Thought on highland cooling

[ilbasso]

This just popped into my head a few minutes ago so I haven't really thought this through but I was wondering if anyone can see a potential problem with this setup.

I have a dorm fridge that hasn't been used in years. If I built a good sized chamber in my basement and put the fridge in there-with the door removed-and put it on a timer to kick on at night...could this work well enough? Obviously it would depend on the size of the area, but my house is small so it wouldn't be much.

Thoughts?

 

[MrFlyTrap2]

Keep the coils out of the setup, otherwise it won't do anything, in fact it would make it hotter. Your enclosure might also need insulation in order to keep the temperature difference.

 

[JB_OrchidGuy]

The better idea would be to keep the fridge running. Door in tact. Drill a large hole with a hole saw in each side of the fridge. Connect conduit from the fridge to the chamber. One is an in flow one is an out flow. You have a fan connected to a thermostat to control the temps bu coming on to suck the warm air from the chamber into the fridge and then out the back flow into the chamber. It actually works better with a freezer than fridge, but you could try it anyway. By keeping the fridge running it stays cool where as if it was on a timer it would have to cool down using more energy than the setup I suggested.

 

[ilbasso]

Holy crap.

Since this is in the basement which is already fairly cool, would the freezer still be that much better than a fridge?

 

[seedjar]

Vent terrarium air out (preferably a window, and certainly from the top of the tank where the warmest air is.) Take in air from the basement floor, as the ground stays nice and cool to begin with, run it through your cooling device, and then humidify it. Running humid air through the fridge will cause condensation to build up, and I think recirculating from the terrarium will invite all sorts of nasty stuff that you'll have to clean later. Don't cut into the fridge - just leave the door slightly ajar build a jig to give an inlet and an outlet and seal the rest off. Then all you need to do is detach the jig and you have a serviceable fridge that you can use or sell off, should you decide to upgrade your cooling capacity or scrap the terrarium. Plus it's easier and has a drastically lower chance of your breaking the fridge or poisoning yourself with refrigerator coolant.
Once you get all the connections set up, I'd suggest finding the lowest fan speeds possible while still giving the temperature you're looking for. If your plants need more air circulation, use a separate fan within the enclosure for that purpose. If you can find a way to cool the coils on the back of the fridge, it'll decrease your operating costs. If there's a water main in the basement or something, you could back the fridge up against it so that your plumbing acts as a radiator. Come to think of it, you might be able to find a heat exchanger to physically connect the coils to your pipes - I know they have water-cooling kits for PC modders, and it's almost exactly the same idea. JB could be right about leaving the fridge on all the time, but it also likely depends on the fridge itself; a small compressor vs. the air volume of a large terrarium would likely mean running all the time when cooling is needed, so it might not make a difference at the scale in question. I think you'd have to experiment with your setup to be sure.
(Wishing I had a basement.) Way to set your sights high - I've wanted to do this kind of thing for a long time. I'm sure your plants will thank you.
~Joe

 

[Clint]

A freezer would be better than a fridge. A fridge is basically an air conditioned box, so the air would be dry. A freezer, however, doesn't add cold dry air, it just removes the heat without doing anything as far as gas exchange. Freezer is also faster

Someone mentioned removing the tubes. Although that does sound like an accident waiting to happen, I wonder if you could tear apart two or three large freezers and use the tubes to make a REALLY big growing area. Like 75 cubic feet if you used three 25 cubic foot freezers. Can you bend the tubes?


Another alternative is to find a used chest freezer and grow directly in it, remove the top or modify it, and put a light over it. I plan on doing just that, minus the used part. The largest commercial chest freezer they make is 25 cubic feet. It doesn't sound like a lot, but when you think of it as really being a 187 gallon "terrarium" it does sound like a lot. A lot of highlanders won't outgrow that. Once something you really don't want to cut, like N. villosa or N. rajah outgrows that width, I don't know what you can do, though. For N. villosa, I can't see air conditioning getting a large chamber down to 40 degrees (unless you're blessed with a cold basement in Canada... looking at you, Varun), and I really think you'd need a room-sized walk-in freezer (well, a "cold room" like these: http://walkinrefrigeration.com/) but I can see the more lenient N. rajah growing to full size if you use air conditioning.

Of course, you could go ahead and build a big chamber and buy an air conditioner and fogger to humidify the AC'd air. I guess it depends on how much cash you want to blow and how much space you need.

 

[ilbasso]

I think I'm happy with my lowlanders.

 

[seedjar]

Are you sure all fridges circulate air? A friend of mine left his dorm fridge in my shed over summer break one year... when we opened it up the next fall, there definitely had not been much contact with the outside world.
You can re-bend the tubes used in fridges, but as they've already been bent and subjected to a lot of temperature stress, they'd probably shatter if you tried to rework them. Better to just get some newly made pipe and bend your own (a soft-metal pipe bender costs like $10, and makes a very menacing home-defense item as well.) The trick is handling the refrigerant and decompressing/recompressing the rig to work on it.
~Joe

 

[Clint]

I guess not a thermoelectric fridge.

"The trick" hehe. I don't trust myself enough. I'd blow up my house or something hehe.

 

[seedjar]

Ack, stupid refresh button. Ignore.
~Joe

 

[D_muscipula]

http://walkinrefrigeration.com/floralwalkincooler.htm
that would be cool.

 

[billylh]

how about just using a window a/c unit? they sell small ones for under $100 that has a digital thermostat to control temps.

--oops, didnt see basement part

how about.... get a jigsaw, cut the top open on the fridge, foam seal plexiglass on it and set your light on that and just grown in the fridge?

fyi, if you look online at beer brewing diy sites, they show you how to wire a thermostat on one of those small fridges..

~b

 

[JB_OrchidGuy]

Seedjar The system I described has already been done and I have pictures. I might as well post them here. I have posted them before I think. These are not mine and these were done for cool growing orchids and they are the same conditions for highlanders.

This guy is in Sweden who made this.

Here is the link explaining how he did it. Take from it what you will, but orchids are a lot more sensitive to stagnant air in my opinion. By pulling the air out you will seriously increase the cycle times of the freezer or fridge and not be able to keep up. To keep the air frm stagnating keep a clean chamber and have circ fans in there to keep the air moving.

Cool growing Viv

 

[Clint]

I wonder if a better alternative would be to fill a chest freezer with water (since it can hold water, unlike the kind he uses) and put a fogger in it to pump cold fog into the terrarium until. hook the fogger to a separate thermostat from the freezer so it would go off at the desired temp. This seems like it would work well for highland Nepenthes, since being wet like this wouldn't bother them like I imagine it would orchids.

If you got a larger freezer that what he used, I wonder if the freezer wouldn't have to work as hard. It also seems as if it wouldn't have to work as hard for Nepenthes, since almost all highlanders don't require days in the 60's. It just seems like a little PC fan wouldn't do very much, especially for that huge setup he has. The fact that he cut into the sides of the freezer to install the ducts seems like an accident waiting to happen, too. I wonder if, instead of a front-opening freezer, you could use a chest freezer, cut two holes in the top (not risky since there's nothing to damage in the lid), have the input tube going down to the bottom of the freezer, and have the output tube shorter, at the top of the freezer. That way you could still have space for the freezer to cool the air. You'd just be using vertical space instead of horizontal space. Add a little water to the bottom of it to increase humidity, unless it had to be set on it's designed temperature of freezing to work properly for a setup like this (since he mentioned defrosting.)

I'd like to see how his setup is working, and looks, now.

 

[JB_OrchidGuy]

Well dude he grows highland Orchids in there. Masdi's are cool growers. PC fans move a lot more air than you think. You don;t need filters because plants are the best filters on the planet. That is what they do.

I guess if your talking about children cutting into the fridge then your probably right. Accident waiting to happen. I forget that many of the people here are children. As for adults then I would not hesitate to cut into a freezer if that is what I am making.

Yes he mentioned defrosting because your pulling humid air into the freezer. Just a minor inconvenience. Maybe the cold water circ would be another variation to be used. The setups are limitless. Of course many are going to not work so good.

I thought this was a very good idea and wanted to share it because I know it works. Will it work to 40? I dunno. Does it work for highlands yes because masdevallia's are highlanders or in orchid terms cool growers. Same condition as highlanders.

How about this? Running a freezer at full blast, but you have a closed coil system continuously circulating water through a large coil based inside the freezer to a coil on the outside that is inside the chamber with a fan to cool it. Moving water does not freeze. Maybe it will not work as well who knows. It might be more involved than some want to get, but the sky is the limit.

Personally I would like to make my own cooling system as one would make for phase change cooling for computers. Yes people are making mini freezers for their computers to keep them cool and you can make a little larger one a slightly larger one for your chamber.

 

[Clint]

You lost me when you mentioned filter. I can officially say I'm an adult, and I still think I'd screw up lmao. I'd have to pay someone to do it for me. How did he move the tubes to install the ducts?

I think it's a great idea, too! I think your water idea would work, too.

 

[seedjar]

Seedjar The system I described has already been done and I have pictures.

No doubt - I never said it couldn't be done. Just that cutting the freezer is an unnecessarily complicated step in the process, not to mention it ruins a perfectly good freezer, making it both frivolous and wasteful. In less time than it takes you to cut into the $40-$250 freezer, you can build a perfectly good jig to run an inlet and outlet in with $10 worth of insulating foam and some scrap wood, plus an extra foot or so of whatever hoses you used to connect to the cooler.

Take from it what you will, but orchids are a lot more sensitive to stagnant air in my opinion.

Did I ever say what orchids were or weren't?

If your plants need more air circulation, use a separate fan within the enclosure for that purpose.

Did you read this part of my post? Air circulation and cooling are different things. They're both appropriate for some plants, but that doesn't mean the most effective way of providing both is with a single apparatus. It's easier to cool the air if it moves slowly through the system - even better if it can be passed through a coolant with a higher thermal capacity. Fast moving air doesn't have time to exchange heat.

I'll give you that there may be merits to recirculation, but that's a tertiary issue. I suppose it really depends on what (if any) heat sources are in the tank. If the lights are within the airspace, or they warm up/cast enough IR light that the enclosure warms up as well, then I really think it would be easier to just slowly percolate the cold air up and provide an exhaust outlet for the lights' waste heat. If waste heat isn't an issue, then you can recirculate, but you can still save power by doing it at a low speed. However, I have read a number of sources on terrarium culture that say that moving air is no substitute for fresh air. (Contrarily, I grow several almost totally sealed terraria with no fans that do just fine with all sorts of things.) In any case, if the plants need air circulation, it can be dealt with by using low-power fans closer to the plants themselves. You don't need to force the entire air volume through the fan to get it to move within the enclosure - gases are convenient that way.

~Joe

 

[JB_OrchidGuy]

Sorry Joe if my post came out wrong. I was in class and had to type a fast response to it. It is time to get to bed now, but again sorry if it came across badly.

 

[JMurphy97]

I can't see air conditioning getting a large chamber down to 40 degrees (unless you're blessed with a cold basement in Canada... looking at you, Varun),

Or Wisconsin. I think it gets too cold in the winter, down to 37 a couple times and they seem to like it. I'll take 50's in the summer for a couple months.

 

[JMurphy97]

I can't see air conditioning getting a large chamber down to 40 degrees (unless you're blessed with a cold basement in Canada... looking at you, Varun),

Or Wisconsin. I think it gets too cold in the winter, down to 37 a couple times and they seem to like it. I'll take 50's in the summer for a couple months.


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