My Extended Glowforge Exhaust Solution

If you're looking to purchase one of these, then your first project will be to design a Glowforge exhaust solution.

I had a spot in the corner of my office where I would set the new unit. It was close to the window and should work correctly.

My friend, who was also a Glowforge owner, helped me to get everything connected. We had all the venting attached, and for now, I opened the window and stuck the vent duct against the screen. It was far from a perfect solution. The window seal plate did not have a way to attach the flexible duct, so I did not even open the package after it arrived.

As it turned out, I received a defective unit. The laser light did not work, so it could not do anything except make some noise. Glowforge customer support was easy to use. Within a couple of days, they had issued me a return authorization and had also ordered me a brand new replacement unit.

Even though I was happy with their resolution to this point, it would be another couple of weeks before I had a working Glowforge Plus laser. I decided to use that time to re-engineer my Glowforge exhaust solution completely.

My Permanent Glowforge Exhaust Solution – Design Phase

Now that we knew how the Glowforge laser cutter would fit in the room, I realized several difficulties. The 6-inch flexible ducting took up a lot of space. Along with the inline fan, it filled that corner of the room, blocking the window.

I also realized that the window seal plate was not weather-tight. We get some frigid Winter weather in west-Michigan. I had two choices, open the window while using and placing the seal plate during that time. It would not keep all the drafts out but would be better than an open window.

The other option would be to seal the vent adapter into the window permanently. We had just recently built this new home, and the window I was using sits right next to our front door. Having a DYI vent in the window would not be attractive. It would also be difficult for me to open the window in milder weather.

I began looking for an alternative venting solution other than the front window. There was no room to drill a vent-hole through the front wall, as the window took up the whole width.

The only reasonable option was to go through the floor and out the side of the house. The basement underneath my office was an unfinished mechanical room with access to an outside wall. It was about the only place in the house where this solution would work.

My concern, though, was that I estimated it could be nearly 50-feet from the Glowforge laser to the vent on the outside wall. I spent several nights researching and could not find any good examples or recommendations for this kind of Glowforge vent.

I briefly considered calling a professional to help, but this was the summer of the COVID-19 pandemic, and good contractor availability was scarce in our area. I had already called around for help with a garage heater and learned it could be several months before service availability.

I put together my plan:

It was about 50-feet in total length with about three 90-degree elbows. It seemed like a perfect plan; what could go wrong?

Installing the Exterior Wall Exhaust Vent

The task I was dreading most was drilling a 6-inch hole through a wall of our new house. There were several existing mechanicals already going through this section of the wall, so there was only one spot I could put it.

The spot between the outdoor faucet and some plastic electrical conduits I had installed the previous year was the only location.

I should have bought a 6, and 1/8-inch hole saw as the vent did not initially fit in the hole. Some time with a curved wood file solved this problem, and it ended up being an excellent snug fit.

The next picture shows the finished wall exhaust vent install from the inside of the basement. It also offers a couple of significant issues that could have made this install go wrong.

I didn't want to drill the outside vent hole until I knew exactly where it should be. No measuring, as depending on your point of reference, this could be slightly off.

I separated the hole saw and the auger bit (see the two images below).

I had a siding guy doing some work for me on the outside of the garage heater vent we were also installing. He applied a nice bead of caulking across the top of the Glowforge exhaust vent, completing the installation.

The Basement Flexible Air Duct Installation

I continued working backward with the installation from the exterior wall to the Glowforge laser. Since the exhaust vent itself was up in the basement rafters, I used some steel, adjustable elbows. I thought that the flex duct would collapse with the sharp turns and restrict the air flow. So I used steel here instead.

However, using these adjustable elbows ended up being a mistake, as I'll later describe.

The next step was to mount the AC Infinity CLOUDLINE S6 Inline Fan on the wall.

I installed an electrical outlet nearby the fan. I also installed a separate switch for it, higher up the wall than standard light switches. I didn't want the younger grand-kids to be able to reach it.

Connecting the 25-foot flex duct to the fan outlet brought my project to about the half-way mark. I was now on the home-stretch.

Finishing My Glowforge Exhaust Solution

The remaining 4-feet of 4-inch flex duct, I connected to the splice in the basement. Note the speed controller wire from the inline fan. I had just enough length included with the fan to get the connector above the floor into my office.

The final steps were to mount the remaining 15-feet of 6-inch flex duct coming from the AC Infinity inline fan. I connected this duct to a 6-inch to 4-inch duct adapter.

All that was remaining was to connect the 4-inch flex duct to this same adapter.

In the picture below, you'll notice I ran the cable from the AC Infinity inline fan speed controller alongside the flex duct.

First Time Testing My New Glowforge Exhaust Solution

My Glowforge Plus replacement unit arrived at about the same time I finished my new exhaust setup. The setup of the new machine was much quicker this time as we just needed to push the exhaust port extension on to the back of the Glowforge Plus.

This unit was working correctly. So we did some cuts of simple projects. After turning off the internal fan and using the AC Infinity speed control to turn on the inline fan, I was delighted at the low noise level and how well it exhausted the smoke.

We finished some cutting projects and then went downstairs to show off my venting setup. Unfortunately, all of the smell was in the basement, near the external wall. I had left the fan on high, so I felt around all of the flex ducting.

It turns out that the steel elbows were leaking air through their joints. You could adjust these elbows from 0 to 90 degrees. This extra flexibility allowed more air to escape.

The solution at this point was more aluminum tape.

After replacing the elbows, I did notice a small improvement. While doing some online research, I read some complaints about the 6-inch flex duct I used having very small pin-holes. That was the next piece I replaced.

The hanging straps I used to support the flex duct made it surprisingly easy to swap out. I just unscrewed one side of the hanger, taking out the old flex duct. After removing all the old, I then came through with the new insulated duct and screwed the strap back up.

Finishing My Glowforge Exhaust Solution – Part 3

So far, I had already replaced the 25-feet of 6-inch flex duct with an insulated flex duct. I had also replaced the last 6-feet of steel elbows with a semi-rigid aluminum duct.

While the result of all this was a near-perfect solution, I did smell some lingering odor after running the Glowforge laser for a time. It was coming from the section of the duct near the external wall of the house. So I knew where my problem lie.

Due to my perfectionist tendencies, I was not ready to call the installation finished, although I could have.

I realized that I could have punctured the aluminum duct somewhere I did not see. I didn't want to cover the entire section with aluminum tape, so I went online for options.

I initially searched for insulation options or some plastic enclosure that was sealable. While reading through different forums, I stumbled on this Red Devil 0841DS RD-DS 181 Acrylic Latex Duct Sealant, 1/2 Gallon, Gray.

According to what I read online, it was a sealant used where two steel duct pieces join together. It could be applied using a brush or putty knife.

My plan with it, however, was to cover the whole section of the aluminum duct. Since the duct was ribbed, the sealant would still be filling the area between two steel pieces. That logic sometimes gets me into trouble.

I recognized the Red Devil brand, and at the time, it was only $8.79 a half-gallon, so I bought it. The two-day delivery time gave me time to buy a couple of cheap 2-inch brushes from our local True-Value hardware store.

While reading online, someone said the sealant was a peanut-butter type texture. I thought the brushes would be easier to apply to a round duct than a putty knife.

After it arrived, I opened it, and yes, a peanut butter texture was pretty accurate.

The brush worked pretty well. I did try to scoop it out of the container, putting a thick coat on the duct.

I then smoothed it out with the brush, filling in all the grooves in the flex duct.

After coating the entire section, I still had about half the container remaining. It was messy but nowhere near as bad as spray foam insulation. I'm guessing this had to do with Latex in the name. It cleaned up very quickly.

The directions indicated 48 to 72 hours of drying time before pressurizing. Since I was not following standard usage, I knew I would need at least that amount of time.

I also had enough left over for a second coat. I did not want to do it again after it was thoroughly dried. So that is what I did after 24 hours had passed.

Final Conclusions

One last thing that needs to be said:

I worked as an electrician for a few years earlier in life. I'm comfortable doing this kind of work in my own home, especially the electrical portion. I would instead have hired out the venting, but it wasn't a convenient option.

If you're not comfortable drilling large holes in your house, then don't! Hire a reputable professional.

It's not worth the risk. Below is the same picture I had earlier with four issues circled, any of which could have been a significant problem.

Glowforge Exhaust Solution Materials List