Understood. I can't buy a Nortek myself, need a dealer. That's usually where I cross the brand off the list, but will keep it on the list because of the insane power savings while I look at other brands that I can buy myself.
Bedroom STILL Hot At Night (Even With Vornado)
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I think by "black" curtains he meant "blackout" curtains.
I don't really have any useful info, but we have a problem in our house with some of the rooms being hotter than others in summer and colder than others in winter. Don't know if its insulation or lack thereof or a problem with the ducts or something else.
I don't really have any useful info, but we have a problem in our house with some of the rooms being hotter than others in summer and colder than others in winter. Don't know if its insulation or lack thereof or a problem with the ducts or something else.
Eddie_T
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I couldn't find Nortek from my normal supplier. Does it require a licensed installer?
My Harbor Point mini HP has failed and is not on the market any more. I chose it because it had a 21 SEER (which was good at the time) no backup heat strips and a flexible line set that plugged in rather than requiring wrenches.
At present I have only a PTHP (motel unit) the SEER is low but installation/replacement is easy and I never have to involve a professional. A slide-in inverter driven replacement is only about $800 but SEER is still low. I don't understand why they don't have a high SEER mini replacement for PTAC/PTHP units designed to fit existing shells. There are a lot of motels out there.
My Harbor Point mini HP has failed and is not on the market any more. I chose it because it had a 21 SEER (which was good at the time) no backup heat strips and a flexible line set that plugged in rather than requiring wrenches.
At present I have only a PTHP (motel unit) the SEER is low but installation/replacement is easy and I never have to involve a professional. A slide-in inverter driven replacement is only about $800 but SEER is still low. I don't understand why they don't have a high SEER mini replacement for PTAC/PTHP units designed to fit existing shells. There are a lot of motels out there.
I read a blog yesterday that blew "High SEER" out of the water.
https://phyxter.ai/blog/whats-a-good-seer-rating
Eddie_T
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Reminds me of the people with unlimited smartphone minutes If they could but do the math they would realize there is no such thing as a free lunch.
Last month I only had to run the PTHP a few days, not long enough for advertised SEER to even matter.
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I have a couple rolls of the Bubble style left after a project, would need to order more for the entire attic, but why do you think that won't work? For my project, I cut pieces of the Double Bubble to fit my garage windows and attached a cardboard backing to them, cardboard facing outside.
I will have to remove them when it's in the high 90's this week, take a before and after temp test... Without doing the test, I know the window blockers reduce the Summer heat and the Winter cold a lot.
Many of the bubble foils have a clear, plastic coating, thus rendering the radiant benefit void. Some also tested as not pure aluminum. We experimented in the lab at work and none of the bubble brands that we tested worked. The only benefit is some blocking of the sun's light, just as a window shade would. Eventually, the bubble stuff was saturated and started giving off heat, just as mass insulation does.
Also note that the bubbles add a very, very minimal amount of R-value from the bubble's air gap. Very minimal.
Household aluminum foil is not pure aluminum, so it does not work well.
Pure aluminum radiant barrier from 2 suppliers worked in testing. The lab got the rated 97% reflectivity and 3% emissivity. Those samples came from both AFS Foil and Attic Foil Com. My house has both brands in perforated with scrim. The results in the house are amazing- heating and cooling season.
They also make it in mylar if you need the fire rating for a commercial job. (Mylar burns so fast that the underlying material does not have time to catch fire, thus the fire rating.) Keep in mind, however, mylar can not be recycled locally. You have to pay and mail in the scraps for recycling. It's one of the "forever in a landfill" plastics, so that's a bad plan.
And, the radiant barrier foil was much less expensive and easier to work with than the bubble stuff.
Hope This Helps!
Paul
Thanks for the info. The only thing I find for AFS is Surfing Broski! Hang Ten!
Attic Foil looks to be a reseller from Alibaba, which is exactly where I would get it from if I was building near a port, but they don't come close to pricing at other places.
That said, I will take your advice and use perf barrier when building a shop and see what happens!
Attic Foil looks to be a reseller from Alibaba, which is exactly where I would get it from if I was building near a port, but they don't come close to pricing at other places.
That said, I will take your advice and use perf barrier when building a shop and see what happens!
Albania?
Attic Foil is a family owned company in Texas, if I remember correctly. (atticfoil com) Phone 800 595-8772 They are nice people.
I tried to find AFS Foil for you, but got redirected to another company's web site. I don't know anything about that other company. Perhaps Mr. Akers (owner of AFS) retired.
An Aritcle you may enjoy: Radiant Barriers
Paul
Eddie_T
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Beware of claims that violate the laws of physics. The reflectivity of the foil is what counts not the purity of the aluminum. Absorbed heat is better radiated from black objects by the law of reciprocity. Reflected heat has to have a path to escape or it can damage asphalt shingles. Probably perforated material over ceiling along with a well ventilated attic would be the best solution.
Alibaba;
https://www.alibaba.com/trade/searc...m+foil+insulation&isPremium=y&secondFlag=true
Alibaba;
https://www.alibaba.com/trade/searc...m+foil+insulation&isPremium=y&secondFlag=true
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I was fortunate that I learned from Roy Akers, the former chairman of ASTM's radiant energy division,. He connecdted me to a radiant energy specialist at NASA who taught me even more. NASA uses gold as the radiant barrier due to it having the highest reflectivity/emmissivity rating of all metals. That is what is on the tiles that protect the spacecraft during re-entry. I even had the opportunity to speak with some physicists that I know about the subject. (And promptly got lost in the mathematics)
For more information, read on the US Department of Energy, ATSM, MIT, NASA and several other web sites, especially universities in California and Germany, you will see lots of verification about many types of metals and reflectivity/emmissivity. Without question, the purer the metal, the closer it is to the goal of maximum performance.
Two Things Are Paramount:
A) There must be a gap of 19mm or greater on at least one side. That is why foil coated foam boards sandwiched between layers of sheeting don't work.
B) No coatings on at least the radiant gap side is critical. That is why many bubble foils don't work. Even painted white, silver or black, uncoated reflects the most and emits the least.
For a fun experiment, do some heat-source testing with painted aluminum, aluminum foil and pure aluminum. The differences are certainly noticeable. Then try various metals. There is sure a difference aluminum, copper, brass, iron & steel. (Didn't have any gold or silver to test. Their percentage is higher than aluminum.)
What you said, Eddie_T about letting heat escape is very important and thank you for mentioning it!
Perforated foil is very important when it is against mass insulation, such as laying on an attic floor. An example of proper attic rafter installation would be to staple it to the bottom of the rafters and leave a gap at the bottom and at the ridge board so that heat can travel by convection up and out, preferably from eave vents to a ridge vent. In the absense of a ridge vent, it will escape the top and find its way to the pot vents or gable vent.
There are lots of installation methods and explanations on many vendors' web sites. Attic Foil Com also is generous about answering questions and giving example photos. It is what they do for a living. They aren't a "we sell everything" place. I'm sure there are other reputable vendors, too.
But, this thread is about helping someone cool a room, so I apologize for making it go so far off track.
Paul
Eddie_T
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We do get on rabbit trails but they make life interesting and may be of some help to the OP. I retired from NASA and what we used to wrap satellites to reflect the sun were gold or silver because of reflectivity, shuttle tiles were primarily black on the bottom of the shuttle and white on top of the shuttle. Your guy got it wrong else you misunderstood. The black reentry tiles were for insulation not reflectivity. I held a sample of a prototype tile in hand and it was matte black on the outer surface and lighter colored beneath. Thickness varied depending on location. I didn't see the final version but in photos they were white on the sunny side and black on the earth side.
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Alibaba. Attic Foil undoubtedly gets the supplies from Alibaba, AKA China suppliers. The suppliers ship to a port in Texas, then AF picks up the rigs and stores the foil in their warehouse.
If I had any interest in being a competitor, I would set up a similar operation on the West Coast and do the same exact thing.
As a private person, buying enough foil from Alibaba for a 2000sf job is about $25. Then the freight gets tacked on, which may be cheaper than AF or not.
Eddie_T
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Foil might really have some effect in RV windows where the sun shines in. However the sun doesn't shine in my attic and what good would superior reflectivity be after a layer of dust dulls the sheen. Just like the EdenPure heaters there may be a sliver of truth there somewhere but is there enough benefit to outweigh the cost?
Maybe this radiant energy stuff does not belong here. I started it by trying to give the original poster an idea for room cooling, but it ended up clogging up the original poster's question. Maybe this side track should get moved to its own post?
Check out some of the DOE articles as well as those from Cal Tech, MIT and others. You'll have to dig around a bit for them.
Also note that the "sheen" does not matter. You can put either side as the reflecting side except mylar-foil which is coated on one side. It's marked so you won't go upside down.
Once I read a study about dust on the material and it was inconclusive. I suppose if it is a flat-on-floor installation, you'd have to vacuum it once in a great while. I have some that has been flat in an attic for over 25 years and there is no dust on it. (Don't remember ever seeing dust, so I checked when I read your post, Eddie_T) Attic ventilation currents must vacuum it out by convection before it settles.
Quote From Above Post: "The sun doesn't shine in my attic"
The visible light from the sun is certainly not in your attic, but the energy is, thanks to radiation and conduction of energy.
The sun radiates energy onto the roofing materials. All the layers of the roof conduct energy to each other. The bottom layer (in the attic) radiates energy into the attic.
We want to "bounce" it back out before it heats the ceiling materials for the room below.
Aluminum can "bounce" 97% of it out.
You can put the aluminum across the floor or across the bottoms of the rafters for a lower temperature attic. (Follow ventilation & perforation guidelines no matter the meothod)
That is how your house heats up on a sunny day. The radiant energy strikes your roof and the layers of roofing material conduct into each other until reaching the bottom layer. The bottom layer then radiates the energy into the attic space.
The whole thing begins again when the energy in the attic radiates to the ceiling's mass insulation and building materials. The radiant barrier's job is to keep the ceiling material cool so they don't radiate heat into the rooms below. When it is saturated, it saturates the ceiling materials and heat radiates from the ceiling into the room below.
In winter, it works backwards. The barrier's job is to block emission from the ceiling's insulation & building materials. Aluminum blocks all but 3% of emitted energy.
To Illustrate Radiant Energy Where The Sun Does Not Shine With An Experiment:
Take two cardboard boxes that are the same color.
Place one upside down on the pavement or other flat surface where the sun IS shining
Place the other upside down on pavement or other flat surface where the sun IS NOT shining
After about 4 or 5 minutes, lift an edge of a box and stick you hand under it.
When you do the second box, you will feel a tremendous temperature difference, yet no visible sunlight shone into the box.
You can also do the same experiment by using one box with pure aluminum inside the lid and one without. Put both in the sun & check the temperature difference inside.
Then...
Repeat but with a heat source inside each box. Check the temperature on the outside of the box. The heat source inside experiment illustrates that radiant barriers are not only high reflectors, they are low emitters.
Another Example:
I have two skylights 5 feet apart. They are on the same side of the same pitched roof. Both face south. Inside, they sit on top of curbs, forming a box. On one, I have a white shade which is at the bottom of the curb box, about 6" below the glass. On the other, a radiant barrier home made shade installed the same as the white shade window.
The difference in temperature on the floor below the windows is remarkable.
Fun Fact: Aluminum is not only a 97% efficient at reflecting and emitting radiant energy, but it is also a very good conductor. In the above skylight example, if one were to hold a hand just below the aluminum shade, you'd feel not heat (radiant energy) If you touch the shade, it's hot (conduction of energy).
The Magic of Physics!
Paul
PS: The question of cost versus benefit in the quote above is easy to answer for radiant barrier. I live in a hot-in-summer and cold-in-winter climate (Detroit). Immediately after installing the barrier over only the first two rooms, our next air conditioning power use dropped considerably, even though the days were much hotter the subsequent month. The temperature in the rooms below where I was working dropped noticeably even before I was done installing the barrier.
In some hot climates, radiant barrier is often accepted as the only insulation required. (Once mass insulation is saturated with radiant energy, it's not useful. The energy is radiated or convected to the space it was protecting.)
Our winter heating gas usage also dropped dramatically, but 4 rooms were done by winter. I studied "Heating Degree Days" from the previous years' gas bills versus the post-foil bills. It was colder in the post-foil year- the one with the lower costs. One of my brothers laid perforated across his attic floor. He said his gas energy use dropped enough to pay for the materials in 2.5 months His summer temperatures in the living areas dropped. His cost for a 4,700 ft-sq attic = $760.00. Time = 2 Hours.
Is Edenpure one of those heaters that claims to get more BTU than the others for the same wattage? Unless the laws of physics have changed since I was in school, watt can only yield 3.41221 BTU no matter how overpriced the heater is.
Check out some of the DOE articles as well as those from Cal Tech, MIT and others. You'll have to dig around a bit for them.
Also note that the "sheen" does not matter. You can put either side as the reflecting side except mylar-foil which is coated on one side. It's marked so you won't go upside down.
Once I read a study about dust on the material and it was inconclusive. I suppose if it is a flat-on-floor installation, you'd have to vacuum it once in a great while. I have some that has been flat in an attic for over 25 years and there is no dust on it. (Don't remember ever seeing dust, so I checked when I read your post, Eddie_T) Attic ventilation currents must vacuum it out by convection before it settles.
Quote From Above Post: "The sun doesn't shine in my attic"
The visible light from the sun is certainly not in your attic, but the energy is, thanks to radiation and conduction of energy.
The sun radiates energy onto the roofing materials. All the layers of the roof conduct energy to each other. The bottom layer (in the attic) radiates energy into the attic.
We want to "bounce" it back out before it heats the ceiling materials for the room below.
Aluminum can "bounce" 97% of it out.
You can put the aluminum across the floor or across the bottoms of the rafters for a lower temperature attic. (Follow ventilation & perforation guidelines no matter the meothod)
That is how your house heats up on a sunny day. The radiant energy strikes your roof and the layers of roofing material conduct into each other until reaching the bottom layer. The bottom layer then radiates the energy into the attic space.
The whole thing begins again when the energy in the attic radiates to the ceiling's mass insulation and building materials. The radiant barrier's job is to keep the ceiling material cool so they don't radiate heat into the rooms below. When it is saturated, it saturates the ceiling materials and heat radiates from the ceiling into the room below.
In winter, it works backwards. The barrier's job is to block emission from the ceiling's insulation & building materials. Aluminum blocks all but 3% of emitted energy.
To Illustrate Radiant Energy Where The Sun Does Not Shine With An Experiment:
Take two cardboard boxes that are the same color.
Place one upside down on the pavement or other flat surface where the sun IS shining
Place the other upside down on pavement or other flat surface where the sun IS NOT shining
After about 4 or 5 minutes, lift an edge of a box and stick you hand under it.
When you do the second box, you will feel a tremendous temperature difference, yet no visible sunlight shone into the box.
You can also do the same experiment by using one box with pure aluminum inside the lid and one without. Put both in the sun & check the temperature difference inside.
Then...
Repeat but with a heat source inside each box. Check the temperature on the outside of the box. The heat source inside experiment illustrates that radiant barriers are not only high reflectors, they are low emitters.
Another Example:
I have two skylights 5 feet apart. They are on the same side of the same pitched roof. Both face south. Inside, they sit on top of curbs, forming a box. On one, I have a white shade which is at the bottom of the curb box, about 6" below the glass. On the other, a radiant barrier home made shade installed the same as the white shade window.
The difference in temperature on the floor below the windows is remarkable.
Fun Fact: Aluminum is not only a 97% efficient at reflecting and emitting radiant energy, but it is also a very good conductor. In the above skylight example, if one were to hold a hand just below the aluminum shade, you'd feel not heat (radiant energy) If you touch the shade, it's hot (conduction of energy).
The Magic of Physics!
Paul
PS: The question of cost versus benefit in the quote above is easy to answer for radiant barrier. I live in a hot-in-summer and cold-in-winter climate (Detroit). Immediately after installing the barrier over only the first two rooms, our next air conditioning power use dropped considerably, even though the days were much hotter the subsequent month. The temperature in the rooms below where I was working dropped noticeably even before I was done installing the barrier.
In some hot climates, radiant barrier is often accepted as the only insulation required. (Once mass insulation is saturated with radiant energy, it's not useful. The energy is radiated or convected to the space it was protecting.)
Our winter heating gas usage also dropped dramatically, but 4 rooms were done by winter. I studied "Heating Degree Days" from the previous years' gas bills versus the post-foil bills. It was colder in the post-foil year- the one with the lower costs. One of my brothers laid perforated across his attic floor. He said his gas energy use dropped enough to pay for the materials in 2.5 months His summer temperatures in the living areas dropped. His cost for a 4,700 ft-sq attic = $760.00. Time = 2 Hours.
Is Edenpure one of those heaters that claims to get more BTU than the others for the same wattage? Unless the laws of physics have changed since I was in school, watt can only yield 3.41221 BTU no matter how overpriced the heater is.
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Eddie_T
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The foil promoters depend highly upon testimonials as did EdenPure. One can't have it both ways saying purity and reflectivity are important then trying to downplay the impact of dust.There is a lot of government info on the con side. I don't think the subject is worthy of a forum thread as it isn't going to affect many of us and would but become a Google copy and paste exercise. Most do not understand enough about physics to know what's applicable and what isn't. The NASA shuttle tile implication being but one example.
