venting car exhaust from shop

[lschwarcz]

Hi Everyone,

I'd like to be able to work on my car in the winter with the doors in my shop closed. I've been looking around for a way to vent the exhaust like in commercial shops where they have a hose that slips over the exhaust tip and using an in-line fan vent to the outside.

What I'm not finding are any details about what I need to find.

• Will any in-line exhaust fan work or do I need one that can handle the heat of the exhaust and the nasty stuff in it too?
• What temperature is car exhaust (in my case it's a 2009 Range Rover with a V8 and also for my '69 MGB and '71 TR6)?
• How many CFM is the car producing?
• What type of hose would I need and how to vent through the wall without letting the cold outside air get in?
• Any brands of fan or hose that I should look to buy or avoid? How about places to buy them?
• Anything I'm forgetting to ask here?

Thanks in advance!
Larry.

 

[jkuro]

Vehicle Exhaust Removal Systems | Vehicle Exhaust Extraction | Fume-A-Vent

Fume-A-Vent is a leader in vehicle exhaust removal systems for automotive repair shops, dealerships, fleet vehicles, buses, motorcycles, and more.

www.fumeavent.com

 

[DGersic]

I didn’t want to modify my door, and very rarely need to run a car inside the garage in the winter, so I use a 4’ piece of exhaust flex pipe (the stuff that used to be sold to replace removed catalytic converters). One end gets attached to the exhaust pipe with a Fernco, the other end goes under the door. Having the door open a couple inches makes me feel safer than running an engine with the door closed.

 

[lolaetype]

This looks appropriate for a home garage.

Crushproof Hoses DSS25 2.5 Inch Service Station Kit

Crushproof Hoses DSS25 2.5 Inch Service Station Kit

www.mobiledistributorsupply.com

 

[bluedog225]

These home brew setups always seem risky to me. My understanding of CO poisoning is either just pass out. Done. Or become lethargic and confused then pass out. Done.

I’d want some pretty serious safeguards.

 

[ATC]

I always just left the garage door open. My garage isn't insulated or heated anyways. Run a box fan blowing out if it's a really bad runner...

 

[Rusted Nut]

I use an in line ventilator, like this below. Either leave the garage door open about a foot, or cut a vent in the wall and use piece of duct connector to connect to flex hose from the fan. I just position the fan near the exhaust, blows it right out.

https://www.harborfreight.com/power-tools/vacuums-blowers/ventilators-fans-accessories/shop-fans-ventilators/8-in-portable-ventilator-59156.html

 

[BruceMc]

If you run a hose under a slightly open door, make sure it's long enough to get the exhaust away from the opening. Otherwise it will just get sucked back into the shop due to the chimney effect - as warm air exits through the top opening, anything close to the bottom opening will get sucked back in. Been there, done that.

 

[Rusty Wrench]

• Will any in-line exhaust fan work or do I need one that can handle the heat of the exhaust and the nasty stuff in it too?

Wouldn't worry about nasty stuff. Do you need an exhaust fan? See below.

• What temperature is car exhaust (in my case it's a 2009 Range Rover with a V8 and also for my '69 MGB and '71 TR6)?

You gotta measure that.

• How many CFM is the car producing?

You know displacement and idle speed. The equation is in there somewhere.

• What type of hose would I need and how to vent through the wall without letting the cold outside air get in?
• Any brands of fan or hose that I should look to buy or avoid? How about places to buy them?

I'm planning similarly. I have 3" gates that will go thru the overhead door. I have a metal housed Can-Fan, inline 140 cfm. But have to check it's temperature limit.
You have to use your specs against your variables.
The variables at play for the need for a fan: cfm from exhaust and static pressure loss through the length and corrugateness (sp?) of hose. Splurge for a good one and its fitting.
I think it's preferable to breach the door rather than the building or opening the door by the hose diameter.

• Anything I'm forgetting to ask here?

Have you been a witness in court before?

I

 

[xjfish]

They make neat little hole covers for shop doors. You can use a powered ventilator and vent out anywhere, even a side wall. Commercial ones are expensive. I have no ventilation at home shop yet. Doors and/or windows get opened as needed. Small engines, such as snowmobiles, not ideal running indoors with doors and windows open at -20* outside...

 

[lschwarcz]

Hi Everyone,

I'd like to be able to work on my car in the winter with the doors in my shop closed. I've been looking around for a way to vent the exhaust like in commercial shops where they have a hose that slips over the exhaust tip and using an in-line fan vent to the outside.

What I'm not finding are any details about what I need to find.

• Will any in-line exhaust fan work or do I need one that can handle the heat of the exhaust and the nasty stuff in it too?
• What temperature is car exhaust (in my case it's a 2009 Range Rover with a V8 and also for my '69 MGB and '71 TR6)?
• How many CFM is the car producing?
• What type of hose would I need and how to vent through the wall without letting the cold outside air get in?
• Any brands of fan or hose that I should look to buy or avoid? How about places to buy them?
• Anything I'm forgetting to ask here?

Thanks in advance!
Larry.

Hi again,

I know it's been a while since I first posted this question. Sorry about the long delay to reply to everyone but I've been busy working on other areas of the shop (electrical, plumbing, painting, and more!).

In the meantime I have made a little progress.

I found a local seller of some used Crushproof exhaust tubing. I bought three 11' segments of FLT300 (3" exhaust hose) and a Y-Assembly for my Range Rover with dual exhaust.

I'm now looking for a fan to draw the car exhaust out of the shop. I'm actually thinking I'll route the hose to some ABS pipe to a fan that'll exhaust to the outside. I'll step up the 3" hose to some 4" ABS Sch. 40 pipe.

Some quick calculations show I would need a 176.5 CFM fan (assuming my 4.2 liter V8 at 1,000 RPM). But, the fan motor would need to be out of the air flow so any combustible gases in the exhaust don't ignite from a spark in the electric motor.

jkuro recommended equipment from Fume-A-Vent. I did check them out and got a quote from them. But, their exhaust fan is $1,600! Way out of my budget.

Any suggestions on a fan that's closer to the under $200 range? I'm thinking something like a squirrel cage fan with at least 300 CFM.

Thanks again!
Larry.

 

[81malibu81]

I would consider the heat capacity of the ABS plastic (or PVC). Exhaust gas temps could cause it to melt...

 

[Jackfre]

Not sure if they make anything for this app, but Tjernlund make a lot of good ventilating products. I’d give them a call and ask. On the flip side of your question, I’d be looking into a really good CO detector

 

[Crazyjake8493]

Not sure if they make anything for this app, but Tjernlund make a lot of good ventilating products. I’d give them a call and ask. On the flip side of your question, I’d be looking into a really good CO detector

Something like a Sensorcon Inspector is a good personal CO monitor to have in a situation like that where CO could spike. Gives a real-time readout and you'll see results before you're in danger. Unlike the cheap CO-detectors most people have in their house.

I have one for working in boiler rooms and attics and such at work, but I keep it near me in the garage at home if I'm running any kind of engine.

 

[MikeC55]

Good idea on the CO monitor. I seem to remember seeing some service stations using a hose that went from car exhaust end to a pivoting cover in the overhead door with no in-line fan. I would think as long as hose was only a few feet in length (~5'), a supplemental fan wouldn't be needed.

 

[jimindm]

I had a co detector in the garage for a month or so. It would sound spaying car or brake clean. It went off so much that I just unplugged it and threw it in a box.

You can by the hose from many parts stores. There is a kit that will cover many set up. Many times the outlet in the door is for the two inch hose. Crushproof brand sort of threads together to make longer hoses or to use accessories.

Two inch fits in most situations. If you are using them on your vehicles, you can sure get what you need. Dual exhaust or chrome tips and any number of things that go onto a tail pipe can be bought. Or you can then improvise.

Last thing I would say is keep in mind of any movement of air to the outside needs some make up fresh air. That has not been mentioned, and you don't say if or how your garage is heated and insulated.

 

[mikedodge]

What kind of work are you doing that you need to run it for long with the door closed? Even when it takes times like carb tuning or ignition stuff or start up after engine swaps I've always opened the door or my bigger shop has an exhaust fan to quickly clear the room. Worst case a hose out the door a little ways does it, don't need anything fancy.

 

[Fav Onefour]

I had a co detector in the garage for a month or so. It would sound spaying car or brake clean. It went off so much that I just unplugged it and threw it in a box.

You can by the hose from many parts stores. There is a kit that will cover many set up. Many times the outlet in the door is for the two inch hose. Crushproof brand sort of threads together to make longer hoses or to use accessories.

Two inch fits in most situations. If you are using them on your vehicles, you can sure get what you need. Dual exhaust or chrome tips and any number of things that go onto a tail pipe can be bought. Or you can then improvise.

Last thing I would say is keep in mind of any movement of air to the outside needs some make up fresh air. That has not been mentioned, and you don't say if or how your garage is heated and insulated.

What type of CO detector? Combo unit?
I'm asking because I typically see less false alarms on CO vs smoke detectors. I've gone to heat sensors in the shop for fire because the standard smoke units were such a pain.

If it was a combo unit, it's worth trying a decent CO unit. I get nervous running motors with the doors closed. In my case, I keep one overhead cracked with crossflow through a man door. I'm not using power venting and I've seen CO numbers climb on still days.

 

[BurtEggley]

do it right. I have a 70's classic car with catalytic that only puts out 1% CO running in the garage while tuning it one day, and it set the house CO detector off when I went inside to get something. Garage door was open and the exhaust was maybe 2' from the outside but the wind was blowing just right and was pushing the CO back into the house when I opened the side door.

 

[Jack_K]

I have only just made it and used it once but what I did is use one of these cheap dust extractors. For the hoses I used the cheap flexible aluminium ducting.

From my research heat isn't a big issue unless it is for dyno use.



I have roller doors open at both ends of the "shop" but I always stank after tuning due to the fumes building up. I knew it wasn't a good idea so I made the fume extractor.