Grow Room A/C

[CannabisJohn]

hey john, have question on a new build/setup.. i am looking at a roughly 25'x45' room build out.. would probably start out at 16K in lights and soon bump it up to 24K. they would be open hood with ballasts outside the room. had a couple questions about sizing the ac.. do you think that a 10 ton unit would cut it for when all 24k lights were going, and is there any concerns in running a too large ac for the lights..(like if i had a 10 ton going with only 16K) i am not in cali.. summer time highs are mid 90's for maybe a week or 2...

A 10 ton may not handle it completely for every day and temperature outside. I would do 12 tons with multiple units like 2- 5 ton units and 1- 2 ton unit. You can go bigger units if you have 3 phase power such as a 7.5 ton and 5 ton. The 7.5 ton should handle 16k in lights so install both and leave the 5 ton off until you add more lights. I like multiple units so in case 1 goes down you still have some cooling.

 

[el boyo]

A 10 ton may not handle it completely for every day and temperature outside. I would do 12 tons with multiple units like 2- 5 ton units and 1- 2 ton unit. You can go bigger units if you have 3 phase power such as a 7.5 ton and 5 ton. The 7.5 ton should handle 16k in lights so install both and leave the 5 ton off until you add more lights. I like multiple units so in case 1 goes down you still have some cooling.

will have 3 phase... will installing 2 units cost a bunch more than just doing the single 12 ton?

 

[CannabisJohn]

will have 3 phase... will installing 2 units cost a bunch more than just doing the single 12 ton?

Install is more but equipment maybe a little less total. Word to the wise. Spend the extra NOW so you get some piece of mind later.

 

[el boyo]

thanks john.... you are the man......

 

[soaringfast]

How do I disconnect my mini split? I have a vacpump and the manifold so I guess what I'm missing is a vessel to put the oil from the lines in?

 

[CannabisJohn]

How do I disconnect my mini split? I have a vacpump and the manifold so I guess what I'm missing is a vessel to put the oil from the lines in?

You need to pump down the unit down or recover the refrigerant with a recovery machine not a vacuum pump.

 

[manicgrower]

I have a question. I have a 36kbtu Frederich mini split. Its at my old location and I need to move it to my new op. Is there a best way to un-hook it? Is there a way to save the coolant? Im going to have a certified a/c guy re-install it, but need to remove it myself. Thanks in advance!

 

[CannabisJohn]

I have a question. I have a 36kbtu Frederich mini split. Its at my old location and I need to move it to my new op. Is there a best way to un-hook it? Is there a way to save the coolant? Im going to have a certified a/c guy re-install it, but need to remove it myself. Thanks in advance!

Saving the coolant is what we call pumping down the unit. Start the unit. Then at the outside unit there is 2 valves located where the copper lines hook up to outside unit. These should be operated by an allen wrench. Close the smaller one. Let unit run for 7-10 mins. Then quickly turn unit off and close big valve. This should trap the coolant in the outdoor unit or at least most of it.

 

[funkysmoker]

just wanted to say great thread , ;)

 

[BrosephStalin]

So my Mitsubishi mini-split started acting erratically lately. Some days it keeps it cool just fine, then one day my temps will raise WAY up. Then the next few days it's fine. For example, 2 days ago it got over 90* in the room and yesterday it stayed at 77* right where I set it. Outside temps have remained consistent. No codes are being thrown on the indicator light. What could be wrong and how can I troubleshoot? Thanks.

 

[silverhaze]

Hey CJ,

I have a 22k Soleus with heat pump. Unit works great but just tried the heat pump and it is unresponsive. Light comes on but no fan or heat. Is there something I can check on my own that could cause the heater not to fire? Thanks John,

 

[CannabisJohn]

So my Mitsubishi mini-split started acting erratically lately. Some days it keeps it cool just fine, then one day my temps will raise WAY up. Then the next few days it's fine. For example, 2 days ago it got over 90* in the room and yesterday it stayed at 77* right where I set it. Outside temps have remained consistent. No codes are being thrown on the indicator light. What could be wrong and how can I troubleshoot? Thanks.

Too many possible problems.

 

[CannabisJohn]

Hey CJ,

I have a 22k Soleus with heat pump. Unit works great but just tried the heat pump and it is unresponsive. Light comes on but no fan or heat. Is there something I can check on my own that could cause the heater not to fire? Thanks John,

You have no heater per say. For a heat pump the a/c compressor provides heat and cooling. So if it cools good then best guess would be you set something wrong on remote or you don't have a heat pump.

 

[silverhaze]

You have no heater per say. For a heat pump the a/c compressor provides heat and cooling. So if it cools good then best guess would be you set something wrong on remote or you don't have a heat pump.

Thanks John.

 

[silverhaze]

I checked to be sure and it is surely supposed to have a heat pump. Is there some special procedure on the remote that I'm missing? Let me know if you can think of anything, this is the one I have:
SOLEUS KFHHP-22 22000 230 12.83 / 33.07 46.38 / 37.40 8.94 / 16.54
HEAT PUMPS
Single Zone - 16 SEER - R410A - Elegant Design - Energy Saving With Low Power Consumption - Ultra Quiet Operation - Attractive LCD Wireless Remote Controller - Efficient, Easily Removable and Cleanable Air Filters - 5 Operating Modes: Cool, Heat, Dehumidify, Auto, & Fan - Oscillating Louvers - Programmable Settings: Timer, Temperature, & Mode - Low Noise Level, High Efficiency Compressor - Operates in High Outdoor Temperatures.

 

[CannabisJohn]

I checked to be sure and it is surely supposed to have a heat pump. Is there some special procedure on the remote that I'm missing? Let me know if you can think of anything, this is the one I have:
SOLEUS KFHHP-22 22000 230 12.83 / 33.07 46.38 / 37.40 8.94 / 16.54
HEAT PUMPS
Single Zone - 16 SEER - R410A - Elegant Design - Energy Saving With Low Power Consumption - Ultra Quiet Operation - Attractive LCD Wireless Remote Controller - Efficient, Easily Removable and Cleanable Air Filters - 5 Operating Modes: Cool, Heat, Dehumidify, Auto, & Fan - Oscillating Louvers - Programmable Settings: Timer, Temperature, & Mode - Low Noise Level, High Efficiency Compressor - Operates in High Outdoor Temperatures.

Not to be stupid but make sure it is in heat mode and temp set point is above room temp.

 

[silverhaze]

Yeah I hear ya. I feel stupid asking. Heat (Red) light is on when in heat mode, room is in the 60's and I've tried it all the way up as high as it will go. You're saying if the cool works though, the unit should work in this mode too right? Hmmmm...

 

[srs bznz]

Hi CJ,

I've spent a while lurking your thread and would first of all like to thank you for the effort you put into that thread. You've set quite a few dangerous ideas right before some terrible decisions were made, so here have some smiley faces and internet karma back patting or something :cool::):D I'd also like to apologize if this is all redundant, this threads a little difficult to navigate.

that said, I'd like to double check with you before I invest thousands of dollars. In a few months I'll be running 8 x 1kw HPS in vented hoods and ~2kw unvented supp bulbs.
ballasts outside of the room, building and room poorly insulated, sealed room, tank co2, soil
The space is ~14 x 16 x 8 in a garage in the bay area, and the lights will run 6pm to 6am (decently cold night temp here)
Calculating at 4k btu per kw of vented light and 5k per kw for the unvented MH(orCMH, which should be more efficient/less heat) that's still something like 40-50k BTU. I'm all for guessing on the safe side of things, but this seems like overkill to me. I feel like I should be looking for a unit close to half that size, is that correct?

I'd also love recommendations on minisplit purchasing and installation. I'm willing to void my warranty to save 50% as long as the installation isn't too complex - those precharged line kits seem just right. I'd also entertain the idea of having an HVAC guy do the final line charging - I'm legal but I'd rather keep new folks out of my garage...

Also, if anyone is running a similar setup I'd like to know how their conditions differ and what equipment they use for cooling.

 

[CannabisJohn]

Hi CJ,

I've spent a while lurking your thread and would first of all like to thank you for the effort you put into that thread. You've set quite a few dangerous ideas right before some terrible decisions were made, so here have some smiley faces and internet karma back patting or something :cool::):D I'd also like to apologize if this is all redundant, this threads a little difficult to navigate.

that said, I'd like to double check with you before I invest thousands of dollars. In a few months I'll be running 8 x 1kw HPS in vented hoods and ~2kw unvented supp bulbs.
ballasts outside of the room, building and room poorly insulated, sealed room, tank co2, soil
The space is ~14 x 16 x 8 in a garage in the bay area, and the lights will run 6pm to 6am (decently cold night temp here)
Calculating at 4k btu per kw of vented light and 5k per kw for the unvented MH(orCMH, which should be more efficient/less heat) that's still something like 40-50k BTU. I'm all for guessing on the safe side of things, but this seems like overkill to me. I feel like I should be looking for a unit close to half that size, is that correct?

I'd also love recommendations on minisplit purchasing and installation. I'm willing to void my warranty to save 50% as long as the installation isn't too complex - those precharged line kits seem just right. I'd also entertain the idea of having an HVAC guy do the final line charging - I'm legal but I'd rather keep new folks out of my garage...

Also, if anyone is running a similar setup I'd like to know how their conditions differ and what equipment they use for cooling.

Those pre-charged line sets come with shitty units IMO. I would avoid those if possible. Get a good HVAC tech and do Mitsubishi mini splits. Your calcs are good. If you can afford it get two 2 ton Mitsubishi minis. Either that or insulate better and try one 3 ton unit.

 

[srs bznz]

Thanks for the quick response. I think I'll start with a single 3 ton as it'll be cold season here for a while, and we're only running 4kw thus far (ramping to 6 or 8 shortly)

A question on insulation: I assumed that weak insulation would actually work in my favor as the outdoor temperatures will always be lower than my room temps from 6pm to 6am, but you seem to imply otherwise. Does the A/C loss to insulation somehow outweigh the heat loss to insulation?