another duct collection system question

[Frank Fusco]

A friend of mine has just had a shop building built that we all would drool over. It is 50'X61', very high ceiling, insulated. He will be installing his dust collection system with the collector inside. I asked why not outside to avoid the noise. He said doing that would suck the heat from the building in the winter. I can see where it would to some extent. But is this really an issue?

[Al Willits]

Depends on where you live I think.
Here in Minn with a average temp in the 40's, heating is a major expense, southern states would be A/C costs.

Venting to the outside could amount to the national debt in heating/A/C costs...

A air to air exchanger might be worth it, but at 2k or so, not sure.

A baffle system to direct air either outside or recirculate it may be another alternative.

You know who's web site, mentions running a exhaust blower much longer than I thought to clear the air, I'm thinking of installing solar collectors on the roof of my garage to help defray the cost.


Al

[Cecil Arnold]

Assuming the ceiling is 10' and the DC is pulling 800 CFM it would evacuate the heated air on around 38 minutes. [61*50*10=30,500 cu.ft/800cfm=38.125 min.]

[Frank Fusco]

Assuming the ceiling is 10' and the DC is pulling 800 CFM it would evacuate the heated air on around 38 minutes. [61*50*10=30,500 cu.ft/800cfm=38.125 min.]

His ceiling is more like 20'. But, from what you say, the answer is 'yes', it is an issue.

[J. Scott Chambers]

What kind of heating system is he using? If he using a conventional forced air heating system, he'll be paying a premium anyway with 20' ceiling, unless he has good insulation in the roof.

[Steve Clardy]

I have a monster shop, along with a monster wood stove to heat it.
My collector is outside, everything gets blowed outside.
I don't notice heat going out in the winter.
I do use a remote I carry with me, and shut my collector off when not in use.
I use 8-10 cords of firewood a year in the shop, and the insulation isn't quite all finished.

[Jim O'Dell]

Does your friend plan on filtering the air? or exhaust outside? If he filtered the air and returned into the shop, no matter where the cyclone was (within reason ) he should not run into a heat loss problem. If he exhausts outside, then the heat goes bye bye with the air. I've heard that radiant heat isn't as bad of a loss, but don't understand why that would be. Still would be exchanging the heated air. Jim.

[J. Scott Chambers]

Does your friend plan on filtering the air? or exhaust outside? If he filtered the air and returned into the shop, no matter where the cyclone was (within reason ) he should not run into a heat loss problem. If he exhausts outside, then the heat goes bye bye with the air. I've heard that radiant heat isn't as bad of a loss, but don't understand why that would be. Still would be exchanging the heated air. Jim.

Radiant heat does heat the air directly, rather it heats mass - your tools, yourself, your floor.

[Jim O'Dell]

Scott, I do understand that part, but it would have to warm the air some too, maybe just from the machines and bodies warming the air. That air would have to leave, and then be rewarmed. Although it might not really be noticeable I guess if the body is constantly being rewarmed. Hmmmmm. Might have to look into something there. Can you tell I think while I talk?? Just don't slip something in front of me I'd trip over.
Thanks! Jim.

[glenn bradley]

Not in SoCal. I have seen folks put the DC outside and vent the filtered air back into the shop. A little return noise but when it's 5 degrees, I think they like the heat enough to bear it.

[Frank Fusco]

What kind of heating system is he using? If he using a conventional forced air heating system, he'll be paying a premium anyway with 20' ceiling, unless he has good insulation in the roof.

The roof is insulated. He hasn't installed the heating system yet. It is one honkin' huge building.