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hvac:dehumidifier [2020/03/25 14:42]
frater_secessus [insufficient humidity] |
hvac:dehumidifier [2020/10/11 19:48]
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| ====== Humidity ====== | |
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| Relative humidity of 25%-60% is generally comfortable for humans.((https://en.wikipedia.org/wiki/Humidity#Human_comfort)) ((https://en.wikipedia.org/wiki/Thermal_comfort#Relative_humidity)) | |
| ((https://www.engineeringtoolbox.com/relative-humidity-d_895.html)) | |
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| ===== excessive humidity ===== | |
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| **Excessive humidity** is a common challenge for vandwellers. It can cause mold/mildew, damage to electronics from water condensate, discomfort, wood expansion, and diminution of insulative properties of items like sleeping bags. | |
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| Common causes of high humidity / condensation include: | |
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| ==== full-time habitation ==== | |
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| Humidity due to constant habitation can be reduced with increased ventilation, as with [[hvac:roof vent|roof vent]], assuming exterior humidity is lower than that of the interior. | |
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| [[http://amzn.to/2Dy19L3|Window vents]] can be used to crack windows without allowing rain in. | |
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| A "sacrificial window" may work as an unpowered option.((http://www.cheaprvliving.com/forums/Thread-Condensation-AGAIN?pid=109944#pid109944)) | |
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| Relocation to a drier climate sounds like a severe response, but [[camping:snowbirding|snowbirds]] often follow comfortable weather. | |
| ==== fossil fuels ==== | |
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| Humidity due to use of [[fuel:propane]] or [[fuel:butane]] can be reduced with increased ventilation, reduced cooking/heating times, and the use of more efficient propane appliances to reduce overall consumption. | |
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| ==== cooking ==== | |
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| Water vapor is often released during cooking, most visibly during a boil. Methods to reduce the production of water vapor include: | |
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| * covering anything that steams: pots, cups, etc. | |
| * reducing beverage temperatures if appropriate - coffee requires near-boiling temperatures but most other hot beverages do not. Green tea is generally steeped at 160F and black tea at 190F. | |
| * reducing food reheating temperatures if appropriate. Already cooked commercial foods (canned or bottled foods) do not need to be boiled. | |
| * reducing water temperatures for drinking water sanitization if appropriate. //Boiling// is the traditional method but this has more to do with knowing the water temperature without a thermometer. For comparison, milk is pasteurized at 161F for 15 seconds or 145F for 30 minutes.((https://en.wikipedia.org/wiki/Pasteurization#Process)) Enteric bacteria, spores, and viruses are killed by sufficent time at 160F.((https://academic.oup.com/cid/article/34/3/355/388050)) If using **boiling as a reference point**, merely bringing the water to the boiling point is more than sufficient and holding the boil is "excessive".((https://academic.oup.com/cid/article/34/3/355/388050)) There is nothing magic about boiling. | |
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| ==== dehumidifiers ==== | |
| Products containing calcium carbide ([[http://amzn.to/2DXyiNO|DampRid]], etc) or silica gel ([[http://amzn.to/2DoJDpg|Eva-Dry]], etc) may help control excessive moisture, particularly in very small or confined areas. | |
| [[http://amzn.to/2h8QeIO|{{ https://images-na.ssl-images-amazon.com/images/I/41j242B4RdL._AC_US160_.jpg}}]] | |
| Some silica gel units can be "refreshed" by plugging them into a 110v socket whenever the color indicator advises. This gently heats the gel and drives off the moisture, so do this somewhere other than your camper!((https://www.eva-dry.com/frequently-asked-questions)) | |
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| Eva-Dry units are named after the cubic feet of space they are designed to handle. Example: the | |
| [[http://amzn.to/2DoJDpg|E-500]] is made for 500 cubic feet, approximately 8x8x8'. Units larger than 500 are peltier or some other non-chemical technology. | |
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| In some cases [[http://amzn.to/2h8QeIO|an electric dehumidifier]] may be necessary. Bitty recommends [[http://amzn.to/2gWtXyB|the Eva-dry Edv-1100]].((http://www.cheaprvliving.com/forums/Thread-Condensation-AGAIN?pid=109733#pid109733)) Some users drain the receptacle into a sink or other drain.((http://forums.sailboatowners.com/index.php?threads/12v-dehumidifier.167895/#post-1170395)) | |
| Eva-Dry confirms the [[https://www.eva-dry.com/dehumidifiers/edv-12v-power-cord/|12v adapter for this model]] passes 12v and not 9v;((https://boondockplan.wordpress.com/2016/12/06/eva-dry-12v-humidifadapter/)) this should make it easier to wire from [[electrical:12v:intro|house power]]. | |
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| Peltier devices are power-hungry and run constantly; the dehumidifier might best be used as an [[electrical:solar:nonessential|opportunity load]]. | |
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| Video: [[https://www.youtube.com/watch?v=_hH-8KqQtys|teardown of a typical peltier dehumidifier]] | |
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| ===== insufficient humidity ===== | |
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| In some very dry regions humidity may be too low (=<20%)for comfort. Evaporative coolers or ultrasonic misters may help improve the interior humidity. | |
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