 Posted 3/29/2007 7:37:40 AM
|
|
|
|
| The subject pretty much says it all. I'm wonder if this would be worthwhile. I have a Santa Fe Advance, and during the day the outside air is dry enough to "help" with the crawlspace moisture (the dehumidifier cycles), but at night when the humidity outside goes up, the unit will run continuously at some point. I was wondering about ducting one of the vents and blowing the dehumidified air into the crawlspace. Of course more work is required to dehumidify this air when it is moist outside, but the dehumidified air would also actually displace the moist air in the crawlspace and prevent other air incursions. With the input at 100% R.H. and 70 degrees, any idea what the temperature and R.H. of the output would be? Of course, if this is just a bad idea, then that's good answer also, but if the output above is anywhere near 50%, seems like it might work.
|
|
|
Posted 3/30/2007 11:46:59 AM
|
|
|
|
| The measurement of moisture in the air is dew point, grains, or lbs. of water per lb. of air. %RH is amount of moisture the air is able to hold at a specific temperature. An example is 70^F, 100%RH has the same amount moisture as 90,^F, 50%RH. The dew point is 70^F, 112 grains, or .016 lbs. of moisture per lb. of air. The reason the dehu operates more in the evening is cooling of space which elevates the %RH. The control on the dehu responds to the increase in %RH. Usually the water content of the air has more to do with the weather system than time of day. Feel free to respond if clear. Thanks Ken
|
|
|
Posted 4/4/2007 10:41:35 AM
|
|
|
|
| It was just a thought. I was wondering if the Advance could dehumidify moist air from outside enough so that the output would be dry enough for the crawlspace. On the surface, this seems like it's silly since the crawlspace is often dryer than it is outside, but the dehumidifier comes on because it has become damp. Rather than dehumidify the air in the crawlspace, it seemed possible to simply blow it out and replace it with dehumidified air from another source. This also would prevent damp air from coming in other openings into the crawlspace since it is now "pressurized". On the other hand, if the Advance is going to take 70F, 100% RH air from outside and output (for example) 80F, 60% RH air, then of course this won't work. The output would need to be in the 30-40% RH range or even lower for me to even consider trying it.
|
|
|
Posted 4/4/2007 12:17:08 PM
|
|
|
|
rb1 (4/4/2007)
It was just a thought. I was wondering if the Advance could dehumidify moist air from outside enough so that the output would be dry enough for the crawlspace. On the surface, this seems like it's silly since the crawlspace is often dryer than it is outside, but the dehumidifier comes on because it has become damp. Rather than dehumidify the air in the crawlspace, it seemed possible to simply blow it out and replace it with dehumidified air from another source. This also would prevent damp air from coming in other openings into the crawlspace since it is now "pressurized". Sometimes this would work. Usually less operation required by removing moisture from the space when humid. Moderate wind makes a crawlspace breathe despite pressurization. Air flowing through a dehumdifier has a 10-12^F dew point reduction. That's not enough with +60^F outdoor dew points. With lower outdoor dew points, no dehumidification is required. On the other hand, if the Advance is going to take 70F, 100% RH air from outside and output (for example) 80F, 60% RH air, then of course this won't work. The output would need to be in the 30-40% RH range or even lower for me to even consider trying it. 70^F, 100%RH, 70^F dew point in equals 90^F, 30%RH, 57^F dew point. After that air cools to the crawlspace temperature of 75^F, the % RH is 51%RH. This is more dehumidification than recirculating inside air and maintaining 50%RH. You could try it and report your findings. Thanks for the post. Keep us posted. Ken
|
|
|
|