Grow Room A/C

[CannabisJohn]

Hi CB, Just installed my 2nd 30k btu LG for a total of 60k btu's. room is approx 30 x 10(on one end and 15' on the other, triangular kinda?), dual dehumid, 4 burner CO2 generator, ballasts all outside room running 7400w bare bulb verts, 10 wall fans. Seems the AC's can't keep my temps where i want them. got (4) different thermometers throughout the rooms. I have the AC's about 15' apart from each other on the same side. What do you think?

Depends on where you are measuring the temperatures. The units sense temperature internally. Temps will vary thru out the room.

 

[Chrondondalae]

Hey CJ. Setting up a new place and i've got a couple of questions. There will be two flower rooms each 24x30 completely sealed. 20k in each w/ co2 burner, ballasts in room, dehu and humidification. 2x 5 ton in each. My question has to do with placement of the units and ducting. Rooms will have 4 rows of 5 lights. My plan was to have both units at one end 8 feet apart each with a 12" duct running the length of the room between rows 1 and 2 and rows 3 and 4. Ducts would have 2" holes every 10-12" on each side.

Do you think this will work ok? Would it be better to put the units at different ends of the room? I could run two ducts off each unit also if that would be better. Just looking for some direction. I have run 24k in 24x36 sized rooms with this set up and it always seemed either too cold or too hot. AC was either cranking to catch up or it was just cold from the AC's blasting so hard. Hard on the plants, VPD issues. I truely appreciate you taking the time to respond.

 

[CannabisJohn]

Hey CJ. Setting up a new place and i've got a couple of questions. There will be two flower rooms each 24x30 completely sealed. 20k in each w/ co2 burner, ballasts in room, dehu and humidification. 2x 5 ton in each. My question has to do with placement of the units and ducting. Rooms will have 4 rows of 5 lights. My plan was to have both units at one end 8 feet apart each with a 12" duct running the length of the room between rows 1 and 2 and rows 3 and 4. Ducts would have 2" holes every 10-12" on each side.

Do you think this will work ok? Would it be better to put the units at different ends of the room? I could run two ducts off each unit also if that would be better. Just looking for some direction. I have run 24k in 24x36 sized rooms with this set up and it always seemed either too cold or too hot. AC was either cranking to catch up or it was just cold from the AC's blasting so hard. Hard on the plants, VPD issues. I truely appreciate you taking the time to respond.

I like your idea of both at same end then the opposite thermostat is not affected by running unit. I would do at least 16 inch duct. 18 would be better. Also skip the small holes. See a sheet metal shop and have some saddles made for the round duct to a rectangle register and then install supply air registers on sides only. 12x6 registers work fine. Maybe 4-5 registers per side per duct run for a total of 8-10 per unit. Works better than a shit load of small holes. Also make sure stats are not affected by cold air for either unit.

 

[advanced396]

CJ
I was told I need to purchase a low ambient controller for my AC to run in the winter. Will a RANCO 016-616-000/72H51 LOW PRESSURE CONTROLLER/SWITCH 170447
Work on a Goodman 5 ton 13 seer? Also how do I wire this up?
Thanks

 

[CannabisJohn]

CJ
I was told I need to purchase a low ambient controller for my AC to run in the winter. Will a RANCO 016-616-000/72H51 LOW PRESSURE CONTROLLER/SWITCH 170447
Work on a Goodman 5 ton 13 seer? Also how do I wire this up?
Thanks

No. You need a fan cycling switch to cycle the condenser fan. Try Johnson controls Mfg. # :P70AA-400C. This is adjustable. Connect pressure tube to your high pressure line and wire to interrupt one leg of the condenser fan circuit. Pressure adjustment depends on type of refrigerant. If you do not understand this then get a pro. Also check with Goodman and see what they say.

 

[advanced396]

No. You need a fan cycling switch to cycle the condenser fan. Try Johnson controls Mfg. # :P70AA-400C. This is adjustable. Connect pressure tube to your high pressure line and wire to interrupt one leg of the condenser fan circuit. Pressure adjustment depends on type of refrigerant. If you do not understand this then get a pro. Also check with Goodman and see what they say.

The units are r410 so where would I set the pressure to?

Thanks

 

[advanced396]

Cj
also I came across this one a Ranco Low Pressure Control 010-1402. Is this the same as a Johnson control 70AA-400 ?
Thanks

 

[CannabisJohn]

The units are r410 so where would I set the pressure to?

Thanks

About 300 lbs with a 60-70 lb differential.

 

[CannabisJohn]

Cj
also I came across this one a Ranco Low Pressure Control 010-1402. Is this the same as a Johnson control 70AA-400 ?
Thanks

Ranco is not as good. A low pressure control is not the same as a fan cycling switch. Look at the specs.

 

[advanced396]

Ranco is not as good. A low pressure control is not the same as a fan cycling switch. Look at the specs.

Do you think I need a crankcase heater?

 

[CannabisJohn]

Do you think I need a crankcase heater?

How cold does it get where you are? If below 40F then would be a good idea.

 

[sicinsane]

hey CJ is there any easy to install do it yourself mini splits?

 

[CannabisJohn]

hey CJ is there any easy to install do it yourself mini splits?

Hire a pro or follow directions exactly

 

[advanced396]

How cold does it get where you are? If below 40F then would be a good idea.

Yes it gets to 15F
Any other ideas on what more I might need?
Thanks

 

[CannabisJohn]

Yes it gets to 15F
Any other ideas on what more I might need?
Thanks

Make sure the outdoor unit is set higher than the snow line if you get snow. Other then that can't think of much else right now.

 

[Chrondondalae]

I like your idea of both at same end then the opposite thermostat is not affected by running unit. I would do at least 16 inch duct. 18 would be better. Also skip the small holes. See a sheet metal shop and have some saddles made for the round duct to a rectangle register and then install supply air registers on sides only. 12x6 registers work fine. Maybe 4-5 registers per side per duct run for a total of 8-10 per unit. Works better than a shit load of small holes. Also make sure stats are not affected by cold air for either unit.

So are you talking flexible or solid ducting for the main run? Thanks again.

 

[CannabisJohn]

So are you talking flexible or solid ducting for the main run? Thanks again.

Solid duct. Either spiral ( comes in 10 ft lengths) or KD ( comes in 3 ft lengths). KD can be hung by one person if needed. Spiral is better duct but more expensive.

 

[Chrondondalae]

Ok. A bit more entailed than running 12" flexi duct with a bunch of holes in it, but so be it. If it will work better I'm all for it.

 

[CannabisJohn]

Ok. A bit more entailed than running 12" flexi duct with a bunch of holes in it, but so be it. If it will work better I'm all for it.

It is but it will work better.

 

[Chrondondalae]

You are the man CJ. Got another question for you. I was planning on using some H20 coolers for my veg but my dumb ass didn't winterize them in storage. Some froze up and some copper pipes cracked, so I'm fooked on those. Room will have 8k adjust a wings and 4x 8bulb T5's. I do have an extra 5 ton Excel, would that be too big?