Off-grid pumps [RE-wrenches]

[Windy Dankoff]

<x-flowed>
Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Get up to 4 No-risk mortgage quotes – No SSN needed
Competitive rates from the nation’s top lenders in minutes
Lower your mortgage payments by up to $303/month!
http://click.topica.com/caaeYi1bz8Qcsbz9JC9a/ BestLenderFinder
-------------------------------------------------------------------

Kelly,

To restrict the flow of a standard (multi-stage centrifugal type) AC  
sub pump is to waste a great deal of the efficiency of a pump that is  
already low-efficiency. That's the worst choice. The pump is  
generally about 35% eff. and if you restrict flow to half (down to 3  
GPM), you're going to see half that!  It will also cause (to some  
extent) an AC voltage dip whenever it starts.

The other choices mentioned are all pos-displacement and in the range  
of 45-55% eff. If AC, you'll have to multiply in the inverter loss,  
of course.

Grundfos SQ-Flex will run on DC but not on 24V battery system. Must  
be 48. (needs over 30V).
Lorentz from Conergy is good for 24V battery system and has low-shutoff.
Shurflo 9300 is cheaper, but in regular home use it needs repair at  
probably 4-5 year intervals, usually when the mother-in-law is  
visiting, or a house-sitter is in charge.

Pressure pump -- for economy and efficiency, I'd suggest Conergy  
classic Flowlight Booster Pump -- but consider the filtration  
requirement. If water is sandy, sand will settle in the tank and with  
standard filter option, it may be little issue. With the 10 ft.  
suction lift you mention, and low demand of a cabin, I'd go with the  
Slow Speed Model of Flowlight. It will be more resistant to  
cavitation from the total suction of lift + partly clogged filter.

The cheap option for pressure pump is a Shurflo top-of-line RV pump.  
I'd make it easy to replace using braided vinyl flex-hose (which also  
absorbs pulsation if outlet hose is over 6' long). I'd then suggest  
customer replace the pump after a few years and keep old one as a spare.

For either of these pumps, use a min. 40-gallon pressure tank because  
they are low in flow rate.

Now, back to my rocking chair ...
Windy


- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php

Check out participant bios: www.mrsharkey.com/wrenches/

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------


</x-flowed>