Huh??? I'm probably missiing something here. What happens when the powervent
fails???
I replace it with another, the same thing I do when other equipment in our whiz
bang
industry fails. 

The difference with the powervent is that it is easy and relatively inexpensive.
I've also had good luck using screens on the vent inlet and outlets, per the
instuctions, 
albeit a high tech solution.  :-)

Seems inverters, charge controllers, batteries, DC breakers, even modules fail
more frequenty.
Rant off.

Dick Ratico
Solarwind Electric



--- You wrote:
Jeffrey,

I'll second Jay's suggestion that sealed AGM batteries are the best 
choice in this circumstance. Presumably this is a grid backup system so 
the poor endurance of AGMs for cycling applications shouldn't be an 
issue. If you use a Zephyr power vent horizontal runs shouldn't be 
problem, but what happens when the power vent fails? It will fail. I've 
seen the bearings wear out on one and another that failed when insects 
got into the blades and gummed it up to the point that the motor stalled.

Kent Osterberg
Blue Mountain Solar, Inc.
www.bluemountainsolar.com
t: 541-568-4882


On 12/31/2011 6:59 AM, JRQ wrote:
> Wrenches,
>
> I'm looking at a potential battery backup system wtih a 200 AH @48V 
> flooded battery bank in the basement electrical room of a 3 story 
> building. There is a window in the electrical room. The batteries will 
> be located about 10' from an outdoor wall. The building is all 
> reinforced concrete, so I can not run a vent pipe vertically from the 
> batteries. Does anyone have a rule of thumb for how much the vent 
> pipes can be angled from the batteries? Would it be more lenient for 
> short sections of pipe (say <2') versus one long angled piece from the 
> batteries? My instinct would be to keep the pipe no more than 45? from 
> plumb.
>
> Or with bending the vent pipe: does anyone have a best-practice rule 
> for the sum of the angles of bends?
>
> Thanks,
> Jeffrey Quackenbush
> NABCEP Certified PV Installer
> Peripatetic Solar Technician
--- end of quote ---

