Humidity confusion

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Old 11-30-15, 06:47 AM
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Humidity confusion

I'm confused. Typically in the winter, the colder the temperature the dryer the air. So to keep the feel of the home more comfortable and help preserve the furniture joints I add moisture to the air via humidifier. However, my humistate (spelling?) dial says to provide less humidity to the home as the temperature outside gets colder.
Explain!

 
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Old 11-30-15, 07:18 AM
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Sorry Norm, these old eyes can't read all the instructions to the right. Can you type out what it says?

Bud
 
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Old 11-30-15, 07:50 AM
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I would suppose they mention the OUTSIDE temperature because if you don't turn your humidistat down, your windows will be dripping with condensation otherwise.
 
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Old 11-30-15, 08:24 AM
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I have never owned one, but I always thought the idea was to "set it and forget it". Generally you want your indoor humidity to be around 40-45%. Set your humidistat to that level and it will turn the humidifier on and off as nessicary to maintain that level inside the house, regardless of the temperature.
 
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Old 11-30-15, 08:31 AM
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Sleeper has it correct.

This is what is found on most mechanical humidistats.

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Old 11-30-15, 08:42 AM
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Don't worry Keith... most homeowners think that way, which is why we get so many people asking questions about why their windows fog up and sweat during winter months.

I especially like the questions where they insist on keeping the humidity at 50% because otherwise their skin gets dry (waah!) or the wood floors get creaky, but then they also insist that there MUST be some way to keep the windows from sweating! There is- turn your freakin humidistat down like the mfg. says to! LOL
 
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Old 11-30-15, 09:08 AM
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The newer electronic h'stats have outdoor temperature sensors and are completely automatic.
 
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Old 11-30-15, 09:37 AM
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I have to ask, based on that chart above, if the outside temp is -20F, and I set the humidistat at 15%... well, what is the point of having a humidifier if the relative humidity in the house is only going to be 15%? Isn't the whole point to maintain a comfortable relative humidity at room temperature in the house?
 
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Old 11-30-15, 10:05 AM
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If it's that critical to maintain high humidity in ultra low outside temps then good insulation and excellent windows are required or the condensation will be a problem.
 
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Old 11-30-15, 10:09 AM
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To put Pete's answer a different way, it's a compromise - unless your home was specifically built to handle it, you won't be able to run those 'normal' humidity levels at extreme low outside temps without encountering issues with condensation.
 
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Old 11-30-15, 10:45 AM
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Yes, I understand the condensation concerns, but with newer construction, that seems to be less relevant. I am right on the Atlantic coast, so we are usually more concerned about dehumidification than humidification, so I am less familiar with centeral air humidifiers.

I guess to me it seems pointless to have one if you have to live with 15% humidity in the winter anyway... I do see the benefit in warm and dry climates.
 
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Old 11-30-15, 10:46 AM
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what is the point of having a humidifier... Isn't the whole point to maintain a comfortable relative humidity
Keith brings up a good point. Humidifiers are STUPID.

I have never walked into a room and thought to myself... "Gee, you know what this house needs? More humidity!!!" I haven't noticed a house being more comfortable one way or another. But I can certainly tell when a house is too humid as soon as I walk in. Like a freakin rain forest. Sorry, I suppose some ppl here make a living off of selling the blasted things.

Seems like this is one of my hot buttons. LOL
 
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Old 11-30-15, 11:08 AM
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OK. I understand the idea of the house being properly built for humistate controller and using outside temps as a trigger. Just as Stickshift, PJ and Xsleepeer have explained.

In my case the controller and sensor have been located on the cold air return as it enters the main furnace plenum. The water is piped to the media where it is sucked or drawn into into the warm air plenum of the main section to be distributed to all parts of the house. The sensor is reading the return air condition and supplying moisture accordingly or as I have it set at 35% or there about.

Keith makes a good point about how it should be automatic, "set it and forget it". My controller/sensor should be on the 1st floor so that I can at least reset as temps change. But if I use my indoor temp, say 67 degrees as a steady set point then I suppose it reads that temp for the most part and is OK or near as automatic as possible. Truth be told I forget about it no matter what the setting is.

Xsleeper also makes a good point about how people set it way too high and then complain about excessive moisture. Fortunately my home was originally built as an all electric back in the 1970's gas moratorium and is well insulated (later converted to gas). That and along with my new windows I don't have a sweating problem. Only during showers or baths or if there is a large crowd of people during a very cold day.

On a side note. I've had my humidifier for the past five years now and it defiantly makes a big difference in comfort and furniture not creaking and losing glue joints. This will be my first winter with the new windows. I'm hoping the 2nd floor will be a bit warmer because of them.
 
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Old 11-30-15, 11:15 AM
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I had intended to move to Phoenix at a point in my past and can recall a day in the summer when I was there where the RH was 9%. I thought that was fantastic. Yeah, I agree, who needs a humidifier anyway?
 
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Old 11-30-15, 11:34 AM
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I would love to live in a area with 9% humidity!! I deal with 90-100% for most of the year, and I can tell you, it is not plesent, espcially when the temp is over 100F!!

Didnt mean to hijack the thread, I just never understood the point of humidifiers (except certain cases), especially if you have to constantly adjust it.
 
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Old 11-30-15, 11:43 AM
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Didnt mean to hijack the thread, I just never understood the point of humidifiers (except certain cases), especially if you have to constantly adjust it.
Don't worry about it. I do it all the time!

As you say, in certain areas it makes a big difference. Almost everyday during the winter months I have customers coming in asking for a good quality glue for their chairs and furniture that won't dry out. The first thing I ask them is if they have a humidifier. In most cases they don't. I also ask them if they wake up with a dry scratchy throat. At the very least I tell them to put damp cloth with a water reservoir over their heater vent to add moisture. A few have come back and Told me it worked and they are feeling a lot better.
 
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Old 11-30-15, 11:44 AM
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Try living in a house with a woodstove. Before getting a cast iron pot to keep on top filled with water, my wife and I were constantly zapping each other every time we walked by each other.

If we had carpeting I'm thinking it would be even worse.
 
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Old 11-30-15, 12:00 PM
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Oh, man - I forgot we're coming back to the season where my daughter walks around to build a static charge and then zaps me.

Maybe I do need a humidifier....
 
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Old 11-30-15, 12:02 PM
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I love zapping the dog. Right on the nose tip.
 
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Old 11-30-15, 12:05 PM
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A self adjusting humidifier with an external temperature sensor makes sense, but it would still not be a perfect system since it can be 40F one day and 0F the next... it seems that it would always be at least day behind as far as the air quality is concerned.

But it would clearly be better than a manual adjustment that no one ever makes.
 
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Old 11-30-15, 12:12 PM
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I love zapping the dog. Right on the nose tip.
I'm pretty sure our dog would just tear my hand off if I did that.
 
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Old 12-03-15, 03:07 PM
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He sure is a beauty!!!!!!!!!! and he looks good and healthy.
 
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Old 12-03-15, 06:05 PM
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I service these systems and still have a plain old humidistat for my humidifier. I don't set it by the %..... I set it by the feel in the house. I change it slightly almost every day. I keep it on the low side. A little extra humidity is a good thing. Static electricity as well as dry throat at night are two reasons.

Many people here as well as some of my customers insist upon 30%-35% +. Not needed to be that high.
 
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Old 12-03-15, 06:28 PM
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Pete, correct you are. I keep mine at the 35% range but only because it's in the basement and a pain to go and change it every day or as the temp changes. But you make a good point about the scratchy throat problem. Haven't had that since putting the humidifier.
 
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Old 12-06-15, 10:59 AM
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The proper amount of moisture needed for winter is where there is a small amount of moisture present in the corner of the windows.
Too much and the warm, moist air will overcome the thermal barrier inside the insulation inside the walls and change from moisture to liquid water at the dew point. (This can lead to a mold growth inside the walls).
Too little and building materials shrink (esp. wood).
Adding small amounts of humidity to the air will make the home "feel" warmer as well, because it takes longer for sweat to evaporate. (Which of couse is the difference why we feel so miserable when then temperature is 80 with 50% rh vs. 80 with 25% rh.) Adding humidity allows the thermostat to be turned down and still feel comfortable.
You certainly can use a "set and forget" process of winter humidity, just decide of what the outside temperature is expected to drop to during the night and set accordingly. At worst, you will run low, but running low humidity is better than running high.
The best process is to adjust as needed.
 
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