Grow Room A/C

[El Cerebro]

Best way to put it about box. I would build it the same dimensions as the condenser coil height and length and then build it minimum of 2 ft deep. No window units I know that are inverter.

Gotcha, thanks.

 

[CannabisJohn]

You're right, of course, and I don't want what I'm trying to say to come across as 'my growroom is more efficient then yours' or any variation of such a pissing contest. Lots of different ways to skin this cat and I'm not saying what I'm doing is better or worse than any other approach.

That said, I am researching something specific, which is how to reduce the electrical consumption (biggest variable cost of growing) per unit weight of finished product as much as feasible and cost effective with gear that's currently available, and that does invite some comparisons. Who knows? Maybe the vertical lighting rooms with bare bulbs are actually more efficient! All I'm trying to do is figure out how to measure and quantify what I'm doing, even roughly. Since cooling is the next biggest consumer of power after the bulbs themselves, I'm thinking this is information people will be interested in when making growroom design decisions.

One more point; even bare bulb rooms need fans and ducting, leaving the main cost difference to be the sealed and vented hoods. At a couple hundred bucks each full retail, they aren't cheap. Yet, if you're running 10kW and your cooling costs are halved, how long does it take at 15-30 cents a kWH for those hoods to pay for themselves? I'm betting only a few months... Food for thought.

I love your train of thought. I think it would need an engineer to make a good number. I believe that bare bulb vertical lighting is a big improvement in end weight (at least for my buddy). He has added 4-6 oz per plant with vertical bare bulb lighting. I'm sure he has made other changes but I feel the biggest was the lighting.

 

[ttystikk]

I love your train of thought. I think it would need an engineer to make a good number. I believe that bare bulb vertical lighting is a big improvement in end weight (at least for my buddy). He has added 4-6 oz per plant with vertical bare bulb lighting. I'm sure he has made other changes but I feel the biggest was the lighting.

Thank you- I figured once I explained what I was up to well enough, you'd appreciate it as much as anyone!

I know lots of engineers- they do numbers because they have trouble with relationships, lol. Seriously, I just want to get a rough idea of a percentage change in cooling needs between one configuration and another. That would be plenty for my needs.

Your comment about your buddy's vertical bare bulb setup is intriguing. The setup needs more power usage to cool bare bulbs sitting literally inches from tender plants, yet clearly it has advantages in terms of output. Does the increased production justify the extra expense? That's the question I'm trying to get an answer to eventually...

The basic line of inquiry is really about increased efficiency. Efficiency as defined in our little world includes; higher quality product, higher yield, lower input costs, lower power consumption, smaller footprint, lower effort. This kind of increased productivity also means lower production costs per unit of finished product, which means more money in the grower's pocket at harvest time, or in a competitive market, the ability to make money at lower price points than others can.

 

[outwest]

Hey Cannabis John -

First, thanks a ton for your offer to help. My needs are pretty basic, but as we head into summer, I need to start thinking about cooling. I've got 2 600s(mh/hps) in a single hood (growzilla), cooled by a 6" active air exhaust fan. This is in a 4x4 tent that is exhausted at the top with a second 6" active air exhaust fan pulling through a scrubber. In the winter cooling is not an issue. I don't run my heat, and this setup, with a strategically placed space heater warms my home. The ambient heat in the tent is a steady 76F, and the radiant head 1 foot from the light is a steady 80F Obviously summer is a different story. No central AC here, and a window unit is not an option.

I'm considering cooling the room with one of these: http://www.tripplite.com/en/products/model.cfm?txtModelID=4462 My thinking being that if I can keep my room at it's normal 72F, then the tent will stay within the ranges stated above. This particular AC is pretty sweet because there is no drainage, it pumps the humidity out with the exhaust fan.

What do you think? Thanks again.

outwest

 

[fishwhistle]

ttystick,You must be located in an area that allows you to use outside air to cool rooms/lights and try to keep your costs down,many of us dont have that luxury most of the year so the next best thing at least for me is inverter mini's,as energy efficient as i can get of course.

 

[CannabisJohn]

Hey Cannabis John -

First, thanks a ton for your offer to help. My needs are pretty basic, but as we head into summer, I need to start thinking about cooling. I've got 2 600s(mh/hps) in a single hood (growzilla), cooled by a 6" active air exhaust fan. This is in a 4x4 tent that is exhausted at the top with a second 6" active air exhaust fan pulling through a scrubber. In the winter cooling is not an issue. I don't run my heat, and this setup, with a strategically placed space heater warms my home. The ambient heat in the tent is a steady 76F, and the radiant head 1 foot from the light is a steady 80F Obviously summer is a different story. No central AC here, and a window unit is not an option.

I'm considering cooling the room with one of these: http://www.tripplite.com/en/products/model.cfm?txtModelID=4462 My thinking being that if I can keep my room at it's normal 72F, then the tent will stay within the ranges stated above. This particular AC is pretty sweet because there is no drainage, it pumps the humidity out with the exhaust fan.

What do you think? Thanks again.

outwest

A portable a/c sounds like a good option for you. I can't recommend one brand over another because I don't install those cause anyone can do it. Be careful about the condensate cause our humidity in our rooms can get high especially if dehuey fails. This unit most likely can't dissipate humidity over 60% or so.

 

[outwest]

I'm in a pretty dry climate, so I was worried the dehuey would take more moisture out. Normally the RH is a steady 55% with a humidifier running. How do you think this AC will effect RH in my setting?

Thanks!

outwest

 

[ttystikk]

ttystick,You must be located in an area that allows you to use outside air to cool rooms/lights and try to keep your costs down,many of us dont have that luxury most of the year so the next best thing at least for me is inverter mini's,as energy efficient as i can get of course.

Today set a record for high temp here (83) for this date. It gets plenty hot here in summer, 100 plus. The outside air I was referring to was air from outside the growroom, so it could easily be air from inside your house, just not from inside the growroom. That's what I do, and it works tits... In fact, I don't recommend people use air from outdoors because the large temperature swings make mantaining stable conditions more difficult, plus the possibility of drawing nasties into your sealed growroom.

Let's take a worst case scenario, however, and you'll see this still saves cooling costs; let's say you bring 100 degree air in to cool your bulbs. Let's say that this air is kept separate (like it's supposed to be!) from all other air, including the growroom air. To do this properly, you'll want to use insulated ducting and perhaps hood blankets too, but unless you have some long runs it isn't required. You'll still come out ahead, I promise. If the temperature rise drawing that air through your hoods is 25 degrees, the air being pulled (never push air through hoods if you can help it!) out of the room is 125 degrees. Place the duct fan of your choice Downstream of the bulbs and as close to the exit as possible. For sure, insulate any ducting between the fan and the exit, it will be hot no matter what its temp was when it came in. The hot air then goes outside. You've still successfully gotten rid of most of the heat the bulbs are generating! The only thing left for the AC to cool is the radiant heat from the bulbs, which is what the plants are using to power their growth, and of course whatever else is in the room generating heat.

While this approach will not eliminate the need for active cooling, it will reduce the amount needed. As a bonus, the air used to cool the hoods should not pick up any smell on its trip, since it's supposed to be fully sealed off from the growroom air anyway, so there's no need for odor mitigation. It can be shut off when the lights are off, I suggest a 15 minute delay on startup and shutdown, so it allows the room to warm properly in the 'morning' and shed the residual heat at 'dusk'.

 

[CannabisJohn]

I'm in a pretty dry climate, so I was worried the dehuey would take more moisture out. Normally the RH is a steady 55% with a humidifier running. How do you think this AC will effect RH in my setting?

Thanks!

outwest

All depends on how much it runs. My guess is with only 1200 watts that it won't run a ton so it most likely won't lower it too much but it'll lower it. The humidifier may keep up.

 

[outwest]

Than

All depends on how much it runs. My guess is with only 1200 watts that it won't run a ton so it most likely won't lower it too much but it'll lower it. The humidifier may keep up.

Thanks a lot for contributing your expertise to the community. It's incredible valuable.

outwest

 

[El Cerebro]

I can help a little on portables - ha, they all suck! literally.

Seriously, if it's a model that vents the condensation, it's sucking air out of your space, not sealed, and horribly ineffecient. These things can end up running constantly and costing a fortune to do it. There are only a few I've found that are true dual-ducted systems, SPT advertises "no negative pressure", and I think Whytner has some better models too. Check efficiency ratings there are a few showing up lately with better SEER (relative). And even the good ones can pass some stink through the exhaust, if that's an issue for you.

 

[outwest]

I can help a little on portables - ha, they all suck! literally.

Seriously, if it's a model that vents the condensation, it's sucking air out of your space, not sealed, and horribly ineffecient. These things can end up running constantly and costing a fortune to do it. There are only a few I've found that are true dual-ducted systems, SPT advertises "no negative pressure", and I think Whytner has some better models too. Check efficiency ratings there are a few showing up lately with better SEER (relative). And even the good ones can pass some stink through the exhaust, if that's an issue for you.

Thanks for the response. I'm going to vent the exhaust out of the room. The cold output has a 6" output fitting options, so I can pipe that right into my tent. I'm hoping the combination of the two will keep things cool and happy. This model is also intended for server rooms so it's a little more robust. Fingers crossed.

outwest

 

[El Cerebro]

Link didn't work for me before, but just now had a look. Is that the price you're paying for it? Maybe more industrial quality? Still awfully pricy for 12k.

 

[outwest]

No. It can be had for under $700 new. Under $400 refurb.

outwest

 

[meg0tnutz]

Long time lurker, thanks all!..Anyhoo, CJ or anyone else, some CO's advertize precharge condenser and also precharged lineset..Does the sys still need vacuuming the line/sys, if no cutting of precharged factory lineset is needed?..TIA..

 

[CannabisJohn]

Long time lurker, thanks all!..Anyhoo, CJ or anyone else, some CO's advertize precharge condenser and also precharged lineset..Does the sys still need vacuuming the line/sys, if no cutting of precharged factory lineset is needed?..TIA..

I guess not but I don't install those type of units.

 

[Calgreen]

Can anyone recommend a good portable unit?

 

[oscar169]

Well it appears that my thread disappeared from the forum during the server change. So here goes a new one. Ask away about your grow room a/c questions.

That sucks, your thread was one of the best to read about, all the diff types of setups everyone was running, regarding A/C...:cool:

 

[CannabisJohn]

That sucks, your thread was one of the best to read about, all the diff types of setups everyone was running, regarding A/C...:cool:

True but we an restart it. Just be some work.

 

[meg0tnutz]

I guess not but I don't install those type of units.

Thanks for the quick response CJ..:cool:..You said " those type of units", do you mean mini splits in general or the precharged type?..here's the thing, if it doesn't need vacuuming the line/sys , then no AC tech needed, b/c loose lips sink ships savy!..If it does in fact need a vacuum test, then I will definitely get er done.. I'm a sparky by trade and can do everything else, just not going to purchase the tools needed when an AC guy(trust worthy) has all the right gear for specific needs..
Thanks again!..