IncredibowlBoss
Member
I've noticed people spending a lot on ventilating their growspaces - I've seen friends drop $250 on a 650 CFM fan and another $100 on a variable speed controller. 
Here's a little DIY guide to getting 100% of that performance at about 25% of the price - we're currently running this setup with a 1000w MH that has a history of getting toasty and find that with the variable-speed, we can control to the temp within 2 degrees.
Down to the nitty-gritty.
What you need
Note: Home Depot SKUs & lookup numbers where available for nationwide convenience; IF YOU HAVE THE OPTION, SUPPORT YOUR LOCAL HARDWARE STORE INSTEAD!
Another Note: You don't need any specific brands - these are just what I found and used - only you know what works for your budget and garden.
The Fan
1. 10" Aero-Flo InLine Duct Fan (available from Airflow Technologies) - $55.95
2. Husky 9 ft. 14/3 Power Tool Replacement Cord (Model # AW62632 Internet # 100661452
Store SKU # 342576) - $10.96
3. IDEAL Twister Wire Connectors (10-Pack) (Model # 30-131 Store SKU # 638586) - $1.29
Subtotal: $68.20
The Variable Speed Controller
1. Leviton Outlet-to-Socket Light Plug (Model # R52-00061-00W Internet # 100170446 Store SKU # 149682 Store SO SKU # 162677) - $2.29
2. Westek 100W Full Range Lamp Socket Dimmer (Model # 6009B Internet # 100644831) - $6.85
3. Leviton Socket with Outlets (Model # R52-01403-00W Internet # 100184555 Store SKU # 152008 Store SO SKU # 162677) - $2.69
4. Leviton 15 amp Polarized Grounding Adapter (Model # R55-00274-0GY Internet # 100356839
Store SKU # 224676 Store SO SKU # 162677) - $0.79
Subtotal: $12.62
Project Total: $80.82
Phase One: Wire the fan
Step 1. Get your fan out of the box - notice the cord coming off the end. It will have a white wire, a green wire, and a black wire inside the black cord.
Step 2. Get your tool replacement cord out of the cardboard sleeve - it has the same three colors of wire coming off the end without the plug.
I'm no electrician, so this is no place for an electricity primer, but briefly - the black wire is your "hot" lead, your white wire is neutral, and the green is your ground, so you want to use your wire connectors to make sure the fan's hot lead connects to your cord's hot lead, the fan's neutral to the cord's neutral, etc. Theoretically, if you wire the hot and neutral cords backwards, your fan will spin backwards - depending on the fan, it might just *try* to spin backwards, and then break, though. Which leads us to...
Step 3. Slide the black wire from the fan and the black wire from the *UNPLUGGED* cord into a connector. Twist the connector till the wires are held firmly. (For bonus safety, wrap that little bundle in electrical tape). Repeat with the white and green wires.
Step 4. Plug in your fan - if all the wires are making solid contact, it should spin up and be ripping in a few seconds. If it doesn't work, go back to Step 3 and re-evaluate. Unplug your fan.
Congratulations! You just built a $200 fan for under 70 bucks! Now to mount the sucker.
The only thing that you *have* to remember is to look at the arrows on the fan - they show you the way the air's blowing. I'll spare you a primer on running ventillation - there are better posts on that - but by way of example (I tend to learn better with something tangible to visualize), I have my fan mounted on the rafters above my growspace. I used aluminum foil tape (Home Depot Model # 3220020500 Store SKU # 915245) to attach the INTAKE on the fan to a 10" to 6" duct adapter, which I connected to 6" ducting (HD Model # A068/4 Store SKU # 190543), and ran the free end of the ducting through the ceiling in the grow room and onto the vent hole on my reflector, where I taped it nice and tight.
So now you've got your 650 CFM fan pulling air over your bulb and reflector. The air is cooler than the bulb and the reflector surface, so it steals some of their heat as it passes. After I run mine for about 20-30 minutes, I can comfortably put my hand about 1-2 inches from my 1000w MH. This is great for when it's too hot, but sometimes I depend on some of that lamp heat to bring the room temp up a few degrees. Of course, with no fan at all, the light can add 15-20 degrees F
, but what about when you only want it to add 5-10 degrees? Well, less air moving over the bulb means less stolen heat - so if you can control your fan speed, you can get a pretty decent handle on your temperature. Which calls for...
Phase Two: Assemble the speed controller
[NOTE: There is information available online that indicates that this may at best shorten the life of your fan, and at worst lead to serious electrical concerns. For my own case, I don't mind replacing the cheap fan, but you should never do something you read on the internet without fully understanding and intelligently accepting the associated risks. Read THIS POST for a more informed take on the subject that I can offer.]
The dimmer switch on a light works by limiting the power, which limits how brightly the bulb glows. A fan turns that same power into air movement instead of light, so logically, if you can control the power, you can control the airflow.
My first thought was to wire a lightswitch dimmer into the hot lead, but like I said before, I'm no electrician, and I'm in no rush to take dangerous risks with my garden. While I was scratching my head evaluating the risk, I noticed some much less potentially shoddy options.
Step 1. Put your polarized grounding adaptor on your fan cord's plug (my adapter outlet is only two-bladed; if yours has a ground lead, you can skip this).
Step 2. Screw your socket with outlets into your lamp socket dimmer
Step 3. Screw your outlet-to-socket plug into the other end of your lamp socket dimmer
Step 4. Plug your fan into your outlet-to-socket plug
Step 5. Plug the contraption in, play with the dimmer switch and make sure you can get the fan speed to vary. The fan probably has a minimum amount of power that will be required to make it move - so the switch may not do anything until it gets past the first 1/2 of its range of motion. Turn the knob slowly until the fan starts, then mark that with a sharpie. Between there and the end of its range of motion, you have variable control.
Twist a fatty and stop cursing the grow store under your breath.
That's it! In less than 15 minutes, for about $80, you made $350 worth of ventilation equipment!
Here's a little DIY guide to getting 100% of that performance at about 25% of the price - we're currently running this setup with a 1000w MH that has a history of getting toasty and find that with the variable-speed, we can control to the temp within 2 degrees.
Down to the nitty-gritty.
What you need
Note: Home Depot SKUs & lookup numbers where available for nationwide convenience; IF YOU HAVE THE OPTION, SUPPORT YOUR LOCAL HARDWARE STORE INSTEAD!
Another Note: You don't need any specific brands - these are just what I found and used - only you know what works for your budget and garden.
The Fan
1. 10" Aero-Flo InLine Duct Fan (available from Airflow Technologies) - $55.95
2. Husky 9 ft. 14/3 Power Tool Replacement Cord (Model # AW62632 Internet # 100661452
Store SKU # 342576) - $10.96
3. IDEAL Twister Wire Connectors (10-Pack) (Model # 30-131 Store SKU # 638586) - $1.29
Subtotal: $68.20
The Variable Speed Controller
1. Leviton Outlet-to-Socket Light Plug (Model # R52-00061-00W Internet # 100170446 Store SKU # 149682 Store SO SKU # 162677) - $2.29
2. Westek 100W Full Range Lamp Socket Dimmer (Model # 6009B Internet # 100644831) - $6.85
3. Leviton Socket with Outlets (Model # R52-01403-00W Internet # 100184555 Store SKU # 152008 Store SO SKU # 162677) - $2.69
4. Leviton 15 amp Polarized Grounding Adapter (Model # R55-00274-0GY Internet # 100356839
Store SKU # 224676 Store SO SKU # 162677) - $0.79
Subtotal: $12.62
Project Total: $80.82
Phase One: Wire the fan
Step 1. Get your fan out of the box - notice the cord coming off the end. It will have a white wire, a green wire, and a black wire inside the black cord.
Step 2. Get your tool replacement cord out of the cardboard sleeve - it has the same three colors of wire coming off the end without the plug.
I'm no electrician, so this is no place for an electricity primer, but briefly - the black wire is your "hot" lead, your white wire is neutral, and the green is your ground, so you want to use your wire connectors to make sure the fan's hot lead connects to your cord's hot lead, the fan's neutral to the cord's neutral, etc. Theoretically, if you wire the hot and neutral cords backwards, your fan will spin backwards - depending on the fan, it might just *try* to spin backwards, and then break, though. Which leads us to...
Step 3. Slide the black wire from the fan and the black wire from the *UNPLUGGED* cord into a connector. Twist the connector till the wires are held firmly. (For bonus safety, wrap that little bundle in electrical tape). Repeat with the white and green wires.
Step 4. Plug in your fan - if all the wires are making solid contact, it should spin up and be ripping in a few seconds. If it doesn't work, go back to Step 3 and re-evaluate. Unplug your fan.
Congratulations! You just built a $200 fan for under 70 bucks! Now to mount the sucker.
The only thing that you *have* to remember is to look at the arrows on the fan - they show you the way the air's blowing. I'll spare you a primer on running ventillation - there are better posts on that - but by way of example (I tend to learn better with something tangible to visualize), I have my fan mounted on the rafters above my growspace. I used aluminum foil tape (Home Depot Model # 3220020500 Store SKU # 915245) to attach the INTAKE on the fan to a 10" to 6" duct adapter, which I connected to 6" ducting (HD Model # A068/4 Store SKU # 190543), and ran the free end of the ducting through the ceiling in the grow room and onto the vent hole on my reflector, where I taped it nice and tight.
So now you've got your 650 CFM fan pulling air over your bulb and reflector. The air is cooler than the bulb and the reflector surface, so it steals some of their heat as it passes. After I run mine for about 20-30 minutes, I can comfortably put my hand about 1-2 inches from my 1000w MH. This is great for when it's too hot, but sometimes I depend on some of that lamp heat to bring the room temp up a few degrees. Of course, with no fan at all, the light can add 15-20 degrees F
, but what about when you only want it to add 5-10 degrees? Well, less air moving over the bulb means less stolen heat - so if you can control your fan speed, you can get a pretty decent handle on your temperature. Which calls for...Phase Two: Assemble the speed controller
[NOTE: There is information available online that indicates that this may at best shorten the life of your fan, and at worst lead to serious electrical concerns. For my own case, I don't mind replacing the cheap fan, but you should never do something you read on the internet without fully understanding and intelligently accepting the associated risks. Read THIS POST for a more informed take on the subject that I can offer.]
The dimmer switch on a light works by limiting the power, which limits how brightly the bulb glows. A fan turns that same power into air movement instead of light, so logically, if you can control the power, you can control the airflow.
My first thought was to wire a lightswitch dimmer into the hot lead, but like I said before, I'm no electrician, and I'm in no rush to take dangerous risks with my garden. While I was scratching my head evaluating the risk, I noticed some much less potentially shoddy options.
Step 1. Put your polarized grounding adaptor on your fan cord's plug (my adapter outlet is only two-bladed; if yours has a ground lead, you can skip this).
Step 2. Screw your socket with outlets into your lamp socket dimmer
Step 3. Screw your outlet-to-socket plug into the other end of your lamp socket dimmer
Step 4. Plug your fan into your outlet-to-socket plug
Step 5. Plug the contraption in, play with the dimmer switch and make sure you can get the fan speed to vary. The fan probably has a minimum amount of power that will be required to make it move - so the switch may not do anything until it gets past the first 1/2 of its range of motion. Turn the knob slowly until the fan starts, then mark that with a sharpie. Between there and the end of its range of motion, you have variable control.
Twist a fatty and stop cursing the grow store under your breath.
That's it! In less than 15 minutes, for about $80, you made $350 worth of ventilation equipment!
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