Anyone ever use a big shop vac as a central vac. How does the suction of a
shop vac compare to a central vac. I see some central vacs rated by water
suction height such as 130".

I looked at that a few years back. For a central vac you want fairly
good suction (100-130 inches of water), decent air flow, and
reliability. Shop vacs are ok on the first 2, just don't have it for
long term built in use.

I also looked at using the cheaper schedule 40 PVC or ABS pipe instead
of the expensive vac fittings. Found that nothing matches up in terms of
fittings size. Also, the suppied fittings have a tighter radius that is
usefull for the wall outlets.

But don't try and use the shop vac for a shop system, the one and two
bag units have huge airflow and much less vacumn than the standard
(Sears) shop vac.

habbi wrote:

Anyone ever use a big shop vac as a central vac. How does the suction of a
shop vac compare to a central vac. I see some central vacs rated by water
suction height such as 130".

"habbi" wrote in message
...
Anyone ever use a big shop vac as a central vac. How does the suction of a
shop vac compare to a central vac. I see some central vacs rated by water
suction height such as 130".

About 35 years ago I had a large central vacuum system (made by BVC)
installed in the Rank Xerox UK photocopier refurbishment facility when I
worked there. Installation was expensive - both the cost of the central unit
and the piping. It was ultra-reliable and liked by the workers, apart from
when someone broke a stink bomb at one of the inlets and the people near the
central suction unit got rather cross about it. 8-)

I can't see an ordinary shop vac doing the same job.

Leon
--
Leon Heller, G1HSM
http://www.geocities.com/leon_heller

"habbi" wrote in message
...
Anyone ever use a big shop vac as a central vac. How does the suction of a
shop vac compare to a central vac. I see some central vacs rated by water
suction height such as 130".


Don't the shop vacs usually say, "not for household dirt" or something like
that? I think their filters are set up for sawdust and such. I know mine
tends to spout a cloud of dust when I turn it on. I think the filter would
clog up pretty fast or just past dust through. That sounds like the kind of
problem you wouldn't want in a whole house cleaner.

Regards,
LB

"habbi" wrote in message
...
Anyone ever use a big shop vac as a central vac. How does the suction of a
shop vac compare to a central vac. I see some central vacs rated by water
suction height such as 130".

Having personally installed a commercial central vacuum system, I'd have to
suggest that at best, a shop vac is a joke. The best one I've seen doesn't
come close to the level of performance the purpose built units have. I was
going to do exactly as you suggest, but checking into the commercial units
changed my mind, in spite of the fact it was expensive. A poorly
performing unit would serve no real purpose. That made making the right
decision easy.

You can avoid using a built in with a filter by selecting the right
manufacturer. Some are equipped with a cyclonic separator and discharge
outside. I highly recommend going that direction. Filters limit the
ability of the best units and are but one more thing to maintain. By
discharging outside instead of inside, you remove troublesome dust instead
of placing it back in circulation, along with the smell of dead tissue,
which you find in all habitats.

Harold

In article , Harold and Susan Vordos says...

Having personally installed a commercial central vacuum system, I'd have to
suggest that at best, a shop vac is a joke. The best one I've seen doesn't
come close to the level of performance the purpose built units have. I was
going to do exactly as you suggest, but checking into the commercial units
changed my mind, in spite of the fact it was expensive. A poorly
performing unit would serve no real purpose. That made making the right
decision easy.

I've found that doing the reverse of this is quite nice.

I've scrounged a couple of true "whole house vac" units
and use them to clean chips off machines in my shop here
at work, and also at home.

(the one at work was in the warehouse here, free for the taking,
and the one at home was snagged during one of the local trash
pickup days. It didn't work because it was clogged with
dust and hair)

Those things develop a huge pressure differential and will
suck the chrome off the proverbial trailer hitch. The only
thing I haven't done yet is to discharge the one at home
to outside, and find some spot on the wall to hang it.

Jim


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==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
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I have been using a shop vac as a central system for about 15 years and I
would not trade it for nothing. Somebody mentioned fine dust getting
throught the filter. That has not been a problem and my system is not
vented to the outdoors like the central vacs are. The only problem I find
is that when the filter is clean it is hard to clean the floor the brush
wants to glue to the floor. On carpet you can lift the carpet off the
floor. Once the filter is dirty it seems to work just fine. It was a lot
cheaper and I did use the proper piping and fittings with an adapter on the
end for the shop vac.
Eric

"jim rozen" wrote in message
...
In article , Harold and Susan Vordos says...

Having personally installed a commercial central vacuum system, I'd have
to
suggest that at best, a shop vac is a joke. The best one I've seen
doesn't
come close to the level of performance the purpose built units have. I
was
going to do exactly as you suggest, but checking into the commercial units
changed my mind, in spite of the fact it was expensive. A poorly
performing unit would serve no real purpose. That made making the right
decision easy.

I've found that doing the reverse of this is quite nice.

I've scrounged a couple of true "whole house vac" units
and use them to clean chips off machines in my shop here
at work, and also at home.

(the one at work was in the warehouse here, free for the taking,
and the one at home was snagged during one of the local trash
pickup days. It didn't work because it was clogged with
dust and hair)

Those things develop a huge pressure differential and will
suck the chrome off the proverbial trailer hitch. The only
thing I haven't done yet is to discharge the one at home
to outside, and find some spot on the wall to hang it.

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

Eric J. Comeau wrote:

SNIP

I did use the proper piping and fittings with an adapter on the
end for the shop vac.
Eric

BTDT ~ about a dozen years ago when Sears made some fairly decent Vacs.
I use a big 15 Gallon Vac and I plumbed the whole shop making an
outlet at each device, I.E., table saw, planer, vise, radial saw,
grinder, 9x20 lathe, mill/drill, etc. I used 2" class 125 PVC water
pipe with short sweep elbows and DWV plumbing sanitary tees for the
connections. A 2" is cap slipped over the ends of the pipes for terminal
points. The hoses use ONE 2" coupling turned to accept the Vac hose,
and The whole shebang is plumbed into an enclosed cabinet to keep it
quiet. There isn't much chrome left in my shop either.... the shop vac
has PLENTY of suction.

Bill P. PhxAz.

"habbi" wrote in message
...
Anyone ever use a big shop vac as a central vac. How does the suction of a
shop vac compare to a central vac. I see some central vacs rated by water
suction height such as 130".


Yes.

Some may complain about the relative reliability of a shop vac vs. a
high-end central unit -- fooey! At $800+ for a good central, and less than
$99 on sale for a _good_ shop vac, you can wear out one every year and a
half, and still be ahead.

I built our system around a Sears $99 heavy-duty vac. The vacuum 'head'
lasted six years of thrice-daily in-house use, plus double-duty in my shop,
because I plumbed my workshop with overhead gates and floor scuppers.

The problem of standard PVC pipe not mating up to, say, ManorVac fittings is
trivial. Hey, guys... this is a metalworking forum. Just use one of your
eighteen lathes to bore standard PVC couplings out the few thou necessary to
match up with the commercial wall plates.

All this, I did. I built up a low-voltage relay system from an old filament
transformer and a 12vac relay.

The rest was six years of trouble-free, wonderful performance for a _total_
expense of about $300 for both the house and workshop.

(don't forget to use long sweeps for turns, rather than ells, or those socks
and cats WILL get caught at the corners G)

LLoyd

outside. I highly recommend going that direction. Filters limit the
ability of the best units and are but one more thing to maintain. By
discharging outside instead of inside, you remove troublesome dust instead

Discharging outside seems the best for removing dirt. However I wonder
how much heated air it removes from the house? Is it significant?

Similar question. I have a baldor 10 inch grinder with dust collecter
which discharges into a big cloth bag. I considered discharging
outside but at 500cfm, but I figure I would be loosing LOTS of heated air.

I would also like to plumb this dust collector to remove the dirt from
my small rockwell toolmakers grinder. The tool makers grinder might run
for 30-60 minutes for big jobs. Blowing 500cfm outside for an hour seems
like a lot of heated air. I figure a multistage dust filter makes more sense.

chuck

"Charles A. Sherwood" wrote in message
...
outside. I highly recommend going that direction. Filters limit the
ability of the best units and are but one more thing to maintain. By
discharging outside instead of inside, you remove troublesome dust
instead

Discharging outside seems the best for removing dirt. However I wonder
how much heated air it removes from the house? Is it significant?

Similar question. I have a baldor 10 inch grinder with dust collecter
which discharges into a big cloth bag. I considered discharging
outside but at 500cfm, but I figure I would be loosing LOTS of heated air.

I would also like to plumb this dust collector to remove the dirt from
my small rockwell toolmakers grinder. The tool makers grinder might run
for 30-60 minutes for big jobs. Blowing 500cfm outside for an hour seems
like a lot of heated air. I figure a multistage dust filter makes more
sense.

chuck

Yep, losing heated air is the down side. Not a problem during warm
seasons. Lots of problems with filters if you use your system in the shop,
though, one of which is starting fires when grinding. It's not very
difficult to ignite the contents of a vacuum if you pick up sparks, makes no
difference if you filter, or not.

Harold

"Eric J. Comeau" wrote in message
news:6ZuUd.13704$TB.9249@edtnps84...
I have been using a shop vac as a central system for about 15 years and I
would not trade it for nothing. Somebody mentioned fine dust getting
throught the filter. That has not been a problem and my system is not
vented to the outdoors like the central vacs are. The only problem I find
is that when the filter is clean it is hard to clean the floor the brush
wants to glue to the floor.

You must match the tools to the job. If your floor brush is gluing down, you
have the wrong brush. Vacuum cleaners work ONLY when there's air movement,
so a good brush will provide a large volume of air movement without
attaching to the floor. If you achieve the same results by slowing down the
process of air movement, you also slow down the process of cleaning,
lowering the quality of the job. Think of it this way. Your brush will
move over the floor effortlessly if you don't turn on the system. That's
the direction you're headed when you run with a plugged filter. What's the
point? I use my system to get clean, not push things around. Go to a
commercial janitorial supply house and check out good floor brushes. You'll
be amazed that they actually work.. even without plugged filters.

One other thing. If you think your vacuum emulates a large industrial built
in unit, you're sadly mistaken. I've seen some of the largest of shop vacs
and they don't come close to the level of performance----not even close.

Harold





On carpet you can lift the carpet off the
floor. Once the filter is dirty it seems to work just fine. It was a lot
cheaper and I did use the proper piping and fittings with an adapter on
the
end for the shop vac.
Eric

"Charles A. Sherwood" wrote in message
...
outside. I highly recommend going that direction. Filters limit the
ability of the best units and are but one more thing to maintain. By
discharging outside instead of inside, you remove troublesome dust instead

Discharging outside seems the best for removing dirt. However I wonder
how much heated air it removes from the house? Is it significant?

Similar question. I have a baldor 10 inch grinder with dust collecter
which discharges into a big cloth bag. I considered discharging
outside but at 500cfm, but I figure I would be loosing LOTS of heated air.

I would also like to plumb this dust collector to remove the dirt from
my small rockwell toolmakers grinder. The tool makers grinder might run
for 30-60 minutes for big jobs. Blowing 500cfm outside for an hour seems
like a lot of heated air. I figure a multistage dust filter makes more
sense.

You could calculate this pretty easily by Googling for some numbers. Based
on a quick search (and no time spent on reality checks or detailed
analysis) it looks like you'd be losing about 13k Btu/hr. That's assuming
500 SCFM at 0.075 lb/SCF and 6 Btu/lb air. At 6$/MM Btu, it will cost you
about 8 cents per hour.

Maybe someone that does this for a living can double check those results.