This is very helpful. The combustion vents are of the inverted cone variety that you've described. I'm still wondering if the building or mechanical codes would prohibit panels located 4 ft above plumbing, bathroom or non-combustion exhaust vents.

Regarding Benn's earlier question about minimum allowable height for plumbing vents, I believe that it's 6" as described in section 906.1 here: http://tinyurl.com/ll3fqt7

Bruce

On 9/24/2014 6:38 AM, Bill Loesch wrote:

Bruce, August, et al,

This is but one more example of confusing terminology. A plumbing vent is not an exhaust vent!

A plumbing vent (what August calls a cold vent) is provided to allow the sanitary drain traps (and perhaps more) to operate properly. Without the properly functioning traps you would have sewer gas smell and sewer gas from the plumbing fixtures. This was commonplace when indoor plumbing was introduced to early adopters.

An exhaust vent is another animal entirely. An exhaust vent carries the combustion products to a suitable exterior location for dilution with ambient air. With the advent of power vented combustion appliances, a direct vent (one that takes in combustion air from the outside and naturally exhausts combustion products to the outside) is IMHO the only responsible way to install any power vented appliance in a freezing climate. (Power vented appliances come in both condensing and non-condensing flavors-they can penetrate the side wall or the roof). Originally, two separate pipes (with two independent properly separated penetrations) was used. That technique is still often used today. More recently concentric vents have been introduced both for condensing and non-condensing applications. A concentric vent can simplify some installations by putting the exhaust pipe inside a larger air intake pipe allowing for one, albeit larger, penetration. As you might imagine if the exhaust flow is hindered/diverted/redirected by an inappropriately located solar module combustion gasses will be re-ingested into the intake air. Not good for equipment performance. My understanding is the power vented _appliance manufacturer_ dictates what kind of separation/clearances are needed with their product. My guess is you find they want at least a foot of separation between the top of the " inverted cone" and the module. Probably not what you had in mind for an aesthetically pleasing installation.

I hope this helps,
Bill Loesch
Solar 1 - Saint Louis Solar
314 631 1094
On 23-Sep-14 6:54 PM, August Goers wrote:
Bruce and All,

Sorry, I hit send before I had a chance to complete my thoughts. What I
meant to say was that I've found AHJs often allow us to cover cold
plumbing vents but I've never tried or had any luck with covering hot
vents including condensing boiler PVC vents. Once again, if in doubt you
could see what the plan checker or inspector thinks.

Best,

August

-----Original Message-----
From: August Goers [mailto:aug...@luminalt.com]
Sent: Tuesday, September 23, 2014 4:15 PM
To: 'RE-wrenches'
Subject: RE: [RE-wrenches] Modules over vents

Bruce,

I'll send you the CA plumbing code vent section offlist (attachment too
large for this list). The way I read the code is that you technically
can't cover any type of plumbing or hot vent. However, and I've run into
little resistance from AHJs in the Bay Area by covering these. You might
want to check in with your plan checker.

Best,

August

Luminalt

-----Original Message-----
From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On
Behalf Of Bruce Leininger
Sent: Tuesday, September 23, 2014 3:49 PM
To: RE-wrenches
Subject: [RE-wrenches] Modules over vents

Hi all.  We're designing a system on a roof that is literally infested
with plumbing, exhaust and combustion vents.  The combustion vents are PVC
and none of the vents are more than 1.5' above the roof.

A racking company says that we can cover them with modules, since the
modules will be at least 4' above the roof.  They have not yet provided
any building code references to say that this is ok.  Do any of you know
if the building code allows this?

Thanks.

Bruce
_______________________________________________
List sponsored by Redwood Alliance

List Address:RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive:
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.htm
l

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org
_______________________________________________
List sponsored by Redwood Alliance

List Address:RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive:http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org



-----
No virus found in this message.
Checked by AVG -www.avg.com
Version: 2014.0.4765 / Virus Database: 4025/8265 - Release Date: 09/23/14



No virus found in this message.
Checked by AVG - www.avg.com <http://www.avg.com>
Version: 2014.0.4765 / Virus Database: 4025/8265 - Release Date: 09/23/14



_______________________________________________
List sponsored by Redwood Alliance

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: 
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org


_______________________________________________
List sponsored by Redwood Alliance

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: 
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org

Reply via email to