Venting DC Outside?

[Marc Spagnuolo]

Hello. I am considering venting my DC outside and I would love some input. We are doing a shop renovation that will include adding AC (5 ton). The shop will be just under 1000 sq. ft.

As a one-man shop, the DC is only turned on when I need it. And usually its on for a few seconds then off again. During milling operations, the DC will be on for maybe 5-10 min at most.

So how bad will this idea be for my AC efficiency. Realistically, with 12 foot ceilings and 1000 sq. ft, how much do you think venting ourside will hurt? For most of year, I will have windows and garage doors wide open so there will be plenty of fresh air.

Thanks guys.

[Keith Outten]

Marc,

I dump my DC directly to the outside of my shop into a large box when routing plastics and to the yard when diposing wood chips other than walnut. In spite of the numbers which indicate the loss is massive I don't even notice a major drop in temperature. My 24 by 36 two story shop has a 1.5 ton heat pump which can easilly handle the load unless the temps are in the teens. Another bonus is my DC works more efficiently with zero exit restrictions and the fine dust is gone in a flash outside without the hassle of bags.

I should note that I live in a rural area with no neighbors close by.

[Dan Forman]

Marc---I have read that it's not a good idea to turn the DC on and off frequently, it's much harder on the motor than to just leave it running. Might be a good idea to try and do as much of your power tool work as you can together. They say you should only start up the DC 3 or 4 times a day to avoid premature motor failure. I wish I could remember where I saw that, maybe someone else will chime in.

Dan

[Marc Spagnuolo]

I hope someone does chime in. Thats an interesting thought. I often wondered about that. But I just couldnt imagine it making much sense to keep in on when I am not using it. Now that would certainly change things if I keep it on for extended periods of time.

[Dennis Peacock]

Well...it's supposed to be true....but my 5 HP Cyclone, I operate it just like you Marc. On when I need it and off when I don't. So it's off more than it is on. Its a 5HP Leeson Compressor Duty motor......so it's built for starts/stops. Shorten the motor life...? I guess so.....but what will I know in 6 to 10 years down the road when I need another motor? :rolleyes:

[Jim Hager]

I have a Grizzly 3hp dust collector piped into central dc and blowing the chips outside into a pile out behind the shop. My DC is sitting outside on a steel stand with 6" galvanized pipe going to it and power cord coming from a long ranger remote. I routinely turn it on 12-15 times or more a day. I never leave it on for an extended period of time. On when I need it off when I don't. Been doing it that way for a long time. At least 7 years on the same dc unit.


I don't have shop air but my dc system set up this way does not seem to affect the heating in the winter. I use natural gas radiant plaque heaters and I don't notice any reduction in temp due to running the dc.
I hate dc bags:( Blow it outside!!!!!!!!!1

[Steve Clardy]

My complete system is outside on a concrete pad. 4HP grizzly bag unit that I changed around and just used the blower assembly.
I blow it into a two-wheel pickup bed trailer, or try too. Have a slight problem with this system. Wood chips hit the bottom of the trailer and bounce out on the ground. Pipe is about 7' from the bed. I either need to raise it up, or put sideboards on the trailer.
Sometimes it runs for a hour or two at a time, sometimes for a minute or so.
No AC, but haven't ever really noticed a heat loss from the monster wood stove I have.

[lou sansone]

I am not sure that my set up is what you are looking for, but it works for me. the cyclone is outside, but the return air is brought back inside for heat loss considerations in the winter.

lou

http://www.sawmillcreek.org/showthread.php?t=17721

[Peter Gavin]

As Jim Becker pointed out to me when I asked this same question, be very careful if you are using a gas furnace in the shop while evacuationg the air. If you create enough negative pressure, poisonous gas fumes could be sucked back into your shop. Now my question is, I am getting a new high efficiency furnace installed that sucks that uses direct venting for both the combustion air and the exhaust air. Will I still face the risk of drawing air combustion fumes back into the shop?

Peter

[Allan Johanson]

Marc---I have read that it's not a good idea to turn the DC on and off frequently, it's much harder on the motor than to just leave it running. Might be a good idea to try and do as much of your power tool work as you can together. They say you should only start up the DC 3 or 4 times a day to avoid premature motor failure. I wish I could remember where I saw that, maybe someone else will chime in.

Dan

I've heard of max 3-4 times per hour, not per day. On Leeson's site I came across some info that said at least some of their motors were built to withstand up to 20 on/off cycles per hour. I'm hoping mine is one of them. :D

Cheers,

Allan

[Dave Tinley]

Marc-
I am doin like Keith, my unit is outside and it vents the sawdust outside. I am also in a rural area with no neighbors near by. I had been discharging the sawdust into a pile, but weeds are groing up thru the pile so LOML said I had to come up with a different method. I am thinking about a 55 gallon plastic barrel to catch the sawdust, then use a two wheeler to dump it in the back field.
I have micro switches hooked to all my blast gates so when I open one it turns on the DC and when closed it shuts the DC off. Very handy, and even tho the DC is outside, the noise will still remind me to close the gates.

HTH
Dave

[John Shuk]

I think the real problem comes with a furnace. I think you may see some loss with the AC. I think the real trouble is with a furnace which as peter pointed out you could cause a reverse draft on your flue and get soot or gases. So if you don't mind having the AC kick on a little sooner then go for it.

[John Thomas]

How much noise do these DC's make? I am thinking about putting on outside also. I have some neighbors that are about 100 yards away. I guess I could put baffels around it.

[Ray Bersch]

Now my question is, I am getting a new high efficiency furnace installed that sucks that uses direct venting for both the combustion air and the exhaust air. Will I still face the risk of drawing air combustion fumes back into the shop?Peter

Peter - No, you will not face that risk. Those units have sealed combustion chambers and draw air only from the outside. As proof, look at the instructions and you will not see a requirement for "make up air" - the term used to describe the replacement of air used for combustion. On conventional furnaces make up air is pulled from the space immediately surrounding the furnace - the basement, for example. One big advantage of these high efficiency units is that they can be placed in very small enclosed spaces, like closets, and even adjoin living areas.

Be careful to heed the distance requierment between the exhaust and intake - you don't want to pull exhaust air back into the furnace via the intake air pipe.

Ray

[Marc Spagnuolo]

well fortunately, everything in the garage is electric. No gases and no fumes. Only concern is AC efficiency. But, I think I have decided to get a filter unit, and use that during the hot summer months. So for most of the year I will vent outside. Seem like a good plan to me. :)

[Bill Fields]

Hey Marc--


PHOENIX--we Phoenicians live in an area not very similar to most others in the USA.

Some of the posts don't seem to realize we can work outside 90% 0f the year if we wish.

As to your question, when my new "Master Cool" portable "swamp-cooler" does not work due to humidity over 25%, IMHO there would be nothing wrong in using your modern heat-pump based AC to put more cool into your shop area.

I would do 2 things:

-Make sure there is sufficient air inflow into the house--a couple of 4" cracked windows should do it---and make sure there is sufficient concomitant venting from the shop.

-Look into one of those ceiling mount dust filters--blow it out weekly and change monthly.

As to my situation, I try to work outdoors on my 3-car garage apron.

I have a bunch of DC stuff I bought--as yet uninstalled.

Mask, glasses, cap--pretty well elininate most of the dust

So far can get away with occupying the entire garage with all my "works in progress".

Best

BILL FIELDS