zero energy home and heat pump sizing.... [RE-wrenches]

Todd Cory, Mt. Shasta Energy Services toddcory at finestplanet.com
Sat Mar 4 09:11:34 PST 2006


<x-flowed>
Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
First Month Free! Save up to 50% on your phone bill. 
Free Activation, Free Equipment! Packet8
30-day money back guarantee. 1-877-868-1135
http://click.topica.com/caaexdQbz8Qcsbz9JC9a/ TMONE
-------------------------------------------------------------------

Remember, there is more than R-value to making a super efficient home. 
If you consider the heat loss through the framing members you need to 
consider alternative framing. Wood being ~R1/inch, our local energy 
guru, built a zero energy triplex with 2 X 8 framing 2' on centers, 
single top plate, 2', 4', 6' windows that fit within the framing 
members, BCI's for headers etc. Turns out that with the framing changes, 
he actually used LESS lumber using 2 X 8's rather than conventional 2 X 
6's. He also wrapped the whole building in 1" rigid foam. R-60 cellulose 
in the attic etc.

Requiring a 14 kw PV system to meet the energy loads of a 4000 ft home 
sounds to me like the efficiency homework was not done in the 
construction phase (and did they really need 4000 ft?).

Remember, sustainability is about using LESS, not throwing a bunch of 
resources (even if they are active renewables) to offset waste and 
inefficiency.

Todd


Geoff Greenfield wrote:

>friends, wrenches, countrymen - lend me your ears (and brains!)
>
>While I DO know that the PV panels go shiny side up, I am very short on the
>HVAC knowledge - so please give me some help on this one!
>
>I have a great project in design phase - customer is doing new construction
>with the goal of net zero energy home.  I am comfortable coming up with a
>load analysis/projection of kwh for everything except the HVAC plant.  They
>are looking at either a super efficient heat pump or possibly geothermal.
>
>And of course - we are in conceptual stage and have no firm plans...  He is
>planning on super insulating (but also wants plenty of windows).  He is
>planning on maxing passive solar design with calculated overhangs, thermal
>mass etc. In fact the building envelope etc may be somewhat driven by the
>"sweet spot" of HVAC sizing (in other words - we may throw in some more
>cellulose insulation to keep from jumping from a 2 ton unit at efficient
>capacity to the next size up...).
>
>Our target is 2,600 SF of conditioned space located in southern OH - I
>(think) we have an annual requirement for 1134 F cooling degree days and
>4927 F Heating degree days (not days but cumulative degrees based on 65
>degree comfort - though the customer is happy to wear a sweater when it is
>20 below and let the temp rise in the summer - humidity is the target more
>than temp.
>
>I know that true sizing/energy use projections require plans with window
>sizes, wall R-values etc., but at this stage do any of you have any rough
>guidance on an approach to finding the kwh of this type of system?
>
>Thanks in advance!
>
>For a brighter energy future,
>
>Geoff Greenfield
>NABCEP Certified Energy Practitioner
>
>  
>

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Get your VoIP on with Packet8's Videophone.
Crystal clear images of your loved ones. Free Month.
30 day money back guarantee. 1-877-868-1135
http://click.topica.com/caaexdTbz8Qcsbz9JC9f/ TMONE
-------------------------------------------------------------------

- - - -
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>



More information about the RE-wrenches mailing list