[RE-wrenches] Tight roof layout questions: edge walkway requirements & "small gap" hardware options

[Dan Fink]

Brian;

I think you laid out the challenges quite well. Keep firefighters safe, 
but don't pose unrealistic constraints on PV systems.

You also mention "true accessibility" -- which is a big issue here.

I learned on the first day of class in FF1 Academy from our FDNY 
instructor (a real hard-ass) that "firefighting is 200 years of 
tradition, unhampered by progress," and how he wanted to change that, to 
make firefighters learn new tactics, try new gear, to think things 
through to the end result....no injuries or deaths, and maybe even save 
the structure.

 I also learned, at about the same time, from the top magazine in the 
business... that "guerrilla solar" was really cool. We'll show those 
government and utility folks a thing or two. (Damn, I wish I had got one 
of those T-shirts....I missed out.) Obviously, that didn't turn out to 
be the way to go either.

Thus the dichotomy here.

Are there other ways to ventilate buildings and quickly knock down a 
room and contents fire, besides vertical ventilation through the roof 
timed precisely with a water fog inside? Yes....a variety of options, IF 
proper knowledge and training and equipment are in place. Does your fire 
dept. have all that?

Are there easy steps that PV system designers and installers can take to 
make their PV installations "firefighter-friendly"? Yes...and they don't 
need giant sidewalks of asphalt roofing between each PV module. 
Actually, some succinct signage can solve many issues. And PV 
module-level isolation with micro-inverters or shade-mitigation boxes is 
a fairly big deal---I'll cut into an 18 volt PV module with my carbide 
chainsaw any day. I just don't want to cut into that 600 VDC string...

More info on this is coming soon, from a variety of channels: wrench, 
nerd, governmental and firefighter. Stay tuned. If you see something 
pending ( a new rule, code etc.) that doesn't seem right or would 
greatly impact your business, make your voice heard! This is all new 
territory, for everyone involved.

DAN FINK
Buckville Energy Consulting
http://www.buckville.com/
danfink at buckville.com



Brian Sipp wrote:
> Dan, let me start by saying that I am not trying to attack you here and that
> I do appreciate the valuable and dangerous job that fire fighters have.
> However, this issue is of great concern to me when it comes to the majority
> of residential PV systems.    
>
> Since this is a residential, trussed roof, installation; I imagine that the
> north slope of this roof will be untouched.  Also, since we are talking
> about 12 modules, I would be willing to bet there are also other roof
> surfaces that are less ideal for solar and will not be covered with PV
> either.  If pathways are included on this roof, it will go from a modest 2kW
> system to an unreasonably small 1kW or less.  At that point, the project
> will probably not even happen.    
>
> I am very concerned that the AHJ's are going to start killing residential PV
> projects with the assumption that any surface that has modules needs 3'
> walkways.  Right now most of the AHJ's are telling me that their setbacks
> are simply advisory and can be waived.  However, many have also told me that
> the those setbacks will soon be mandatory.  If that is the case, I would
> have to turn away approx. half of my clients because we are only covering
> one ideal section of roof out of many possible access points.      
>
> Would a reasonable fire department really let a house burn because one
> section of the roof was covered with PV but the rest was clear?  I
> appreciate the difficult job that fire fighters have and I want to make
> their jobs as safe as possible.  However, I have heard a lot of alarming
> talk lately about "letting it burn" and "too dangerous to fight" when in
> fact there are many alternative access and vent points in most pitched roof,
> residential installations.  This sort of talk seems to lead the AHJ's to
> implement standards without regard to true accessibility. 
>
> Is there some way that we can keep fire fighters safe, while at the same
> time recognizing that residential solar is unique from the large flat
> commercial roofs for the reasons that I mentioned above?  
>
> Brian M. Sipp
> First Source Solar Systems
> www.FirstSourceSolar.com 
>  
>