Combination venting and cooling setup

Continuing the discussion from Exhaust hood options:

I’m new to roasting on the Bullet.

This box houses an upcycled cooker hood extractor that clears a hefty 427m³/hr (250cfm). It has an 8" inlet at each side.

I’ve routed the left one via two reducers and some 4" ducting to be the smoke collector, and the right one via one reducer and some 6" ducting to an integrated bean cooler on the right. The bullet’s SS bean tray just sits on top of it, with an airtight-ish seal created by a piece of silicone hose around the edge of the empty chocolates tub … I mean cooling tray!

It all works like a charm. After a smoke-free roast, I managed to cool 600g of beans to be genuinely cold to the touch in 60s.

Sealing one side boosts all of the airflow on the other - hence the chocolate tub … I mean cooling tray - lid on the first pic when I was roasting to increase the airflow at the smoke-collector.

I think the whole thing cost me less than £60. I plan to cover it in matte black vinyl so it matches the bullet.


Pretty cool idea… would be great to see what it looks like inside your box :wink:


I second this motion! Let us take a peek inside!

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Not so easy to show the inside as it’s all glued together but here’s the best I can manage from the underside. I also added the vinyl covering and I’m very pleased with how it looks now. Just need to paint the white bit on the end of the 4" ducting :crazy_face:. Maybe going a bit OTT for something that lives in my garage!

Uploading: Screenshot_20211219-


This is pretty cool … to use the intake side to draw air through the beans thereby having a bean cooler.

Is the left side (last pic) hose connected to another intake of the vent blower? If I recall how the blower of my hood vent looks like there are openings for the fan on left and right side, then the exhaust out. I’m guessing the left side is connected to the left intake fan of your upcycled vent blower?

The black just ties everything together nicely! :slight_smile: :clap:t3:

Great idea, thanks for sharing! This seems the way to go if I decide to start using a proper ducting setup.


Yes, you’re correct. The unit is basically a centrally mounted fan with air pulled in on both sides. I didn’t know that when I bought it but I’m happy that it works that way as I’ve been able to come up with something better than I originally planned.


Awesome! I’m glad that worked out so well for you!

@ davidalexander2ard,
This is a very neat application.
Forgive me for asking, but I don’t see and filters in your unit.

I am currently using a range hood that I mounted in the garage and I end up with the aluminum mesh grease filters clogged with the ‘hard to remove’ sticky tan coffee dust. I would be concerned about the tan dust sticking to everything inside your fan unit/kit.

The way that I clean the grease trap now is to spray them down with Cafiza (that I have in a spray bottle), rinse them off and then spray with Cafiza again and then run them through the dish washer.

I have two layers of fine mesh for the bean cooler and thanks to a helpful post I read earlier I’ve added some fibre and mesh on the extractor side. Given the amount of grease the average kitchen extractor has to deal with, I’m hoping it will be fine with the low level punishment it gets from this new life :grin:

I had originally installed the range hood several years ago when I had a Behmor. I never had to clean the filters. Then I got a HotTop and it produced more smoke, but still I didn’t have to clean the filters but every 6 months or so.

Now that I have the Bullet (for ~4 months) I have had to clean the filter every month. I just went a took a good look at the range hood and found that it is buggered. When I turn the fan on high the motor is struggling.
The filter is not filtering enough to keep the fan getting from getting clogged.

When I bought the range hood, I didn’t need a lot of air movement. Now I do.
Most of my roasts are light, occaisonally going halfway past the start of first crack.

I am going to redesign my exhaust system and am planning on using slide in, inexpensive, disposable house furnace filters.

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@BillC Keen to see what your new setup looks like when you get around to it. I currently have nothing in place, but am looking at piecing together some sort of a solution soon.