Recent content by Grinkle

One "B" level poster to another .... What I read from @PeroK is not that using the word 'perspective' is objectively wrong, rather that 'perspective' not a concept that physicists would directly wrap math around to map 'experience' (another fuzzy word I'm using here, I acknowledge) from one...

Thanks for taking the time to give that response, much appreciated. It has got to be fatiguing continually articulating things at a "B" level, I don't take those efforts by everyone here for granted. If its possible to explain conceptually, what is new about the reconstruction that would make...

@RUTA SR threads here often have a shared plotline, which I'll illustrate by example below - Q: Why do clocks move differently in different inertial frames? A: It follows directly from SR, which is based on the empirical observation that c is the same in all inertial frames. Q: Why is that...

@Greg Bernhardt @Borg I have been looking to a place to start a couple threads that are a mix of politics and economics. I will post them on Civics Watch to see if they get any traction - but I am posting here to ask if you think a sub-forum on Civics Watch for questions that are mostly about...

@Dullard Thanks for the references and discussion - very helpful.

How does one seal them? I'd end up spending more on lights than I did on the insulation, not sure I'm going to go there, but its good to know in any case.

I get it. No option for me, though, unless I want to install a third split system to cool the attic. Thanks for flagging this - I have a LOT of leaks, most of them are canister light fixtures. I'll have to consider what I can do about them. My entire home is lit with them and they are not...

I can't get my head around that. If there is no dirt on the foil, it is trying to radiate into the attic space, and it is not a very efficient emitter. If there is dirt on the foil, it is instead conducting energy into the dirt, and the dirt is an efficient emitter, compared to bare foil. The...

Maybe so - I don't know if I improved its insulation value by re-working it or not. Most of the air was missing, it was pretty much solid fiber. Here's an image. On the left you can see un-worked flattened insulation, on the right is the same stuff re-worked on top of the installed batting -...

I think if there is a layer of dirt on top of the foil, the dirt will increase the emmisivity of the entire material stack, lowering its effectiveness. Is this not the case? Heat will conduct all the way to outermost layer of material, and the emmisivity of that outermost layer will dominate...

@Flyboy After some reading, I'm going to stick with passive venting approaches. Seems there are ways to shoot below the waterline with attic fans - in my leaky house if I have enough airflow to make a difference I'm likely to draw cool air out of my living space and into the attic. Thanks for...

Thanks, you have given me something to think on. My instinct is that this approach is much less beneficial than installing a barrier with an air gap to the roof. The OSB foil will always be at the same temp as the roof and so it will be radiating more into the attic than a barrier that has a...

Post 5, Dallas. If your home has a radiant barrier, do you know how it was installed? Stapled to the roof rafters, or something else? I like the idea, but I'm concerned I'd need a really big fan to make a difference. My home is single story and including the attached garage the sq footage...

@BillTre I agree that if in fact I have little or no air flow, that's likely a bigger priority than a radiant barrier. I'll figure that out, and if I don't have any deliberate air flow, figure out how to best address that. I am a bit nervous about DIY'ing a hole in my roof, I'll admit.

@BillTre Insulating the inside of the roof directly with batts is an interesting idea - thanks for the response! I don't have roof vents, and I have to say I don't know how the air flow is intended to happen. I don't have soffit vents, either. The house was built in the 80's and has never had...