Humidity going up to attic

[joesxm3]

My mother had a nose bleed and it was assumed to be related to the house being too dry. The doctor told me to make sure I had enough humidity. I have set up three humidifiers.

The warm moist air seems to be rising up to the attic.

The outside humidity is 16% with a temperature of 30.

The attic is 70% humidity with a temperature of 48.

The second floor is around 40% humidity with a temperature of 70.

The first floor where the humidifiers are running is between 38% and 45% depending on the room and a temperature of 74.

In the attic I have one layer of fiberglass insulation between the floor joists with the vapor barrier on the bottom. On top of that I have a layer of fiberglass insulation with no vapor barrier. As I understand things that is the correct way to do it.

Does it make sense that the warm air is rising?

I think that relative humidity is related to temperature. Is that the way it works?

That is would the humidity number be higher for the same amount of moisture if the temperature were lower from point A to point B?

I have poor ventilation in the attic as I have mentioned in other posts. I have a ridge vent and a gable exhaust fan on one end and an inadequate gable intake on the other end. The fan is not running now since it is controlled by temperature.

The idea occurred to turn the fan on to see what that does. But if I have to lower the temperature setting enough to make it run, it will probably run all the time or may not even go that low.

I suppose I could try to hire an electrician to install a humidity sensor to control the fan as well as temperature.

At this point I have to give priority to my mother since she had to be rushed to the ER with a nose bleed last week.

 

[Mr._Graybeard]

Colder air has a lower capacity for moisture. So when the air reaches the attic and cools, the percentage of that capacity goes up.

Forty percent humidity at 70 degrees is a well-hydrated environment.

 

[joesxm3]

So are you saying that the percentage number is the percentage of the capacity of the air at a given temperature to hold water that is used up?

It was just now 64% at 52 degrees in the attic. I was able to barely turn the fan adjustment enough to make it run.

Is the fact that the attic temp is as high as 50 at problem, air leak etc? Is 70% in the attic a problem? I already have seen some black mold on the decking a few months ago.

 

[Mr._Graybeard]

That's why they call it "relative" humidity. I would say 70% in the attic is high. I don't know your location, but my attic at the moment is probably below 32 degrees.

I think you could drop the humidity in your living space. Thirty percent should be adequate.

 

[joesxm3]

Thanks.

I had it around 30% when she got the nose bleed. She was stuffed up an put her to finger up her nose with long finger nails. I have cut the nails.

The doctor said to spray saline mist up the nose every 4 hours. He also said do not blow the nose for a week. The spray makes her want to blow so I am holding off. I suppose I can drop a little once I am spraying the nose.

Thanks again.

I saw the other thread on attic insulation and some mention of moisture going up to attic and making sure things are sealed well. I will study that thread.

 

[Mr._Graybeard]

I think you're better off hydrating your mom than hydrating your home further. Does she drink enough water? I like sparkling mineral water this time of year to keep up internal hydration. It's hard to keep indoor humidity up here in Wisconsin during the winter, so I try to be mindful of fluid intake.

 

[OldShooter]

... The warm moist air seems to be rising up to the attic. ... Does it make sense that the warm air is rising? ...

Yes. Warm air rises. Insulation is good, but if there is warm air leaking from the living space into the attic, the insulation cannot help. In addition to other advice here I suggest that you mount a campaign to find and seal air leaks. There is a lot of material on this available on the internet as sealing is step #1 on reducing heating bills. You can buy foam gaskets to seal outlets and light switches. Foam (like "Great Stuff") can be used to seal where an electrical wire comes through a hole between the living space and the attic. It's messy and miserable work as you have to be moving the insulation around to discover leaks, but it doesn't cost very much. I'm sure there are contractors who will do this, too, if you can spend the money for that. Your local heating utility (natural gas, electric, fuel oil, etc.) almost certainly has a staff that helps with heating costs. That's not exactly your problem, but that warm, wet attic will benefit from the same sealing methods that reduce heating costs.

 

[ERD50]

....

I think you could drop the humidity in your living space. Thirty percent should be adequate.

I find 40~45% RH much more comfortable.

Though we just had a spell of single digit (F) temps, had to drop it down to ~ 30~35% RH to keep the windows from getting too much condensation.

Down around 30% RH, I'll get static shocks from some things. At that point, skin starts getting dry/itchy.

BTW, I don't trust even the digital hydrometers too much. I have two side by side, one reads 32%, the other 37%. The analog seem to be almost useless, other than did it go up or down.


-ERD50

 

[Qs Laptop]

I saw the other thread on attic insulation and some mention of moisture going up to attic and making sure things are sealed well. I will study that thread.

I think it was me that commented on the humidity in the attic. If you live in a climate where outside temps regularly get below freezing and you run a humidifier(s) as frequently as you do, you run the danger of warm humid air entering the attic via openings in the ceilings (light fixtures, bathroom exhaust fan openings, pipes, electrical cables, etc.)

This warm air condenses on the cold roof trusses and supports in the attic and then freezes, forming frost. Over time, especially during a long cold snap, this frost builds up. (think of how frost builds up on older freezers that don't have the frost-free feature.) Then, when the weather turns warmer, the attic heats up and the frost melts and the water drips onto the back of the drywall that forms the ceiling(s) in your rooms.

This happened to me after a particularly cold winter we had in 2018. I have a whole house AprilAire humidifer attached to my furnace and I was using it, probably overusing it. Here is the result when frost melts off the joists in the attic and the melted water drips onto the ceiling drywall:



Notice how straight the stain is. I measured and looked in the attic and located the 2X6 support beam in the attic that was positioned in the attic directly above the stain mark in the ceiling.

The solution is to not use the humidifier (not an option for you, it appears) or if you run the humidifier, then seal up every opening where warm air can seep into the attic.

 

[Mr._Graybeard]

I find 40~45% RH much more comfortable.

Though we just had a spell of single digit (F) temps, had to drop it down to ~ 30~35% RH to keep the windows from getting too much condensation.

Down around 30% RH, I'll get static shocks from some things. At that point, skin starts getting dry/itchy.

BTW, I don't trust even the digital hydrometers too much. I have two side by side, one reads 32%, the other 37%. The analog seem to be almost useless, other than did it go up or down.


-ERD50

Heh, mine is at about 15% right now. Way lower than ideal, I know, but with the temp around zero this morning, the greater environment is relatively dry.

I'd work to pump up the indoor humidity, but the dryness doesn't bother me. We have mostly hardwood and vinyl floors, so no static shocks. And I keep myself hydrated.

 

[joesxm3]

My mother suffers from SIADH (low sodium for short) and is restricted to 30 ounces of liquid per day plus 16 ounces Ensure (will skip the details). So keeping her well hydrated is problematic.

I removed all the old improperly installed insulation 10 or 15 years ago and replaced it with what is up there now. I am pretty sure that I went around as much as I could and sprayed in that yellow foam in cans wherever I could. I am not sure if I dd anything with light fixtures.

I have four six inch light fixtures in the ceiling plus the opening for the pull down stairs. The stairs are the obvious culprit. I considered just putting duct tape around the edges but then I can't go up there. I will look into getting some soft foam or other method to make a tight seal on the edges.

One other possible area is a three foot crawl walk that goes the length of the attic on one side. I think I pushed the base layer of insulation with the vapor barrier on the bottom under those but I will have to check.

I did put the foam gaskets on the living area light switches and sprayed the foam in some window recesses but pulling the molding off was a disaster for me. I bought one of those scanning thermometers to look for leaks.

 

[old medic]

Colder air has a lower capacity for moisture.

I had a great laugh the other day with the live news... Holding a circular thermometer showing it was 4 below 0....
Same unit had a humidity scale showing 72% humidity.

 

[OldShooter]

... I have four six inch light fixtures in the ceiling plus the opening for the pull down stairs. The stairs are the obvious culprit. I considered just putting duct tape around the edges but then I can't go up there. I will look into getting some soft foam or other method to make a tight seal on the edges.

One other possible area is a three foot crawl walk that goes the length of the attic on one side. I think I pushed the base layer of insulation with the vapor barrier on the bottom under those but I will have to check. ...

Yes. Take the low-hanging fruit first and the fixes are cheap. For the stairs try "v-seal" type weatherstrip. 3M used to make it and I have had good luck with their product, but Google is not finding it for me. Here is a similar product:

and https://www.frostking.com/products/weatherstripping/V-Seal Weatherstrip

 

[Mr._Graybeard]

My mother suffers from SIADH (low sodium for short) and is restricted to 30 ounces of liquid per day plus 16 ounces Ensure (will skip the details). So keeping her well hydrated is problematic.

I see. Is there a single room or area of the house where she spends a lot of time?

 

[joesxm3]

Yes. Take the low-hanging fruit first and the fixes are cheap. For the stairs try "v-seal" type weatherstrip. 3M used to make it and I have had good luck with their product, but Google is not finding it for me. Here is a similar product:

and https://www.frostking.com/products/weatherstripping/V-Seal Weatherstrip

I just ordered three different sorts of weather stripping from Amazon.

The hatch has some sort of old stripping that is not attached well and falling out in places. It may even be preventing it from closing completely.

I will get the step ladder and take a better look.

Thanks.

 

[Mr._Graybeard]

Yes. Take the low-hanging fruit first and the fixes are cheap. For the stairs try "v-seal" type weatherstrip. 3M used to make it and I have had good luck with their product, but Google is not finding it for me. Here is a similar product:

and https://www.frostking.com/products/weatherstripping/V-Seal Weatherstrip

I have an ample supply of this stuff! It does work fairly well. That and the shrink-wrap window film...

 

[joesxm3]

I used that window film a while ago on some of my less used rooms. I had some left over but I can't find it. We are getting a deep freeze this weekend so I ordered 3 more windows worth that should arrive today. I am going to put it on the windows near my mother's bed.

 

[Masquernom]

I was tasked once with building a very low humidity production room for the company I worked for. Researching it, I found it is very difficult to keep different humidity levels between spaces. A very small opening will transfer humidity between rooms. The higher the difference in humidity levels, the more force pushing the moisture toward the lower humidity.

 

[joesxm3]

Well I made a less than optimal attempt to seal the hatch. it does not look pretty but I think it is better than before.

I put a one inch wide piece of stick on foam around the inside edge of the hatch door hoping it would push up against the edge of the recess where it closes to. That worked for most of it but the door is warped and there was a foot or so gap. No put some of the hollow tube stuff on the ceiling part of the opening and it seems sealed better than before. Good enough for tonight. I also shrink wrapped the two windows in moms room. Sub zero temps tonight.