Make up air question, please help!

[burnt sand beads]

:-) I am setting up my studio in my basement and was going to have my work bench right in front of one of the windows with my Glasscraft hood 18-36 inches above the bench top. Looks like I would have the right type of passive make up air, but from what I've read my vent hood/duct would be too close to my make up air. Am I right?
My basement is U shaped and I could move to the other side of the U. I would have 2 windows on that side. I could be facing one of them and keep it closed, and then open the other one which would be behind and to the side of me. It would be at least 10 feet from my exhaust duct. I wonder if it would be much better to move everything to the 2 window side or if makeup air works just as well as long as it is 10 feet from the exhaust duct. Does it makes any difference (the distance and placement of makeup air? If it doesn't I'd rather keep everything where it is- really close to natural gas pipe to easily T off new tap.
Fortunately I am asking this BEFORE I have everything connected! Please help!

[kbinkster]

Yes, your make-up air source should be at least 10 feet away from your exhaust. I think it is better to have your make-up air coming from behind you than from in front of your bench.

There are set-ups where you can duct in your fresh air to your bench by your torch, but that is not the same thing as what you are describing - opening a window for make-up air in front of your bench. It would be better to arrange things so the window is behind you.

[burnt sand beads]

Thank you so much for responding to my long-winded question! O.k., so behind me is better, got it! Does it matter if I stay on the one window side and open the windows on the other side of the basement? They would be at least 200 feet or more away on the other side of the basement. The basement is unfinished (no solid walls or doors seperating all of the various areas). If I can safely stay on the one window side I would want to do that- closer to natural gas pipe for tap and closer to electrical outlets.

[Dale M.]

Also consider that if there is appliances in basement like forced air heaters and gas water heaters there are venting issues there too.... If you draw to much air though studio with out sufficient make up air, you can reverse flow the flues of these appliances and draw carbon monoxide gasses into your breathing space, and mistakenly thinking you are safe when you are actually doing the exact thing you are trying to avoid. Breathing contaminated air.

Bottom line is basements are the hardest place to get ventilation correct....

Dale

[burnt sand beads]

The gas forced air furnace and water heater are down there in the same room. They do have large fresh air returns. Unfortunately I am stuck with the basement local, but am really trying to get it as safe as possible.
Does it matter how far away the make up air is (as long as it is at least 10 feet away from the exhaust vent and furnace hot water heater etc.?) Or does it work better if I am on the same side as the open window and therefore closer, but not too close!

[Just Nancy]

I'm not a safety guru. I think the answer is it doesn't matter. Let me answer what I do understand and see if I am answering the right question. First it is important not to accidentally pull from these other systems. So make up air is going to be important. Next you want to have fresh make up air so the 10 feet is important (and not pulling from the other appliances).

Some people exhaust and intake from the same window as long as they can put the two ends of the vents 10 feet apart. To do so you would have to take the extra length of vent into any equations for the strength of the fan, but it is an option. I have most of my make up air from behind. I also have some planned from underneith my bench.

[burnt sand beads]

Thank you Nancy! O.K. so unless I try to do the venting of exhaust and make up air from the same window (which would be right in front of me) it would be o.k. to vent in front of me to the outside, and keep the other two windows open for make up air. Do I have that right? The gas furnace and water heater would be at least ten feet away from the windows (all three) and the exhaust vent. Would this be acceptable?

[kbinkster]

The gas forced air furnace and water heater are down there in the same room. They do have large fresh air returns. Unfortunately I am stuck with the basement local, but am really trying to get it as safe as possible.
Does it matter how far away the make up air is (as long as it is at least 10 feet away from the exhaust vent and furnace hot water heater etc.?) Or does it work better if I am on the same side as the open window and therefore closer, but not too close!
The closer it is, the easier it will be to draw out through the exhaust. Keep in mind that when you have a make-up source across a large space, you are moving air across a large space. In the winter, this could mean a very cold basement.

[burnt sand beads]

Thank you for your kind help! I guess it sounds like I am o.k. on either side of the U. I am glad to hear that the make up air doen't have any distance requirements other than the 10 feet from exhaust rule. Now, am I right- simply opening the windows provides the make up air?

[kbinkster]

You need to make up as much air as you exhaust. So, if you are exhausting 300 cubic feet of air per minute, then you need to replace 300 cubic feet of air per minute through your make-up source. A typical open window should be able to provide enough make-up air for a typical one-station lampwork set-up.

[burnt sand beads]

Thank you Kbinkster! I see you are in Colorado too!

[Dale M.]

And if a furnace or water heater kicks in and uses 50 cfm of air your make up air source needs to be apply the supply the additional 50cfm the heater is using....

So your fresh air source has to be able to handle the 300 cfm for lampwork hood and 50 cfm for heater, that is 350 cfm and then if other appliance kicks in then there is even more air required....

Dale

[burnt sand beads]

O.K. so I think from what everyone has been saying, I can do the following:

Set up my studio on one side of the basement. Exaust fumes out in front of me.

Glasscraft hood, lose the flexible ducting and use smooth rigid ducting instead.

Make up air from the 2 open windows way on the other side of the basement. Keeping both open, one for the vent hood and one for the furnace and hot water heater...oh question... my appliances have large fresh air returns so do I still need both windows open?

If I put in a more power fan, would I have to have more make up air than what the windows would supply?

[kbinkster]

And if a furnace or water heater kicks in and uses 50 cfm of air your make up air source needs to be apply the supply the additional 50cfm the heater is using....

So your fresh air source has to be able to handle the 300 cfm for lampwork hood and 50 cfm for heater, that is 350 cfm and then if other appliance kicks in then there is even more air required....

Dale

Well, the furnace and water heater should already have their own fresh air sources in place regardless of anything else.

[kbinkster]

Thank you Kbinkster! I see you are in Colorado too!

Yes, I am. Where are you?

[burnt sand beads]

I am in Erie Colorado (east of Boulder, south of Longmont). Whereabouts are you?

[kbinkster]

I have two homes, but spend most of my time at the one in Parker. The other is on an 80 acre ranch out further east (between Colorado Springs and Limon). I'm thinking about starting a teaching studio/glass retreat out there.

You should really go to one of the Bead Cluster (local ISGB chapter) meetings if you haven't already. There are so many great glass people in the Denver metro area - really a nice bunch of people.

[burnt sand beads]

Hi KBinkster!

A teaching retreat ranch-how glorious! I think that would be just a dream come true. Good luck with it, and for sure let me know if you get that started!I will have to check out "The Bead Cluster" sounds like a great group to get involved with- thank you!

We have a home in Howard Colorado also. Howard is just outside of Salida,an awesome town and art community- beautiful galleries without the snootiness or prices of places like Aspen or Telluride. I'd love to move there when our kids are grown and make beads, browse the galleries and then make more beads!!!

Thanks for all your help and friendly posts!

Pamela

[kbinkster]

I love Salida! It has been years since I have been there, and I think I need to make a trip sometime this summer to show Willy more of Colorado!

It sure has been nice "visiting" with you through these posts. Maybe someday we can meet in person.

[burnt sand beads]

Nice to chat with you too KBinkster! Who knows, someday maybe we'll bump into each other in Salida!