The equipment documentation should identify the total cfm required to
properly vent the total system, however in many of the older units as this
the documentation is nowhere to be found.

If I remember correctly the total cfm for exhausting a system is somewhere
around 600 to 800 cfm. What typically occurs is the acquisition of a blower
system usually mounted in line with gate valves on the exhaust tubes. I
think that three or four vents are required. One vent is typically over the
fluxer unit, the second is over the solder pot, the third is the lip vent of
the solder pot and the fourth, which could be a moveable vent to be used
when the pot is removed or pulled away from the equipment for maintenance.
This fourth vent is typically a hooded type of enclosure for capturing the
fumes from the solder pot during maintenance.

All the vents have to be balanced so the heat is not removed from the
equipment. All you want the venting system to do is remove the smoke and
fumes from the equipment and this is all adjusted with the gate valves. If
those valves are not adjusted properly and you are using a foam fluxer for
example, you will accelerate the evaporation of the alcohol in the flux,
changing the flux activity levels. As the alcohol levels drop the activity
levels of the flux increase. The vent over the solder pot should be set up
to capture the vapors coming off the solder pot itself as the boards are
being soldered.

You should also keep in mind where the final exhaust is going. If it is to
be vented outside, there may be some aromatic fumes going outside which
could be obnoxious to the local environment, remember this is not a bakery
and the smell is not of pastry. One way to address this is to install an
electronic smoke precipitator inline with the vent system and this will take
out the particulate matter from the smoke off the wave. Then you could also
have a charcoal filter to remove the remaining gaseous aromatic fumes from
air flow.

This is where I would start. I had 23 of these types of lines while employed
with Digital Equipment and each one was vented in a very similar fashion.
Our manufacturing plants were located worldwide.

If you have any questions and want to talk about this, please contact me
offline at 603 673-7822 ext 15

Leo Lambert
Technical Director
EPTAC Corp
Amherst, NH. 03031

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Jack Goble
Sent: Monday, March 17, 2003 8:01 PM
To: [log in to unmask]
Subject: [TN] exhausting a wave solder machine


Hi,

We have recently installed a wave solder machine (Hollis Future 1, the same
one with the flux drip question of a few days ago) and have a professional
but temporary set-up for exhaust.  The reason it is not permanent is that
we have had quite different recommendations from a few contractors.  Does
anyone have any recommendations on a proper and effective method for
exhausting this machine?

Thank you,

Jack

---------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------