Regarding dust in the fans.... that's a concern of mine as well since a lot of my driving will be on dirt roads (since my EV won't have enough range to make it to town (boulder), it'll be mostly errands around the mountains. I used to work on a solar test site slightly downwind of a cement plant... we burned out many inverters when the cooling fans died (after a few weeks in some cases), from the fine cement dust everywhere. The more expensive inverters seemed to have better fans (enclosed bearings perhaps), because they lasted several years.
For cooling needs on my EV, I am using automotive fans (higher quality radiator cooling fan on the controller heat sink, so far), so presumably they are made to resist dust a little better than some cheaper ones -- I've rarely had them burn out on ICE's at least). On Wed, Jul 10, 2013 at 8:08 PM, Mike Nickerson <[email protected]>wrote: > Thanks, everyone for all the input. To answer several questions and > comments at once: > > The fans are mounted directly to the top of the controller which is > essentially a sealed metal box. The top looks to be an extruded aluminum > case with mild fins (1/8" deep). The fans are not intended for wet use, > but > I don't think they will get wet on top of the controller under the hood. I > am more worried about dust from my gravel driveway; it gets everywhere. > > I am going to see how well they last. These are meant to be computer case > fans, so this usage is outside their design, but they were cheap. > > For now, I will probably leave the fans blowing away from the controller. > As much because they are already that way, as anything. I will measure how > hot the controller is above ambient after my commute home in the evening. > If I ever reverse the fans, I will measure again. > > Mike > > > -----Original Message----- > > From: [email protected] [mailto:[email protected]] On > > Behalf Of Lee Hart > > Sent: Monday, July 08, 2013 5:38 PM > > To: Electric Vehicle Discussion List > > Subject: Re: [EVDL] Fans Up or Down? > > > > Mike Scott wrote: > > > Is the possible entry of water a problem? I've always though that the > > > gap between the impeller and the frame should be on the bottom so that > > > water could not fill the airspace in the fan motor. > > > > If the mounting location is such that it may get wet, then you really > should be > > using a fan with fully enclosed motor -- not one intended for dry indoor > use. > > Especially on a fan, water is going to get into *everything*, no matter > how > > you mount it. > > > > Dach Savage <[email protected]> wrote: > > >> In most any ventilation or cooling scheme it is best to use the fan > > >> in an exhaust mode, IE pulling the air out of a cabinet. > > > > You really have to look at the blade design. The manufacturers have > > performance curves, showing air flow versus air pressure. Propeller fans > are > > very sensitive to air pressure, and the pressure difference between inlet > and > > outlet. Some blade designs will have a drastic reduction in airflow with > even a > > slight restriction or reduced air pressure at their inlet. Others can > tolerate it > > much better. > > > > The fans I've happened to use in product designs have generally worked > > better by pressurize the cabinet. It extracts a bit more heat (the things > being > > cooled run a bit cooler), and it makes sure that any air leaks will let > air out, > > rather than suck in air (or dirt or water or bugs etc.) from uncontrolled > cracks > > or openings. > > > > -- > > The greatest pleasure in life is to create something that wasn't there > > before. -- Roy Spence > > -- > > Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > For EV drag racing discussion, please use NEDRA > > (http://groups.yahoo.com/group/NEDRA) > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130710/373db789/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
