High humidity levels INSIDE house

[jmc325]

I need some home owners advice- I'll probably DD

My husband and I recently built a house and been living in it the last 8 months. As the outside temperatures have crept up, so have the humidity levels inside of our house. We know that 40-60% is the normal range, and our thermostat was reading anywhere between 70-90%. We live in Houston, so we know the outside climate will cause us to be on the higher end of humidity levels, but where we are now puts us beyond the normal range. The air in our house feels sticky, thick and damp. We have double paned windows and now you can barely see out of them as they're full of condensation. We spoke to the builder and he alluded that others in our neighborhood have been experiencing the same. To give some relief, yesterday we started running 2 portable dehumidifiers that we purchased, moving them between the upstairs and downstairs every few hours.

The HVAC people are coming out to our house to take a look tomorrow and we will stay on top of the builder, but being a first time home owner with no experience my H and I feel lost. The builder said if they can't find the root of the issue then installing a whole house dehumidifier (at their cost) would be the route to take. Overall our home building experience was good... 8 month in and we're STILL waiting for a few minor things to be taken care of and my H and I have been more than patient. All the back and forth trying to get those minor things done has made me start to lose trust in the builder, especially with dealing with something more serious like humidity issues. This is a very reputable, well known builder so maybe my expectations are just too high?? My husband doesn't share this concern.

We have a smart thermostat, so checking the humidity levels is super easy; I started noticing them creeping up at the beginning of May, but only mentioned to my husband that I was starting to get concerned last week. The thermostat and portable dehumidifiers are reading the humidity at different levels (the thermostat has it higher, but even where the portable dehumidifier reads is out of normal range).

I would really appreciate anyone who can offer advice or insight. This is not how I envisioned new home ownership being... especially with a brand new house that is only a few months old!

[icedcoffee]

I would expect the builder to add a whole house dehumidifer at his cost NOW. High humidity levels can be really bad for your house. I would not let him drag his feet on this.

[karinothing]

Hmm. I am not sure what about a specific way a house is built would increase humidity, but I don't know much about this stuff. I will say we have a whole house de humidifier which basically means the AC runs beyond the set temperature to bring the humidity level down. Have you tried turning the AC to a lower temp and see if that has any effect?

What is the outside humidity rate?

[VillainV]

Do you run the air conditioner often?

A/C’s work by taking the humidity out of the air, and if you run even a few hours a day it should keep the humidity level low. For comparison, we are in the FL panhandle and at a very similar climate to Houston, and our house sits at about 45-50% after running it about 6hrs a day (per our Nest report). If you don’t run the A/C as much, you can expect the humidity to be higher.

My concern is that there is either water intrusion into your house that is contributing to excess moisture (through your roof, foundation, or basement), or that your air conditioner isn’t properly scaled to your house. Simply installing a dehumidifier isn’t going to solve either of those problems.

[VillainV]

Also, it wouldn’t hurt to buy a few cheap ($5) digital thermometer/hygrometer thingies and place them around your house do double-check the humidity in different locations. It’s possible your thermostat is wrong, or is just pulling from one spot in the house.

[georgeglass]

New houses can have higher initial humidity, especially if they're built really tight.

www.probuilder.com/humidity-control-high-performance-homes-humid-climates

www.greenbuildingadvisor.com/question/high-relative-humidity-in-new-construction-house

Even knowing that, though, I would not excuse the builder or hold off on solutions. If they try and convince you that it will take care of itself, get something in writing that they'll resolve any residual issues outside of the warranty period.

[wonderfezz]

Has your thermostat been calibrated? Sometimes it's just reading wrong, although you're saying you feel sticky, so it may be moot. Is the thermostat near a bathroom? Where is your air handler located (attic/closet)?

The HVAC people should be able to tell you what the issue is, but a dehumidifier isn't a bad idea.

[icedcoffee]

To the people suggesting the thermostat might just be wrong...her windows are fogging and it’s uncomfortable. That’s enough of a sign that I’d want a solution ASAP.

[candreco]

May 24, 2019 11:12:07 GMT -5 VillainV said:

My concern is that there is either water intrusion into your house that is contributing to excess moisture (through your roof, foundation, or basement), or that your air conditioner isn’t properly scaled to your house. Simply installing a dehumidifier isn’t going to solve either of those problems.

This was my first thought... it sounds like the A/C unit doesn't have sufficient capacity to pull enough moisture out of the air.

[jmc325]

May 24, 2019 11:08:33 GMT -5 karinothing said:

Hmm. I am not sure what about a specific way a house is built would increase humidity, but I don't know much about this stuff. I will say we have a whole house de humidifier which basically means the AC runs beyond the set temperature to bring the humidity level down. Have you tried turning the AC to a lower temp and see if that has any effect?

What is the outside humidity rate?

We have two AC units and been running them consistently between 68-70 degrees, so we try to keep the house cool. Current humidity level outside is 56%. I just checked our thermostat from the app and the upstairs humidity is at 70% and the downstairs humidity is at 69%. When we left for work this morning we left both dehumidifiers running upstairs.

[jmc325]

May 24, 2019 11:15:16 GMT -5 VillainV said:

Also, it wouldn’t hurt to buy a few cheap ($5) digital thermometer/hygrometer thingies and place them around your house do double-check the humidity in different locations. It’s possible your thermostat is wrong, or is just pulling from one spot in the house.

Unfortunately, I think it's more than just the thermostat being wrong, but grabbing some of those thingies and placing them around the house is a good idea, if anything just to hopefully narrow down where the higher humidity spots are. Thanks!

[jmc325]

May 24, 2019 11:38:21 GMT -5 wonderfezz said:

Has your thermostat been calibrated? Sometimes it's just reading wrong, although you're saying you feel sticky, so it may be moot. Is the thermostat near a bathroom? Where is your air handler located (attic/closet)?

The HVAC people should be able to tell you what the issue is, but a dehumidifier isn't a bad idea.

We've had them come out twice already! Albeit, that was during the winter when we felt like the heater wasn't sufficiently heating the house. They're coming out tomorrow, so I'm sure they'll do it again. Both thermostats are by bathrooms, but they are the guest bathrooms that really don't get used as it's just me, H and our dog living there. Our air handler is in the attic.  

[jmc325]

May 24, 2019 11:48:25 GMT -5 candreco said:

May 24, 2019 11:12:07 GMT -5 VillainV said:

My concern is that there is either water intrusion into your house that is contributing to excess moisture (through your roof, foundation, or basement), or that your air conditioner isn’t properly scaled to your house. Simply installing a dehumidifier isn’t going to solve either of those problems.

This was my first thought... it sounds like the A/C unit doesn't have sufficient capacity to pull enough moisture out of the air.

We don't have basement, but I'm with you on this. It's exactly why I worry about them installing a dehumidifier. It almost feels like it's just a bandaid to another issue. We had some really crazy rains last week and we noticed what may be a water leak on a guest bedroom windowpane. We couldn't tell where the water is coming from, all we see is what looks like a large water spot on the windowpane. I feel like maybe the windows aren't completely sealed, causing that water leak, condensation between the double paned windows, and now high humidity.

It's all a guessing game though, I seriously have no fling clue. We had an inspector come out and check during each phase of the building process and nothing seemingly related to this was red flagged during those walk throughs.

Our house is just under 3,000 sq ft. and we have 2 AC units- one for upstairs, one for downstairs.

[cmeon]

A more likely issue these days (in a new home) is having TOO MUCH efficiency in A/C equipment. They don't have to run as long and aren't effective at removing humidity from the air.

For some relief while you get this sorted out, make sure you run bathroom fans with the door shut during showers/baths and for half an hour after. Running all your outside venting fans (bathrooms, hood) overnight will help, too. Those humidity levels are miserable- I hope you find out what's going wrong soon.

[candreco]

May 24, 2019 12:05:55 GMT -5 jmc325 said:

May 24, 2019 11:48:25 GMT -5 candreco said:

This was my first thought... it sounds like the A/C unit doesn't have sufficient capacity to pull enough moisture out of the air.

We don't have basement, but I'm with you on this. It's exactly why I worry about them installing a dehumidifier. It almost feels like it's just a bandaid to another issue. We had some really crazy rains last week and we noticed what may be a water leak on a guest bedroom windowpane. We couldn't tell where the water is coming from, all we see is what looks like a large water spot on the windowpane. I feel like maybe the windows aren't completely sealed, causing that water leak, condensation between the double paned windows, and now high humidity.

It's all a guessing game though, I seriously have no fling clue. We had an inspector come out and check during each phase of the building process and nothing seemingly related to this was red flagged during those walk throughs.

Our house is just under 3,000 sq ft. and we have 2 AC units- one for upstairs, one for downstairs.

When you also mentioned that you didn't feel like your HVAC was heating the house well, that also made me think that the whole system is undersized.  There is definitely a range in various factors in HVAC calculations that can lead to a more conservative design with a higher capacity that gives you a healthy margin, or a smaller one that operates right on the edge of effectiveness. 

If other houses in the neighborhood are having similar issues with the same HVAC vendor, that would be my guess.  It could be a little bit about new construction being tighter and the house not "breathing," but this sounds more significant than that would cause.

ETA: cmeon is right, it could also be that the system is cooling very efficiently and doesn't run long enough to dehumidify (though that wouldn't explain issues with heating).  Basically HVAC is about balance, the system has to be the right size to work, and have thermostats in the right places. 

[cmeon]

Do you heat with heat pumps or a furnace? Assuming it's the former, there does seem to be a pretty big learning curve when it comes to learning how to heat with a heat pump if you're used to furnaces. If heat pumps aren't super common in your area yet, you might be getting bad instruction or advice.

[SusanBAnthony]

Where is the window humidity? If it is between the glass pants that I'd whole separate issue (and you end all new windows) then if it is inside the house.

[abs]

I’d guess there is some faulty HVAC equipment that was installed. Builder grade generally is code for cheap and I would not be surprised if something was installed wrong.

I live in Houston as well. When we had high humidity in our house this spring it was because the coil was leaking.

I’d also be concerned about a leak somewhere.

[Deleted]

Assuming both a/c units are working properly, 2 should be plenty for that size of house.

With my previous work with house builders, I’d fork over the money for a private HVAC company to come check out your house to see what’s going on and make sure it’s all working properly. Then you can work on getting the builder to fix the issue.

[lessel]

What are the specs on the A/C units and how many sq ft does each one cover?

I’m wondering if you don’t have enough returns or something (ie, enough air being sucked into the system). Or if you do, then the units don’t have the right capacity maybe?

[sillygoos15]

Normally a lurker but we also just built a home in south alabama so similar humidity issues. Our builder installed a whole house dehumidifier that we did not even discuss or know was going to be installed. We had never heard of it. Our builder explained that when he does spray foam insulation, he also installs a whole house dehumidifier because it's easier for it to get trapped inside due to the spray foam. Do you have that type of insulation? If so, I'd definitely be asking for him to install the unit at his cost. This might be a lesson he needs to learn for future builds.

[jmc325]

May 24, 2019 13:03:35 GMT -5 SusanBAnthony said:

Where is the window humidity? If it is between the glass pants that I'd whole separate issue (and you end all new windows) then if it is inside the house.

The window humidity is between the glass.

[jmc325]

May 24, 2019 13:54:06 GMT -5 sillygoos15 said:

Normally a lurker but we also just built a home in south alabama so similar humidity issues. Our builder installed a whole house dehumidifier that we did not even discuss or know was going to be installed. We had never heard of it. Our builder explained that when he does spray foam insulation, he also installs a whole house dehumidifier because it's easier for it to get trapped inside due to the spray foam. Do you have that type of insulation? If so, I'd definitely be asking for him to install the unit at his cost. This might be a lesson he needs to learn for future builds.

We have the spray foam too. The builder mentioned a few things that made my H think that this is something that's becoming an ongoing issue with others in our neighborhood. How have your humidity levels been with the whole house dehumidifier? Does it stay on all the time with the AC or automatically kick on when needed? Have your humidity levels been in the normal range? I need to do research on how they even function.

The builder did mention maybe installing one for us, but that was just initial talk, they haven't even come to check anything out yet. I don't want this lingering on for forever, so we've been staying on them about it as best as we can.

[redheadk]

May 24, 2019 14:46:01 GMT -5 jmc325 said:

May 24, 2019 13:03:35 GMT -5 SusanBAnthony said:

Where is the window humidity? If it is between the glass pants that I'd whole separate issue (and you end all new windows) then if it is inside the house.

The window humidity is between the glass.

Your double-paned windows should not fog between the glass. There is something wrong with the windows. They should be filled with argon gas and sealed. 

I don't know, I live in Houston, too, and we built our last house. The builder used a unit that was sized properly for the house but we were at the top end of the range. It struggled during the summer keeping the house cool but I don't remember having issues with the humidity inside the home. Our current house is 20 years old and we have zoned units that our sq footage falls more in the middle of the range of. The house is always nice and cool. 

[gummy]

May 24, 2019 11:48:25 GMT -5 candreco said:

May 24, 2019 11:12:07 GMT -5 VillainV said:

My concern is that there is either water intrusion into your house that is contributing to excess moisture (through your roof, foundation, or basement), or that your air conditioner isn’t properly scaled to your house. Simply installing a dehumidifier isn’t going to solve either of those problems.

This was my first thought... it sounds like the A/C unit doesn't have sufficient capacity to pull enough moisture out of the air.

This is my thought too. New builds in our area notoriously come with undersized units.

[imojoebunny]

I have two newer houses, one 5, and one 15 years old, so well in the tyvek, super seal house age. We do not use the 15 year old one all the time, 1-2 times a month, so it sits. We run a self draining dehumidifier in the basement, and leave the air on 55 or 88, when not there, but haven't had any problems with humidity or mold in the house (They are in Georgia, so a humid state.) What kind of foundation do you have (Basement, crawl space, slab)? Does your lot have good drainage? How big are your HVAC (tons) for the square footage each serves?

The condensation between the window glass is a failure of the window. It happens sometimes, we have 2 out of 50+ windows between both houses, but it should not happen to more than one or two, and they should be replaced by the builder, if you have a pretty standard warranty. Look at the specs on your windows, some have gas in between that has insulating properties, so just replacing the panes, is not the same.

For the humidity issue, I would hire my own inspector, or at least have an independent HVAC companies come give you an opinion. Make sure you find an individual who has been around, not just mega HVAC's latest trainee. It would be well worth the cost, and save you a lot of headaches fighting with the builders people, if you have a third party opinion.

[Eagles]

May 24, 2019 11:38:21 GMT -5 wonderfezz said:

Has your thermostat been calibrated? Sometimes it's just reading wrong, although you're saying you feel sticky, so it may be moot. Is the thermostat near a bathroom? Where is your air handler located (attic/closet)?

The HVAC people should be able to tell you what the issue is, but a dehumidifier isn't a bad idea.

I love when you talk technical.

[SusanBAnthony]

May 24, 2019 14:46:01 GMT -5 jmc325 said:

May 24, 2019 13:03:35 GMT -5 SusanBAnthony said:

Where is the window humidity? If it is between the glass pants that I'd whole separate issue (and you end all new windows) then if it is inside the house.

The window humidity is between the glass.

This is a huge issue and likely has nothing to do with the interior humidity.

I work in the building and construction industry. Builders are notorious for using terrible vinyl windows* until you get to the ~1 million dollar price point. They care primarily about delivery schedule and price, not quality.

It sounds like your insulated glass (the two panes) is not properly sealed. This is likely covered under warranty from the window company and they should replace any glass that this is happening in.

*Pretty much all vinyl windows are terrible.

[sillygoos15]

Sorry for the delay in responding. With the humidifier we usually stay between 50 and 70%. I was told we want to be at 50%. Yes, it's always on. I'm not exactly sure how it works but there is a panel that shows it's on and the readings. I do not know if it's hooked to the HVAC. My builder said he had issues with condensation inside a couple builds so now he always puts them in when people choose spray foam.
jmc325,