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This is a test rant for a future video that may or may not happen.

But seriously, I cannot fathom how HVAC stuff in attics (or crawlspaces!) got normalized. Especially in new construction.

You virtually never see that around here (the most common application is old homes with radiators for heat who want to add central air) and for good reason!

@TechConnectify You’re not wrong, you’re just advocating the wrong solution. Conditioned attic spaces with insulation under the roof deck is the best approach for slab on grade new construction with high solar loads and AC demands.

@transcendentape But that's the thing, isn't it? A conditioned attic space becomes a conditioned space.

If you want to spend the money to turn it into one, I ain't gonna stop you. But most people just leave their attic an attic for one reason or another. And if that's the route they've chosen, ducts and the air handler should go somewhere else.

Plus, in many of the homes I'm talking about, the attic ain't tall enough to turn into a useful space anyway.

@TechConnectify The point of making an attic include d into the conditioned space isn’t to reduce the relatively minimal AC losses, it’s to deal with the condensation that results when an attic that reaches 150F and 80% humidity reaches an interior space conditioned to 75F or so. Your solution doesn’t address the fundamental problem we deal with in the South where we have night-time temperatures higher than desirable, high humidity, and no basements.

@TechConnectify What is fundamentally different between a wall and a roof? A wall can be shaded from the vast majority of solar thermal load simply by building overhangs. The roof cannot.

@TechConnectify So, instead of continuing the building scheme we’ve used since before there was A/C, it’s better to remove the pressure cooker that is an attic entirely. Is it cheap? No. But in new construction, the price differential is a handful of dollars per square foot and in my area, far superior than any other alternative.

@transcendentape I mean, if you want to remove the attic space, go ahead.

But understand that for homes around here, *NOTHING* goes in the attic. The attic has tons of vents at the eaves and the peaks to keep air flowing through it. Does it get beastly hot up there when the sun shines? Absolutely! But there's a layer of R-50 insulation above the ceiling to battle that intrusion.

And that beats the pants off of any insulated ductwork.

@TechConnectify I mean, go ahead. We live in entirely different climates with entirely different residential construction norms.

@transcendentape my central point is that I think people in different climates could learn a thing or two from us. Our summers can be just as bad as down South, if less consistently. Perhaps that's the only reason our attics don't get moldy, but I'm doubtful.

You pointed to duct losses as minimal, but the first estimate I found puts them at 25-40%. That's a lot of energy being wasted and money being spent to condition space you're not in.

We just... don't do that.

@transcendentape our M.O. has largely been to treat the attic as a space which is there to frame the roof and that's it.

It's functionally outside, so once the sun sets the conditions up there equalize with the outdoors quickly. And sometimes we even use a fan controlled by a thermostat to force some airflow! But that's relatively uncommon.

From my perspective, the reason we don't deal with mold is mostly that there's nothing up there colder than ambient temps.

@TechConnectify I’d really like you to re-read this reply and understand how it entirely ignores the argument I was making.

@transcendentape Sorry, to be more clear, "entirely different" feels like something of a stretch to me when, for three months of the year, we have extended periods where we might as well be Orlando with only slightly less humidity.

But, I will agree to drop that comparison.