Givat Posted March 11, 2011 Posted March 11, 2011 Hi all,I bought on Ebay 2 peltier chips for use as dehumidifier in a drying box for pyro.before I'll start building this project I want some advice on the plan: Any one had any experience building a dehumidifier for drying box? givat.
oldguy Posted March 11, 2011 Posted March 11, 2011 (edited) Peltier chips get hot on one side & cool on the other.For a dryer, that would seem to be sort of self defeating.Same goes for having a drip catcher inside the box. MY BIG BERTHA DRYER You can often find ready made "dehydrators" at thrift & second hand stores, craigslist, garage sales or ebay cheap.The ones with adjustable tempurature settings are best.Works like a champ. A heating pad for plant starts raises temp 20 degrees over ambiant. So does a so called "hot rock" for reptiles cages.Either of those or a chicken brooder type light bulb & a computer fan, in any sort of box with wire mesh shelves works fairly well. All a dryer requires is a slightly vented box, screen shelves, a safe slight heat source & a mild little fan to move the air.Toilet flush simple to build. Edited March 11, 2011 by oldguy
dagabu Posted March 11, 2011 Posted March 11, 2011 I'm with you old guy! The best part is that I keep mine outside in an insulated plywood box so if it goes up, it just burns. They are the best to dry stars with hands down.
oldguy Posted March 11, 2011 Posted March 11, 2011 (edited) I had planned on cutting a 55G steel drum in half the long way.Then hinge the halves so it will open with ease & is slightly vented.Then setting big bertha inside it. As for now, I just run it on a concrete slab that has a metal roof over it.So, if it goes, it cannot damage much besides leaving a smoldering pile of melted-burnt plastic. I might add, not sure if Givat is in the USA.Dehydrators can be tough to find sometimes in other countries. But, they are not tough or expensive to build. Over a span of a month, I found several of the same type dehydrators at thrift stores cheap.I bough 4, that is why I have so many racks. If I am in a rush to dry anything.I invert another base blower-heater unit upside down at the top of the racks.So, bottom 1 blows up, top 1 blows down.Racks are not air tight, so no need for a vent.The slight positive pressure vents itself. Edited March 11, 2011 by oldguy
Mumbles Posted March 11, 2011 Posted March 11, 2011 Oldguy, I think you missed the point. The cold side is inside the box, and the hot side is located outside of the box where that heat sink and fan are. It looks pretty good to me. I would potentially move the peltier chip to the bottom of the box to avoid the dripping problem, but then of course you get worse airflow to cool it. With the fan that may not be an issue You may want to consider using a funnel and tubing to just route the water outside of the box instead of storing it somewhere. To me, warm airflow is more important than dehumidification. I've been using a modified version of the box on Skylighter. A hole cut in the side of a large plastic container, screens stacked inside, and a ceramic heater blowing in warm air. It can dry most cut stars, lift, break, etc in a day or so. Larger charcoal streamer cut stars and large comets can take up to about 3 days. I only make comets up to 2" most of the time, but I bet that if I had larger comets they'd take a bit longer, maybe a week.
oldguy Posted March 12, 2011 Posted March 12, 2011 Mumbles, I see what you are saying. With all due respect, at the same time nothing more than a heat source, fan & vented container is required to dry things.I don't think the peltier would add much efficiency to that.But, since he has one, nothing wrong with using it. A little Pelonis ceramic disc heater with an internal fan & thermostat will heat a 4X4X9 ft closet sized dehydrator very well.They are safe, energy frugal & will last a decade or more.
Kaokin Posted April 7, 2011 Posted April 7, 2011 I am building a drying box also, Has anyone experienced fires or explosions with these dehydrator units? It seems like the heating element is completely exposed....
WSM Posted April 9, 2011 Posted April 9, 2011 Here in drier climes (the Southwest US), dryer boxes are made from a metal cabinet fitted with shelves for screens, a baffled fan and vents. The outside can be painted flat black to take advantage of solar heating (to great advantage). Everything dries very fast in these things. They can be run out in a field at the end of a long extension cord or, better yet, in a pit or behind an earthen berme for greater safety. Turn the power on and off remotely for the same reason. WSM
DeepOvertone Posted May 30, 2011 Posted May 30, 2011 I like the dehumidifier. In louisiana, just having a heater would not dry things as efficiently as if the air was also being dehumidified. It can get to 100% humidity down south so it would be hard for the air to pull that much more moisture out of the stars despite the extra heat raising the water holding capacity of the air. I think its a really good idea if you can get it to work well.
garethjones Posted August 2, 2011 Posted August 2, 2011 (edited) I am building a drying box also, Has anyone experienced fires or explosions with these dehydrator units? It seems like the heating element is completely exposed....<br><br><br>I had an experience overheat but not any explosion...<br><br><br><br>url=http://www.cnmonline.co.uk/Dehumidifiers-c-778.html]Dehumidifier[/url]<br> Edited August 2, 2011 by garethjones
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