- very big snip -
>Roger was saying:
>
>I really enjoy picking up a quality tool and looking for the differences which
>seperate it from a low quality "look alike" tool. My question was aimed at
>>making me a little bit more educated as to what the specifications and
>features >of a $400 Graingers exhaust fan had that a $160 HD whole house fan
>had missing ?
Gosh, sorry Roger, I got so wound up on that one that the focus of the
post glossed over the main issue almost entirely. What I was thinking,
and should have been saying, was that in decisions like this one, I end
up spending some time going through three catalogs, McMaster-Carr, MSC
and Grainger, trying to learn enough about the makes and models, types
of features, advantages, prices, etc. in order to decide which
makes/models/features could be appropriate, and then shop HD as well as
the industrial suppliers to find a good buy (this probably is why it
took me six months to buy a parts washer--clearly not all purchase
decisions warrant this much effort/time).
Having not compared the HD offerings for fans, I really cannot offer a
comparison, but in looking at the industrial models from the McMaster
catalogue, the "heavy-duty" 36" models have totally enclosed, 3 HP, ball
bearing motors, dynamically balanced fans, ball bearing pillow blocks,
15,000 CFM. These are probably overkill for anything other than
24hr/day operation in dusty/fume environments--around $800.
The 36" "medium duty" industrial fans typically have 1/2 HP, open frame,
drip-proof motors and 10,000 CFM. They are recommended for air streams
that are relatively clean--about $400.
The previous two fans are vertical (wall) mount. McMaster also offers a
36" ceiling ventilator, 1/3 HP, ball bearing, two-speed, 10,500 CFM,
heavy-duty venturi unit for $258. This one seems like a very nice
balance of quality, power and price (item# 1919K26, page 443 of cat.
#104), and ought to create a wind tunnel on high.
Grainger has a similar one listed for $520--to be honest, I think
Grainger is pricey compared to McMaster-Carr, well, just pricey period,
as far as that goes. Grainger also lists a 6,500 cfm, 36" unit for $265.
All the above units are belt drive--direct drive fans are cheaper, but
belt drive units are quieter, vibrate less, the bearings last much
longer (no fan torque loading on the motor bearings), and have better
motor positioning.
Though I did not call to compare at HD, most fans costing less than $200
are direct drive, and move less than 6,000 cfm. Maybe HD has one of
these better fans at their volume discounts, though, it would be worth
checking.
Dayton fans are very high quality, and after looking at the motor
ratings, I see we have the same HP inflation at work here as we have
seen in air compressors. The Dayton 1/3 hp motors draw 6.6 amps and the
CertainTeed 1/2 hp motors draw 5 amps. Hmmm......you have got to hate
that.
I would look closely at the motor current ratings at HD, as well as the
CFM delivery and the type of bearings used. Good luck and please let us
know what you find out.
doug
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