DIY: Build Wall Closet to Control Humidity

[joeguam]

I live in Guam, USA where the external humidity never drops below 70% and where it rains frequently (100%). I had the unfortunate experience of watching the top of one of my curly koa ukuleles swell up in a matter of seconds right before my eyes when sudden rain dropped with a temperature of about 88-90 degrees. I was outside playing music with the family and the koa top swelled so much that it cracked right by the bridge pretty bad. As a result, I have now become crazy about humidity control.

I prefer to have my 5 ukes and 7 guitars out of their cases and either hanging on the wall or on stands. I purchased a dehumidifier for $250 from Home Depot but this is not a sustainable solution as it pulled over 5 gallons out of the air in the room in a span of about 10 hours - with all doors and windows sealed. The power that this machine required will cost over $100 a month to run! When the A/C is running, humidity lowers to around a perfect 50%, however, with the cost of power on Guam, running the A/C 24-hours a day is not reasonable (it would be over $500/month!).

I would like to build a WALL CLOSET/CABINET to accomplish the following things:
1. Create a smaller space to control humidity and temperature (significantly less expensive)
2. Prevent from having to take instruments in/out of their cases which will promote the increase of playing hours
3. Provide a visually pleasing display of all instruments on the wall

When we're home, the A/C is on (humidity controlled) and the wall cabinet can remain open. However, when we leave for work and turn the A/C off, I'd ideally close the wall cabinet, turn on the dehumidifier to just control the RH in the wall cabinet.

Here is my initial thoughts for a design:
Length: 12 ft (1 ft per instrument hanging vertically)
Height: 4 ft
Depth (from wall): 1 ft
Doors: Open vertically (like the hatchback of a station wagon) to latch/lock to the ceiling - this way it does not take up any space in the room when open.

My questions are:
1. What's the best (and reasonable costing) material to build this cabinet to keep out humidity? Plywood? MDF? PVC? Specific types of any of these?
2. Should I line the inside of the cabinet with any material? Carpet? Insulation?
3. What dehumidifier should I use to control the RH in the cabinet?
4. Any suggestions on increasing/decreasing the dimensions?

Any help would be greatly appreciated!

Sincerely,
"Constantly fighting water in the air"
Joe

[dhalbert]

I am not any kind of expert but I'm thinking the following:

1. The material of the cabinet does not matter as long as the interior is air-tight. You want it to be dimensionally stable so that the doors don't warp or gap as the humidity changes. So plywood or particle board as opposed to solid wood would be better.

2. You can line the interior with something waterproof: sheet plastic, house-wrap (e.g., Tyvek), etc. You could put carpet, etc. over that to make a nice cushy interior.

3. Put some kind of weather-stripping, rubber molding, refrigerator gaskets, etc. on all the door edges to seal it up.

4. A powered humidifier is going to give off heat, so you don't want to seal it inside the cabinet: the temperature will rise rapidly. Maybe you can use a passive dehumidifier like a bucket of rice or silica gel.

I think you could convert an existing piece of furniture (free-standing Ikea-style cabinet, bookcase with doors, etc.) by lining the inside and putting molding and weather-stripping on the doors.

Without constant checking, the interior could get to be mold/mildew city if the humidity gets too high.

I think maybe you need to fall in love with carbon fiber guitars.

[joeguam]

Thanks for taking the time to respond!

1. I think I'll go with the plywood on this one.
2. I think I'll line the interior with fiberglass resin to seal it then cover that with carpeting to protect contact with the instruments
3. Thanks for this suggestion, I'll look into this - fairly straight forward but didn't even think about sealing the doors.
4. The humidity changes so frequently and drastically here on Guam (i.e. one day it was 72% indoors all day then sudden rain hit and it spiked it up to 88%!) that I need an automatic dehumidifier solution that will turn on/off based on the RH reading - kind of like room dehumidifiers do with their auto-shut-off features. I agree that this will not be in the wall-mounted case because of the heat, but I'm thinking about building an input/output on the side of the case ported by PVC and hoses to the output/input of the dehumidifier which would be on the floor beside it. The machine would have to be able to test the input air for RH or have a remote sensor that I could place in the cabinet. The cabinet itself will be about 48 cubic ft. (12x4x1) so from research it seems I would need less than a 10 pint dehumidifier (as this is recommended for 500 cubic ft.). Any suggestions on a dehumidifier that could solve this requirement?

Because the space in the room is very tight as it is, I specifically do not want this cabinet/closet taking up any floor space, so an old furniture closet wouldn't work. At 4ft down from the ceiling on the wall with the doors opening up and latching to the ceiling, I don't have to sacrifice any room space.

Thanks again for the info, I'll just keep thinking/researching/designing until it's the perfect build. I'm willing to go through the build effort because it's really enjoyable for me to build these things, but mostly because I owe it to my instruments.

...
Joe

[dhalbert]

You're welcome. I have a clearer idea of what you have in mind now, and have just a few comments.

If you don't want to build your own cabinets, kitchen cabinets 48" high are not common, but available (or you could get them made). 12" deep is standard. If you used multiple smaller cabinets then you wouldn't be exposing the entire insides to humid air when you opened a door. A 48" high door is a big door that might warp, and when I read about this on kitchen sites, people suggested stacked smaller doors.

The idea of the door going up to the ceiling is space-saving, but I would worry about just having door hinged in that way. If it comes down uncontrolled it could really injure someone standing in front of it, or at the very least whack a guitar. Car hatchbacks have those pneumatic pistons that keep things safe. Besides kitchen-cabinet-style doors, what about sliding doors in a track, or maybe a roll-up door (e.g. conceptually, like this)?

I have not seen any dehumidifiers with ported air vents. All the ones I know of are just free-standing units with grills. But maybe you have fancier ones for the climate.

[joeguam]

The thought of the doors coming down on my Taylor 700 series just made me reconsider the pistons or at least a supporting/locking brace to ensure the door safety. Thinking about it now, the slight space the door brace would take up in the room is minimal as compared to the safety/security it would provide.

I thought about the size of the door and the warping of the wood, but I have to weigh smaller doors against additional cuts in the wood that would allow moisture in. Hmm... I guess it wouldn't be so bad if I made sure to have weather stripping or gas kits on each door?

Sliding or roll-up doors wouldn't be an option because all the research I've done on humidity control has advised that these types of doors do not provide a good seals. The tracks in the sliding doors always allow air and moisture in/out.

I've looked around online for any humidifiers with ported vents but the only thing I could find are the whole-house humidifiers that install into central air ducts. Although this is exactly the design I need, I only need it for 48 cubic ft. and not the 5000 ft3. it supports - not to mention the $2000 price is pretty steep! It looks like for the 48 ft3., a 10-pint dehumidifier is more than enough. They have devices that are small enough to fit in the corner of the box and don't give off much heat. I'm thinking now that I'm going to just have to modify one of these devices to make a hose drain as these little ones don't usually come with that feature.

So the design and thought continues. So far I know that I'll be using plywood, I know the dimensions and that I'll be using the String Swing Rail System with a carpeted interior. I just need to finalize the door design and dehumidification system.

What are your thoughts on using two (6x4) or three (4x4) plexi-glass sheets for doors? They're light, won't warp and would also provide a nice display right? Hmm...

[ljguitar]

Hi Joe...

I know that someone from this forum, who I believe lives in Malaysia or Indonesia, did build a closet sized enclosure and even built his own dehumidifier for his guitars. He said it works well, and that it is noisy.

Boy I hope he stops in and comments on this thread.

Five gallons a day? Wow that is a lot of water in the air! There are times it is so dry where we live that I add 3-4 gallons a day via humidification. But pulling 5 gallons out of the air is really foreign to my imagination!

[joeguam]

Thanks Larry, I did a search in the forum for anything "Malaysia" and didn't find anything. Would you happen to have a better way to find the thread or the user?

Yes, 5 gallons, both me and my fiance freaked out when we had to dump the bucket into the sink! After one day of this, I immediately decided that dehumidifying the entire room was not an option and that I need to build a smaller space to control the air quality - hence this posting.

As my original post mentioned, I want the instruments on the wall so that when I'm home with the A/C on and the RH down to 55%, I can easily grab it to play even just a couple of measures. This is truly my joy. I just got a new Taylor 700 series that arrived on Guam on 12/21. To get it accustomed to the humidity, I'm keeping it in its case with humidipaks for the first 6 months. I've taken it out every day since 12/21 to play it, but only when the A/C is on and the hygrometer reads below 60% - then I put her back in her case with the humidipaks. The in/out of the case is a real drag. After 6 months, the wood will become a little more accustomed to the moisture and hopefully will live in the wall cabinet I'm trying to build.

Building custom things like this box is very enjoyable for me to try to solve these types of problems, hopefully I can figure it all out for the best design possible!

[cotten]

Not trying to dissuade you, Joe, but if I had to deal with the situation that you are, I'd opt to keep my guitars in their cases, where humidity control is far easier. Yes, it's a bit less convenient, but to me it would be more convenient and cost efficient than what you're attempting.

However, you need to know that I'm prejudiced. I live in far less difficult conditions, humidity wise, and still keep my guitars in their cases the majority of the time. I rarely leave one out on a stand more than a few hours at a time. Works for me, anyway!

cotten

[joeguam]

Thanks Cotten, appreciate you thoughts. In-case dehumidifiers are not sustainable out here. The "better" solution of the products is the Humidipaks and they don't last more than 4 months. At 12 instruments an counting, it would be more costly than to build this wall cabinet solution.

This solution is only for when the A/C is off and we're not home, I wish I could do the whole room but I would might as well just keep the A/C on 24-hr - again another solution that is too expensive.

[ljguitar]

Originally Posted by joeguam

Thanks Larry, I did a search in the forum for anything "Malaysia" and didn't find anything. Would you happen to have a better way to find the thread or the user?

Hi Joe...
Here is a link to a discussion between the member from Malaysia and another from Indonesia about building a dehumidifying cabinet (with pictures). It is from 2009.

Discussion - CLiCK

I posted the link in your other thread as well.

Hope this helps...

[joeguam]

Thanks Larry for finding that post, I actually read through that thread and just didn't realize the user was from Malaysia.

The Eva-Dry dehumidifier is actually at the top of my list right now for my design. I need a small unit that can fit in the 12" deep wall cabinet and that doesn't give off too much heat. The problem that I have is with the small water tank as I think mine will accumulate much more water while I'm away at work than this can hold. I think an easy modification to drill a hole into the tank and build a hose drain that leads outside of the case into either a larger tank or directly into a house drain.

Really appreciate all the info from the AGF users, with every post I read, I'm slowing changing my design and it's getting better and better! I'm now onto the following:

- 4' x 8' x 1' dimension
- 1" x 12" peices as frame structure
- 1/2" Plywood for the back
- 1/8" x 4' x 4' Plexi-glass or clear PVC sheet for the front doors with weather strip lining to seal
- Normal horizontally opening doors that will remain closed instead of vertical doors that will be latched open to the ceiling
- Fiberglass resin to coat/seal the interior
- Carpeting to line the interior
- Eva-Dry dehumidifier with a hose drain modification
- String Swing Rail System to allow for space adjustment
- No lighting as there's strip lighting in the room right in front of the wall where this will be installed, plus, don't want additional heat in the cabinet

If there are any other suggestions I'd be greatly appreciative!
Thanks again!

...
Joe

[ljguitar]

Originally Posted by joeguam

Thanks Larry for finding that post, I actually read through that thread and just didn't realize the user was from Malaysia.

The Eva-Dry dehumidifier is actually at the top of my list right now for my design. I need a small unit that can fit in the 12" deep wall cabinet and that doesn't give off too much heat. The problem that I have is with the small water tank as I think mine will accumulate much more water while I'm away at work than this can hold. I think an easy modification to drill a hole into the tank and build a hose drain that leads outside of the case into either a larger tank or directly into a house drain.

Really appreciate all the info from the AGF users, with every post I read, I'm slowing changing my design and it's getting better and better! I'm now onto the following:

- 4' x 8' x 1' dimension
- 1" x 12" peices as frame structure
- 1/2" Plywood for the back
- 1/8" x 4' x 4' Plexi-glass or clear PVC sheet for the front doors with weather strip lining to seal
- Normal horizontally opening doors that will remain closed instead of vertical doors that will be latched open to the ceiling
- Fiberglass resin to coat/seal the interior
- Carpeting to line the interior
- Eva-Dry dehumidifier with a hose drain modification
- String Swing Rail System to allow for space adjustment
- No lighting as there's strip lighting in the room right in front of the wall where this will be installed, plus, don't want additional heat in the cabinet

If there are any other suggestions I'd be greatly appreciative!
Thanks again!

...
Joe

Hi Joe...

As with all experiments, please be sure to take some pictures to share along the way. I'm sure there are others who could benefit from ventures like yours.

[joeguam]

Absolutely, definitely will do.

...
Joe