snail powered Posted June 27, 2015 Share Posted June 27, 2015 A simple to do but very effective way to keep the cab interior a little cooler. Take off the cab door lining and cover the backside with aluminum duct tape. That will reflect the heat from the sun hitting the metal car body back out towards the exterior. A good place to buy this kind of tape in larger rolls that cost less per foot is at the big box home center stores. Look in the aisles where they sell metal ducting parts for HVAC. Don't buy it in the paint department as it cost more per foot for the very same material. You can see in this photo just how much visual reflection there is on the backside of my door panel that I covered with aluminum duct tape. Quote Link to comment Share on other sites More sharing options...
5Toyota Posted June 27, 2015 Share Posted June 27, 2015 that is an interesting idea I bet that would stop some heat. Quote Link to comment Share on other sites More sharing options...
WME Posted June 28, 2015 Share Posted June 28, 2015 Plan B http://www.eastwood.com/heat-and-sound-barrier-coating-1-5-gallon-kit.html Quote Link to comment Share on other sites More sharing options...
Back East Don Posted June 28, 2015 Share Posted June 28, 2015 I don't know a ton about the science of thermodynamics but do have a pretty good background covering acoustics. As such, have practical issues with the products claim of "up to" (always that disclaimer) 5db of sound deadening. Couple of aspects at play. One is the hole in a bucket principal. You are not going to keep anything in the bucket if there is a hole in it. Sound mitigation works this way. The principal of soundproofing requires all paths of unwanted sound and its transmission be addressed. This also includes mechanical coupling which is hard to do in a vehicle. Pretty sure if I have an AC Cobra, this coating applied to the firewall will do little to contain all that wondrous sound that engine makes. Getting us to the subject of things being relative. Perhaps in a already quiet car, such a product inside the doors for instance might (just love caveats) dampen road noise enough to notice. In that vein, it takes good hearing to notice a 3db difference in sound. 5db would likely be imperceptible by some if not many. On to the subject of thermodynamics. 40 degrees difference with a spray on coating? I have one of those fancy coolers. Super insulated, thick walled with gasket seals. It is designed to keep ice for several days in 90 degree heat. What are the chances of this stuff significantly improving performance of said cooler if I were to coat the entire cooler? Why wouldn't they just use this stuff to insulate the cooler instead of the foam material they use inside them now? While I have little expertise in this area, my understanding is that even the new thin insulation is only marginally better at preventing thermal transfer. I only marginally understand the use of reflective barriers but could stand a primer on the differences in conduction, convention and radiation when dealing with thermodynamics. It's midnight on Sat, the wife is out and it seems I've nothing better to do other than argue with the internet. None of this is directed at anyone but Eastwood. Sometimes such product claims bother the crap out of me. But hey, your results might vary. Quote Link to comment Share on other sites More sharing options...
snail powered Posted June 28, 2015 Author Share Posted June 28, 2015 Plan B http://www.eastwood.com/heat-and-sound-barrier-coating-1-5-gallon-kit.html Why would I paint a liquid on the inside doors of my cab panels that are made of hardboard and in the process of it destroy them by having them warp? Why would I want the extra weight of that product when something far lighter will do a better job? Why would I want the high cost of the product when I can spend less than $2.50 to reliably accomplish the task? Why use chemicals when you don't need to? your plan B is not going to work as a plan B, sorry no cigar for that one The characteristic of thin aluminum foil as a heat reflective material is well established and the documentation is reliable. You could even prove it to yourself if you had a surface temperature sensor. But you do need to remember it has to be a reflective surface, if you coat the surface with adhesive it won't be very effective. So duct tape aluminum foil is only going to reflect heat away from the shiny side that has no adhesive on it. It won't be suitable for every situation as the thin surface is easily damaged by scratching. The aluminum foil won't keep the cold out or in. All it does is reflect heat back towards the source. My use of it is not anything radical, they have been adding a layer of it to insulation bats for a very long time. They use shiny mylar film for the same purpose. So it is not a great leap of intelligence on my part to putting a layer of it on my car door panel to reflect the heat back towards its source. It won't do much of anything to help retain heat inside in the winter as it is facing the wrong direction. I did an experiment and took a thermometer over to my Sunrader yesterday afternoon. I went over there at the hottest part of the day (89 degrees) just to see how effective my heat countering measures are. There are others in place besides the foil on the doors. The sun was hitting my motorhome on the south side which is the way the cab was facing and also on the west side as it is was mid afternoon. There is a metal building against the east side and its steel cladding does absorb some heat during the day which radiates back towards my Sunrader. But at the lower level of the building back away from the nose of the cab the temperature is at ambient as it is always in the shade. The motorhome had not been opened in the last two days other than the two roof vents were cracked open about an inch. The ambient outside air temperature was 89 degrees and the inside temperature measured at 93 degrees. Four degrees above ambient temperature is an excellent result for a vehicle that has been sitting in direct sun much of the day. In under ten minutes I had the inside temperature down to 88 degrees using fans to exchange the air. The intake fan was pulling in air from a window on the shady east side. But 88 is still much too hot for comfortable working so I left. But at least I took the tools and materials I needed over there so I am all ready to go at sunrise. Quote Link to comment Share on other sites More sharing options...
WME Posted June 28, 2015 Share Posted June 28, 2015 Well a food fight, haven't had one in a while This is a new type of sound and heat reduction. Its been well received in the hot rod and audio world. Eastwoods line is new and is the only one claiming heat and sound reduction in one product. Lizardskin and Spraydead have been making this type for several years. How ever they do have sound and heat control as separate products. It controls the many resonances that steel panels will develop and will change the tinny Toyota door slam to a Rolls Royce thunk. The hear barrier wont reduce the inside temp of your Toy to 60 degrees on a 100 degree day, but it will reduce the heat from the cat converter under the drivers feet and reduce the heat coming from the engine and the exhaust through the floor. Replacing seats soon????? perfect time to remove the carpet and interior panels and apply one of these products to the entire cab and to the door skins. Not to the panels On my Toy, before this stuff was available, I used Refeltix on the door panels, the floor, on the walls inside the dinette benches and any where else I could l lay it. It worked within its limits The Chevelle will get 2 coats of this stuff when I strip the insides to redo it. I'll see how well it helps control the rumbles of a healthy V-8 Quote Link to comment Share on other sites More sharing options...
Back East Don Posted June 28, 2015 Share Posted June 28, 2015 Won't be much of a food fight from me. As I indicated, thermodynamics is not my field. Closest I come is a bit of math calculating heat load so I can get architects to specify enough cooling to account for equipment in addition to people occupying a space. Acoustics on the other hand. I built my first recording studio right out of high school. I learned the old adage young. If you want to make a million dollars in the music business, start out with two million. I worked two jobs supporting that recording studio aka, my industrial years. My career since has revolved around audio. I ran a live sound company, built a second recording studio in my home, specialized in repairing audio equipment as a business and worked in a commercial recording studio owned by Bose for several years where I designed the complete rebuild and update of the studio space. While there I took advanced courses that were available to me including a course at MIT in advanced acoustics taught by Dr. Bose. I also took a course in audio measurement and analysis that involved architectural spaces and anechoic chamber work. I've completed multiple specialty courses on architectural acoustics. So I know a tiny little bit about sound. All that being said, I stand by my statement. 5db ain't diddley Sure, any dense viscoelastic material will keep a door from sounding like a tin can just like filling a soda can with water will. Quote Link to comment Share on other sites More sharing options...
snail powered Posted June 29, 2015 Author Share Posted June 29, 2015 The topic of this tread is insulation from summer heat. This thread is not about the acoustic characteristics of audio systems. https://www.youtube.com/watch?v=SSUXXzN26zg Quote Link to comment Share on other sites More sharing options...
snail powered Posted June 29, 2015 Author Share Posted June 29, 2015 My under cab floor cushioning started going in today. It is high density closed cell foam onto which I am applying foil backing. The foam has sound dampening and decoupling properties as well as being insulating and cushioning. The metal is for reflecting heat. The foam I am using was specifically made for auto insulation and sound dampening. I buy it by the foot from a supplier. Its an industry standard product for the purpose rather than something being hyped by a company selling overpriced items. The average consumer simply does not know a lot about what the common products for auto insulation are as you don't typically find them in retail stores. I used this foam in other places in my project and still had enough on hand to do the floor cushion. I also had the adhesive back foil on hand. So I am no money out of pocket to do the cab floor project. Good thing I had enough on hand as when I was there the other day I noticed the supplier was out of stock. There is not a tinny door slam sound in my Sunrader but maybe I have not heard it because I don't go around slamming doors Quote Link to comment Share on other sites More sharing options...
Back East Don Posted June 29, 2015 Share Posted June 29, 2015 A most humble apology. I'm a label and spec reader by nature and trade. I clicked the link and read the product description and there was that number. Hey, I know a little bit about this, lets have a look. Of course there was no specifics about the 5db reduction pretty much rendering it a useless number. It is marketed as a sound barrier. In my trade these numbers are backed up by a NRC (noise reduction coefficient) figure and information in what specific bands the reduction is. Usually some sort of curve data. I know exactly what this product is and have no doubt that used within its limits, it does a great job. The number itself is marketing speak with this product. As such it is a very suspect claim. As to being new. It's mass and in physics, mass has been around since the big bang. Odd tid bit. Sound and thermal are related in many ways and many of the materials used like insulation are exactly the same. Calculated in different ways but things like insulation and seals are used in the same ways to keep energy in or from penetrating out. The main variable is sound acts differently with given materials (like fiberglass insulation) at different frequencies. That is what I went looking for. Heat in many ways is simpler to calculate as in R values. Note: there is no R value spec to back up the up to 40 degree claim. Again, sorry, I'll try to behave. I've just got too much idle time these days. Quote Link to comment Share on other sites More sharing options...
WME Posted June 29, 2015 Share Posted June 29, 2015 The topic of this tread is insulation from summer heat. This thread is not about the acoustic characteristics of audio systems. https://www.youtube.com/watch?v=SSUXXzN26zg No squirrels here. Your post was about heat reduction.... The products I posted DO reduce heat. Using layers of methods to improve something is the best you can do. Quote Link to comment Share on other sites More sharing options...
snail powered Posted June 29, 2015 Author Share Posted June 29, 2015 No squirrels here. Your post was about heat reduction.... The products I posted DO reduce heat. Using layers of methods to improve something is the best you can do. Read down this article to the section quoted below. While the foil on my car door panel is not totally air bound on both sides it is mostly air bound on the side that is reflective which faces to the exterior. And indeed it is doing a good job of keeping the interior from excessive heat building up radiated into the interior. A lot of bang for my investment of about $1.25 in aluminum foil tape for each of the doors. "Aluminum foil, with its reflective surface, can block the flow of radiation. Some foils have higher absorption and emissivity qualities than others. The variations run from 2% to 72%, a differential of over 2000%. Most aluminum insulation has only a 5% absorption and emissivity ratio. It is impervious to water vapor and convection currents, and reflects 95% of all radiant energy which strikes its air-bound surfaces." Quote Link to comment Share on other sites More sharing options...
snail powered Posted July 15, 2015 Author Share Posted July 15, 2015 My cab flooring insulation is about done now. It is working out nicely. Having the foil on both sides of the 1/4" polyolefin foam makes it very easy to conform the material to the curvature of the floor and firewall. I made it in a few sections, one over the center hump, one piece each for under the passenger and drive feet and on up the firewall. Two more sections for behind the seats. Foil tape makes it easy to join the pieces together without gaps. I still have space under the new vinyl floor mat to add another layer of insulation and I will do that under the area of the floor in front of the seats. I do have extra material left so I might as well use it. Cost to do the floor was just under $40.00. The foam is $10.00 a yard @ 60" wide from an auto upholstery supply source. Way less money that purchasing the same type of materials from the car audio store sources. You can also get this product already made up with foil on both sides of the foam from stores that supply insulation to house contractors. But those rolls use thinner foam, 1/8" thick. But it would work well behind the door panels. More layers of foil between foam also means better sound control according to my friend who is a product designer. But for my project I was just using materials I already had on hand which meant no extra cash outlay except for a couple of rolls of aluminum foil tape. Quote Link to comment Share on other sites More sharing options...
WME Posted July 19, 2015 Share Posted July 19, 2015 With folks looking for an edge in dealing with heat gain I found something that might help a bit. I bought a new trailer, it has an uninsulated aluminum roof. In direct sun the inside of the roof was 91 deg. After 2 coats of a white roof sealer the inside temp was 86. So it appears to do some good. On a rubber roof or fiberglass who knows. Quote Link to comment Share on other sites More sharing options...
snail powered Posted July 19, 2015 Author Share Posted July 19, 2015 Shiny aluminum is good at reflecting the radiant heat but I have not seen any photos of a Toy home with a polished aluminum roof. Could be there are some out there though. I have a white fiberglass roof with a decent amount of urethane foam under it. I don't need to do any remedial work on it other than washing and waxing now and again. The glass is the big culprit left for radiant heat transmission. Nice to have on a sunny winter day but not great on a hot summer day. In the summers when parked I have been shading the glass on the exterior with reflectix. This winter I will sew up some special washable shades that have a layer of mylar inside of coated nylon fabric. They will velcro or snap in place to the outside but be easy to store flat under the mattress when not in use. They can also be used on the interiors of the windows in the wintertime to help retain heat if needed. There are some interesting snaps that can be adhered to the outside fiberglass shell of the RV with VHB tape from 3M. VHB stands for very high bond. They are using these snaps on fiberglass boats for installing various Sunbrella type of protective covers. A little pricey per but at least you don't have to put a hole through the fiberglass thereby creating a potential leak. http://www.sailrite.com/easearch#!&ea_q=snad Quote Link to comment Share on other sites More sharing options...
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