HawkinsHollow
Veteran Member
Last winter was a struggle with our new tankless hot water heater. The hot water wait time is agonizing, yes, 100% luxury problems. This is more of a quality of life issue than it is about wasting water or energy. Yes, I hate waste. But I also HATE washing my hands in cold a$$ water all winter. And I am not planning on waiting for 2 minutes to run the faucet for a warm water hand wash.
BUT, there is a solution! And the first step of that solution is to insulate my hot water pipes. Luckily 90% of our new PEX water lines are run through our basement or reasonably accessible crawl space. The rest are in the walls of the house, not much I can do about that. Mind you, I am in SE TN and my basements and crawl spaces do not get below freezing ever. I have decided to go with Armacell Tundra polyethylene foam pipe insulation. It has 1/2 wall thickness as opposed to the HD brand that is 3/8" thickness. Every little bit helps! I am being very careful to do this as well as possible. I am gluing every joint and gluing the slit that allows you to slip it over the pipe. I got 1" insulation to go over the PEX fittings that are bigger than the 3/4" PEX. I am making my own 90s by carefully cutting 2 pieces at 45 deg and gluing them together. And finally I have decided to use the foil tape to cover the outside of the insulation in shiny Al to lower it's emissivity. Again, every little bit helps. HF has 150m rolls of the stuff for $7, no brainer. I am also insulating the 1/2" hot water supply lines that I can reach in the basement. But I am mainly focuing on the main line. With this entire reno/addition project I have tried to do things the right way the first time. I plan on being here for at least 20 more years and I figure the effort will easily pay off over that time period. Here is how it looks.
Any thing I am missing or haven't thought about? This is my first time doing this.
I am leaning towards doing a recirc system. I found one with a timer that has a aquastat on it. The pump runs when the temp falls to 85 deg and turns off when 105 degree water hits the pump. I figure with the pipe insulation it should not run a lot. Also the timer will allow me to shut it off overnight. I was going to use a crossover valve at teh furthest faucet but I now think I am going to do a dedicated return loop. It is only about 20 feet from the last faucet to the hot water heater. The warm cold water that a crossover causes doesn't seem very cool. The only thing I have run into is the issue of cold water sandwiching. Basically the water in the pipes stays reasonably warm but the water in the heater and the heater itself cools off more quickly. SO you get reasonably comfortable water but then get a little "bubble" of cold water from the stuff that comes out of the heater before it heats up enough. Has anyone experienced this? Am I making a bigger deal out of it than it really is? The good thing is I can always add that later if it really is an issue.
BUT, there is a solution! And the first step of that solution is to insulate my hot water pipes. Luckily 90% of our new PEX water lines are run through our basement or reasonably accessible crawl space. The rest are in the walls of the house, not much I can do about that. Mind you, I am in SE TN and my basements and crawl spaces do not get below freezing ever. I have decided to go with Armacell Tundra polyethylene foam pipe insulation. It has 1/2 wall thickness as opposed to the HD brand that is 3/8" thickness. Every little bit helps! I am being very careful to do this as well as possible. I am gluing every joint and gluing the slit that allows you to slip it over the pipe. I got 1" insulation to go over the PEX fittings that are bigger than the 3/4" PEX. I am making my own 90s by carefully cutting 2 pieces at 45 deg and gluing them together. And finally I have decided to use the foil tape to cover the outside of the insulation in shiny Al to lower it's emissivity. Again, every little bit helps. HF has 150m rolls of the stuff for $7, no brainer. I am also insulating the 1/2" hot water supply lines that I can reach in the basement. But I am mainly focuing on the main line. With this entire reno/addition project I have tried to do things the right way the first time. I plan on being here for at least 20 more years and I figure the effort will easily pay off over that time period. Here is how it looks.
Any thing I am missing or haven't thought about? This is my first time doing this.
I am leaning towards doing a recirc system. I found one with a timer that has a aquastat on it. The pump runs when the temp falls to 85 deg and turns off when 105 degree water hits the pump. I figure with the pipe insulation it should not run a lot. Also the timer will allow me to shut it off overnight. I was going to use a crossover valve at teh furthest faucet but I now think I am going to do a dedicated return loop. It is only about 20 feet from the last faucet to the hot water heater. The warm cold water that a crossover causes doesn't seem very cool. The only thing I have run into is the issue of cold water sandwiching. Basically the water in the pipes stays reasonably warm but the water in the heater and the heater itself cools off more quickly. SO you get reasonably comfortable water but then get a little "bubble" of cold water from the stuff that comes out of the heater before it heats up enough. Has anyone experienced this? Am I making a bigger deal out of it than it really is? The good thing is I can always add that later if it really is an issue.
