Fans making my head spin!

This is my first post here after a long time of reading, so I suppose an introduction is in order. I have been wanting to start a grow for a few years now, but the conditions have never been right. The entire time I have been waiting, reading grow logs and building knowledge while mentally planning my dream grow room. Now the pieces are finally falling in to place. I bought my own house and have about $1k set aside to do this the right way.

My house has a closet that is about 5.5'w x 3'd x 8't.. Perfect for a 600w HPS I figured! I want to start simple for my first time around, so I plan on using clones from a medical co-op in FF Ocean Forest soil. For light I plan on going with the 600w digital ballast from HTGsupply w/ the sunmaster bulb and euro reflector.

As I said before, I have been doing a lot of research and want to do this the right way from the start. That brings us back to the question at hand.. I know I need three types of air movement: air circulation inside of the cab, heat removal from the light, and air exchange. Air circulation will be taken care of with a simple oscillating fan. Its the last two that have me stumped.. I found a nice looking inline duct fan called the M-6 made by Tjernlund that claims 530 CFM at 0" static pressure. This seems like more than enough air movement to take care of both heat removal and air exchange, at least until I try to figure out the logistics. The simplest solution sould be to hook it up like this:

Outside<---<Fan<---<Light<---<Carbon Scrubber.

The problem with this is I will be sucking warm air in from the closet to cool the light.. Not very efficient imho. And on second though, I only need to be removing heat from the light when it is on (12-18 hours a day), but I need to keep air circulating in and out of the cab 24/7, right?
So maybe the answer is to get two smaller fans and control each of them independently of each other? Tjerlund also makes a smaller "duct booster fan" that moves about 180cfm at 0" SP.. Is that enough to effectively cool the lamp? It would be enough to change the air in the room once every minute, I would think that is more than sufficient.

Or am I just over thinking this and making it more complicated than it needs to be? Any suggestions would be greatly appreciated! In any case, thanks for all the info!

those duct booster fans are junk and dont move much, their just for a "boost" after the initial air is moving already.

neMMMM said:

those duct booster fans are junk and dont move much, their just for a "boost" after the initial air is moving already.

Click to expand...

Thats about what I had heard elsewhere.. So what do you recommend I do? Use the single fan to do double duty, and just run the air through my light even though its not on?

A booster fan should be fine for cooling the light. Just keep the bends to a minimum. Also it is a a good idea to have the light cooling fan on a separate timer that keep running for 15-30 minutes after lights out. Put the booster fan before the light, pushing air through the reflector and into the attic. This keeps the hot air from damaging the fans motor. For room ventilation you need to move three times your rooms air mass per minute. Rig up a thermostat and dimmer switch in parallel so that the fan is always running, at a reduced speed, until the temps get to your thermostatic set point and then the fan runs at full power to cool the room quickly. When the room is sufficiently cool the fan goes back to running on the dimmer at the lower speed. This helps to keep your room at negative pressure so no smells get out without going through the filter. It is also more efficient to push air through the carbon filter so try to do that if you can. Hope this helps. I can tell you how to build the dimmer/thermo switch if you want. Just let me know. Good luck.

That sounds perfect steve. If you have a parts list and a short writeup that would be awesome! So now I suppose I am getting close to my final parts list:

Digital Electronic 600 watt HPS Grow Light
6" Inch Inline Duct Fan <-- Room air exchange
6" Duct Booster Fan <-- Lamp cooling
Honeywell Oscillating 3-Speed Fan <-- Air circulation
GrowBright Pure Flow 6 Carbon Filter <-- Can probably replace this with a DIY to save on $$
Panda Film 6mil 10' x 25' <-- Covering all walls and the floor with Panda Film because it is much thicker than mylar.
Electronic Thermometer/Hygrometer
Truncheon TDS / EC Meter <-- Is this the way to go? I was looking at the Hanna pH, EC, TDS Meter but I heard not-so-good things..
FoxFarm Ocean Forest soil
FoxFarm Liquid Soil Formula

That should pretty much get me started, and max out my budget..

Simple,
You need
1. 1 attic thermostat, they keep it near the attic vents and roofing supplies.
2. 1 5 Amp or better rated fan speed controller. In the ceiling fan section
3. 1 2 recepticle gang box
4. 1 Male plug
5. 1 switch/outlet cover combo
6. 1 duplex outlet rated at least 15 amps
7. A few feet of minimum 14g wire. I just had some 14/2 w/ ground laying around and i used the male end of an old extension cord for the male plug. You could probably get a cheap 6' or so extension cord and use it for your wire and plug. Just make sure it is rated at least 15A.

The speed controller and thermostat both have 2 black wires coming out of them. You take your Hot (Black) wire from your plug and connect it to one black wire each of the speed control and the thermostat. Then connect a piece of insulated 14g wire to the other black wires from the speed control and thermostat. Connect the loose end of the 14g wire into the "HOT" side of your outlet. The white (Neutral) wire from your plug will connect to the "neutral" side of your outlet. The outlet is marked so it is easy to figure out. Then connect your ground wires. Then put it all together in the gang box. I fastened mine to a piece of 3/4" plywood to keep it all neat. The photo has different parts but the same wiring is used. I just put an outlet on mine for ease of operation. Any fan I plug into that outlet will be run by the speed control/thermostat. In case I needed another fan. Hope this helps. If not, just let me know.


This is Al B. Fuct's diagram.

Alright, things are starting to come together! I hope to place an order this weekend, before I leave on vacation. Right now I have:

Digital Electronic 600 watt HPS Grow Light w/ EasyCool 6 reflector.
6" Inline Duct Fan
6" Inline Duct Booster
Honeywell Oscillating 3-Speed Fan
GrowBright Pure Flow 6 Carbon Filter
Panda Film 6mil 10' x 25'
Tarp Zip-up
Truncheon TDS / EC Meter
pH Testing Kit
Electronic Thermometer/Hygrometer
pH Up and pH Down
FF nutes and soil

Is there anything else major that I am missing?

I don't know if you would need a TDS meter for a soil grow. As far as I know it is most useful in a hydro system. Check with the soil guys to be sure but it is a pretty good chunk of change for a non necessity item. Like I said I am not 100% on this so try to ask maybe in another thread to get some feedback from a soil guy.

dirtysteve said:

I don't know if you would need a TDS meter for a soil grow. As far as I know it is most useful in a hydro system. Check with the soil guys to be sure but it is a pretty good chunk of change for a non necessity item. Like I said I am not 100% on this so try to ask maybe in another thread to get some feedback from a soil guy.

Click to expand...

Yeah, that is one thing I have been debating on.. I would really like to be able to check the PPM of my water because I know it is extremely hard. I thought it would be a good thing to have when adding nutes, but maybe I dont need it?

I have a reverse osmosis unit that is just sitting there.. Do you think it would be worth hooking it up in the grow room? I would have fresh clean water right there in the room. I have read some good and bad things about using a RO system.

I am no expert, but most water hardness problems are related to Calcium and Magnesium. These are nutrients for plants, especially when flowering. The only problem really with municipal water is chlorine. If you let your water sit open to the air for 24 hours the chlorine will evaporate. Some people swear by RO water and others do very well without it. Really just personal preference. IMHO. I have a sink in my room and it is a real time saver. Because I run ebb and flow hydro I use a lot of water so it is a real convenience to me. It would be impossible to lift a full 25 gallon res and running hoses would be a pain. Like I said you should really ask some of the soil guys. There are some super sharp soil growers on here that could better answer your ppm questions. To me it is more a necessity for hydro than it is for soil. But that is only my opinion.

I was hoping some of the soil guys would pop in and give me some advice, but it looks like I may have to start chasing people down..

Bump! Any last advice? I will be ordering my gear tonight. I think I will hold off on the tds meter and just get a simple ph tester for now.

AFAIK, a lot of municipal water utilities are switching to a form of chlorine that doesn't evaporate out as easily as it used to:

http://en.wikipedia.org/wiki/Chloramine

So you really do need some form of water filtration. IMHO, reverse osmosis is just overkill for soil. I'm planning on either a two-stage (carbon/sediment) filter or the GE one at Home Depot ($60 or so + $30 or so for the filter) that claims to reduce chlorine. I haven't researched it too much yet though.

i used city water with my soil grow and had no problems with it, and from what i hear it only takes like 20 minutes for the chlorine to evaporate and is such a low amount it has no effect on the grow and you are more at risk of bacteria starting to grow in the water by leaving it sit for 24 hours

chopper260 said:

i used city water with my soil grow and had no problems with it, and from what i hear it only takes like 20 minutes for the chlorine to evaporate and is such a low amount it has no effect on the grow and you are more at risk of bacteria starting to grow in the water by leaving it sit for 24 hours

Click to expand...

20 mins is a bit too quick if the waters just sitting there, it also depends on the size of the reservoir. you could put an air stone into the water that would speed up the chlorine removal and would keep water oxygenated and stop bad bacteria

Yeah but like I said it varies from city to city now.

I can't say for sure, but I think if your water smells like chlorine, there's a good chance they use the older, less-stable chlorine which you can get rid of with just letting the water sit for a day.

If your water district uses Chloramine, you need a filter.

You can grow just fine with chlorinated water. You and your plants probably won't die. But you'll be stressing out your plant, the soil microbes, and possibly creating organochlorides which are just nasty compounds.

great post here showing how to make a thermostat controlled dimmer for your fans.

dirtysteve said:

Simple,
You need
1. 1 attic thermostat, they keep it near the attic vents and roofing supplies.
2. 1 5 Amp or better rated fan speed controller. In the ceiling fan section
3. 1 2 recepticle gang box
4. 1 Male plug
5. 1 switch/outlet cover combo
6. 1 duplex outlet rated at least 15 amps
7. A few feet of minimum 14g wire. I just had some 14/2 w/ ground laying around and i used the male end of an old extension cord for the male plug. You could probably get a cheap 6' or so extension cord and use it for your wire and plug. Just make sure it is rated at least 15A.

The speed controller and thermostat both have 2 black wires coming out of them. You take your Hot (Black) wire from your plug and connect it to one black wire each of the speed control and the thermostat. Then connect a piece of insulated 14g wire to the other black wires from the speed control and thermostat. Connect the loose end of the 14g wire into the "HOT" side of your outlet. The white (Neutral) wire from your plug will connect to the "neutral" side of your outlet. The outlet is marked so it is easy to figure out. Then connect your ground wires. Then put it all together in the gang box. I fastened mine to a piece of 3/4" plywood to keep it all neat. The photo has different parts but the same wiring is used. I just put an outlet on mine for ease of operation. Any fan I plug into that outlet will be run by the speed control/thermostat. In case I needed another fan. Hope this helps. If not, just let me know.

This is Al B. Fuct's diagram.

Click to expand...

Do these style of fan controllers cause a buzz or humming noise to come from the fan at all? I have the HTG Fan Controller (same thing as the speedster) and it makes my 6" HO Can Fan buzz even louder than the normal noise of the motor. If I can make my own controller that is safe to use on my fan that would be ideal.

To control my exhaust and intake fans I use a normal mercury wall thermometer and a relay that turns off when energized to run the fans.

Anyone else?