Sizing a Dehumidifier for a Gunroom

[spur0701]

I'm nearing completion of my new gun room and want to install a dehumidifier (I posed previously here on ideas for the floor: http://www.thehighroad.org/showthread.php?t=763686&highlight=gun+room+floor )

So there is a sealed drain to the sump in the corner of the room and I want to install a dehumidifier that will handle the whole room, which is about 400 square feet and will empty into that sump. It seems like most new ones are energy star compliant which is good but my question is how large of a unit should I get? They seem to range from 30 pint to 70 pint units are are priced accordingly. I was just going to go with the largest one, say a 70 pint but then saw somewhere on the net that such a large unit would probably cycle too frequently in that small a space given that I'll want to humidity at say 40%. Anyone run into something like this already and have any lessons learned? Any particular brands I should avoid? Would like something not too loud. I looked at Consumer Reports but the ones they recommend get crappy user reviews. Any help is appreciate.

 

[Steel Horse Rider]

How much humidity do you have present in the room? If the humidity is naturally below fifty percent I would not use a large unit. 30 pints per day is a lot of moisture and 400 square feet is not very large. If you have high humidity where you live (I would rate high humidity as above seventy percent) and the room is not well isolated then you might consider a slightly larger unit but if you normal house humidity is below fifty percent in the summer you are probably okay with the small unit.
I am a refrigeration contractor so I am somewhat familiar with loading, just FYI.

 

[oneounceload]

You should be looking at cubic feet, not square feet. 400 sf with a 7' ceiling is different than 400sf with a 10' ceiling. Then measure your current humidity and determine what size unit you need.

 

[Sauer Grapes]

I run a 30 pint in my basement where I do my loading. Pretty humid w/o the dehumidifier. Area is about 200 square feet. Typical basement ceiling height.
Doesn't use much electric and keeps the humidity level around 60 %.

 

[ColtPythonElite]

My basement is 1000 square feet, has a sump pump, and occasionally gets a trickle of water here and there. A 40 pint unit keeps it at about 40%. My reloading gear, a pile of motorcycle parts, tools, and all kinds of metal stuff is down there. In 20+ years, I haven't had a speck of rust on anything.

 

[Damon555]

A 30 pint will work fine for that size room. I use one for a room of similar size that can get quite humid in the summer...If you are going to have it drain to the sump you need a unit with a hose connection. So make sure it comes so equipped.

 

[ColtPythonElite]

My understanding is the number in pints is not the reservoir size....It is the number of pints the unit can remove in 24 hours.

 

[Damon555]

My understanding is the number in pints is not the reservoir size....It is the number of pints the unit can remove in 24 hours.

Thanks for clarifying.....I misunderstood how they specify the efficiency of a dehumidifier.....makes sense to me. I'll edit my post accordingly.

 

[rcmodel]

40% is too low.
Too low will shrink & crack wood stocks.

You need to buy a cigar box hygrometer and find out if you even need a dehumidifier.

http://www.amazon.com/Xikar-xi833-R...11?s=furniture&ie=UTF8&qid=1424280445&sr=1-11

50% at 70 degrees is 'museum grade' storage conditions according to the NRA National Firearms museum.

rc

 

[Steel Horse Rider]

RC: Here in Colorado our natural humidity in the winter is under 20%. I have over 40 rifles and none of them have developed cracks in the stocks as long as I have owned them. I do believe that a rapid change from above 50% humidity to 20% or below might cause shrinkage cracks to form but I do not believe that being in less than 50% humidity would cause damage as long as the wood is also near that percentage.

 

[rcmodel]

Probably true, if that's your natural humidity conditions.

I lived south of Colorado Springs on 115? Highway while I was stationed at Ft. Carson.
Very dry, and no problems with stocks once they attained normal humidity there.

But, problems can occur if stored very dry, then taken out in high humidity to use them.

Best to split the difference and store at 50% if you can.

If you live in a very dry climate, there would be no need for a dehumidifier in the first place.

rc

 

[Drail]

I would advise you to purchase a good humidity gauge first and see what level of humidity you have now. I have been able to keep my guitar room at 45% with a fairly small humidifier for many years. You just have to carefully monitor the level constantly. Then I moved into a house in another state and found I had to buy a dehumidifier because moisture was too high. As Steven Wright used to joke - "I want to put them both in the same room and let them fight it out".