Large Grow AC Help (50+ lights)

I heard the typical amount is a ton for every 1000w light. Can I get away with less Tonnage of AC for a large indoor grow or do I need a 50ton AC for 50 lights? I don't even see 50 Ton ac's online would I get 2 25Tons?

I think it would help to turn the large facility into a flip system, so Im only running half the lights at one time so half the tonnage but then the AC will be running day and night and have more wear?

Thanks for any help!

you got the math wrong
you need approx. 3000-3500 btu's per 1000 watt air cooled light
4,000-4,500 btu's per 1000 watts open bulb

12,000 btu's = 1 ton

20 tons should be good for your setup. Will give you a little less then 5000BTU per 1000W

Generally for doing a rough estimate, heat(btu) generated by most equipment is calculated at watts multiplied by 3.5-4.5. HID lighting and high resistance loads are on the high side of that figure. That gets added to other common factors as well, such as square footage, ceiling height, insulation, climate, etc.

As for the ac running, with 50 lights you're going to be dealing with a large air handler and several mixers, and most likely a decent sized makeup unit to get some fresh air in. Something's always going to be running.

Take a serious look at water chillers as your supply of cold air.

There are many benefits to be had utilizing chillers.

@digging can you recommend a route to go with a chiller 7K in lights.

Hi Jay. I am not sure using a water chiller for 7k of lights would be worthwhile, or the way to go.

7k of lights equals 28,000 btu's which would require a little over 2 ton chiller unit. When you take into consideration the need to purchase air handlers, the chiller, pump coolant reservoir, I am not sure if a water chiller would be the way to go.

My own experience with water chillers is with two 10 ton water chillers, a 30k of lights. My suggestion or advice direction would be that if you had say 10 -12k of lights on a flip, then water chilling would be the way to go.

Water chilling for cooling has many advantages, including dehumidifying, ability to use chiller to keep nutrient reservoir chilled, along with more efficient use of electricity is something worth investigating.

Also if you live in a cooler climate, during winter months dry coolers can be used to chill the water at a mere fraction of electrical use.

Hope this is of help to you )

tyepoe said:

I heard the typical amount is a ton for every 1000w light. Can I get away with less Tonnage of AC for a large indoor grow or do I need a 50ton AC for 50 lights? I don't even see 50 Ton ac's online would I get 2 25Tons?

I think it would help to turn the large facility into a flip system, so Im only running half the lights at one time so half the tonnage but then the AC will be running day and night and have more wear?

Thanks for any help!

Click to expand...

You need to be more specific about a number of things. What is your desired temperature? How large is the space? What are the walls and roof made of? What type of lights are you using? A decently insulated house needs approx 12000btu per 1000 sq ft just to keep it comfortable during the heat. Those are ballpark numbers. Now add the heat load of all your lights. 1000W light doesnt create 1000W of heat so you need to be specific about the lights. My lights are around 40% efficient so thats 600W of heat you would have to dissipate on a 1000W light which is 30kW on 50 lights which is 102000btu. Plus heat produced by any other loads in the cooled space like drivers and fans, etc.

Its hard to just come up with a number...