Idea for a highland grow rack

[JMurphy97]

I've seen those orchiariums and all what it looks like is a sealed up box with shelves lined with myler. A glass window in front to view and enclose it. But how hard would it be to make one yourself?

Get some wood. Seal it so water won't damage it over time. Line it with myler. Cut out a hole in back so you can stick a a/c unit for the summer. In winter just open the window. Maybe have it 48in long, 24in deep, and however high you want it. Screw the lights in. A drip pan at the bottom. Up top have hooks for hanging baskets when they get lager. A fan or two for cirulation and to cool it down. Maybe some vent holes along the sides. A glass door that opens for easy access. A humidifier. A misting system would be too much I think. What would that cost? Not $2500.00. It would not even cost too much. Why use a shelf from Home Depot when this would be way better?

http://www.orchidarium.com/htm/grandcayman.htm

 

[Tony Paroubek]

Well looking at the link.. I think you could make something for a lot less sure. Although the lighting system they employ isn't real cheap and acrylic is pretty pricey also.

The real challenge is of course moisture protection, and proper lighting. Lighting deep structures is difficult to provide enough light to the lower section. Particularly if all the lights are placed up top. Powerful enough lights becomes an issue and shading from plants higher up in the chamber.

So while it may seem simple at first there are a variety of issues to consider. Especially if you are also looking to alter the temperature range over your ambient room.

On a side note I repeatedly see people say things like add a fan to cool things down. Fans do not cool things. Unless you are talking about removing warm air and bringing in fresh air. But they will not reduce temperature below the ambient temperature.

Cooling would require some sort of refrigeration unit or AC. And once you do that you probably also need to add some sort of humidifying system since refrigeration/ac coils remove moisture from the air it cools. Heating would be less complicated and probably wouldn't require more than a waterproof heat mat in the bottom. You of course would need thermostats for heating/cooling and a humidistat for the humidity system. All in all it CAN be quite complicated if you are looking to make something other than a lighted grow chamber with not many frills.

Tony

 

[JMurphy97]

Well for lights if you put some shelves up then you move the plants closer to the light you don't have to worry about it reaching the bottom. Aslo what if instead of wood you use glass or plexiglass? Then you would'nt have to worry about the moisture. Would it really be a problem using a a/c and humidifier at the same time? Would'nt a normal humidifier work or would you have to get a high tech humidifying system?

 

[Tony Paroubek]

I think wood treated properly would be fine. Probably need to coat it with some sort of epoxy paint? What would be the point of making it tall and then putting shelves up high so you couldn't use the lower portion because of insufficient light?

The reason you need the humidifier if you pump AC air in is simply because the AC air is very dry and without a humidier also pumping moisture into the grow chamber you will quickly displace the moist air with the cool dry air. Swords used to have a window AC unit ducted to his grow chamber. He also had the output of a ultrasonic humidifier blowing mist into the duct before it entered the terrarium to put moisture into the cool AC air. There is no problem for the AC unit because you are not pulling very moist air through the AC coils.

 

[D_muscipula]

YES A/C units dehumidify and could make your plants unhappy.

 

[JMurphy97]

It would be tall for when the plants get big enough that they would need to be hanging. I also planed on having a humidifier or two in there running at night. I guess if the a/c is outside of the unit then it would'nt kill the humidity inside.

 

[Tony Paroubek]

Hanging plants sounds great but keep in mind that the plants are going to be dangling down from the baskets so you will still need sufficient light down towards the lower portion. One potential solution is to have some vertical lights in the unit as well as lights on the top. I am not sure what you mean by having the a/c outside of the grow chamber.

 

[adnedarn]

If the AC is outside the grow chamber and blowing inside, then it will be taking room air and cooling it and blowing that into the chamber... Causing positive pressure inside the chamber and blowing the cool humid air out. So I would say not only are you still loosing humidity by the change of air, but the ac will need to run longer to keep it cool since it isn't cooling already cooled air (in the chamber) and instead basically cooling the whole room... And if it isn't a "portable" ac where the exhaust air will blow out a window via a hose, then the room will be pretty warm (remember AC separates hot and cool air.. so the hot air has to go somewhere... It doesn't "make" cool air). So it will probably run A LOT to maintain cool. I'd say it would need to suck air from the chamber, cool it, and blow it back in. And have humidifier countering the drying effect on the air (perhaps ultrasonic that blows right in the path of the AC air so it moistens it right away before it can hit a plant and dry it out). Count on emptying the water from the AC a bunch also!

(I only kinda skimmed so I hope this view isn't already outlined somewhere )
Andrew

 

[JMurphy97]

I'm not seeing how it would blow the cooler air back in if it's going out the window. Don't they take out the hot air and move it out of the window, leaving in cooler air? I have two small ultrasonic humidifiers from wal-mart that were going to run at night. Is that going to be enough or would I need some high tech gadjets?

 

[seedjar]

No, ACs work by recirculating air over a cooling element. A separate device (a compressor run by a motor) cools the element and generates waste heat as a result. The waste heat is the hot exhaust you feel from the back of an AC. No exchange of air is necessary, but many ACs include a fan to draw in fresh air.
~Joe

 

[Tony Paroubek]

So are you saying to cool the room the grow chamber is in but don't blow the cool air into the chamber itself?

 

[JB_OrchidGuy]

Well AC units don't actually separate hot air from cold air leaving the cold air. That is a simple way to put it, but it is actually more complicated than that. AC units and other refrigeration uses what is called phase change cooling. Ever noticed when you spray a can of dust remover when your cleaning your keyboard or spraying some other sort of compressed gas from a can and the can gets cold? That is the same concept with an AC unit. It compresses the coolant inside the closed system and compresses the gas inside the system. The compression process causes heat the gas actually heats up from being compressed. That is what makes the waste heat on the back side of the AC unit. Then as the gas goes through the system it expands on the inside section that cools the coolant coils. Then air is passed over the the coils and it cools the air. Now the other part of the equation is what happens to dehumidify the air. It is a secondary process that happens with cooling systems. It works a little like this. I am sure you have noticed a glass of ice water sweating as it sits on the table. That is because the glass is cooling the moisture in the air and it is compensating on the glass. That same principal happens on the cold coils of an AC unit. The moisture in the air condenses on the coils and that is the water you see dripping out the back of the AC unit or out the drain of house units. That is the phenomenon that dehumidifies the air. So with all that said it should make everyone's resonances make sense.

If you have the AC attached to the back of your chamber it is going to dump the waste heat into the room and dehumidify the air int he chamber. If your AC unit is in the window and you duct the cold air into the chamber it is pulling air from the room and dehumidifying it and pumping it into your humid chamber. Then the dehumidified air is pushing out all the humid air through the cracks in the chamber. So what is being recommended is you pump humid air into the cool air duct so the air coming from the AC unit is rehumidified before it gets to the chamber if you decide to duct it in. If you have the unit attached to the chamber and so not care it heats the room then you will need to rehumidify the air in the chamber and the unit will "sweat" excessively and make a lot of waste water dripping from the AC unit.

Or you can do as I plan to do when I get to MN. Take a chest freezer and remove the lid, then build the chamber, with a floor, on top of the freezer. It will have an intake and output hole with fans in each. One pushing air in and the other pulling it out. Oh there will be a tube on the output side so that it makes it suck the cold air from the bottom of the freezer up to the top grow chamber section. Now this system also needs to be humidified and you would occasionally need to defrost the freezer because it may get buildup from pulling the humid air into the freezer. Now also this system also uses thermostats and humidistats to control the temp and humidity as well, but those are easy enough to setup. The thermostats will just control the fans from coming on and off to pull air up from the freezer. The freezer will always run to keep temp. I got the idea from a guy in Sweden. The guy said he tried using a fridge but the fridge could not keep up with the temp drop he wanted. I think this will give you a better temp drop than an AC unit would. Oh BTW you would need to separate the light system from the chamber like a layer of glass or something. The guys chamber uses fiber optics but that is a very pricey way to go.

Keep in mind this guys vivarium is very very pricey to build but I do believe a lower priced version can be made with the same principals in mind. I plan on using wood or the back and sides and a glass front. I will also put my lights behind glass so they will keep the lights separate from the chamber to keep it a little cooler. The walls will be insulated because I plan on making the wall look real with foam and the foam has a good R factor. If you go to the frog places website it will show you how they made a real looking terrarium with foam and peat over the top of it to simulate a rock face covered in moss. I plan on using a hybrid of the two to make a cool growing vivarium for my villosa and some hellis. Also a hamata when I get one as well as other highlander orchids and things.

Here are his pictures with explanations.

If you want to read the entire thread and the guys full explanation then here is the link.
Cool vivarium thread

 

[rattler]

you want the hot air intake at the top of the tank for maximum efficiency............

if you use a freezer one suggestion.....dont leave it empty....put something such as water bottles in it of something to increase the surface area that the air moving through the freezer hits.....prolly get more life out of the compressor motor and use less electricity in the long run...

i wouldnt do it the way you have the fan running in the pic.....i would put the fan on the output hose, not on the intake hose....i think it would work better.....

the idea i have is more complex than the above.....for one i would insulate the hell out of everything but the front viewing window if i was growing ultra highlands.....

 

[JB_OrchidGuy]

oh I planned on it. I just use those pictures as a reference because it is a nice setup and the first time I seen a cooled vivarium. I am going ti insulate the heck out of mine

I would be interested in your more complex design ideas too BTW.

 

[rattler]

will likely be sitting bored in a hotel room this weekend.....will see 'bout doing up some drawings and a write up on my thoughts for you guys to critique.........

 

[JMurphy97]

So are you saying to cool the room the grow chamber is in but don't blow the cool air into the chamber itself?

Maybe that could work. This sucks. I thought it was a good idea. But now there has to be all this brain work. Is there any where I can get a step by step guide to doing this? I have a freezer already so that keeps costs down somewhat. Do I cut holes in the side and use the tubes/ducts that way?

 

[nightsky]

I just cool the room, and keep a humidifier inside the growchamber/shelf area. It works great, and I have even left a large amount of area open in the chamber walls for gas exchange. This does cause the humidifier to run more, and therefore require filling every other day or so, but so for months it has worked great. I'm in a low humidity environ anyway, so the A/C air isn't much different from the ambient air as far as humidity is concerned.

if you use a freezer one suggestion.....dont leave it empty....put something such as water bottles in it of something to increase the surface area that the air moving through the freezer hits.....prolly get more life out of the compressor motor and use less electricity in the long run...

i wouldnt do it the way you have the fan running in the pic.....i would put the fan on the output hose, not on the intake hose....i think it would work better.....

I agree fully. Put some objects in that freezer to reduce the workload and increase the efficiency of the freezer. And I also agree with the fan placement.

 

[rattler]

yeah but how low are you dropping temps.........im growing intermediates and some highlands with no special equipment, i just keep them in my basement and they get 65 degree nights......but that can be much different than keeping the ones that want to drop to 50 at nights happy........it can be interesting dropping it the rest of the way.......

JB.......my basic thought is to take the frozen water bottle in the small terrarium idea and make it much larger and automatic.......using a closed system pumping antifreeze out of the freezer through copper pipe, into a large container full of water as a sorta back panel to turn it into a heat sink.......and pump cool air in as well but on a much lesser degree than what your planning......if i were to do what your planning i would skip using a freezer and just use a small AC unit instead........

i am thinking this will use much less electricity than what your planning.........the heat sink should keep the temps reasonable during the day regardless of what lighting i use....should only have to pump in the cold dry air at night to get the maximum drop in temps and only have to worry bout the humidity problem for half the day......

just thinking that freezer life may be short trying to use it as an AC unit........

 

[JB_OrchidGuy]

Just to let you know Rattler the freezer in the pictures I posted supposedly does not run much more than it usually did according to the guy that made the vivarium. That is what he said in the thread on it anyway.

I do not think you would shorten the life of it because your basically just expanding the area it is cooling and not trying to cool the room. The AC cannot drop temps down into the 50's without ruining the AC unit. So to get the temp drop into the low 50's upper 40's for a villosa you would need a freezer. I do agree with the Frozen water bottles though. To be honest I have thought about using the antifreeze and pump idea, but not quite like you described. That might help keep the fan from coming on as much, but either way I don't think it will shorten the life of the freezer because your not opening up the freezer like you normally would and that doesn't shorten the life of the freezer.

How about this. I will go over to the other board and revive the thread and ask how it is working and if the freezer is holding up.

Murphy how about replacing the lid to the freezer or the front door. Not sure the setup of the freezer, but that way you do not ruin the integrity of the freezer and if this doesn't work out for you the freezer is not ruined. You make the holes in the new lid or door instead so that you can put it back to the way it was pre-grow-chamber if need be.

 

[JB_OrchidGuy]

I just revived the thread and asked how the vivarium was holding up and if the freezer life had been shortened. Nov 06 was the last post in the thread so it is almost 2 years old. I hope to see if he responds.