solar thermal pumps [RE-wrenches]

[Windy Dankoff, Dankoff Solar]

<x-flowed>
Jeff said:
>  I believe that pushing this cold slush does wear the brushes faster,
>  resulting in more maintenance.

That may be true if the motor is very small, and marginally sized. It 
is not true with our SunCentric, which had a big oversized motor 
turning at slow speed.

>  If a DC pump must be used, seriously look at Windy's. If you must go
>  brushless (and I understand...) then you really must go AC.

Brushless may be ideal, but brush life of the low-head SunCentric 
pumps is very long because the low-head models turn at slow speed and 
they have big fat brushes. The SunCentric specs tell you how to 
estimate the brush life, depending on the model. In most low head 
situations, it will be over 10 years.

>  The advantage of PV direct seems to fad on the larger systems. As the size
>  increases, having one controller doesn't seem like a big added complexity.

Concern about power outages MAY be a fad ... we'll see!

>  Pipe all the collectors in parallel as Smitty says. They'll give you more
>  BTU. Otherwise you're heating progressively hotter water in each collector,
>  cutting efficiency in each one.

It also greatly reduces pump load (friction loss).

Windy

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

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

List rules & etiquette: http://www.mrsharkey.com/wrenches/etiquete.htm

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

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com

==^================================================================
EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9
Or send an email To: RE-wrenches-unsubscribe at topica.com
This email was sent to: michael.welch at homepower.com

T O P I C A -- Register now to manage your mail!
http://www.topica.com/partner/tag02/register
==^================================================================




</x-flowed>