DC heat? [RE-wrenches]

[Todd Cory, Mt. Shasta Energy Services]

<x-flowed>
Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
FREE DVR
And up to 3 additional standard receivers!
Call 1-800- 901 - 5080 Today
http://click.topica.com/caaeas1bz8Qcsbz9JC9a/DirectSatTV
-------------------------------------------------------------------

Our heat pump:
http://ip.smarterwayinc.com:8080/res_systems/ductless/mitsubishi/tzh1.asp

has a variable frequency drive for the compressor, so it does not cycle 
on and off like a traditional unit, but rather it modulates the 
compressor RPM to meet the heating/cooling demand. This is how they can 
drive three indoor units off of one outdoor unit. If one operated this 
unit off a RE system, the load would be dependent on the heating demands.

Todd



Darryl Thayer wrote:

>To all
>Would it be practical to operate using the battery
>from 100% to 90% and then recharge.  This gives a
>longer run time for the compressor of the Heat pump,
>it allows the system to use one  heat pump at full
>power.  
>
>How long should a heat pump run to maintain reasonable
>life expectancy?  If the heat pump could run for 1
>hour on these conditions, and the off time depends
>upon the charging rate?  A three ton HP at 3.3 COP
>would require 3 kW for 1 hr.  This is about 60 amp hrs
>at 48 volt nominal.  Or a 600 AH battery set.  
>
>If the RE source was producing during this period the
>run time would be increased.  How many cycles can a LA
>battery take at 10% DOD?     
>
>It would appear that the RE energy system would have
>to be much too large for the requirements to supply a
>reasonable amount of energy to this expensive energy
>booster.  If it were too large then an extra means of
>power dump would be required.  
>
>just a thought. 
>Darryl  
>  
>

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Is your computer freezing up or slowing down?
Repair corrupt files and harmful errors - protect your PC
Take a 2-minute PC health check-up at no charge!
http://click.topica.com/caaedmqbz8Qcsbz9JC9f/PC PowerScan
-------------------------------------------------------------------

- - - -
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>