Exhaust System/Squirrel Cage Blowers

plynnt · #1 2009-03-13, 11:18am

Hello everyone! I need some HELP! I live in Severn, MD and am setting up my basement studio. I need some help/advise about the exhaust system and any local/internet suppliers that sell/install the systems. I need to make sure the exhaust is done right. I'm a cancer patient and can't risk an inadequate system causing me any further health issues.

I was trying to buy a remanufactured squirrel cage blower from a guy on eBay that I was referred to, however, he must not have any on hand or is no longer doing this. I was trying to avoid paying full retail for a new system if at all possible as money is an issue.

I would welcome any suggestions from anyone taking the time to read this. Any help is much appreciated.

Thanks,

Patti

ricksilver · #2 2009-03-13, 6:23pm

An oven hood ventilator can do the job. Not hard to install and fit an exhaust pipe to. And you get a light as well!

Dale M. · #3 2009-03-13, 6:37pm

Stove/oven hoods in most cases lack the required CFM for adequate ventilation.... No matter what hood design is one probably needs a fan that will push/pull at least 500cfm, and most likely more if hood dimensions are much more the about 18 x 30 inches....

Assumptions that any old range hood will do is not good enough....

http://www.artglassanswers.com/forum...opic.php?t=273

Dale

Puddy Tat Glass · #4 2009-03-13, 6:45pm

Hi Patti ... I just got a new exhaust system for Christmas, it's from GlassCraft and it's wonderful. Here's a link to the system

http://www.glasscraftinc.com/product...ust&txtlevel=1

It's kinda pricy at $345...but, if you just want to get the fan and build your own system the fan that comes with the GlassCraft unit is a Suncourt Pro 2-Speed In-Line Duct Fan. It doesn't look like the fan by itself would be very expensive at all, here's a link

http://www.bestqualitysupplies.com/P...ourt_p/db3.htm

Glasscraft recommends this fan for torches like my Lynx. Don't know if you're using a big boro torch this might not work for ya. I use the lowest setting because I have it sitting right in front of my torch and it seems to do a great job.

Hope this is helpful.

Torched Art · #5 2009-03-13, 7:14pm

I recently installed a better ventilation system. I used an inline duct booster from home depot. It pulls 500cfm and only cost $35 plus shipping. Here is the link: http://www.homedepot.com/webapp/wcs/...roductDisplay?

I have the flame directed into the hole and now all my fumes and gasses are gone! It's super quiet, so I have to make sure it is actually on. It doesn't over heat either and the closer the suction the better it will do. You can see that I have it ready for another torch, I hope it pulls enough. Otherwise I will get another booster for the same ducting line.

I have 6 foot, 8 inch aluminum flex ducting so it can be bent to the correct direction towards the torch. At home depot I got other 8 inch ducting and all the metal screws and parts. In all, it cost about $100.

I had a smaller hose of 4 inches and a different fan that was NOT enough.

I hope this helped.

storeId=10051&langId=-1&catalogId=10053&productId=100396544

NMLinda · #6 2009-03-13, 8:55pm

I'd like to give Dale credit for the link, below, which he's posted elsewhere:

http://www.rangehoodsinc.com/rhi-cav...range-hood.php

He's right, the garden-variety range hoods typically aren't anywhere nearly strong enough. If you're not comfortable building your own vent hood/exhaust fan system, this is not the typical off-the-shelf HD type hood. It looks like a nice choice and it has a fan that, if you install it correctly, should give you enough protection.

To get the max performance out of it, you'll want to be careful not to mount it too hight off your workbench, and be careful not to kill the fan with too much static pressure as you pipe the fumes out of your basement (ie, use smooth-sided vent ducting, not flexible...). As a cancer patient, you might want to add sides to help capture all the fumes possible. Another good link to help you with all this besides the one Dale gave you is

http://mikeaurelius.wordpress.com/ventilation-primer/

Also, Dale has another good link he's posted in the past:

http://www.artglassanswers.com/forum...opic.php?t=150

As well as considerations for setting up in a basement:

http://www.artglassanswers.com/forum...opic.php?t=430

Best of luck
Linda

Dale M. · #7 2009-03-14, 8:54am

Quote:

Originally Posted by RetiredinCoquille

.but, if you just want to get the fan and build your own system the fan that comes with the GlassCraft unit is a Suncourt Pro 2-Speed In-Line Duct Fan. It doesn't look like the fan by itself would be very expensive at all, here's a link

http://www.bestqualitysupplies.com/P...ourt_p/db3.htm

Glasscraft recommends this fan for torches like my Lynx. Don't know if you're using a big boro torch this might not work for ya. I use the lowest setting because I have it sitting right in front of my torch and it seems to do a great job.

Hope this is helpful.

IF you are using DUCT BOOSTER FANS, use the "Free Air CFM" rating... Typically it's about 1/2 the actual "Max Boosted CFM" and since one is NOT using it as a booster fan then the free air value is appropriate valuse to use...

This is what got Glasscraft in a bind because the were advertising their big hoods as 640cfm hood and only had a free air fan rating of about 300 cfm (Suncourt 210)... Now I see they only sell big hood without a fan....And this has nothing to do with Glasscraft and I don't know these people and have not had business dealing with them, this is just BUYER BE AWARE message...

Dale

Torched Art · #8 2009-03-14, 9:42pm

Here are the pics that were intended for my post on this thread.

yeepers · #9 2009-03-15, 1:39pm

Not to be a complete party pooper but....

I would be very careful with the inline duct booster fans. They are almost certainly guaranteed to NOT be pulling enough air to vent your space properly and it is a misconception to think that adding more of them inline will make for better venting.

Torched Art · #10 2009-03-15, 8:36pm

Thanks Yepers. I am looking into this issue more. I have read the posts about the ventilation instructions.

In my previous research, I have read that if you take a tissue and it wants to be sucked into the venting from the point of combustion that it is a good thing. When my ventilation system is in use, how am I to really know if it is working enough? I have burned paper to see if the smoke gets sucked away from different distances from the hole. I also have my torch about 6-8 inches from the ducting pointing directly into the ducting much like I have seen in other studios. I thought this was good enough, but now this is really making me think... again.

I guess my question is: is there a way to test your ventilation to see if it is working properly and if you need to upgrade it?

Any suggestions or advice? Otherwise I was super happy with my new ventilation as I am very sensitive to the fumes, carbon monoxide, etc. and now I feel I can breath with confidence again. Or so I thought!!!!

I am so glad that this was brought up again. I believe that this is one of THE most important safety precautions one should take.

RSimmons · #11 2009-03-16, 6:23am

In-line fans usually don't supply the pull that you need for good ventilation, especially if you have long runs of duct with bends in it. For checking the air flow in and around your ventilation system I would recommend this product or something like it.
http://www.labsafety.com/store/Safet...r_Tubes/16730/

Robert

plynnt · #12 2009-03-16, 7:31am

Thank you all so much for all your information and advise. I'll be looking into the links you all supplied and will hope to get something figured out soon.

What would your general CFM recommendation be? I'm told 1300-1800 CFM.

Thanks again for taking the time!

plynnt · #13 2009-03-16, 7:45am

All,

Would something like this work?

http://fans-plus.com/products/powercat.htm

Opinions?

NMLinda · #14 2009-03-16, 7:25pm

Plynnt - I would heartily recommend you read the information in the following link

http://mikeaurelius.wordpress.com/ventilation-primer/

as well as the other two Art Glass Answers links I posted earlier. The link, above, will walk you through how to decide what fan size is right for the size hood you want. From what I've read here in LE and elsewhere, most folks pick the size hood they want to work under and then pick the fan. Seems like 30" wide by 24" above the work surface is fairly common, but everyone has different preferences or space limitations.

I personally wouldn't buy any fan for which the cfm vs static pressure wasn't available. Some fans, although seemingly beefy, can die under the slightest static pressure (ie 'back pressure' caused by ventilation duct bends, long runs, or flexible ducting). As Yeepers notes, duct booster fans are an example. They aren't designed to be the primary fan in a ventilation system, anyway, so it's not surprising - I've heard they can lose as much as half their cfm under very little static pressure.

I didn't see any cfm vs static pressure for the fan you asked about, so I would assume that the numbers shown are the 'free air' or zero static pressure values. Might be ok if you vent directly outside with no bends and no flex ducting (flex ducting is awful - can absolutely kill a fan's performance....), but you take a risk of having far less output than expected if you have any kind of long or complicated ducting to get the fumes outside.

Like Christina, I've wondered how to verify whether my vent system is giving me the draw I calculate I need. I've been working on one with a tricky fan installation issue, so I've been testing it by timing how long it takes the smoke from a burnt paper towel to travel from my torch flame to the exhaust duct opening in my hood. I compare that to the time I expect it to take (I divide the volume of my hood by the cfm I'm shooting for). If it takes the smoke longer than that, then I'm not getting the draw I want. I'm building a barley box style hood, by the way, so predicting how fast the smoke should be exhausted is pretty straight forward.

Linda

RSimmons · #15 2009-03-17, 6:40am

Products like this:
http://testproducts.com/safecart/pro...roducts_id/237
are good for tracing your air flow patterns. LSS makes a kit too, but I can't find the URL this morning.

Robert

NMLinda · #16 2009-03-17, 8:19am

Thanks for the link, Robert! You'd posted another type a while ago. This looks equally good.

Linda

plynnt · #17 2009-03-18, 12:18pm

Thanks again everyone for all this information. Assuming my head doesn't explode, I hope to be up and running very soon!

GlassPuppy · #18 2009-03-25, 6:10pm

I just spent a couple of hours working with the information that Mike Aurelius presents in his ventilation primer.

http://mikeaurelius.wordpress.com/ventilation-primer/

I actually did the calculations for my existing system with the help of an Excel spreadsheet. The time was so well spent - I came away with a much better understanding of what it takes to construct a ventilation system that really functions - and why mine has never met my expectations.

Save yourself time, money, and frustration - use the information Mike presents to design your system - then be brave enough to cut through that wall, buy that big fan, change that ductwork - whatever you have to do to make your ventilation work!! Your health is worth it!!