High Humidity in apartment, what's wrong?

[kevinkrg6]

Live in a nice, new apartment complex. 750sq ft. 2 bedroom. Place was built 3-4 years ago. 1st floor of a three floor building. My concern is that my Air Quality monitor shows 70% solid. Now, I have done my best to confirm this, I've bought two other handheld humidity monitors at Lowe's and Menards, and so now I have three devices reading the same thing. So the numbers are not due to a faulty device. Plus or minus a few, it's gotta be pretty accurate.

All reading 70%, it's October right now. I know that's not too crazy high, but I have health problems and am worried about mold/mildew growth based off what my doctor is telling me.

If I crank the air conditioning, I can get it down to 56%, but then it's freezing in here (80 outside now, nice fall day) and obviously expensive to run that constantly. I have a dehumidifier coming on order (70 liter, biggest I could get) that might hopefully help, but I'm not sure that's the solution. Doctor says I have toxin/mold issues. I know not everyone believes in that stuff, but I'm just looking for advice regarding HVAC and IAQ.

Is this normal for a ground level apartment? My other apartment didn't have this issue (top floor, 5th floor city studio). Humidity was probably 40-50 there.

Where is it coming from? I guess outside, it's 80% humidity out there here in Northeast Ohio, but what can I do? Hoping the dehumidifier works, just looking to gain a better understanding of what's going on from folks who know more than I. Would a 2nd or 3rd floor apt have been without this issue?

Thanks in advanced to all.

[kdean1]

The source could be infiltration or from occupants.

People perspire, breathe, cook, shower, clean, etc. All of which introduce moisture. Most buildings have a stack effect - warm air travels up and out of the building at leaks so the lower level is under negative pressure which brings in outside air.

Additionally, air conditioners are frequently too big for the space so they don't run long enough, even during peak load times, to dehumidify thoroughly. Your first floor apartment has very little load as you have conditioned space above instead of a hot attic as do the top apartments. I venture to say all the apartments have the same size air conditioner even though the loads are vastly different. That is the nature of apartment building and management.

A dehumidifier is likely to be your best recourse.

[teddy bear]

Crack a couple windows to get some fresh air. Set the dehumidifier for 50%RH.
Keep us posted on the %RH after you get the dehumidifier working.
Regards Teddy Bear.

[osnabruecker]

Which temperature do you have in the apartment? You can make the humidity lower with two simple ways.

1. Most simple, open the windows and let to fresh air from outside go in the appartment.

If you have inside 70% and temperature about 70 F (or 21 C), you take the fresh air with temperature about 57 Grad and humidity 70%. But in the apartment fresh air will be heat till 70 F and humidity of this air will turn to 46%. With the mixture with your inside air and outside air you'll receive about 55-60% of the humidity.

2. Just make the temperature higher. If you have the temparature 70 F and humidity 70% - you can just make the temperature higher till 74 and the humidity will be sink till 62%, f.e.

Generally, sometimes it could don't help. The problems can be in the high volume of the moisture that comes from outside (wet walls due to problem with the walls hydro isolation, f.e.) or inside (a lot of cooking, bath room without good ventilation, drying of the wet clothes in the room) etc.

[Andrew Agar]

You need to do the following things in order to have a comfortable environment.
1. Utilize the dehumidifier at 50%RH inside the interior portion of the house.
2. Go for windows remodeling and have a number of ways in which fresh air can get inside without any inconvenience of daylight.
3. Moreover, the humidity can also reduce with a warm environment temperature wise.
In order to consult a professional contractor near your location, go on websites like Renovaten, Home Advisor, Mr.Handyman

[kdean1]

You need to do the following things in order to have a comfortable environment.
1. Utilize the dehumidifier at 50%RH inside the interior portion of the house.
2. Go for windows remodeling and have a number of ways in which fresh air can get inside without any inconvenience of daylight.
3. Moreover, the humidity can also reduce with a warm environment temperature wise.
In order to consult a professional contractor near your location, go on websites like Renovaten, Home Advisor, Mr.Handyman

Seriously, Home Advisor? I think of it as Hack Central.

[teddy bear]

Additional things to do to lower the indoor %RH.
Check for the supply temperature/%RH verses the return temperature/%RH. You are checking for a humidity removal by the a/c. This is done by comparing the dew point in the space verses the dew point in the a/c supply we are looking a 5-7^F reduction in dew point. The lower limit is 50^F supply temperature (avoid freezing a/c coil). Reduce the air flow through your a/c to lower the coil temperature. MOst a/cs have a fan speed setting on the fam motor. Go for a lower speed setting. If needed, get the most restrictive air filter available.
Operate the fan in the "auto" mode when trying to max dehumidification.
Apartments general need a little fresh air. Most suggest a fresh air change in 4-5 hours to purge indoor pollutants and renew oxygen when occupied. Measuring CO2 is an accurate method of determining actual air change rate. CO2 meters are available from Amazon for 100 bucks.
Get the dehu operating and set at 50%rh. Measuring the water from the dehu also is a way of estimating air infiltration. 25 cfm of 70^F dew point fresh air about 1 lbs. of moisture load per hour, if the space is maintain 75^F, 50%RH, 55^F dew point.

[kevinkrg6]

Getting the dehumidifier today, will report back on how it effects things.

I have a meter for co2 built into a device (awair, a little iaq monitor) and the co2 can get high sometimes in here, but that is also due to a gas range and gas stove. Nonetheless, we open the windows now after using the oven or stove because the levels often jump over 1000, or with the oven, co2 can get to 2000. When we run the ac, co2 seems to stay a little more stable but the stove and oven will mess that up regardless.

Without the stove or ranges being used at All though, sometimes co2 will push 1000 anyway. Only two people living here but it's a new place, probably built pretty tight, that happens after being home all evening. Again, AC helps it maintain stability.

Been running the AC just regular (set to 69F) have humidity at around 64% with it on at this comfortable setting, temp 69F indoor, (73 outdoor now). Still not good right?

I will also take a look at the supply and return %RH, thank you for that bear.

Thank you all again.

[servicefitter]

Check around plumbing pipes in kitchen and bath chalk around them. Dont say where u live when it gets cold check where cold might be coming in. Humidity like heat flows to low or cold. In the bath do you run a exhaust fan?

[JuliBoBuli]

We also have a downstairs 1 bedroom apartment in Southern Indiana. Suddenly in late October I noticed decor on the walls covered in mold. Then began inspecting the rest of apartment- it seemed there were small round spots around each ceiling vents in every room.
I had seen something around the vents a month prior- I assumed they were dust bunnies- so I used a long duster and forced them off our 10 ft ceilings. (All the while breathing this mold in while cleaning- having asthma and breathing congestion to begin with was highly disturbing.)
Our apartment complex did a walk thru-
Said most likely there was moisture between. Our ceiling and second floor unit. And they would open vents and add insulation around vent and put cover back on. I have NO CLUE how that would help?
They had a moisture specialist walk thru few days later- He found nothing with moisture in the apartment- not in walls/carpet nothing.
Then they had an HVAC guy come out- he inspected our system and vents- he found NO reason why we had mold (even though the mold seemed to be concentrated around vents on the ceiling)
Then the maintenance guy from apartments piped in saying that we leave our door open all times of the year and the Indiana humidity was probably the reason.
Then the HVAC guy said that since we keep the air at 69 degrees and have the fan on 100% of the time- that could not be the reason.
Btw when humid we only open the door early in the morning. Humidity is bad for asthma. We like the fresh air.
So thankfully the HVAC shot down the notion that we as the tenants were to blame.
They then did send a guy out to Fog the apartment- While this guy was there the maintenance guy told me that all the candles I burn can cause mold too!!!
I told him if our apartment didn’t smell like mold I wouldn’t have to burn a candle.
We rarely burn them. Like he was trying to make it look like it’s on us!
The property manager also sent us an email- mentioning that we should not have our door open when it’s humid- (seemed to be an attempt to cover their butts)
Meanwhile our renters insurance said I had to itemize the damage to personal items. We had to throw away a ton of our food in pantry (open shelves in laundry room) expensive shoes - all of my lined baskets.
We had to clean EVERYTHING in the apartment with bleach - literally every shelf/closet/nook and cranny….
We did find a special on dehumidifiers at Costco Eva-Dry 1200 for $15 a piece. (May have been priced incorrectly?)
We bought 6 one for every room-
We are pulling 86-96 ounces of water every 5-6 days since we got them at end of October-
IS THIS NORMAL? Seems to me that’s a lot of moisture for our tiny 724 sq ft apartment.
So now that I have vented- any insight would be great!
Sorry so long…

[teddy bear]

How about measuring the temp/%RH on going to give us more info. Should be 70^F/40%RH this time of year. Excess moisture makes the windows sweat this time of year.

Thats not much moisture. How many are in the space?

During cold dry weather, a small amount of fresh air should keep the space <40%RH.
Cold a/c ducts will cause condensation and mold.

Keep us posted.

Regards Teddy Bear

[teddy bear]

More thoughts on your moisture problem. An adult generates .25 lbs. of moisture in a home per hour from their bodies and activities, 4 oz. Apartments may not have consistent fresh air change. Most experts suggest a fresh air change in 3-5 hours to purge indoor pollutants and renew oxygen. Depending on outdoor moisture content, this will dry/wet/maintain indoor moisture levels needed for comfort and health.

The dew point of air is the most common measure of moisture. Homes need a minimum of 40^F and a max of 60^F dew point depending on the season. Outdoor air may be from <0^F to 85^F dew point depending on climate and current weather system. Technically, you may may need to humidify, dehumidify, or just enjoy outdoor air. A side issue in the that outdoor air has 20-21% oxygen with a minimum of 19% considered optimum of health and comfort.

Airtight construction and calm winds make adequate mechanical fresh air ventilation a critical part of health and safety in homes. Many homes are so air tight that the natural air change rate is down to a fresh air change in +12 hours during mild, calm winds, and closed windows. Many states are mandating minimal fresh air ventilation be part of the design.

The air conditioning industry has been slow to adapt fresh air change due to the difficulty of providing humidification/dehumidification or even mechanical fresh air as a standard part of a home. Most homes do not have issue addressed of optimum health and comfort.

High pollutant levels, too dry or damp, high indoor pollutants levels, or just dirty indoor air occasionally occur in most homes. Some occupants are more sensitive to these needs and we here from them on our site.

The most common fix is a humidifier/dehumidifier with fresh air ventilation/merv 13 filter option connected to the central HVAC system. Controls must be included operate the necessary part of the system when needed.

Keep us posted with more info about your problem, many temp/%RH in your home.

Regards Teddy Bear

[kdean1]

We also have a downstairs 1 bedroom apartment in Southern Indiana. Suddenly in late October I noticed decor on the walls covered in mold. Then began inspecting the rest of apartment- it seemed there were small round spots around each ceiling vents in every room.
I had seen something around the vents a month prior- I assumed they were dust bunnies- so I used a long duster and forced them off our 10 ft ceilings. (All the while breathing this mold in while cleaning- having asthma and breathing congestion to begin with was highly disturbing.)
Our apartment complex did a walk thru-
Said most likely there was moisture between. Our ceiling and second floor unit. And they would open vents and add insulation around vent and put cover back on. I have NO CLUE how that would help?
They had a moisture specialist walk thru few days later- He found nothing with moisture in the apartment- not in walls/carpet nothing.
Then they had an HVAC guy come out- he inspected our system and vents- he found NO reason why we had mold (even though the mold seemed to be concentrated around vents on the ceiling)
Then the maintenance guy from apartments piped in saying that we leave our door open all times of the year and the Indiana humidity was probably the reason.
Then the HVAC guy said that since we keep the air at 69 degrees and have the fan on 100% of the time- that could not be the reason.
Btw when humid we only open the door early in the morning. Humidity is bad for asthma. We like the fresh air.
So thankfully the HVAC shot down the notion that we as the tenants were to blame.
They then did send a guy out to Fog the apartment- While this guy was there the maintenance guy told me that all the candles I burn can cause mold too!!!
I told him if our apartment didn’t smell like mold I wouldn’t have to burn a candle.
We rarely burn them. Like he was trying to make it look like it’s on us!
The property manager also sent us an email- mentioning that we should not have our door open when it’s humid- (seemed to be an attempt to cover their butts)
Meanwhile our renters insurance said I had to itemize the damage to personal items. We had to throw away a ton of our food in pantry (open shelves in laundry room) expensive shoes - all of my lined baskets.
We had to clean EVERYTHING in the apartment with bleach - literally every shelf/closet/nook and cranny….
We did find a special on dehumidifiers at Costco Eva-Dry 1200 for $15 a piece. (May have been priced incorrectly?)
We bought 6 one for every room-
We are pulling 86-96 ounces of water every 5-6 days since we got them at end of October-
IS THIS NORMAL? Seems to me that’s a lot of moisture for our tiny 724 sq ft apartment.
So now that I have vented- any insight would be great!
Sorry so long…

That’s some of the worst advice I’ve seen in a long time. “Experts” all giving opinions without measuring ANYTHING! I see no investigation of air leaks or infiltration. No blower door test or zonal pressure readings. No mention of dew point or RH readings. No discussion of air conditioning cycles or blower operation with respect to humidity. Everyone is parroting some line they heard from a utility company or HGTV.
Until you bring in someone knowledgable, you’ll just have people experimenting and hoping for the best.

BTW, you revived a thread from 3 years ago. Etiquette dictates that you should have started a new thread.

[A/C-SuperCool]

recommendation #3 STAY FAR AWAY FROM THESE FOOLS AT ALL COST....