Timer question

i will be using a 1000 HPS light in a 4x4x8 grow area. Does my exhaust fan need to be on at all times the lights are on or can i set the fan on a timer. Say 5 min on for every hour of light?

 

Needs to be on all the time

 

Don't listen to him ^^^

It only needs to be on to maintain the temperature, humidity and if your not using a Co2 Generator then to bring in fresh air.

Besides that you don't want your fan on constantly during the night cycle if the temperature outside is too low(or high) Since there the 1000w won't be on to bring the temperatures up night time temps will be too low and cause problems with delayed flowering, nutrient uptake problems, and a substantial loss on yield.

Now what I'm saying above would suggest that the fan shouldn't be on in the night time hours. And that is not true, if the fan were left off during the night cycle the humidity would go sky high and cause the similar problems as if it were left on.

What you need to do is control the fan based on temperature and humidity. To do this you need a Climate Controller. Such as a Harvest Master, Growtronix.com or a General Hydro type mechanical controller. Cheapy options include a humidistat and thermostat which could be got from Home Depot.

Too many growers fail to maintain there climate and then wonder why they don't get the 2-3 lbs a 1000w like there supposed too.

 

hmm interesting. I know the temp should be between 70-80 degrees F. What should my humidity be? i was thinking about leaving the fan on only while the lights were on but what you are saying makes sense.

 

A. You need both intake and exhaust for optimum ventilation, esp. with that much light in such a small space.
B. You'll need to cut holes and use tools.
C. Fans are rated in CFM, which is cubic feet per minute air flow.
Determine the cubic feet of your grow space (w x l x height) and get fans rated to move that much air per minute.
You should also place an oscillating fan inside the growroom for air distribution and stem strength.

The fans should be on full-time.

Obviously in the intake is directly to the outside and it's chilly outside you might want to have the fan run only part time during lights off.


Btw, it's an advantage to have the lights-off temps lower by 10--15 degrees (F) during lights off than when they're on.

 

Your correct I was reffering to having the fan on during the daylight period. To maintain constant air flow and remove odours you need the fan on all the time. If you need to adjust temp etc either control the fans speed or better still increase you air intake (Easiest way is to make a few holes near the bottom of your grow space). Theres no need to overcomplecate things with fancy computer programs etc.

 

Datman do you have a vested interest in this site you seem to be avertising.

 

Datman please be a little more polite insted of saying dont listen to him try saying 'in my opinion' we all have are own ways of growing most of which work just fine. Not everybody wants to or needs to be as anylitical as growing with a computer. Saying that though if your that way inclined it propably does produce excellent results.

 

recent phot

 

Ranger, I'm glad you mentioned stem strength, seems like folks skip over that part when reading manuals. The wind is there to blow the grass around, just like out doors, which in turn bulks the stem/branches so that when cones get heavy they won't bow down to any law including gravity.

 

An oscillating fan is one of the most important pieces of equipment in your room. Like you say they strenghthen stems enables lights to be closer by cooling tops of plants increase CO2 flow help to prevent pests and mould .Know this is off the subject just thought i would mention it.

 

If you have a 1000 Watter in such a small place as a 4x4x8 closet, you will need monster ventillation to keep cool in there. And you will need it full blast all the time during the day.
Do you have any idea how hot a 1K'er HPS gets?

 

This is a little off topic but it is something I have wanted to do for a while. If you where to use a piece of plywood, or melamine or something to raise up the grow room floor. Then drill a bunch of little holes. Then have the intake go in from there, for a nice even distribution. Any thoughts?

 

As a matter of fact I do :sunglasse at this moment I'm running a 4" exhaust fan in a 5.5x5.5x6 room with a 1kw lite and 1tower fan.

Sounds bad don't it until you realize that the temp here is about 40 - 50f at night year round (when lite is on) and rarely gets over 70f in the day.

See one needs to take local weather into consideration when setting up room, if I took all these other ideas I'd have spent way too much on parts

 

Naturalhi are you fibbing?

 

I might make fun, make jokes, answer weirdly, but I don't lie I can never keep up with the lie to keep it going, soory if I disapoint!

 

I know that naturalhi. Orangatangs cannot lie. Your weather stays very cool at night here in the UK it can regularly be 70 at night during the summer months.

 

I'm told there's a great cold river of water running right by here about 2miles off shore, haven't used AC in 4yrs. by the same token haven't shut the furnace down in 4yrs.

 

Wish I could say that, goes from snow to 106 in a matter of 2 months.

 

Sounds like a few places I've lived, Orangs are nomadic you know.