OK, I admit that it probably looks like overkill, but this is what I'm doing... I have a nice 1/2" valve made by a company here in the Denver area. It's an anodized aluminum ball valve with Teflon seats/seals. It's stupidly expensive, & I bought it during a period of insanity, but it's nice. I like the idea of being able to shut off even the radiated heat in the summertime that's going right back there where my avionics are. I'm also thinking it might be nice to be able to modulate the flow sometimes. It does occasionally get cold in Colorado. I'll control it with a very short push-pull cable from the panel, right next to the fan switch. I'm using the Earl's coil sold by Kitfox.