Dual Room Extraction with One Fan

Got two rooms but just one fan? That's ok! If it's big enough, one fan's enough for both tents.

It's called dual-room extraction. 

If you're gonna try this, pick a fan that can replace the air in both grow rooms 60 times an hour. 

You'll need a couple of bits and pieces to make this happen. We used:

• 1 x 125mm (5") RVK Fan
• 2 x Carbon Filters
• 2 x 5m of 100mm (4") Ducting
• 1 x 5m of 125mm (5") Ducting
• 1 x 125mm (5") Fast Clamp
• 5 x 100mm - 125mm (4" - 5") Quick Release Duct Clips
• 1 x 125mm - 100mm (5" - 4") Reducer
• 1 x 100mm (4") Y Piece
• 2 x Rope Ratchet Heavy Duty Hangers
• 1 x Heavy Duty Chain
• 1 x 4m power lead (with 13a plug)

It's easiest and cheapest to buy an extraction kit, then buy a few extra bits.

You'll probably need a bigger fan than the one we used. For the sake of showing you how it's done, we just grabbed one we had lying around.

First of all, connect each carbon filter to a length of ducting.

We chopped a 10m length of 100mm ducting in half. We ended up with 2 x 5m lengths - one for each filter. It's important that both lengths are equal so you're extracting the same amount of air from each tent.

To secure the ducting to each filter, use Quick Release Duct Clips (one per connection).

Hang one carbon filter in each tent (use one pair of rope ratchets for each filter). Feed your ducting through the exhaust hole at the top of your tent.

Now it's time to focus on your fan.

Once it's been wired up, turn it on to work out which is the exhaust side (air out).

Next you need to attach your Y piece. If the Y piece is too big for the fan (like ours is), first attach your reducer to your Y piece.

Then attach the Y piece to the intake (air in) side of your Fan, using a Fast Clamp.

You'll get a secure, airtight seal. Add a little duct tape anyway if you want to.

Now, attach your last piece of ducting to the exhaust side of your fan, using your last Quick Release Duct Clip.

Connect your fan to your mains and check your system works.

Use the 'S' Hooks and chain to suspend the fan, Y piece and the exhaust ducting.

Connect the ducting from each carbon filter to the Y piece. Again, you can secure them with a Quick Release Duct Clip (one per connection).

Job done! Now you're extracting air from two rooms, using a single fan!