We have heard just about every question about solar pool heating panels. But we never gave much thought to what happens to them in a fire. We just assumed that in a serious house fire or if exposed to flame that the panels would simply melt.
We did some research and found that polyethylene, which is in the polyolefin family. It is only slightly flammable and has an ignition temperature somewhere around 330ºC – 410ºC1. It burns slowly with a blue flame and yellow tip, it drips (melts), and it has the odor of paraffin2. And if you are interested, there is a painfully technical FAA report on plastic flammability that has more details.
Fortunately, solar panels stagnate well under the boiling point of 100ºC. They are not at risk of ignition during normal conditions.
You might recall that we recently has some brush fires in Collier County near Naples. These fires threatened homes in the Forest Glen community near I-75 exit 101. During the fires there was an east wind for a time that showered the area with ash. Along with that ash were some burning embers that landed on homes adjacent to the Picayune Strand State Forest. We took the above picture of burned trees and brush directly across the street from a client. Fortunately, the fire spared her home.
The fire gave us the opportunity to see what happens in reality when burning embers land on solar pool heating panels. We had two clients on Jungle Plum Drive that had recently installed solar pool heaters, and each suffered a single tube leak on a single panel. They were very lucky. We easily plugged these leaks and the systems are good as new.
A small fire reignited a day later near another home on Periwinkle Way where a competitor’s system was installed years ago. We had been to the home previously to give the new homeowner a Solar 101 lesson on how her system worked. Naturally she called us when her pool service reported leaks in the solar panels the day after the fire was extinguished. We knew right away what the problem probably was.
We were treated to a rare look at how solar pool heating panels react to burning embers. The panels did not ignite and burn, fortunately. It is unknown whether there was water in the panels as the embers struck. It is possible that water in the panels, whether flowing or not, extinguished the embers quickly. However, based on the position of the valves at the time of the fire, it is unlikely that there was water flowing through the panels.
How We Responded to Fire Damage
We were happy to help these victims of the fire with free service to repair the leaks. They were all very fortunately to have limited damage to both solar panels and the homes themselves. It was an interesting learning experience about how solar panels react to burning embers. The extent of damage expected from an event like this was minimal.
Had the fires been more intense, causing more extensive damage, we might have recommended an insurance claim to replace the solar pool heating systems altogether. We repaired the systems without much effort because leaks were limited to no more than a few tubes in each panel. That’s the great thing about solar pool heating system repairs – most are simple and cost effective. And now we know what to expect after brush fire damage!
1Source: http://aqcind.com/downloads/MSDS/MSDS%20HDPE-LLDPE.pdf, accessed March 30, 2017
2Source: http://www.boedeker.com/burntest.htm, accessed March 30, 2017