Too Much HEAT!! Help

[bamboomer]

Well, I finally transplanted my girls last week and moved them into the 'grow room' that i've set up. Yesterday was the first time to crank up the used 1000W HPS that i bought. I plan to go 12/12 in about a week or two after the plants get used to their new pots.

I built a wooden frame that is covered in panda film enclosing one corner of a spare bedroom. The space is 4' be 8' and the ceiling is 8' tall. I put a small inline 8" fan up in one corner with an inlet vent at the floor level on the opposite corner. The fan is an inline duct fan rated at 250cfm purchase from HD. Based on these specs i assume i'm turning over the air in just over a minute.

Here's my dilema. When i turned that puppy on and closed the door, the temps went up to about 91 degrees! I now have the door open and it seems to be stable at 88 deg. But this is still too hot and i'm trying to figure out a solution. With a 1000W HPS do i need to get a much larger fan than this? I guess another option is to find a 600W light which would probably be enough for my flowering room since i'm only flowering 4 plants at a time.

Can anyone comment on this? I'm wondering what size fan i should be using for this 1000W HPS. BTW... the light ballist is outside of the grow room and the light doesn't have a cool tube or any type of isolated cooling. It also doesn't have a glass sheet under the bulb.

 

[R00th4x0r]

Get a much more powerful fan (and wider holes to let air in/out).

I used to run a 400w in that kind of space and it would be too hot unless it was the winter.

 

[Mackawber]

Get an intake fan

Get an intake fan

What is the temperature of the air outside? If it's cold outside then you're in luck. If it's hot (down under this time of year) then you would need an AC unit or evaporative cooler (if it's low humidity).

If the air is cold outside then get an intake fan to suck in the cold air from outside and discharge/direct that cold air towards the top of the room. Your exhaust fan for the hot air--Is it blowing out the hot air from the top of the room? (hot air rises, cold air sinks).

I have an intake fan that sucks in cold air and a exhaust fan that blows out the hot air on top. They are controlled by a thermostatic controller (a TMP-1) unit that you set the temperature with. For lights off when it gets cold, I have a small electric heater (set to energy saver mode) that comes on at 60 degrees. The heater is on the floor where it's coldest.

Using all those pieces of equipment, I maintain 74 degrees during lights on and 62 degrees lights off. I can do this when it's cool outside. If I want to grow in the summertime then I would need to get an AC unit.

Happy growing!

 

[bamboomer]

cold outside... hot inside!

cold outside... hot inside!

Hey thanks guys... this really helps. Any idea what size fan i should be using for a singe 1000W HPS fixture? I have an 8" dia inline duct fan which is at the top of the room. It is attached to one of those flexible 'dryer hoses' and takes the air out of the room through a window.

Mackawber, funny you should ask about the temp outside. Today we are getting our first snow of the season and it's been going all day, now accumulated to about 5" deep. Temp outside is about 29 deg F and expected to stay cold the rest of the week.

I didn't think about cycling the cooler air from outside. With the exhaust fan at the ceiling, I guess it would make sense to put the same size fan pulling air from outside with an intake near the bottom. I'm just wondering if i should also step up to a larger fan for both inlet and exhaust. What do you folks think?

 

[FreezerBoy]

How large is your intake? fan-intake calculator

 

[ThisBuds4You]

Are you using one of those Home DePot 8" inline duct fans? You're gonna need a good fan, a kickass, badass fan. Look at some sort of centrifugal fan, like a Vortex. And with a 1K, you will prob need an 8".
--
TB4U

 

[Mackawber]

Get one of those TMP-1 thermostats too and have its sensor located at in the shade at the same level as your plant tops so it can accurately sense the temperature. Let it control our fans. Set the thermostat for the low 70's.

Get a remote thermometer too. That way you don't even have to go into your grow room to know what the temperature is! Their cheap! 20 bucks at ACE, WalMart (0n line) etc.

 

[maryj315]

That light will keep that space 10 degrees hotter than the ambient room temp you can get all the big fans you want but have to get that hot air out of their

I say if you are not going to use air cooled hoods to vent that hot air completely out of the room then you are going to need a dedicated cooling source 10000 btu should cover it and it gives you room for your second 1000 no sense in wasting a 4 x 8 space or turn your thermostat all the way down

I run 2000 watts in southeast Texas all year in a 10 x 12 room air cooled hoods heat vented to the outside using 12000 btu i can keep a temp of 65 degrees in the middle of summer

Mj

 

[bamboomer]

Better, but...

Better, but...

Well, with the temp in the 20's outside I cracked the window open and put a fan blowing toward the open door of the "grow room". The temps next to my plants dropped from 91 deg to 84 deg. So, much better but this is not a permanent solution by any means.

So, i'm thinking I'll prob need to get a bigger fan for the exhaust and maybe put a small fan in the window to duct the outside cooler air into the grow room.

I can't afford to spend too much so looking for the best solution at the lowest cost!

 

[riverrat]

Here is how I’m solving my heat problems. I have 2 HID lights one is a 600 and the other is a 400. I have enclosed them in a box with a sealed glass bottom. I’m using a 6 inch Can-Fan to draw air through the box. With the grow chamber sealed, my temps are running about 88-90 F. My grow is in an attached garage has to be very stealthy. My Can-Fan is up in the attic and far away so I don’t have much fan noise in the garage, but I’m am working on air flow noise. Anyway 90 F is too hot for my liking. ( I want 70 F) and I’m in a rental house so I can’t cut a hole in the outside wall and install an A/C. It would be too noisy to install in a box inside the garage and I’d have to deal with the water condensing from it.
I’m using 6 computer type 4 inch fans rated at 130 CFM each to pull through my filter system and circulate air around the sealed grow chamber. I haven’t added CO2 yet, but that’s next to add after I get a couple of grows done. Anyway, what I’m putting together now is a water cooling system for the grow chamber consisting of a , used auto A/C evaporator coil ($1.00 on EBay),and a used 8 cf. chest freezer off Craigslist ($50.00) . My plan is to put a tank into the chest freezer containing about 15 gal. of a coolant solution, then circulate that 0F or colder solution through the A/C evaporator coil installed in the grow chamber which has air sucking through it from the fans. I have the parts and have run some preliminary test using a ice water bath and have gotten output air temps from the coil down to about 50 F. So I’m pretty sure once I get the freezer plumbed and filled with coolant, the system will work great.
The freezer is very quiet and looks natural in the garage. I haven’t decided on what I’m going to use as a coolant solution yet. I have a source for ethylene glycol but that stuff is toxic and I don’t want it in the freezer where I will also have food. I could use propylene glycol which is non toxic but cost about $25.00 a gal. and I’d need about 10 gal. of the stuff so cost is too high for that. I think I’m going to settle on a salt brine solution which is cheap and effective but will likely corrode up my aluminum evaporator over time. Anyway if you decide to try something like this, make sure you get a evaporator that has the plastic drain housing because water will condense off that evaporator. I drain mine back into the reservoir. Also be very careful cutting holes in the freezer for the piping. Freezers have the cooling coils wrapped around the sides and if you cut into one you will ruin the freezer. I’ll keep you posted on how well it works once I get all the parts installed. I’ll put up some photos of the grow in a few days, I got 2 Blueberries and 2 White Widows about 2 weeks into flower right now and looking forward to my harvest in about 6 weeks. I had to shut my old grow down and move a couple months ago and I’m down to nothing but left over trim to smoke. So you guys know what my weekend project is. I’ll post next week on how it is all working.

RR