Important Considerations

Existing Systems

Do not connect the exhaust output of this laser to any existing exhaust systems. Please consult a qualified HVAC or industrial mechanical professional.

Thunder users have reported that using 4" diameter in the exhaust system provided unsatisfactory results. It is best to keep the minimum diameter of the exhaust plumbing at 6".

Intake Air

Even if you have great exhaust flow out, you must have the same volume of air coming in. A vacuum is not what you are looking for. This can be realized easily if you are in a somewhat airtight area like an interior room in your home or business. The negative ambient pressure is created by the laser sucking 300-1100 CFM out of the room, depending on setup and fan. If the incoming air into the room and the laser is not sufficient, the fumes will not escape.

Negative Pressure Plenum

You want negative pressure throughout the exhaust system itself, or as much as possible. If you are forcing the exhaust through the duct system and it can be ejected through holes in the ducting, gaps in fan housings, loose connections, etc... 

The best solution is to mount the fan right at the exit (or as close as humanly possible) so it pulls the exhaust though the ducting. Some mount their fans outside and have a true negative pressure system. We should clarify that mounting the blower on the exterior is only for fans that are sheltered and/or rated for outdoor use.

Example Exhaust Setup

Here is one setup where the fans and exhaust systems are easily accessible for inspection and maintenance. The fan outlet is less than 24" from daylight. The left one is a Cloudline S6 and the one on the right is a 4" S series. The components in this article were used in this installation:

Flow Restrictions 

And, restrictions of any kind can cause major issues. 6" diameter minimum on all ductwork. Use the shortest runs possible. The helix reinforced cloth flex ducting is plasticized but it can still be permeable if under pressure.  Rigid ducting is recommended for long and/or complex runs. 

Vent Hoods

The nearest standard venting size in the US is  Ø6" (152.4mm). We recommend a 6" weighted damper exhaust vent hood for exhausting through a wall. Like the one below: 

Here is the link: https://www.lowes.com/pd/IMPERIAL-6-in-dia-Galvanized-Steel-R2-Exhaust-Intake-Dryer-Vent-Hood/4598558. 

It is important to get a vent hood with a damper to keep the outside air from entering the laser, especially in the winter. Cold air from the exhaust system can affect the tube temperature. 

If conditions are below freezing this could be an issue. In colder climates, it may be beneficial to leave the lid up on your machine to help equalize the ambient temperature inside the machine. 

A spring-loaded damper may be more efficient at remaining completely sealed but if and when the spring fails, the damper is rendered largely ineffective. 

A weighted damper is less prone to failure. The exhaust system must also be periodically inspected, cleaned, and maintained for optimum performance and safety.

You will need one additional 6" hose clamp (I think) and some duct tape to terminate the connection of the ducting to the vent hood. The difference in diameter makes the exhaust duct a very tight fit but it will adequately engage the rigid ducting.  

Also, watch out for the wire in the ducting as it is very sharp. Trust me on this :).

Cold Weather

A blast gate can be used to greatly reduce outside air flowing back into the machine. If you are in an area with extended cold days and the laser is not in use, disconnect the exhaust system completely from the outside air source. Opening the lid of the machine, Laser Tube door and the Front Access will also allow the laser to acclimate better to the garage Ambient Temperature while the machine is not in use.

https://www.amazon.com/Woodstock-W1009-6-Inch-Blastgate/dp/B0000223YP/ 

Preventative Maintenance

 More information on preventative maintenance can be found here: Preventative Maintenance Checklist

Your stock exhaust fan (q3 2021 and older)

Here is some information about your stock fan PRIOR TO CONTAINER #103 for comparison:

Your stock exhaust fan (q3 2021 and newer)

Here is some information about your stock fan CONTAINER #103 FORWARD for comparison:

AC Infinity Cloudline S-Series Inline Exhaust Fans

This is some basic info on AC Infinity Cloudline S-series axial inline exhaust fans

Other Fans

you can use other similar fans as long as they meet or exceed the minimum airflow and they do not exceed the current draw and other specs of your stock fan.

Since Thunder Introduced the quiet Inline fans in Q3 2022, you do not need to use an aftermarket fan. the supplied peripherals are more than adequate.

The reason people used to buy aftermarket fans is was for noise mitigation, not performance. 

Connecting an aftermarket fan to your Thunder Laser

You can connect an exhaust fan that does not draw more current than your stock fan. You will find that info linked above. To do this you will need an IEC 60320 C14 Male to NEMA 5-15R Female 10A adapter like this:

https://www.amazon.com/gp/product/B00066HQ50/

DO NOT USE AN ADAPTER LIKE THIS TO RUN AN EXTERNAL AIR COMPRESSOR FROM THE COMPRESSOR JACK ON THE LASER.

THIS IS FOR ADAPTING THE EXHAUST FAN TO ACCEPT AN AFTERMARKET INLINE FAN.

Roof Venting

Farbulous Creations did a great video on exhausting through the roof, but there is a lot of great info even if you are not going through the roof. Awesome job Ron!

Exhaust Ducting Sizes

it seems that much of the info about the laser exhaust is derived from the HVAC world, like the information below:

BUT the laser exhaust is different so that info doesn't really apply.

You can realistically move more than 1000 cfm through a 6" plenum, with best practices: