Cob: electrical

[Dorothy Bothne]

I think he was worried about uneven heat dissipation, hot spots or areas where the heat would be held around the wires.  (And he does have the credentials - over 30 years designing electrical and lighting systems for commercial and residential buildings.)  The conduits open to the j boxes, and the jboxes are open to the room, so the air can move through the conduits and vent to the room. This would remove any heat build up much quicker than conduction through the cob wall.  
In the earlier posting, I was referring to pulling wires (#12 green, black and white for 15Amp outlets on a 20Amp breaker) through the conduit not the Romex (much easier to pull wire through the conduit than pulling Romex through it).  Exterior grade Romex (not interior) works great buried in cob, but it's too much trouble if for some reason you have to change out the wire.  You'd have to abandon the romex in the wall and find another way to connect the new wire.  The conduit gives you a little more flexibility if you change your mind about what is connected to the circuit or if the wire goes bad and has to be replaced.  And, you're limited in the wire size that is readily available in the exterior grade Romex.
Also, I think the wire is a little easier to work with than the Romex.  I've found it pretty easy to route the blue "smurf tube" where I want outlets, lights and switches.  Sometimes pulling the wire through has gotten a little tricky, and the whole system's not connected yet.  I'll post the results to the list when I get the area dried in and connect the electrical panel.  
I've done all the electrical rough in myself.  The first building I did, I only had to have an electrician help me connect the breaker box.  
Dorothy


David Knowlton <pilot1ab80 at hotmail.com> wrote:
i have no credentials here, but why would air dissipate heat better than
cob? again - no research available. common sense tells me the cob
would be a better heat sink than air. romex is extra insulated - the
coating is real tough stuff - and if it works in the ground - why not
in the 'earth' that is cob? Air is an insulator, solids are better 
conductors
in general. just thinking out loud.

david


>From: Dorothy Bothne 
>Reply-To: Dorothy Bothne 
>To: coblist at deatech.com
>Subject: Re: Cob: electrical
>Date: Fri, 12 Sep 2003 06:06:31 -0700 (PDT)
>
>Mary,
>I've handled electrical systems in two different ways. In the first 
>structure I built, I used Romex (available at Home Depot) rated for outside 
>(direct burying). I buried it directly in the cob. the structure had 3 
>outlets and 2lights and 1 exhaust fan. everything works fine. I'm 
>working on my second structure now. I consulted with an electrical 
>design engineer and he recommended that I use a conduit buried in the wall 
>and pull the wires through the conduit in lieu of direct burying the Romex. 
> He also suggested that I use the blue "smurf tube" because it's flexible 
>enough to bend around curves and you need fewer fittings.
>The reason that he said to use conduit is that the wire needs the air in 
>the conduit to dissipate heat. also, you can replace the wire in the 
>conduit easier if repairs become necessary.
>Dorothy
>
>Mary Hooper wrote:
>Will someone tell me something about installing electrical systems. Do the
>wires go outside the wall or are they embedded? that sort of thing. I have
>not bought a how-to book yet. This interests me as my honey would not put 
>an
>outlet in the basement (concrete floor) bathroom unless it had a ground
>fault interrupter.
>The solar panels have to connect to inside somehow. Maybe it's wired like a
>"regular" house?
>thanks
>Mary
>
>
>
>
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<DIV>
<DIV>I think he was worried about uneven heat dissipation, hot spots or areas where the heat would be held around the wires.  (And he does have the credentials - over 30 years designing electrical and lighting systems for commercial and residential buildings.)  The conduits open to the j boxes, and the jboxes are open to the room, so the air can move through the conduits and vent to the room. This would remove any heat build up much quicker than conduction through the cob wall.  </DIV>
<DIV>In the earlier posting, I was referring to pulling wires (#12 green, black and white for 15Amp outlets on a 20Amp breaker) through the conduit not the Romex (much easier to pull wire through the conduit than pulling Romex through it).  Exterior grade Romex (not interior) works great buried in cob, but it's too much trouble if for some reason you have to change out the wire.  You'd have to abandon the romex in the wall and find another way to connect the new wire.  The conduit gives you a little more flexibility if you change your mind about what is connected to the circuit or if the wire goes bad and has to be replaced.  And, you're limited in the wire size that is readily available in the exterior grade Romex.</DIV>
<DIV>Also, I think the wire is a little easier to work with than the Romex.  I've found it pretty easy to route the blue "smurf tube" where I want outlets, lights and switches.  Sometimes pulling the wire through has gotten a little tricky, and the whole system's not connected yet.  I'll post the results to the list when I get the area dried in and connect the electrical panel.  </DIV>
<DIV>I've done all the electrical rough in myself.  The first building I did, I only had to have an electrician help me connect the breaker box.  </DIV>
<DIV>Dorothy</DIV>
<DIV><BR><BR><B><I>David Knowlton <pilot1ab80 at hotmail.com></I></B> wrote:</DIV>
<BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">i have no credentials here, but why would air dissipate heat better than<BR>cob? again - no research available. common sense tells me the cob<BR>would be a better heat sink than air. romex is extra insulated - the<BR>coating is real tough stuff - and if it works in the ground - why not<BR>in the 'earth' that is cob? Air is an insulator, solids are better <BR>conductors<BR>in general. just thinking out loud.<BR><BR>david<BR><BR><BR>>From: Dorothy Bothne <DBOTHNE54 at YAHOO.COM><BR>>Reply-To: Dorothy Bothne <DBOTHNE54 at YAHOO.COM><BR>>To: coblist at deatech.com<BR>>Subject: Re: Cob: electrical<BR>>Date: Fri, 12 Sep 2003 06:06:31 -0700 (PDT)<BR>><BR>>Mary,<BR>>I've handled electrical systems in two different ways. In the first <BR>>structure I built, I used Romex (available at Home Depot) rated for outside <BR>>(direct burying). I buried it directly in the cob. the
 structure had 3 <BR>>outlets and 2lights and 1 exhaust fan. everything works fine. I'm <BR>>working on my second structure now. I consulted with an electrical <BR>>design engineer and he recommended that I use a conduit buried in the wall <BR>>and pull the wires through the conduit in lieu of direct burying the Romex. <BR>> He also suggested that I use the blue "smurf tube" because it's flexible <BR>>enough to bend around curves and you need fewer fittings.<BR>>The reason that he said to use conduit is that the wire needs the air in <BR>>the conduit to dissipate heat. also, you can replace the wire in the <BR>>conduit easier if repairs become necessary.<BR>>Dorothy<BR>><BR>>Mary Hooper <MJHOOPER at TRCCOMPUTING.COM>wrote:<BR>>Will someone tell me something about installing electrical systems. Do the<BR>>wires go outside the wall or are they embedded? that sort of thing. I have<BR>>not bought a how-to book yet. This interests me as my honey
 would not put <BR>>an<BR>>outlet in the basement (concrete floor) bathroom unless it had a ground<BR>>fault interrupter.<BR>>The solar panels have to connect to inside somehow. Maybe it's wired like a<BR>>"regular" house?<BR>>thanks<BR>>Mary<BR>><BR>><BR>><BR>><BR>>---------------------------------<BR>>Do you Yahoo!?<BR>>Yahoo! SiteBuilder - Free, easy-to-use web site design software<BR><BR>_________________________________________________________________<BR>Send and receive larger attachments with Hotmail Extra Storage. <BR>http://join.msn.com/?PAGE=features/es<BR></BLOCKQUOTE></DIV><p><hr SIZE=1>
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