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HVAC question

F

fastbacker

New member
First post here. Been growing 22+ years for a living. Getting ready to jump into sealed rooms for the first time...

I'm looking to build two 4000 cubic foot flower rooms inside a warehouse in the SF Bay Area. Each room will have 16) 1000w de lights, 2) Quest 225's and a large sulphur burner. Ambient high temps will be 80 in the summer but only 60 in winter. AC compressor will be inside building in mezzanine with a room sized wind tunnel like exhaust system.

Are packaged units the way to go for simplicity? 7.5 tons per 16 light room sound about right?

Thanks! Hope this question is in the right section.
 
S

Speed of green

Active member
7.5 tons sounds right, 4500-5000btu per DE lamp should be ample.

By packaged unit do you mean a full split system that comes with a condenser and air handler? if so then yes i would go this route instead of trying to piece together a air handler and condenser from different manufacturers.

Most any 5ton+ commercial full split system is going to be three phase on the condenser, not sure what your electrical situation is.

Idk your grow style or if your space allows but you might want to add some additional square footage for walkways. the footprint on the DE's is 25sf or 5x5, and im assuming your ceilings will be 10' so at 4000cuft that leaves exactly enough footprint for your 16 lights.

Do you have any info on the large sulphur burner? ive only seen the coffee can design online and they say they only cover 1000cuft. i need to cover 26,000cuft.
 
F

fastbacker

New member
Speed of green said:
7.5 tons sounds right, 4500-5000btu per DE lamp should be ample.

By packaged unit do you mean a full split system that comes with a condenser and air handler? if so then yes i would go this route instead of trying to piece together a air handler and condenser from different manufacturers.

Most any 5ton+ commercial full split system is going to be three phase on the condenser, not sure what your electrical situation is.

Idk your grow style or if your space allows but you might want to add some additional square footage for walkways. the footprint on the DE's is 25sf or 5x5, and im assuming your ceilings will be 10' so at 4000cuft that leaves exactly enough footprint for your 16 lights.

Do you have any info on the large sulphur burner? ive only seen the coffee can design online and they say they only cover 1000cuft. i need to cover 26,000cuft.
Click to expand...

Oops, I meant CO2 burner not sulphur burner.

As far as cubic footage, the space I'm about to put an offer in on has 8.5' ceilings...plants just off the floor...so small aisles.

I'm trying to figure if I want a package unit like a roof top unit or a split system where the compressor is separate from the air handler.
 
S

Speed of green

Active member
you want it split, compressor on your mezzanine and your line-set ran to the air handler mounted inside/on top of the room.

Are you running the rooms flip flop? if so you can have two air handlers running to one compressor.

Alternatively you could duct the rooms together from the same air handler, but you may run into contamination issues if you ever have bugs or mold. ideally you want these rooms completely separate in the event of an invasion.

8.5' ceilings can work, the canopy will need to be well managed.
 
F

fastbacker

New member
No flip flop...don't want to work at night! Plan is to have to independent systems. Was figuring a split system would be the way to go but am attracted to the ease of a package unit.
 
M

mushroombrew

Active member
Veteran
8.5ft ceilings with DE does not sound good. I like 10ft even with SE. Way better canopy temps.
I like flip flop. Half the draw. Half the AC demand. I flip at 10am/pm. So can you easy get two hours in the morning. 4 for me I am up early.

Two rooms that size I would run ductless. You can run 4 heads off a 5ton. I like two minimum per room in case one needs service.
 
F

fastbacker

New member
With the plants just off the floor and the de hoods all the way up to the 8.5' ceiling (no vertical ballast...remote phantom), I have no worries about bud temps. I know how to keep a flat canopy with proper air movement above it.
 
S

Speed of green

Active member
twins, i see.

If you run it ducted you will need to have two ducts going to each room, one for return to unit and one for cold air from the unit, this leaves more opportunity for odor to escape.

If you only run one duct and pull air from the mezzanine you will create positive pressure and force odor out of the rooms.

What specifically is the ease that attracted you to the ducted unit? it seems like a lot more work to plumb all that ducting VS a couple copper lines and some wire.

https://www.mecart-cleanrooms.com/wp-content/uploads/sites/2/2016/08/modular_etc7-e1476451777787.jpg
 
F

fastbacker

New member
Speed of green said:
twins, i see.

If you run it ducted you will need to have two ducts going to each room, one for return to unit and one for cold air from the unit, this leaves more opportunity for odor to escape.

If you only run one duct and pull air from the mezzanine you will create positive pressure and force odor out of the rooms.

What specifically is the ease that attracted you to the ducted unit? it seems like a lot more work to plumb all that ducting VS a couple copper lines and some wire.

https://www.mecart-cleanrooms.com/wp-content/uploads/sites/2/2016/08/modular_etc7-e1476451777787.jpg
Click to expand...

I guess I know less about ac than I thought...hence the post here.

So, a package unit needs a cold air return? And a split system does not? The reason I was saying I was attracted to the package unit was I thought I could run it without ducting (straight down into room) and I didn't realize you needed a cold air return.

I did consult a pro hvac guy who works in this industry but he charges $2500 just to sit down and design the system over a day or two. Seems a bit pricey.
 
S

Speed of green

Active member
fastbacker said:
I guess I know less about ac than I thought...hence the post here.

So, a package unit needs a cold air return? And a split system does not? The reason I was saying I was attracted to the package unit was I thought I could run it without ducting (straight down into room) and I didn't realize you needed a cold air return.

I did consult a pro hvac guy who works in this industry but he charges $2500 just to sit down and design the system over a day or two. Seems a bit pricey.
Click to expand...

Thats correct, the ductless split system requires no ducts to or from the compressor. just two copper lines and a wire running from the mezzanine(compressor) to the grow room (air handler).

you may want a duct that disperses cool air evenly around your flower area but this is very minimal work.

the ducted all in one system requires two ducts to and from the grow room.


Idk how involved with the construction you want to be on this but once the compressor and air handler are in place the rest of the installation is a breeze & should be fairly inexpensive.

I can almost guarantee any Cannabis related HVAC consultant is going to be at least 2x or 3x more expensive than a regular HVAC guy.

these systems are not complicated to install, running power & refrigant lines, hoisting the units on the mezzanine, & installing the air handlers, this is all simple stuff you could complete before the HVAC guy even arrives.

That way when he gets there all he has to do is hook up some power lines, vacuum the line-set and test the system. saving you thousands.
 
F

fastbacker

New member
Speed of green said:
Thats correct, the ductless split system requires no ducts to or from the compressor. just two copper lines and a wire running from the mezzanine(compressor) to the grow room (air handler).

you may want a duct that disperses cool air evenly around your flower area but this is very minimal work.

the ducted all in one system requires two ducts to and from the grow room.


Idk how involved with the construction you want to be on this but once the compressor and air handler are in place the rest of the installation is a breeze & should be fairly inexpensive.



I can almost guarantee any Cannabis related HVAC consultant is going to be at least 2x or 3x more expensive than a regular HVAC guy.

these systems are not complicated to install, running power & refrigant lines, hoisting the units on the mezzanine, & installing the air handlers, this is all simple stuff you could complete before the HVAC guy even arrives.

That way when he gets there all he has to do is hook up some power lines, vacuum the line-set and test the system. saving you thousands.
Click to expand...

Thanks!!! All great info! Now I just need to figure out how many tons and pick a model.
 
F

fastbacker

New member
Speed of green said:
Thats correct, the ductless split system requires no ducts to or from the compressor. just two copper lines and a wire running from the mezzanine(compressor) to the grow room (air handler).

you may want a duct that disperses cool air evenly around your flower area but this is very minimal work.

the ducted all in one system requires two ducts to and from the grow room.


Idk how involved with the construction you want to be on this but once the compressor and air handler are in place the rest of the installation is a breeze & should be fairly inexpensive.

I can almost guarantee any Cannabis related HVAC consultant is going to be at least 2x or 3x more expensive than a regular HVAC guy.

these systems are not complicated to install, running power & refrigant lines, hoisting the units on the mezzanine, & installing the air handlers, this is all simple stuff you could complete before the HVAC guy even arrives.

That way when he gets there all he has to do is hook up some power lines, vacuum the line-set and test the system. saving you thousands.
Click to expand...

Would a whole house system fit the bill?
 
S

Speed of green

Active member
yeah any split system, residential/ commercial doesnt matter, same principle.

pretty much any residential system is going to be 5 tons or smaller and run on single phase.

commercial is going to be three phase and 5ton+ for the most part.

you could do multiple smaller residential units on a commercial building, it happens all the time, i honestly think this is better in the event of a failure you have some redundancy. the smaller units also have higher efficiency ratings.

Buying in California is always fun, multiple buyers cash at asking price, bidding wars, housing is outta control for sure. ill wait for the next financial crisis or natural disaster to buy.
 
S

Speed of green

Active member
yeah any split system, residential/ commercial doesnt matter, same principle.

pretty much any residential system is going to be 5 tons or smaller and run on single phase.

commercial is going to be three phase and 5ton+ for the most part.

you could do multiple smaller residential units on a commercial building, it happens all the time, i honestly think this is better in the event of a failure you have some redundancy. the smaller units also have higher efficiency ratings.

Buying in California is always fun, multiple buyers cash at asking price, bidding wars, housing is outta control for sure. ill wait for the next financial crisis or natural disaster to buy.
 
F

fastbacker

New member
Speed of green said:
you could do multiple smaller residential units on a commercial building, it happens all the time, i honestly think this is better in the event of a failure you have some redundancy. the smaller units also have higher efficiency ratings.
Click to expand...

I did actually consider that. More expensive I bet!
 
M

mushroombrew

Active member
Veteran
I like multiple units. They need service occasionally. And that always seems to happen when its 100f outdoors. If you only have one you will be turning off lights. Been there done that. Two units is a good idea.
 
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