DIY dry cabinet in case you can't find one suitable

[kahheng]

I had to do this because I couldn't find an off the shelf solution that would fit my existing shelves. I gave away my old dry cabinet to a friend recently.

1. Existing Ikea storage unit with roller blinds - probably about 150 liters

2. E-27 bulb holder

3. Some cable and two prong connector cut out from some old appliance

4. 15W bulb

5. Hygrometer, preferably an electronic one

6. 24 hour repeating timer switch (optional)


Hook up 2, 3, 4, connect to wall socket, place bulb at bottom rear of cabinet, turn on, close the cabinet. Less than or equal to 55% RH is my target.

Achieving 55% inside the cabinet, in my ventilated room with open windows on this muggy day for the last 5 hours.

Cheaper than Dampp Chasers (works on the same principle BTW - i.e., raising the air temperature of a closed but not sealed enclosure by a few degrees; please note that you WANT some gaps to allow cooler fresh air to enter the enclosure), infinitely more flexible than a commercial dry cabinet that doesn't fit my room. Besides, the backlighting from the bulb lets me dig around for stuff more easily.

The 24 hour repeating timer switch is optional. I bought one for about $13 from Mustafa just in case I wanted to control when the bulb switches on and when it should go off. At night, when I am sleeping with the aircon on most of the time, I might turn the bulb off to conserve electricity. With the aircon on and the bulb on, I get about 35% RH which is unnecessarily low.

Costs: the cabinet doesn't count of course since I already own it. The cost of the bulb, bulb holder and timer switch is less than $18. A good hygrometer goes from $20-30 (or get a cheapie car use type for under $10). You'd probably have to replace the bulb once or twice a year.

The only other thing to do now is to cut wood planks so that I can partition the cabinet and use the space more efficiently. The cabinet is already full.

I am testing everything out for the next few days, positioning the hygrometer at various points in the enclosure to see if the humidity varies much at different locations.

Further improvements - well I guess I could seal up some inside edges of the cabinet with sillicone but since 55% RH has been reached on my first attempt, I am not going to bother. (Note that there are enough gaps in the roller shutter so much so that I can see some light coming out of the cabinet.) I guess the only thing I want to change now is perhaps the bulb. A few more watts would proably be good to get the RH down to about 50% steady.

Running cost should be abysmally low for a 15W bulb left on 24/7. I reckon way less than $10 a year.

[tankahn]

You can also add a dimmer for finer control. The whole setup is also great if you want to go into Yogurt making business.

[kahheng]

Originally Posted by tankahn You can also add a dimmer for finer control. The whole setup is also great if you want to go into Yogurt making business.

What a good idea! I love yoghurt. I shall try to make some space in the cabinet for yoghurt making.

The dimmer is an excellent idea, thanks. I'll add one if the new bulb is too strong.

[hongsien]

Try to make one switch with a feedback system, an AirCon person maybe can help you out: once the RH hits a certain value, it turns the lamp on or off....a thermostate is the name I think.......

I am going to make my whole apartment a nice 50% RH environment.......going to costs me a bomb in electricity!

HS

[kahheng]

Originally Posted by hongsien Try to make one switch with a feedback system, an AirCon person maybe can help you out: once the RH hits a certain value, it turns the lamp on or off....a thermostate is the name I think....... I am going to make my whole apartment a nice 50% RH environment.......going to costs me a bomb in electricity! HS

Hmm, that's a reasonable idea but it's a little more complicated than I want it to be. Better to keep things simple man. I just want to leave the bulb running 24/7 since it's so low wattage already. ;-) I am sure my Intel P4 cooker costs more to run everyday.

My non-photographer friends in HK prefer to just buy room dehumidifiers and run them when they go to work. The thing is, room dehumidifiers are not that easy to buy in Singapore from the usual dept stores like Best Denki, Courts, Taka or Tangs whereas they are not too hard to find in HK. The only one I saw retail was at Mustafa but is too expensive for too little performance. I suppose if I go to a gui-lo oriented place like ParisSilk I should be able to get one easily. The angmohs are the ones who buy most of them in Singapore AFAIK. Industrial ones are also available from the Commercial Yellow Pages of course.

[hongsien]

Yeah, they are very expensive! My workplace in SG bought one years ago, a Belgium brand, collected (condensation) water into the bottom shelf.........

I have seen them here, in many variations, don' know the prices, lamp in the shelf maybe better option.

HS

[AReality]

Don't anyone sell portable units?
Put the unit into a cupboard...
Maybe i make 1...

[kahheng]

Originally Posted by hongsien Yeah, they are very expensive! My workplace in SG bought one years ago, a Belgium brand, collected (condensation) water into the bottom shelf......... I have seen them here, in many variations, don' know the prices, lamp in the shelf maybe better option. HS

And running costs wise, room dehumidifiers with a good capacity are rated at 200-300W and higher, so they'll cost a lot of dough to run continuously. Then again, they do make life more comfortable.

[kahheng]

Originally Posted by AReality Don't anyone sell portable units? Put the unit into a cupboard... Maybe i make 1...

You probably shouldn't put an electric room dehumidifying unit into a small enclosed space. It will work too quickly and the RH will hit too low.

Besides, even the smallest unit would be generally quite bulky.

[kegler]

i thought of the idea too.... my dry cabinet looks odd on my table.... i have some empty cupboard might be able to convert into a dry cabinet.... any idea how much is an external dehumifier? need to do any kind of air tight rubber/or watever on the doors n interior of my cupboard?

[kahheng]

I have been using the DIY cabinet for a few days and here are some further observations:

1. I changed the bulb to a 25W one. RH has therefore dropped even more.

2. Instead of running the bulb all day long, I have set the bulb to come on for one hour and off the next and then repeat. RH is pretty well maintained at between 50-53%. Here is where the 24 hour repeating timer becomes indispensable. For $13, it works really good. (I have seen cheaper ones at NTUC at Toa Payoh and Mustafa)

So far I am I rather pleased with how this DIY dry cabinet has worked out.

[Firefox]

Did anyone see the ad. in Sunday times, 3rd April? There was one for closet dehumidifiers.. Looks cheap... Maybe you can pick one up and try..

[kahheng]

Originally Posted by Firefox Did anyone see the ad. in Sunday times, 3rd April? There was one for closet dehumidifiers.. Looks cheap... Maybe you can pick one up and try..

No I am too poor to buy the newspaper on Sundays. Maybe you can tell us what the ad says or scan the ad and post here ;-)

[Firefox]

Originally Posted by kahheng No I am too poor to buy the newspaper on Sundays. Maybe you can tell us what the ad says or scan the ad and post here ;-)

LOL.. Too late la.. I saw the newspaper in camp.. Me also too poor to buy newspaper.. LOL.. Now starting to clear off + leave for ORD liaoz... No time to go back camp to get the papers.. Roughly what I remembered was that it was shaped like a florescent tube and came in 15w, 20w, 25w etc.. And cost about $50 up.. But not more than $150 for the largest model..
I guess it'd be a good alternative to a light bulb since it should heat up the cabinet as much and it's purpose built for cabinets anyway.

[kahheng]

Originally Posted by Firefox LOL.. Too late la.. I saw the newspaper in camp.. Me also too poor to buy newspaper.. LOL.. Now starting to clear off + leave for ORD liaoz... No time to go back camp to get the papers.. Roughly what I remembered was that it was shaped like a florescent tube and came in 15w, 20w, 25w etc.. And cost about $50 up.. But not more than $150 for the largest model.. I guess it'd be a good alternative to a light bulb since it should heat up the cabinet as much and it's purpose built for cabinets anyway.

You can get them at Tangs.

They were branded "Dampp Chasers" last time, now not branded as such but are the same things. Basically mica heating rods. I mentioned this in my post above. Bulb plus timer = less than $18. Smallest Dampp Chaser is quite a bit more than that. Both work on the same principle.

I suspect that Rodex Marketing still brings these things in.

You can Google "Dampp Chaser" for a pic of the rods.

[Jellyfish]

Interesting topic, May I know whats the principle behind dry cabinet? how it works?
many thks

[milroy]

Like the idea of saving money and using available closet space
But does it really work as well as a dehumidifier ?

At least with the dehumidifier your equipment is stored in a cool dry space. whereas using a light bulb you're gonna have a.. er .... warm dry space?

If your objective is preventing fungal growth on your camera and expensive equipment.....is it really a good idea keeping your equipment warm ?

Plus all your rubber/plastic parts may degrade faster in the warmth.

Of course, being a pessimist, I worry about an electric fire caused by overwarming a wooden cabinet since there is no temperature monitor.

Having said this, I recently left my cabinet humidity too low and now my favourite 16-35L no longer focuses so smoothly

[kahheng]

Originally Posted by milroy Like the idea of saving money and using available closet space But does it really work as well as a dehumidifier ? At least with the dehumidifier your equipment is stored in a cool dry space. whereas using a light bulb you're gonna have a.. er .... warm dry space? If your objective is preventing fungal growth on your camera and expensive equipment.....is it really a good idea keeping your equipment warm ? Plus all your rubber/plastic parts may degrade faster in the warmth. Of course, being a pessimist, I worry about an electric fire caused by overwarming a wooden cabinet since there is no temperature monitor. Having said this, I recently left my cabinet humidity too low and now my favourite 16-35L no longer focuses so smoothly

Does it work? Yes it does. My hygrometer says so.

How much does it warm up. About 2 degrees above indoor ambient or thereabouts when the bulb is on after 15 minutes. It's not the same as leaving the gear in your car on a hot day. A 25W bulb turned on every hour for one hour doesn't really heat things up a lot. If you like, you can install the bulb at a lower section of a multi-tiered cabinet away from your precious cameras and lenses - that would alleviate any direct heating of the equipment.

Electric fire? Overwarming? Well, we're not talking about an iron, or a high wattage watt lamp or a bare heating element here. Is it safe? Many people's homes have wood and glass cabinets say in their kitchen with halogen lamps of much higher wattage than what I have installed and you don't hear of display cabinets going up in smoke all the time ;-) And besides, the bulb only comes on every other hour.

I am sorry if you don't think it's safe but I think you might be just a little paranoid. But paranoid is good. Only the paranoid survive! If you're willing to pay for a certified lab testing by the local safety authorities, I don't mind sending them the whole cabinet and 25W lamp

[kahheng]

Originally Posted by Jellyfish Interesting topic, May I know whats the principle behind dry cabinet? how it works? many thks

I don't know the exact science but it works something like in an enclosed airspace, as temp goes up, RH drops, ceteris paribus. I read this from some stuff I Googled before.

[Jellyfish]

Originally Posted by kahheng You can get them at Tangs. They were branded "Dampp Chasers" last time, now not branded as such but are the same things. Basically mica heating rods. I mentioned this in my post above. Bulb plus timer = less than $18. Smallest Dampp Chaser is quite a bit more than that. Both work on the same principle. I suspect that Rodex Marketing still brings these things in. You can Google "Dampp Chaser" for a pic of the rods.

In another words u can install this dampp chaser into ur DIY dry cabinet instead of the 25W bulb?