Trailer Vented With Furnace On?
DW thinks opening vents or windows with the furnace on will help cut down on condensation. I'd just as soon close it up tight & not lose the heat. Aaaand, discuss....
Forum Discussion
- It's simple. For the same amount of moisture, the relative humidity is higher with colder air. With the furnace off, at high RH moisture condenses everywhere. With the furnace on, it warms interior surfaces and it condenses mostly on the exterior walls/windows. A standard RV furnace doesn't add any moisture to the air, and in fact lowers the RH. What does happen is that it condenses on a much smaller area, so may be more obvious.
mike-s wrote:
Chuck and Di wrote:
Tain't got nothing to do with nothing. I asked where the additional moisture came from.mike-s wrote:
darsben1 wrote:
Bzzzzt. Wrong Answer. I'll claim that the OP breathes whether the furnace is on or not.
RESPIRATION IS THE ANSWER to your question.
Mike, you need to get your buzzer fixed. Google is your friend.
People breathe out lots of moisture.
To be fair, yes you did ask where the additional moisture comes from.
Realistically, there likely isn't any additional moisture - it is moisture that is there all the time. Ambient humidity in the air, moisture from living in the trailer. But a few things are different in the colder temps than in the warmer ones.
During colder temps:
1. You generally have the windows closed, so moisture that is generated can't escape.
2. The cold windows and walls are where the moisture condenses. This doesn't happen in warmer temps because there is much less difference between the air temp and the windows and sides of the trailer.
3. In the hot summer, people run their air conditioners which can cause a big difference in outside air and inside temps, but the A/C removes a lot of the humidity - which is why air conditioners generate a lot of dripping water from the roof.
So while there may not be a lot (or any) sources of additional humidity/water in the winter, the humidity that is present all the time is much more problematic in the winter because it condenses on the cold interior surfaces of the trailer like windows, walls, and especially behind cabinets and wardrobes that have little air circulation and the heat doesn't get to as readily.Chuck and Di wrote:
Tain't got nothing to do with nothing. I asked where the additional moisture came from.mike-s wrote:
darsben1 wrote:
Bzzzzt. Wrong Answer. I'll claim that the OP breathes whether the furnace is on or not.
RESPIRATION IS THE ANSWER to your question.
Mike, you need to get your buzzer fixed. Google is your friend.
People breathe out lots of moisture.mike-s wrote:
darsben1 wrote:
Bzzzzt. Wrong Answer. I'll claim that the OP breathes whether the furnace is on or not.
RESPIRATION IS THE ANSWER to your question.
Mike, you need to get your buzzer fixed. Google is your friend.
People breathe out lots of moisture. If you sit in a camper or car with no heat on - the walls, ceiling, furniture, everything will get covered in frost in a couple hours. Cold air can't hold as much moisture, so it will condense (and freeze) immediately and fall, stick, or blow wherever. If you've ever been outside on a calm winter day, you'll see that frost on your clothing near your face.
Warm the temperature up, and the air holds that moisture and it does not end up on anything. Cool the moist air (like on a cold wall or window) and the moisture will condense on the cooler surface.
Venting the camper pushes that moist air outside and replaces it with drier air. You'll still have condensation - just less of it.GordonThree wrote:
That's first I've ever heard about co2 build up being a problem in an rv. I'd be astonished that Elkhart builds any brand with a fit and finish so precise that it's literally air-tight.
It can be an issue if you're using a propane catalytic heater - not so much if you're using the furnace. "Fresh air" can be desirable for other reasons besides humidity and CO2 though - odors.- That's first I've ever heard about co2 build up being a problem in an rv. I'd be astonished that Elkhart builds any brand with a fit and finish so precise that it's literally air-tight.
- Open vents and use exhaust fans when showering or cooking. Use a dehumidifier to remove other moisture, conserve heat.
There is no difference how much moisture a body produces through breathing related to temperature, there is relative to humidity. Our exhaled breath is near 100% , regardless of what the relativy humidity of the air inhaled.
In the 4 winters we overwintered in Canada our dehumidifier averaged 4 quarts of water a day, with venting shower and cooking moisture, we never had condensation on windows or doors, in walls.
Cold air is drier, so outside humidity is not the issue, what you produce is, will condense on any surface colder than its dewpoint.
Invest in a hygrometer to measure your indoor humidity, keep it below the outdoor dewpoint.
Max - Go for it, that wooden post might even believe you. ;) :)
Boon Docker wrote:
This I believe.Huntindog wrote:
mike-s wrote:
How things work, part two:darsben1 wrote:
Bzzzzt. Wrong Answer. I'll claim that the OP breathes whether the furnace is on or not.
RESPIRATION IS THE ANSWER to your question.
Ever noticed how much faster water evaporates on a hot day? Or how slowly it does on a cold day?
That is what happens when you breathe in a warm TT vs a cold TT.
So yes, you DO breath out more vapor on a hot day...(ever noticed that you get thirsty faster on a warm day? It isn't all due to sweat) You just can't see it. This DOES increase the humidity level in a heated TT.
The air expelled from your lungs is always saturated with moisture.
So what you are saying is the air you expel on a hot day is over saturated.
I hope it never gets above 110f, I'm afraid of drowning. :B
I am done. Gonna go talk to a wooden post now... It has a better chance of learning than some here do.Huntindog wrote:
mike-s wrote:
How things work, part two:darsben1 wrote:
Bzzzzt. Wrong Answer. I'll claim that the OP breathes whether the furnace is on or not.
RESPIRATION IS THE ANSWER to your question.
Ever noticed how much faster water evaporates on a hot day? Or how slowly it does on a cold day?
That is what happens when you breathe in a warm TT vs a cold TT.
So yes, you DO breath out more vapor on a hot day...(ever noticed that you get thirsty faster on a warm day? It isn't all due to sweat) You just can't see it. This DOES increase the humidity level in a heated TT.
The air expelled from your lungs is always saturated with moisture.
So what you are saying is the air you expel on a hot day is over saturated.
I hope it never gets above 110f, I'm afraid of drowning. :B
