10-12-2007, 12:28 AM #1
Info. wanted on venting around solar panels.
Help- I am looking for information regarding venting roofs with solar panels. What are the hazards? Wires or tubing under the shingles, vent around them or rip them out of the roof?
Any info. would be apprechiated.
10-12-2007, 07:42 AM #2
Solar Water Heating Panels are filled with a solution (I can't remember exactly what it is) that is under slight pressure. Convection is the main form of transferring the fluid between the panles and the heat exchanger, but again there is a slight pressurization (to prevent the fluid from boiling & becoming steam.) You need to use extreme caution working near/around them, if you were to puncture the panels or any of the piping carrying the solution to the heat exchanger, it wouldnt be pretty (ie extremely high temp fluids)"Loyalty Above all Else. Except Honor."
10-14-2007, 09:33 PM #3
10-15-2007, 11:45 AM #4
- Join Date
- Aug 2007
I would deffinatlly stay right away from them all together, most of the time you can get away with venting off to the side of them and if your using a roof ladder i wouldnt put it on top of the panel either.
10-15-2007, 12:55 PM #5
There are too many diffrent types out there to give any sort of diffinative answer. The solar panels we have on the pool house at the beach to warm the pool are just rubber tubs the water is pumped through as part of the regular filteration system. Cut through them and all that you are going to do is release some water in the 70-95f range and dump a little water into the vent hole. Cutting through a photo voltaic cell is going to be tough except with a sledge hammer, and they are going to be as sharp as jagged glass when you are done. Just too many versions out there to give a good answer. I would avoid them when possible, and just be very aware and careful when you can't.
11-11-2007, 01:21 PM #6
UPDATE- I just had this article forwarded to me. Solar panels will continue to be the wave of the future. Something I think the fire service need to stay on top of.
Here is the link- http://www.almanacnews.com/story.php?story_id=4495
08-29-2008, 12:15 AM #7
- Join Date
- Aug 2008
- Los Angeles
Solar panels on roof? Not for long
The issue will become more urgent as more systems are installed. Here is a 'not yet complete' answer as a starting point.
First identify which type:
Solar Domestic Hot Water systems will be a small array of framed panels with glazing or evacuated tubes to achieve a much higher temprature than the simpler pool heating systems.
Solar Pool Heating systems will be a large array of plastic corragated mats, plastic parallel tubes on headers, metal tubes with fins, or metal tubes with fins inside a framed panel. The pipes will be visible with a vaccuum break at the highest point. It may be obvious that the pipes lead to the pool equipment.
Some pool systems will use a heat exchange fluid described earlier in the thread. (need to add some plumbing expertise here)
Solar Electric (PV) systems will be solid framed panels above roof surface with wires visible below, small shingles integrated in roof with wires hidden below, or flexible PV membrane glued or bonded to roof finish layer.
Each will require a slightly different approach.
When you shut off the main power, all these systems will stop circulating fluid and electrons. There are still some hazards present.
The most common pool heating systems circulate only heated pool water, some newer systems will drain down when power is off. The plastic units are easy to disgard, the metal is very heavy and faster to just work around it.
The smaller domestic hot water units circulate either hot potable water or an exchange fluid. They will have high tempratures and pressure even with power off. I would leave them in place.
Solar Electric (PV) systems will cover more square footage and most can be removed quickly with the right tools and procedure. In all but the smallest systems you should find a rooftop disconnect and/or a combiner box with fuses. Shut down or remove fuses at this point. (after the AC power is off) There is still potential for a DC arc in any lines cut between the disconnect and the roof mounted array. Most arrays will have plug connectors on each module. Here are the different configurations:
Shingles: I would avoid them. They are slippery when wet. The wires are connecting all of them together in an unpredictable pattern. They are installed with screws into the battens below the lower edge. That means lots of fasteners. If you must ventilate, be aware the wires should run horizontally between the battens and are usually loose.
Membranes: Electricity will try to travel the length whenever the sun is up. To ventilate through one of these modules unplug or clip the exposed wires and cover them, as long as the wires are disconnected, you can cut through the module. Watch out, though, the entire exposed cut edge is a potential live electrical conductor if the cut wires are restored.
Framed Modules: Reach below and unplug (or clip wires) the modules you need to remove. I cap any exposed wires with a wire nut to prevent contact with conductive material. You could fold the end back a few inches, to form a loop, and wrap the exposed conductor against itself with tape. I don't know if this is practical for your team but it is quick and removes the risk of stabbing a conductor. each module has two plugs, plus and minus. once you have disconnected both, the module is de-energized (externally) the wires will still short out if the sun is up so leave the module intact.(so far)
Most framed modules are held in place by four clips. Use a Sawzall, grinder, or cutoff saw to cut each clip next to the hex bolt or nut which holds it in place. Lift the module and be preapared to clip a #6 bare copper ground wire. once clipped, you can toss the module out of the way. If the installer bolted the modules in place from below, you must cut the framing and watch for the vertical supports below. The job could get more difficult if they used a non-standard support method.
I can see a need for more detail. This could get you started, though. I have started to create a more comprehensive document to present for a training with a local FD. Once filled out a bit, I would like to distribute it more widely. Could this forum be an effective and informative venue?
09-01-2008, 01:33 AM #8
Vent around them. These are popping up on new homes in our district a lot. Typically the main power does not kill current to these panels. There is a separate shut off close to the main. These tiles are slic and hard to recognize in the dark as well.
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