I am a single woman, living in a large apartment building in NYC with a built-in AC/heating unit. I had custom built-in cabinets added for storage alongside the AC/heating unit and for aesthetics, I covered the AC/heating unit's front and the non-vent part top so it looked pretty and seamless with the cabinets. It does look great, but the level cold air flow felt from the AC was greatly diminished. The air was getting trapped in the front wood panel which has about 2 inches of space between it and the AC/heating unit to align with the front of the built-in cabinets.I did a little reading and thought if I used the black foam pieces to seal 'leaks' in window AC to take up the depth between the front wood panel up until the vent begins on the AC/heating unit (the black foam is squishy so you can easily make it fit your space), then cut a piece of this bacteria, flame and water retardant Reflectix Spiral Duct Wrap to cover the black foam, ensuring it reached from the AC/radiator top to the top of the built in and covered the width of the entire AC/radiator no black foam showed I'd have a great heat/cold air protective barrier which would be both water and flame proof. I then used foil tape (I used Nashua's because it said "Waterproof" on the label and AC gives off moisture) to adhere the Reflectix Spiral Duct Wrap to both my radiator and the built in to secure the insulation in place and leave no gaps or holes. My theory was this should stop the mis-flow of the AC air and my apartment would be cooler.I was right! I can't say the difference in exact measurements, as I did not take a temperature check before and after, but I can say I immediately felt the difference. I now feel the LOWEST AC level in all parts of my apartment. Before, I would have the AC on with a fan in my bedroom when it was hot out. Now, I simply turn the AC on and can sleep without a fan - WITH covers on. HUGE difference.Thank you Reflectix!!!Given my super recommended adding another piece of wood, which would have still absorbed the cold air and would have eventually become moldy due to the moisture in the AC, I think my solution was MUCH butter. And even though it's reflective silver, you can't see really since it's on the inside / underside of the radiator/AC built-in cover. Strongly recommend this to others with a similar problem.Thank you Reflectix!

I have a 12000 BTU Portable Air conditioner I use to cool my living room during the summer. I have a Window Kit so that the exhaust duct has proper mount. The Window Kit is sealed and very effective. The problem with portable air conditioners is the exhaust hose gets really, really hot. I have used a surface thermometer and it is more than 115 degrees on the surface of the hose at the hottest point.I tried wrapping it with towels but it just lowered it to about 96 degrees. So I decided to try this. And it is a good thing I did.After wrapping the exhaust hose with this and sealing it with Reflectix Tape, I tested the temperature. It was 84 degrees. that is 30% cooler that before with just a single layer of this. I could probably wrap it twice to even get that lower.The portable air conditioner is blowing really cold air now, and it not having a hard time anymore. A must have for Portable air conditioners. Highly recommended with the Relectix Tape.******UPDATE September 3, 2013******Since my first Portable AC was so successful, I went and got a Portable AC for all our rooms. For my 10K BTU AC units, I would only need a single layer of this. I do not do the spiral wrapping as the hoses are bent. Common sense is to cut them and then overlap.WIth my 12K AC units, I triple wrapped the hose and got 3 degrees over room temperature on the average. When I double wrapped, it was about 5-6 degrees above room temperature. This testing was done after running the Portable AC non stop for 4 hours.With my 14K Dual hose unit I use for the main living area, I triple wrapped it. Well, actually I wanted to put 4 layers but I ran out of insulation since my 14 K has 2 hoses. But boy does it make a difference when you use this wrap. The 14k would get as hot as 120 degrees at the hottest area. I got that down to 3 degrees over room temperature.Now, the way I install it is that I make sure that it is snug with the hose. The only way to do this since the hose bends during installation is to install and mount the hoses first, then proceed to wrap the hoses. I make sure that is wrapped tight with the hose.A must have is the Relectix Insulation Tape. I use a lot of that during the install to make sure that it is really snug. I use it to seal the overlap between each joining of the wrap. I also use it to do a spiral taping of the entire hose and I apply a lot of pressure so it squeezes the wrap against the hose. There is absolutely no play anymore after I am done. The only way to reposition the hose or the portable AC for that matter is to redo the insulation. So I make sure I really want it in that location before I start insulating the hose.I always wait a day or 2 so that I can make up my mind as to the final location.Anyway, my electric bill 3 years ago with central AC was $180 my bill this month was $89. My portable AC units are far more efficient than my Central AC. My Central AC eats about 4.5 KWH. The portable AC units use only 1 KWH on the average. I only turn on the rooms that are being used which is what saves me so much money. And we can set the temperature to each room individually.This wrap is still a must have for any Portable AC install.