I was wondering if anyone's using a heat exchange tower in a closed system. In most designs I've seen, ventilation (for fresh air) & heat rejection are treated as the same thing...resulting in the need for odor filtration and control as stinky, humid air is constantly ejected from the room taking water and heat with it. What if you instead used an inline fan to send air from your hoods into a mesh of pipes that went through your water reservoir. While cooling the hot air, you'd simultaneously increase reservoir water temperature. In an insulated environment, this would effectively use your lights as a water heater and your reservoir as an air cooler, and eliminate the massive water loss (in dry climates), the smell of a full ventilation system running, and the power consumption of a water heating coil. A passive, post-fan, secondary vent could release some air through a smaller odor filter, and a venturi on the "air-cooled" side of the system could suck in fresh air, ensuring the o2 and co2 levels don't become depleted. All this using one fan. A tray placed at the output of the system could collect condensed water from the air system and return it to the reservoir. This would also create a dehumidifier to balance regular evaporation into the room's air. If you're running a CO2 system in your room, this would seriously increase the effectiveness and lower the time you needed to run the tank. CO2 that floated to the ceiling would be recirculated instead of vented. -- I want some feedback. Lemme know what you know. Dialectics. Debate. Innovation...give it to me.
Sounds like a good idea, you might need to add a dehumidifier during flowering to keep your humility below 60%. You might also be surprised as to how much heat you add to your res, but overall it sounds like a good plan.
DO (Dissolved Oxygen) levels of the water would drop significantly at high temps (and also terribly low temps) thereby promoting root rot and ultimately leading to plant death.. But otherwise it wouldn't be very efficient. Air conditioners are pretty inefficient. I think you would just end up with super hot air blowing through the closed loop. I don't think the water would absorb the heat as well as you imagine. Plus you have a limited supply of water. What happens once the water reaches a plateau of lets say 100 degrees? The water releases the heat somewhere too, back into the air? Maybe it would work if you had a HUGE external reservoir and a TON of surface area to transfer heat from air to water....
Read up. You're right. Thanks for the info. I still keep my cloner up in the 70F range as I've found this increases speed of rooting. However, I've got a bubbler running 24/7 that agitates the surface and dissolves more oxygen into the water keeping up with demand (it seems). Possibly....by bubbling your vent air through your reservoir (instead of through tubes of a closed system) you can increase thermal conduction between the air and water and insure DO levels aren't depleted. This'd be loud and probably increase RH a good degree... Thanks for the comments.
Ah yeah, you'd need a pretty powerful fan but you'd essentially be almost making a bong out of your bubble buckets lol. A nifty idea to say the least. Let us know if you try it though because I'd be very interested in the results. Worth of an experimental attempt I think if you've got the cash flow to support research.
Do you have any resources regarding the thermal curve of oxygen saturation in water? What's the ceiling temperature range for plants' DO requisites? And how cool would it be if my growroom doubled as the biggest bong this side of the Mississippi! Mmmm...requisites....sounds tasty....with a side of ostentatious preclusion, topped with a creamy juxtaposition sauce, served on a bed of esoteric vernacular and doused in an oxymoron vinaigrette.
I ran across a super awesome graph the other day regarding it but I can't find it so this graph from Google will do: http://docs.engineeringtoolbox.com/documents/639/oxygen-solubility-water-2.png I'd take the lower temp side with a grain of salt though I think its more parabolic with the maximum at ~20C... I took a class for environmental engineering that dealt with DO a while back but I don't remember specifically. From what I've read on here low and high temps fuck up DO I actually read 70F is the best for DO. Most of us run boxes around 78-81 degrees so I'd say you're good at that. Honestly if you're injecting huge amounts of air through/into the water to dissipate heat and everything I wouldn't worry about DO levels I think they'd be taken care of. That's quite a tasty sentence. I think that's all I can say about that lol.