Cool Growing Orchidarium

a computer fan or one for some kind of electronics might work. a repair store or special electronics sales store. bob.

 

Very few places will accept returns on small electric stuff, so I'd not be so concerned about ordering online.

Personally, I prefer 115v muffin fans, so I didn't have to hassle with a power supply. I found a low-speed "Cooltron" brand that work great in my "incubator", and are very quiet. Remember, the idea is gently tumbling air movement, not a hurricane.

I also recommend against a steel tube for the fogger - don't forget it will rust. Plastic is a better idea. If you arrange the humidifier so it must blow the fog up to the tank entry port, and small amount of condensation will drain back into the humidifier.

 

I should check out the AC fan Ray suggested. When I measure a couple AC fans, they appear to have higher energy consumption than DC for some reason. But it wasn't a fair test because the output was different between the AC and DC fans (AC fans moving more air). AC fans seem to last longer.

Computer fans work well, but I killed a couple when I splashed water too many times (they can take occasional splash). Noctua NF-A14 iPPC-3000 PWM is my current favorite. Since it is one of the best, it is not cheap. It can handle water somewhat (IP52 level). It is quiet for the output (but you need to use lower voltage to make it really quiet). They have models with IP67-level water proof, too (link here, which can operate under water. But the IP67 model has lower output (maybe perfect for the small space like 57 gallon).

I used to use O2Cool DC fans. They are quiet and energy efficient but they don't last more than a year for the continuous run (from about 5 dead samples).

I use vinyl tubing from HomeDepot (need to make some way to attach it to the outlet), so the humidifier stays outside of the grow tent. But it rarely kicks in (controlled by hygrostat). In a moderately well enclosed area, if you have a water tray at the bottom, the RH is usually in the right range (around 80%) without an active humidifier. But I'm guessing that you need a humidifier because of the A/C unit. How are you cooling your tank?

Or are you talking about using fans to vent out the air from the tank? You'll waste cooled and humid air, and I don't see the needs. If it is completely sealed, it is a problem, but most of the time, there is enough air exchange from small holes.

 

If you're willing to invest some money, Jaybird Manufacturing (Jaybird-mfg.com) sells a humidistat that has a male/female AC plug. Put the sensor in the chamber, and plug it into the wall, then plug the humidifier into that, and it will control the RH inside.

 

I've been using a humidistat similar to what Ray is recommending for controlling a bigger ultrasonic humidifier in a smallish greenhouse for almost 2 years with good results.

I use this model from Sentinal in the $100 range

You just plug the humidifier into this guy, run the 6-foot sensor into your tank and you can dial in a different RH for days and nights as it has a photosensor in the unit.

 

I use a couple of hygrostats: Zoo Med HygroTherm. They have fantastic customer service, but the RH sensors seem to shift after a couple years.

This is a cheaper alternative (need a little bit of wiring): Image WH8040

Chris, I don't know why you want to keep it running, it seems pretty wasteful. Once you hit a certain RH (e.g. 70-80%), I don't see any advantage of getting 100% RH.

 

As far as controlling the humidifier, I can suggest two things: a simple timer that has 24 half-hour increments. Just have it fog three or four times per day, that's probably all you really need. If you want to get fancy, use an Arduino with a DHT22 temperature/humidity sensor, and a relay to turn the humidifier on. All can be had from Sparkfun Electronics for reasonable price. (As in under $50, I think).

A shop-vac hose will work well for ducting the fog. Just cut the hose to length. Be sure to use DI or RO water for your humidifier - it'll last longer, and your plants won't get covered in white dust.

I use 12 volt fans for air movement in my tanks and smaller cabinets, and have bought 4" fans from Walmart for less than $10 each for some of my bigger cabinets. Fans can be had from many sources, for as little as $2.50 for small ones. Check here <http://www.allelectronics.com/make-a-store/category/220/fans/1.html> for a good selection. I have tons of wall warts kicking around that I use to power the fans. You can usually get them dirt cheap at yard sales.

 

This has been by far the best fan I've ever used for terrarium circulation: http://www.ebay.com/itm/AQUARIUM-CO...744944?hash=item43dbeff4f0:g:BJYAAOSwv0tVRrAT. I've used them in my orchid tanks and also in frog tanks where they receive indirect misting 2x a day and have held up for years.

When I first started growing in tanks, I used a humidifier as well. I've come to feel that they are really a waste of time in my conditions. They would keep my plants too wet for too long, and I had to deal with many cases of rot due to it. I've since moved to ExoTerra/Zoomed style enclosures that are totally sealed up top but the bottom vents are exposed. My results are much better now.

 

That centrifugal fan looks good, Zach. Is it DC (i.e. is there a AC/DC brick between the AC plug and fan)? How is the noise level?

 

Yes, it has an AC/DC adapter. My plant tank is in my bedroom and any noise that this fan may create is muffled by the ceiling fan, so it isn't very loud at all. My oldest one is mounted directly to the roof of an acrylic panel on one of my frog tanks, so that causes a slight vibration and noise, but other than that, it's pretty silent. I use a single fan pointed directly up in a 36x18x36 Exoterra. Top is 100% sealed, bottom vent is open. This (and whatever air circulation the ceiling fan may provide) is the only circulation I use in this tank, and it is by far my most successful attempt at growing orchids indoors to date.

 

How are you planning on orienting that? If you have it blowing down, along one wall of the tank, the plants under it will likely get too much air, while those away from it will get none. Remember that the goal is gently tumbling air throughout the volume, not a strong breeze.

 

...or two of them so you get a swirling effect?

I think either could work.

 

What lights are you using? If you're having problems with heat, consider moving to LEDs. I swapped a 13 w CFL in my nano terrarium with a Jungle Dawn 9W bulb and I am very happy with it. It makes a lot less heat and actually seems brighter (judging visually, I haven't actually checked with a light meter) then the CFL. Ray also has some LED bulbs for sale on his site.

 

I use one of these digital humidity controls (~$20 eBay) with an ultrasonic mister under my orchidarium. The mist is delivered by a tube you cans get from the hardware store.
The control is super easy to set and will operate from 0% to 99%!