rooftop solar installations

[linnrg]

So I have a couple of new rooftop solar installations going onto Existing commercial
buildings. Both are planned to be grid tied including rapid shutdown. Each are
intended to be solidly attached to the roof tops. I have reviewed NEC 690 and
IFC 605. One project, a fish processing facility: Has probably 6 plumbing vents
and at least 4 B vents for unit heaters, one exhaust vent for the smokers, and one
large vent for the large water boiler (at least 12"). The proposal is to have panels
right up to the edge of the sidewalls, 3' paths at each endwall, 3' path at the ridge.
Building is a PEMB that is at least 16' at the sidewalls. The second is a typical
strip mall that includes plumbing vents, some b vents, 5 or 6 air handlers (each
with electrical disconnects) and one up draft exhaust fan (commercial kitchen). Roof
is a flat roof without parapets on three sides and a small parapet at the front, type
5 construction. Intent is to have the 3' path all the way around and some path due
to the locations of the equipment.

I have cited UPC 906 to possible extend any plumbing vents - is there any other
clearance requirement for them?
I have cited IMC 802 so that the chimney/vents may need to be extended to get
the 2' above anything within the ten foot horizontal.
I have cited IMC 306.1 for the appliance maintenance space.
I have cited NEC 110.26
So far it seems that they have met the access (per IFC)

Are the reviewers out there requiring a roof as-built to determine the possible
setbacks or clearances that may be necessary?

What would you cite if you had wood burning chimneys that need to have a
chimney sweep ever so often? What do you cite for roof drainage and overflow?

Hoping to get some answers today, because I will be out on a fishing trip the
rest of the week.

 

[Mr. Inspector]

IMC 306.1 So you want them to have a working space to clean out or repair the vents and chimney? Do you require that for the bottom of the chimney and vent too? Seems like a stretch to me. A working space needs to be level too, what do you do about vents and chimneys on sloped roofs? But the HVAC and kitchen fan will need working space.

NEC 110.26 Do you mean the panels themselves, a panel box or something else? I never saw anything on a roof solar panel system that will likely to require examination, adjustment, servicing or maintenance while energized. But the HVAC and discos will need working space.

 

[e hilton]

I would think the solar designer would have an as-built of the roof so they could plan the installation. They would need to avoid stick-ups of all kinds that could cast a shadow on the panels, or interfere with mounting hardware.

 

[ADAguy]

"Go Fish" when you come back we can answer.

 

[ICE]

Ask the fire dept. about clearances to the edge of the roof. It is typically 3' here. They also might want to keep a space open for their ladder access that is not over a window or door.

 

[MtnArch]

I wouldn't be surprised if they weren't just using Google Earth to get an approximate square footage if it was for a 2-story home. After seeing some of their "permit" drawings I wonder if the salesman ever even visited the building before the installation crews did!

I would think the solar designer would have an as-built of the roof so they could plan the installation. They would need to avoid stick-ups of all kinds that could cast a shadow on the panels, or interfere with mounting hardware.

 

[ADAguy]

There you go being logical.

 

[north star]

% = % = %

`18 IMC, Section 304.11 - Guards.

Question: Can the designer of the "proposed" solar system,
design a system and associated structure away from the existing
plbg. vents & and other exhaust vents without altering the vents
in any way ?

% = % = %

 

[ICE]

Plumbing vents can be horizontal and under an array until they emerge and turn back to vertical. Mechanical vents just need a gap between solar panels and maybe an extension.

 

[linnrg]

received revised drawings today- they omitted panels where the vents were - and yes they do use google earth! Trouble is the roof is white and I could not see the shadows of the vents. They sent a local contractor up to measure all the roof penetrations, They lost 29 panels.
I am not requiring ""working space" for plumbing vents or for the chimney/vents. But in my area they are often damaged by wind and sometimes by snow.
I am concerned that they are possibly needing extensions per UPC and IMC heights above the roof. I had several reports of damaged vents due to last years heavy snow and there was one carbon monoxide event that was blamed on a vent that had been broken off.