<div dir="ltr"><div>Hi Jason,</div><div><br></div><div>I know the sound you are describing well and can confirm that it is likely related to expansion/contraction of the metal roof panels. Down here in Jamaica, we have an exposed-fastener corrugated metal roof. Whenever the roof has been sitting in shade for some time (or if it has been overcast) and then a sudden burst of sunshine hits it, a distinct popping sound can be heard. The effect is usually pretty immediate—and, since we do not have an attic or any ceiling insulation, it is also quite noticeable. Over the years, though, we have become very accustomed to it, and it now blends into the background. I've never understood what it is exactly that we are hearing, but it is definitely related to the expanding metal.</div><div><br></div><div>I installed a couple modules on the roof last summer—see attached photo. I haven't noticed that the frequency of the sound has either increased or decreased since then. As Tyrone suggested, in your customer's case, it might be that the area surrounding the array is heating up quicker than the area underneath it - and perhaps that is causing some differential expansion of the roof panels (that causes them to 'pop').</div><div><br></div><div>Corey Shalanski</div><div>Portland, Jamaica</div><div><br></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Wed, Mar 5, 2025 at 4:11 PM Christopher Warfel <<a href="mailto:cwarfel@entech-engineering.com" target="_blank">cwarfel@entech-engineering.com</a>> wrote:</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><u></u>
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<p>I have heard this too, no solar involved. Chris</p></div>
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