Toxophilite
Silver Supporter
Yes, a radiant barrier on walls seem to becoming more common in use. Even on stud walls, radiant heat transfers from studs to drywall.
16 July 2024 Finishing Up my OB Pool
- Thread starter setsailsoon
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- Nov 12, 2017
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Just anecdotal. I just battled with the original builder of my house (I'm the second owner) because I discovered half the blown-in insulation was missing in my attic. I won in small claims and had the whole attic re-shot. I put R-30 over the garage and it's made a big difference. Why they think garages don't need insulation around here is beyond me. For an extra 50 bucks profit?
I was nosying around a new build down the street and noticed the fan in the laundry room was running. The realtor said it has to run non-stop, 24-7, because the insulation and weather-stripping is so tight that they run the fan to get a little air exchange! So the energy-saving technology exists now, if you know how to achieve it.
I know what you mean about the insulation of block. Weird. I learned here at TFP that the 8-12" thick wall of a pool doesn't do much to retain the water's heat either. I wouldn't have guessed that. Are you doing anything about that? Planning on a pool cover? (That's where you lose most of the heat.) Will your pool area be enclosed? I don't know anything about insulating pool walls, or even if that can be done. Are you going to run a heater (or do you need to down there)?
I still can't get decent temp control at the end of the house opposite my HVAC. That's two houses in a row! They don't put enough engineering into the ducting, so in addition to your attention to your insulation, put some of that into the HVAC design, which can go a long way into your actual comfort level. My house is so long that there should have been two smaller HVAC units, one at each end. Mine is at the end where my master is, so at least that's good. When I'm cold or hot at night, my unit blasts my bedroom and heats/cools it in minutes, so at least there's that.
I think it was a poster here that was having a heck of a time with his siding and even something to do with his pool, because his e-windows were reflecting the sun so efficiently that the heat was destroying stuff in its path. It was one of his upstairs windows that was shooting at the pool. And his neighbor's that was destroying his siding! Something to do with how the panes were curving just enough due to some sort of force (I don't remember well enough) that the windows were turning into magnifying glass and scorching things outside. I don't know how you'd plan for that, but it'd be hard to fix after the fact. I think he had to put some sort of external louver on the window that was blasting his pool. Something like that.
Tinker on, brother tinkerer!
Toxophilite
Silver Supporter
Yes, with newer insulation tech, houses these days are more like Igloo coolers and require a bit more HVAC planning. It's more than just insulation loss that an HVAC system in controlling for. There needs integrated to be a system of continuous outside air refresh, like Aprilaire, and higher humidity control. With showering, washing, drying, cooking, breathing, etc..... the more sealed the structure, the more a standard A/C really cannot control humidity, and, there's the buildup of VOC's to be cleared. A major builder here recently had to buyout most of the homes they had put up after just a year or so of occupancy due to mold from poor HVAC designs, but the houses were sold as highly energy efficient.
- Nov 12, 2017
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- Pentair Intellichlor IC-40
Humidity and mold control... yikes. Maybe the realtor explained it wrong. Maybe the fan was running 24/7 for some of those other reasons... What are VOCs?
Toxophilite
Silver Supporter
Running any and all of your vents during use of showers and wash room really do help expel the added humidity. VOC's are volatile organic compounds, emitted from about everything. With a sealed enclosure, you need a system to bring in outside fresh air to exchange the air in the house. In the old days, houses were drafty enough.
- May 23, 2015
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I once read through this …. when needing to cure a case of insomnia …
- Nov 12, 2017
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I could only understand page ii, the one the reads "[This page left blank]"...
When I had my home theater done last fall they put this in all the walls and ceilings as well as a product called "quiet rock" sheetrock. Shut the door and you're in what feels like an isolated island. Really strange to get used to lol, especially before turning on anything noise wise. When I get some other projects done (like the pool lol) I plan to remove the ceilings in all the downstairs bedrooms and install it plus the quiet rock, just to dampen noise from upstairs into the bedrooms. Its not as good at "impact" noise (ie walking) vs "airborne" noise (ie talking) but it should help, Reverse floor plans are great for the views but that was an unknown negative to it.Rockwool … give it a look. If not for thermal insulation than maybe for interior acoustic isolation … not everyone wants to listen to your loud parties in the disco-room …
Products & Applications | ROCKWOOL
We make and supply a full range of smart and sustainable stone wool insulation products for the construction industry.www.rockwool.com
- May 23, 2015
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Matt Risinger did a segment on the stuff in The Build Show. He had a handheld acoustic meter and ran a large shopvac in one room of his mostly unfinished interior and measured the noise level then moved up to a bedroom that had been fully Rockwool’ed. The decibel change was impressive. There was also guys installing the stuff and banging around the house while he was demonstrating it and you couldn’t hear them either. The house was framed and finished on the outside but the inside was still open so the reflective echo noise alone should have been enough. But with the sound dampening in place, it was incredibly quiet. I can only imagine what it would be like in a fully finished interior.
Around here most garages aren't insulated either, unless they are planned to be heated and cooled. My house has an attached garage, that is not only not insulated but it's vented too. I think the issue is not just $50 worth of insulation, but if you start insulating, you need to properly install vapor barrier and the whole shebang to avoid mold issues. Leaving it uninsulated and vented is therefore easier.
The house on the other hand had at least 2x6 walls, which if it was the only insulation would be R-18. But I think there was probably an inch of closed cell foam on the outside of the walls which would bring it up to like R-23 (minus the heat loss of the studs, which I didn't want to calculate). Unless they were 2x8 walls and then it would be R-29 or so. This is assuming fiberglass insulation, though it could have been something else. The half the house with a regular attic had probably two feet of blown insulation or about R-60. I never did get myself over to the cathedral ceiling part of the house to see what the ceiling insulation was.
In any case, it was pretty dang good insulation, and unlike the house I grew up in, it never felt cold near exterior walls.
Are you going to have some sort of siding, or is it just the cinder blocks on the outside. I ask because ideally you would have a radiant barrier on the outside of any insulation, reflecting the heat of the sunlight before it touches anything conductive. But if you don't have siding to stick over it, it's not going to work well on the outside of cinder block.
Yeah, me too. A pure film has no R-value. R-value is for conductive heat loss or gain, and a simple film doesn't reduce conductive gains or losses. Is it a pure film, or a bubble-type film?
- Oct 25, 2015
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Just cinder blocks but they will have stucco on the outside. Don't think it's very practical to do the foil on outside since the stucco has to adhere to the block. I'm guessing it must have some kind of foam layer in the middle but it's definitely not very thick.Around here most garages aren't insulated either, unless they are planned to be heated and cooled. My house has an attached garage, that is not only not insulated but it's vented too. I think the issue is not just $50 worth of insulation, but if you start insulating, you need to properly install vapor barrier and the whole shebang to avoid mold issues. Leaving it uninsulated and vented is therefore easier.
The house on the other hand had at least 2x6 walls, which if it was the only insulation would be R-18. But I think there was probably an inch of closed cell foam on the outside of the walls which would bring it up to like R-23 (minus the heat loss of the studs, which I didn't want to calculate). Unless they were 2x8 walls and then it would be R-29 or so. This is assuming fiberglass insulation, though it could have been something else. The half the house with a regular attic had probably two feet of blown insulation or about R-60. I never did get myself over to the cathedral ceiling part of the house to see what the ceiling insulation was.
In any case, it was pretty dang good insulation, and unlike the house I grew up in, it never felt cold near exterior walls.
Are you going to have some sort of siding, or is it just the cinder blocks on the outside. I ask because ideally you would have a radiant barrier on the outside of any insulation, reflecting the heat of the sunlight before it touches anything conductive. But if you don't have siding to stick over it, it's not going to work well on the outside of cinder block.
Yeah, me too. A pure film has no R-value. R-value is for conductive heat loss or gain, and a simple film doesn't reduce conductive gains or losses. Is it a pure film, or a bubble-type film?
- Nov 12, 2017
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I had to think about that. There is no moisture barrier for blown-in insulation over the ceiling. It just lays on the sheetrock. Same for garage or interior. The garage is vented, down low. Probably more for the water heater than anything else. And of course the garage door doesn't seal all that well. The greatest heat exchange in a garage is through an uninsulated metal roll-up garage door (which is what I have). Even insulated rollups don't block much transfer. So I'm not sure I agree that not insulating the attic over a garage has anything to do with mold issues.
It's certainly not as nice as my interior, because of the leaking air, but it's definitely better than it was. On a recent 100° day, my interior was 70° (no air cond.) and my garage was 80°, which means I can go out there and putter if I am so inclined. Point being, I'm stickin' with the notion that insulating the attic over a garage is worth doing.
Hmm. Now that you mention it, I've never seen moisture barrier in an attic either. Well, I'm also not in the construction business so shows what I know.
And yes, I'm certainly not saying it's bad to insulate. An insulated, but unconditioned garage would stay warmer or cooler, on average, than an uninsulated one.
Heh. Almost missed the water heater in the garage part. You guys in your mild climates with water heaters and softeners in the garage or outside. Around here, they are always in the house, unless the garage is insulated and heated. Almost universally they are in the basement, if the house has a basement, otherwise they are in a utility closet.
Pretty sure it's partly because a roof leak is only a matter of time and the plastic sheeting will mask the problem for quite some time. The water would puddle up and find a way out down an exterior wall and could do lots of damage before it's discovered.
Condensation also becomes an issue when the airflow can't easily go around the barrier like it would travel up the exterior wall on either side.
Then, it would also stop alot of needed airflow throughout the house. You want the house sealed, but not too sealed.
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You don't want a leaky house. Ideally you want a perfectly sealed house, and then you use a heat exchanger for the required fresh air.
See, the problem with leaky houses is the leak rate varies based on ambient conditions. If it's still, this could be almost none. If windy, this could be a lot. But if you have a perfectly sealed house, you now control the fresh air exchange to what is needed by running a fan on a schedule. And you use a heat exchanger, so the air being blown outside to a large extent heats the fresh air coming inside. If you get fancy, and depending on your climate, you can do a partial humidity exchange in the same heat exchanger. So if it's dryer outside the house than inside (as is most places in the winter), some of the outgoing humidity is sent back inside, helping to avoid drying the air out in your house. And vise versa for humid climates.
So by perfectly sealing a house, then adding a heat exchanger, you get a consistent "leak" rate, but this "leak" is much more efficient cause you've passed it through a heat exchanger, so you're not just leaking in completely unheated air. You run the fan on a schedule so you get as much fresh air as you need or want, and no more. And so you end up with a more efficient building. According to this, household fresh air heat exchangers are somewhere around 75-80% efficient. In practical terms, this means if your house is 70 °F, and it's 0 °F out, the fresh air coming into your house via the heat exchanger is 56 °F. So would you prefer a leaky house that's letting in uncontrolled amounts of 0 °F air, or would you prefer a perfectly sealed house with a heat exchanger that lets you select exactly how much fresh air you want and that air comes in at 56 °F? (The reverse is of course also true, if it's 70 inside and 100 outside, then the air coming in would be 76° with an 80% efficient heat exchanger instead of 100 °F)
Plus you get added benefits. Burned dinner and it's -20 °F out? You can still get fresh air to help clear the smoke by manually engaging the fresh air fan and pull in fresh air that's mostly warmed, as opposed to opening a window up.
By the way, this heat exchanger may very well be what @Dirk saw. Or rather the fan for the heat exchanger. I took a quick look at the latest ASHRAE standards, and it appears they are very focused on very, very tight building construction for energy efficiency in the latest (2019) standards. Like the NEC, local jurisdictions have to adopt this standards to have force of law, but the trend is very much towards very leaktight construction and using fresh air heat exchangers for the reasons outlined above.
Of course, as outlined in the mold cases, you have to do this properly to avoid issues, but if done properly it's certainly IMO the best way to do it.
Rattus Suffocatus
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- Jun 5, 2019
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It's amazing how differently the actual physical building requirements are between areas. What @jseyfert3 is describing about vapor barriers, insulation, siding and mold is 100% correct for the Upper Midwest. Humidity is a major issue there. So is inhumanely cold temperatures in January and February. I mean I still had boxes of "stuff" I opened from Iowa and my mother's estate from Illinois, and they smelled a bit green to me. Both houses didn't have mold in them. It's just that humid there that you'll pick some of it up in the cardboard! Frankly I don't know how I could have stood that on retrosepct for all of my life. Heat + Humidity is miserable. But after a year or two in the dry climate stuff from the wet climates smell a bit like mold for a few days after you unpack them. It's kind of scary. (You don't have to worry about "valley fever" and wildfires every week and a half there though so there is that!)
The way houses are built here, the stuff you need to worry about are fire resistance from ash from brush fires (hence the use of concrete shingles and stucco-- which I hate with a passion regardless) as roofing and siding... And UV and heat protection. Inside insulation is just as necessary, but a radiant barrier is needed for the insulation to work here.. the silver lining as it seems. Plastic vapor barriers and stuff like TyVek you won't even see here. They don't take mold seriously enough here, but you never see anything more than tar paper for a vapor barrier. And what do I mean by not taking mold seriously? The dumbkopfs here finish the inside of the houses before the roof goes on! Honestly the most stupid thing I've ever seen anywhere. Yeah it's a desert. We get exactly 1/3 of the rain we did in Iowa. That still is enough to make a moldy house when it does rain during construction.
The fan being on 24/7 is just a builder cheaping out. The new energy star rated houses need to have some forced ventilation. That is handled in my house by turning on the laundry room fan (which is a typical "low cost" ventilation solution)... ON A TIMER for like 1 hour per day. 24/7 is over kill. $30-$40. In our house the wife and kids go in and out so much that the fan is probably not even needed at all.
Something like ventilated air from the outside would be a super idea on houses here during 9 months out of the year when there is nice cool air at night. The couple of times I suggested it to people here I got looked at like I had three heads.... Open the windows up is the usual response, but the timing is such you'd have to get up in the middle of the night to close them (or you'd freeze, even in summer). I still would like to eventually do something like that heat exchanger idea here someday-- it could be brilliant if properly done.
My actual guess on a continuously blowing fan is either it being on a timer (hopefully) and you heard it when on, or what you are actually hearing is a radon abatement system. You don't need the laundry room vent if you have one of those running, they use a lot of energy and waste a lot of energy unfortunately...
The way houses are built here, the stuff you need to worry about are fire resistance from ash from brush fires (hence the use of concrete shingles and stucco-- which I hate with a passion regardless) as roofing and siding... And UV and heat protection. Inside insulation is just as necessary, but a radiant barrier is needed for the insulation to work here.. the silver lining as it seems. Plastic vapor barriers and stuff like TyVek you won't even see here. They don't take mold seriously enough here, but you never see anything more than tar paper for a vapor barrier. And what do I mean by not taking mold seriously? The dumbkopfs here finish the inside of the houses before the roof goes on! Honestly the most stupid thing I've ever seen anywhere. Yeah it's a desert. We get exactly 1/3 of the rain we did in Iowa. That still is enough to make a moldy house when it does rain during construction.
The fan being on 24/7 is just a builder cheaping out. The new energy star rated houses need to have some forced ventilation. That is handled in my house by turning on the laundry room fan (which is a typical "low cost" ventilation solution)... ON A TIMER for like 1 hour per day. 24/7 is over kill. $30-$40. In our house the wife and kids go in and out so much that the fan is probably not even needed at all.
Something like ventilated air from the outside would be a super idea on houses here during 9 months out of the year when there is nice cool air at night. The couple of times I suggested it to people here I got looked at like I had three heads.... Open the windows up is the usual response, but the timing is such you'd have to get up in the middle of the night to close them (or you'd freeze, even in summer). I still would like to eventually do something like that heat exchanger idea here someday-- it could be brilliant if properly done.
My actual guess on a continuously blowing fan is either it being on a timer (hopefully) and you heard it when on, or what you are actually hearing is a radon abatement system. You don't need the laundry room vent if you have one of those running, they use a lot of energy and waste a lot of energy unfortunately...
- May 23, 2015
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Agreed. Midwest or East coast building practices are not necessary out here. There are different requirement in the desert.
One of the neatest natural solutions I’ve come across is locally. There is a road nearby that runs across a wash (dry River bed for you non-desert rats). It’s the lowest point in the area. There are couple of very old houses built down by the wash. The homes are surrounded by some very tall elms and sycamores and the owners planted bamboo as tall hedging at their property line. They installed spray irrigation around the bamboo and they flood the ground daily. What they created are homes basically completely shaded and the bamboo acts like wicks that draw up the moisture. When the wind blows through the bamboo, it cools considerable. Also, being at a low point the colder air settles there. It can be 105F at my house but when you drive by their homes, the temperature is almost 10 deg cooler. At night if drive by on that road the air temps drop considerably just around their homes and you can watch your dashboard temperature drop several degrees. It’s a very neat effect and one that uses the natural landscape, and their well water, to create some seriously efficient cooling. The tall shade trees help a lot too. I’m sure their houses are anything but sealed.
- Nov 12, 2017
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That's entirely possible. The realtor's explanation didn't make sense to me at the time. Yours does. Just running a ceiling fan and hoping that sucks in fresh air from some leaking door can't be right. My house is newish but doesn't have anything like what you describe. I certainly wish it did. Amazing what they can do now.
- Nov 12, 2017
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Hey, I absolutely love both. Having dealt with redwood siding, T-111, cedar shingles, asphalt shingles and worse all my life, I absolutely love my concrete exterior. It'll last longer than me, probably will never need repair or paint, and from inside my house, looks exactly like any other exterior I've ever lived in!
- Nov 12, 2017
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Well, I can't match that, but I seem to have lucked out a bit. The previous owners planted like 60 trees, so I'm in a bit of an oasis compared to my neighbors. My water bill sucks, but it's worth it to me. But better still is that the ridge of my house's roof seems to be aligned perfectly with the path of the sun. So in the hottest part of the year, all the heat is on the roof and doesn't come in through the walls or windows. I have to use my air conditioning maybe five or six times a year. 100° outside will be 70° inside. I just have to open the windows at night and close them when I get up. I'm sure my house's orientation was not something the builder or an architect thought through. Just a happy coincidence.