Humidifier and moisture

[supton]

Wife wants to try out a humidifier. Problem is I have condensation on all the windows in the house already; I can't imagine adding more water to the air. If we try out a humidifier do I need to get dehumidifiers too? I'm not quite sure were to dig in on this one.

I already have 3-4 year old skylights doing just as the pic in this link does:
http://www.structuretech1.com/tag/moisture-problems-with-humidifiers/
The wood was never painted/sealed; I meant to, but I'm guessing it would have rotted anyhow since I would not have prevented water from running between the glass and the wood.

House has circulating hot water not forced hot air, and wife will make soup stock on occasion. Bathroom shower has a vent which vents to the outside, but the kitchen does not have any sort of venting, and it'd be rather fun to add (there is a cinderblock chimney right in the way of the range hood). I've been trying to run a dehumidifier in the basement to control moisture down there, as it does have water issues.

Maybe I should find some decent hydrometers(?) and first measure RH?

 

[Quattro Pete]

Yes, first thing is to actually measure the humidity. This will tell you whether you need a humidifier or not. You can pick up an inexpensive humidity monitor from ChinaMart for less than $10.

 

[Pop_Rivit]

Measure what you have first, then decide what you need from there. From the amount of moisture damage and water on the windows, I'd guess you're already too moist, but without an actual measurement it's only guesswork.

 

[supton]

We do have issues with dry skin and my son has nosebleeds, so something is amiss. I think we have one of those cheapo things from Walmart, but IIRC they have no numbers on them. Will track those down or buy new ones.

Thanks!

 

[SHOZ]

Anything over 50% is getting to be too much. The condensation really depends on how cold it is on the other side and how good the material is at insulating. 60% in my house will wet the windows and the aluminum frames with a 30-40F difference.

 

[Quattro Pete]

Originally Posted By: supton
I think we have one of those cheapo things from Walmart, but IIRC they have no numbers on them. Will track those down or buy new ones.

Thanks!

http://www.walmart.com/ip/AcuRite-Digital-Humidity-and-Temperature-Monitor/16888914

 

[IndyIan]

How is your diet for fatty acids? A lack of those can cause dry skin.

 

[supton]

Ah, that looks very usable. Was just there this morning too! Will have to run over at some point then and get that.

 

[DoiInthanon]

Definitely get a humidity reader and determine the facts. More importantly, begin the process of reprogramming the problem sensor - WifeHumidityInputMark1. The sweet spot according to ASHRAE is 75F and 50% relative humidity http://www.coolerado.com/wp-content/uploads/2012/03/Coolerado-IP-0ft-Ledger-11x17-Chart.pdf

With regard to condensation, notice the vertical scale on the right labeled Dew Point Temperature F. If your window surface is 40F you can see you would have condensation even at the relatively low relative humidity of 30%, 75F. In addition, the relative humidity at the ceiling will be much higher than near the floor. Moist air is lighter than dry air. This is shown on the chart, but is hard to pick since it is the inverse of the specific volume shown. But just think about clouds. They are high in the sky because moist air is lighter. Also, the mirror in the shower. It condenses from the top down. Again, moist air is lighter. All this to say the WifeHumidityInputMark1 may be reporting an accurate relative humidity at her eye level in spite of the skylights.

You definitely don't want to hint that the wife is wrong on this until you have the data. We all know the danger of telling the wife she is wrong when she is correct.

 

[GGorman04]

Pete,
I do have a hygrometer. What is considered high humidity in the house?
Is there certain numbers to look for that would indicate a need for a humidifier?

 

[supton]

Fatty acids? Dunno, not a dietician. I had to look that up, and I'd say, probably low on intake of that. Will ask the wife to look into that.

 

[supton]

Originally Posted By: DoiInthanon
Definitely get a humidity reader and determine the facts. More importantly, begin the process of reprogramming the problem sensor - WifeHumidityInputMark1. The sweet spot according to ASHRAE is 75F and 50% relative humidity http://www.coolerado.com/wp-content/uploads/2012/03/Coolerado-IP-0ft-Ledger-11x17-Chart.pdf

With regard to condensation, notice the vertical scale on the right labeled Dew Point Temperature F. If your window surface is 40F you can see you would have condensation even at the relatively low relative humidity of 30%, 75F. In addition, the relative humidity at the ceiling will be much higher than near the floor. Moist air is lighter than dry air. This is shown on the chart, but is hard to pick since it is the inverse of the specific volume shown. But just think about clouds. They are high in the sky because moist air is lighter. Also, the mirror in the shower. It condenses from the top down. Again, moist air is lighter. All this to say the WifeHumidityInputMark1 may be reporting an accurate relative humidity at her eye level in spite of the skylights.

You definitely don't want to hint that the wife is wrong on this until you have the data. We all know the danger of telling the wife she is wrong when she is correct.

75F? Not even my disabled FIL keeps his house that warm! We bump the temp to 68 for a couple hours out of the day (6-7am, and 8-9pm), 66 during the day, 64 at night. Outdoor temps right now are in the 30's during the day, below that at night (it is almost winter after all), with lots of 20F and colder weather to come.

 

[Quattro Pete]

Originally Posted By: GGorman04
Pete,
I do have a hygrometer. What is considered high humidity in the house?
Is there certain numbers to look for that would indicate a need for a humidifier?

In the winter, I try to keep mine between 30% to 50%, but it varies with outside temps, as other have mentioned. If you're significantly below 30%, I'd say that's too dry.

 

[wymi516]

We keep the heat on a constant 68 degrees all winter. I try to keep the humidity at 30%. Anything more and the windows get moisture.

 

[SF0059]

Originally Posted By: SHOZ
Anything over 50% is getting to be too much.


This is correct. 50% and above can promote black mold growth. 35-40% is optimal. As others have said, measure it before buying a humidifier. Remember, during the winter months often times chapped skin and nosebleeds are due to outdoor exposure, not your living environment.

Our house was equipped with a humidifier hooked up to the central blower. I have never used it. In fact, to keep 35% I have dehumidifiers in both the basement and second floor.

 

[SF0059]

Originally Posted By: DoiInthanon
More importantly, begin the process of reprogramming the problem sensor - WifeHumidityInputMark1.


Wife-o-meters are notoriously fickle instruments!

 

[Papa Bear]

As we get older we need more humidity too. I keep the house here near 50%.

Less than that and I start cracking .....

 

[cchase]

Keep in mind that everyones comments on how they're maintaining proper humidity in their houses will vary widely depending on where in the country they live.

Interior New England is BONE dry in the winter. Even if you're getting condensation on the windows I would wager your house has extremely low humidity. Our humidity levels have already dropped below 15% this year in the house. Our humidifier in one room only will use over 1.5 gallons per night just to maintain a good humidity level of 40-45%.

All you need to get condensation on windows is an air leak from the outside or just a high temperature differential on both sides of the glass. Having regular, non-insulated glass, especially near heater outlets/radiators will only make the condensation problem worse. My point is that even though humidity in your house may be very low, it may be saturated on that 1" space near windows.

 

[DoiInthanon]

As many have noted, their house is moist in the winter and they don't use their humidifier. Others report dry indoor conditions in the winter.

This is a result of infiltration. Normal activities in a home generate significant water vapor. Kitchen, laundry, bathing, and floor cleaning activities will quickly saturate an air tight home. If just enough outdoor air displaces the warm moist indoor air, your humidity level remains comfortable. If excess outdoor air enters, indoor humidity is low.

All of us could save energy costs and have better control of indoor humidity by locating and sealing air leaks in our homes. Some good webpages found on Gary Reysa's BuildItSolar:

http://www.builditsolar.com/Projects/Conservation/Insulation/AirSealing26448.pdf

http://www.oikos.com/library/airsealing/index.html

http://www.michiganenergyoptions.org/component/content/article/95-weatherization-guide/250-air

I don't know Gary personally, but in my opinion, he is a person that has made more difference in the energy conservation arena than any other. All of his work is geared toward providing free information for all to use. Truly a man giving back to mankind with only the knowledge of a job well done as his reward. A hero in my book.

 

[Rolla07]

Yeah I wouldnt jump to conclusion to say nosebleeds and dry skin is from air being too dry. My apartment is insanely humid (bad for mold) I run my dehumidifier and keep the air around 35-40% humidity. It keeps it dry and warm in winter. I wish it didnt blow out hot air, because it would help keep humidity lower in summer, but because it shoots out hot air.. its not so beneficial in summer. Get a cheap room humidity meter and check it. I think 30-50 is normal. I would keep it on the low end if possible. 30 to me is my ideal humidity.