds]

As yet, no one has addressed the whole home dehumidifier aspect of your question.

We have a whole house dehumidifier. Our relative humidity is 40%, and our A/C is set on 81*...any cooler setting than that and we are cold. Yes, when ones A/C is on, it dehumidifies, while running. Why run the A/C, at 240 volts, just to get the moisture out of the air, when you can do that with a whole home dehumidifier, at 120 volts...way less energy, and way more comfort. Also, when we are out of town, the A/C is set on 87*, but the relative humidity is still 40%.

Go to You Tube and look for the This Old House feature on Whole Home Dehumidifiers.

Just another option...to each his own.

[DonnaNi4os]

Check the humidistat setting. It should be set to 60%.

[Tmarkwald]

I bought a set of 5 humidity meters form Amazon. Not incredibly accurate, but I put them in one place and checked that they worked, then put them all over the house. Real cheap - $35

[irishwonone]

Probably biggest thing missing is mature trees that shade your home.🤔

[DAVES]

I recently purchased a home in the villages. The house was built in late 2017, so it's fairly new. I've noticed that it feels very humid in the house. The thermostat is set on 74 degrees and it maintains that temperature but it registers a humidity of 63%. The humidity would be great if I wanted to turn my home into a humidor!!! I don't think my wife would go along with that idea.

I moved here from Poinciana, FL so I'm familiar with the Florida humidity. My home A/C in Poinciana was set at 75 degrees and it was cool to the point we used blankets in the evening to watch TV.

Is there something I'm missing, e.g. have the freon checked in the A/C unit? Flush out the condensate line (although there doesn't seem to be much condensate exiting the house). Or could it be something else. Is a whole house de-humidifier the answer?

All feedback is welcome!:coolsmiley:

I would call an air conditioning service company. It should really be serviced at least once a year. If, the same as ours the control can be set for both temperature and humidity separately.

As far as your home in Poinciana that really means nothing. Some of the thermostats the
set degrees are little more than a reference number older ones would have a thermometer as well.

[DAVES]

Humidistat - How to Set It - YouTube (https://www.youtube.com/watch?v=P1wsamQxpC0)

I was told when occupying the house set to on?

Anybody notice when it rains the A/c kicks on more? It feel it feels cooler due to all the moisture in the air?

The a/c needs to run to dehumidify. If, you have the temp set to say 72 and it is humid your a/c will/can drop the temperature below the 72 you have set in order to run to reduce the humidity. Nothing is perfect. Improperly set you can have your heat pump rock back and forth between cooling and heating mode.

[hvac877]

You should have the system checked the humidity problem could stem from any of the following
1. humidity set point too high on tstat
2. air supply dampers may not all be open and set
3. filters could be plugged and need to be changed
4. evaporator coil needs to be cleaned.
5. system may have a leak
6. Return air may be blocked or need cleaning
7. evap fan motor may not be on the correct speed setting
Call DeSantis HVAC 352-330-4433 they do a lot of work and trouble shooting in The Villages

[Quent]

How often does your AC run?

“Keep the AC running
One of the best ways to dehumidify your home is to keep the AC running at all times. Yeah we know, it doesn’t sound cost effective. But when you’re not running it, it’s not doing its job of dehumidifying your home. Yes, duh. Thank you Captain Obvious! So let’s say it’s raining outside and your AC is set on Auto. It will shut off once the rain has cooled the house down, but if it’s muggy outside, it will eventually get that way inside too. And while the temperature inside might be fine, it’s still going to get muggy due to the excess moisture in the air. Keeping your AC running all day during muggy weather might not sound like the ideal solution when it comes to energy efficiency, but it helps.”

This is spot on. Leave it on Auto and your concern with the refrigerant being low should be checked during your yearly preseason check-up.
This is just from experience that I speak.

[Notsocrates]

I recently purchased a home in the villages. The house was built in late 2017, so it's fairly new. I've noticed that it feels very humid in the house. The thermostat is set on 74 degrees and it maintains that temperature but it registers a humidity of 63%. The humidity would be great if I wanted to turn my home into a humidor!!! I don't think my wife would go along with that idea.

I moved here from Poinciana, FL so I'm familiar with the Florida humidity. My home A/C in Poinciana was set at 75 degrees and it was cool to the point we used blankets in the evening to watch TV.

Is there something I'm missing, e.g. have the freon checked in the A/C unit? Flush out the condensate line (although there doesn't seem to be much condensate exiting the house). Or could it be something else. Is a whole house de-humidifier the answer?

All feedback is welcome!:coolsmiley:

The "humidity" is really relative humidity: the amount of moisture in the air compared with the total amount it could hold at that temperature. The capacity of air to hold moisture increases as the temperature goes up and decreases as it is cooled.
So, if you start with air at 95 degrees with relative humidity of 70% and cool that same air to 75 degrees the relative humidity will increase.

[jimkerr]

Assuming you have the same thermostat as most of us do, just set your humidity to 50% or less and it will adjust the humidity to where you have it set. It might take a day or two but you’ll quickly notice the difference. I noticed our house feeling muggy and discovered the previous owners had it set at 60% humidity. At 60% and above you can start having mold problems. Luckily it was an easy fix!

[dadoiron]

I recently purchased a home in the villages. The house was built in late 2017, so it's fairly new. I've noticed that it feels very humid in the house. The thermostat is set on 74 degrees and it maintains that temperature but it registers a humidity of 63%. The humidity would be great if I wanted to turn my home into a humidor!!! I don't think my wife would go along with that idea.

I moved here from Poinciana, FL so I'm familiar with the Florida humidity. My home A/C in Poinciana was set at 75 degrees and it was cool to the point we used blankets in the evening to watch TV.

Is there something I'm missing, e.g. have the freon checked in the A/C unit? Flush out the condensate line (although there doesn't seem to be much condensate exiting the house). Or could it be something else. Is a whole house de-humidifier the answer?

All feedback is welcome!:coolsmiley:

Set the thermostat humidity to 50 and you'll get 50. You probably have it set to 63 and over looked this step.

[PugMom]

Also for maintenance...a 50/50 mix of bleach and water down the condensate tube twice a year to keep the mold/critters down and make sure it is draining out. There is a cap at the furnace that unscrews and just pour it in.

we were told to do this every other WEEK!

[cassjax2]

When we moved into our home we had the same problem. Found out the fan had been left in the On position. Switched it to Auto and the problem disappeared. Hope this helps.

[rjm1cc]

Do some research on bleach. My impression is that it can do some damage to the pipes.
I pour a gallon of hot water down the drain each month (started this after I had a problem). I am hoping that the flow of water would push out anything that has accumulated in the pipe.

Then I put in a cup of vinegar to kill any alga etc. I think bleach was recommended in the distant past and this has changed to vinegar. At any rate due it monthly.

After about 8 years notice pipe was partly clogged. I used my garden hose at the outside end of the pipe to put water into the pipe at a high rate for several seconds. Trying to break up anything. Then went to the heater and I have an opening (not the pipe you usually use) I could use the hose to run water through. Did this on a low volume to flush the line. This work. Also using air or a vacuum to suck out the stuff might work.

[snbrafford]

I recently purchased a home in the villages. The house was built in late 2017, so it's fairly new. I've noticed that it feels very humid in the house. The thermostat is set on 74 degrees and it maintains that temperature but it registers a humidity of 63%. The humidity would be great if I wanted to turn my home into a humidor!!! I don't think my wife would go along with that idea.

I moved here from Poinciana, FL so I'm familiar with the Florida humidity. My home A/C in Poinciana was set at 75 degrees and it was cool to the point we used blankets in the evening to watch TV.

Is there something I'm missing, e.g. have the freon checked in the A/C unit? Flush out the condensate line (although there doesn't seem to be much condensate exiting the house). Or could it be something else. Is a whole house de-humidifier the answer?

All feedback is welcome!:coolsmiley:


I have an older home and just moved here in 2018. I don't know what my percent humidity is. However, I've been told by other residents to put something in the house to take out the excess humidity - especially during the summer. I use "Damp Rid" product to do this. I used to use the bags but one leaked and the "water" is very difficult to clean up. I switched to using DampRid canisters that have a "tablet" refill. I put one in every room plus one in the space in the garage where the air handling unit is located. You have to empty those canisters about once a month but you can tell they are taking out the moisture.

[ithos]

How often does your AC run?

“Keep the AC running
One of the best ways to dehumidify your home is to keep the AC running at all times. Yeah we know, it doesn’t sound cost effective. But when you’re not running it, it’s not doing its job of dehumidifying your home. Yes, duh. Thank you Captain Obvious! So let’s say it’s raining outside and your AC is set on Auto. It will shut off once the rain has cooled the house down, but if it’s muggy outside, it will eventually get that way inside too. And while the temperature inside might be fine, it’s still going to get muggy due to the excess moisture in the air. Keeping your AC running all day during muggy weather might not sound like the ideal solution when it comes to energy efficiency, but it helps.”

Most professionals would disagree.

If the fan is set to AUTO, that moisture collects and sits on the refrigerant coils. And once the fan shuts off in between cooling cycles, that moisture has time to slide off the coils and drain away outdoors.

But if the fan is set to ON, the moisture on the refrigerant coils does not get the chance to drain away. Because the fan blows constantly, most of the moistures evaporates and gets blown right back into your house!

Hate Humidity? Don’t Set Your Thermostat Like This – Cool Today (https://www.cooltoday.com/blog/hate-humidity-dont-set-your-thermostat-like-this)

[ithos]

In many commercial buildings, they have electric or hot water reheat in the ducts so that if the amount of HVAC cooling needed to dehumidify lowers the room temperature below setpoint, the air is heated back up before it enters the space.

Ideally the home would have a variable speed compressor and fan. Lower energy costs with humidity and temperature much more stable. Also won't have that blast of hot air in the summer when your AC fan kicks on.

Variable Speed HVAC Technology | Heating and Cooling Benefits (https://www.goodmanmfg.com/resources/hvac-learning-center/hvac-101/what-is-variable-speed-technology)

[C. C. Rider]

There are several issues at play here. First, having the FAN running is not the same thing as having the AC running. Depending on temperature, your fan could run all the time, but the AC would never do any dehumidification.

Second, as some have said, the AC (or the heat) must be on in order to dehumidify. By "on", I mean RUNNING, not just set to the "ON" position. The AC is "on" when it's compressor is running, not just when the fan is on.

Here is what confuses a lot of people. How much the AC actually RUNS depends on what the outside temperature is. If it's 90* outside, then your AC will run enough to dehumidify your house nicely. If the outside temperature is in the 60's or 70's, then your AC WON'T run enough to do much dehumidifying.

If the outside temperature happens to be in the 60's or 70's and it's raining or humid outside as we had several days ago, then your AC is NOT going to do much, if any, dehumidification because it won't be running. In that case, you will need to purchase 1 or 2 individual dehumidifiers for your home if your thermostat doesn't have a "Dehumidify" setting.

A "Dehumidify" setting on your AC simply means that when it kicks on, it runs the AC on low speed even though the inside temperature demand on the thermostat has been met. This may make it cooler in your home than you want, but that's the price you'll pay for using the "dehumidify" setting.

High humidity is not usually a problem in most homes in this area when it's hot (83* and above) or when it's cold (30's and 40's). The problem occurs when the temperature is mild (60's and 70's) and the weather outside is rainy and damp. THAT's when you'll have a humidity problem in the house and need either a dehumidify setting on your thermostat or a separate dehumidifier unit (or two).

Actually, having separate dehumidifier units will work best under extreme conditions, but most of the time, having a dehumidify setting on the thermostat will be sufficient. Hope this helps your understanding of the problem.

[ithos]

The "humidity" is really relative humidity: the amount of moisture in the air compared with the total amount it could hold at that temperature. The capacity of air to hold moisture increases as the temperature goes up and decreases as it is cooled.
So, if you start with air at 95 degrees with relative humidity of 70% and cool that same air to 75 degrees the relative humidity will increase.

This is a very important point. Heating a room may lower relative humidity but it will not "dehumidify" as no moisture is being removed. It is astounding how many HVAC techs do not understand that.

Controlling RH is also important in areas where condensation can cause damage.

[Nofiner]

CTry going to the A/C temperature control and see if there is a Humidity setting and if so set it about 50 to 55. The A/C unit will run and should indicate Dehumidify on the control. You might feel some heat but that is normal as the A/C works.
Good Luck

[Indydealmaker]

I recently purchased a home in the villages. The house was built in late 2017, so it's fairly new. I've noticed that it feels very humid in the house. The thermostat is set on 74 degrees and it maintains that temperature but it registers a humidity of 63%. The humidity would be great if I wanted to turn my home into a humidor!!! I don't think my wife would go along with that idea.

I moved here from Poinciana, FL so I'm familiar with the Florida humidity. My home A/C in Poinciana was set at 75 degrees and it was cool to the point we used blankets in the evening to watch TV.

Is there something I'm missing, e.g. have the freon checked in the A/C unit? Flush out the condensate line (although there doesn't seem to be much condensate exiting the house). Or could it be something else. Is a whole house de-humidifier the answer?

All feedback is welcome!:coolsmiley:

We experienced the same thing. Our Hvac guy attributed the problem to the fact that we kept the fan running full time which sucked in humidity when the AC was not running.

[C. C. Rider]

So, if you start with air at 95 degrees with relative humidity of 70% and cool that same air to 75 degrees the relative humidity will increase.

That's not true if you use an air conditioner to cool the air because the air "conditioning" process removes moisture as it cools. That's what the condensate drain line is for... to carry away the moisture that has been condensed out of the air. This leaves you with cooler, drier air for your living space.

Now if you were living in a cave and had a giant fan to pull hot air into your cave where it was much cooler, then the humidity of your cave would be higher than the outside air, but that's not what happens with air conditioning in our homes because air conditioners REMOVE moisture. That's why they're called air CONDITIONERS and not air COOLERS... because they "condition" the air, i.e. remove moisture AND cool the air.

[barbyboc]

We just had the same problem fixed by Priorty Air Conditioning. It was the fan motor. Immediate reduction in humidity.

[silver.bullet]

Grump, Take a look at the April Air whole house dehumidifier. We had one installed 3 years ago at $3.5k , 2400 sq foot electric a/c, gas heat, I use it about 5 months it samples air every hour and turns on the dehumidifier if necessary. The other months the a/c or heat dries the air. I love it, keeps air at 55% and so comfortable. Good Luck my friend!

[retiredguy123]

Grump, Take a look at the April Air whole house dehumidifier. We had one installed 3 years ago at $3.5k , 2400 sq foot electric a/c, gas heat, I use it about 5 months it samples air every hour and turns on the dehumidifier if necessary. The other months the a/c or heat dries the air. I love it, keeps air at 55% and so comfortable. Good Luck my friend!
I don't understand why you would need a dehumidifier to maintain a relative humidity of 55 percent in your house. I keep the heat pump thermostat set at 78 degrees all year, and the humidity never even comes to 55 percent. The humidity level in my house is almost always between 40 and 50 percent, with only heating and cooling, and no dehumidification at all.

[Topspinmo]

I am really confused now? Would some explain what the control that controls humidity supposed to set on. Some say 50% some say 60% and some say to the on position. So what is it? IMO has nothing to do with A/c cause it’s set to desired temperature on automatic.

[retiredguy123]

I am really confused now? Would some explain what the control that controls humidity supposed to set on. Some say 50% some say 60% and some say to the on position. So what is it? IMO has nothing to do with A/c cause it’s set to desired temperature on automatic.
The typical builder installation does not include a dehumidifier. But, the standard heat pump thermostat includes an optional "humidity" setting that will allow the AC to cool down the house to about 3 degrees below the thermostat temperature setting to remove moisture when the humidity goes above the humidity setting. This is a "compromise" because you need to cool down the house to below the desired temperature to reduce the humidity. Personally, I don't use the humidity setting because it makes the house too cold when the humidity setting kicks in. But, for snowbirds, the humidity setting can save electricity by allowing a higher temperature setting when the house is unoccupied. A "real" dehumidifier will overcool the house to reduce humidity, and then reheat the air to the desired temperature, so you can control both the temperature and the humidity as desired. The standard builder system does not include a real dehumidifier, so you cannot control both the temperature and the humidity. I hope this makes sense.

[Topspinmo]

The typical builder installation does not include a dehumidifier. But, the standard heat pump thermostat includes an optional "humidity" setting that will allow the AC to cool down the house to about 3 degrees below the thermostat temperature setting to remove moisture when the humidity goes above the humidity setting. This is a "compromise" because you need to cool down the house to below the desired temperature to reduce the humidity. Personally, I don't use the humidity setting because it makes the house too cold when the humidity setting kicks in. But, for snowbirds, the humidity setting can save electricity by allowing a higher temperature setting when the house is unoccupied. A "real" dehumidifier will overcool the house to reduce humidity, and then reheat the air to the desired temperature, so you can control both the temperature and the humidity as desired. The standard builder system does not include a real dehumidifier, so you cannot control both the temperature and the humidity. I hope this makes sense.

Yes, I am guessing older houses don’t have heat pumps? My don’t gas furnace.

[retiredguy123]

Yes, I am guessing older houses don’t have heat pumps? My don’t gas furnace.
Actually, a lot of the older houses do have heat pumps, but some houses, newer and old, have gas heat.

[silver.bullet]

I don't understand why you would need a dehumidifier to maintain a relative humidity of 55 percent in your house. I keep the heat pump thermostat set at 78 degrees all year, and the humidity never even comes to 55 percent. The humidity level in my house is almost always between 40 and 50 percent, with only heating and cooling, and no dehumidification at all.

When the A/C and heat run, the dehumidifier is not needed, the humidity in the house is low. In the spring and fall is when I use the dehumidifier. Works like a charm!