Browse Forums Heating, Cooling & Insulation 1 Sep 30, 2009 11:30 am This has been bugging me since we moved into our house 5 years ago! For about 20 metres, the cold water pipes run along the length of the outside of the Western wall, at around knee-height. This wall gets very very hot in summer. So in summer the pipe is heated by the sun, and the water inside is very hot - in fact, it is hotter than the water coming from the hot water tank!!! So to get water we have to run the cold water tap and waste about 15 seconds' worth of water. It's so hot that, on a summer's day, if I want cold water within about 5 minutes of the last time I opened the cold water tap, I have to run the cold water tap for another 15 seconds until the hot water runs out. It's a *huge* waste of water. There's no problem at all on cool or cold days. I was thinking of insulating the length of pipe that runs along the western wall . . . but have no idea if it's possible, or how to go about it, or what to use. I have seen pipe insulation at harware stores but it's all black or grey dense foam so it seems to me like it's designed to keep heat in the pipes. Is that sort of insulation also going to work to stop the baking sun from heating the water in my pipes? Any advice or suggestions gratefully received!!! Thanks in advance, everyone. Re: How to insulate cold water pipes to stop wasting cold water? 2Sep 30, 2009 4:58 pm You are right. The foam is better at keeping heat in but it will still help in keeping the heat out. If you want better radiant protection, wrap the pipe in foil (shiny side out) around the foam as well. That should do the trick. Re: How to insulate cold water pipes to stop wasting cold water? 4Oct 06, 2009 10:58 pm Painting it white won't help as much to keep the water from getting cold. Re: How to insulate cold water pipes to stop wasting cold water? 5Oct 07, 2009 10:20 pm had a similar problem with one of my pipes although not on a brick wall, used a piece of cardboard and spray can and problem drastically reduced.im thinking a dark copper pipe would be the main prob and if this doesnt work sufficiently then not much time or money is lost.Any light colour should work the lighter the better Re: How to insulate cold water pipes to stop wasting cold water? 6Oct 07, 2009 11:12 pm I decided to investigate Mac's claim. He's actually right. White paint or any reflective surface significantly reduces heat loss from a non-metallic hot water pipe. Rate of heat loss by radiation and conduction is about 125W per lineal metre. White paint or foil wrap reduces heat loss by a third. (NB the effect is for non-metallic pipe since copper doesn't radiate much heat anyway). 1 inch foam reduces heat loss by half. These effects are additive. * Therefore the best product is foil covered or white painted foam. Calculations below: Based on the Stefan-Boltzman formula a 1 inch non-metallic pipe with 60 degree water radiates about 600W per m2 of pipe surface area. ~ 600W for 12 lineal metres of pipe or 50W/m. Bare copper 1 inch pipe conducts heat into the surrounding air at about 75W/m. That is a total of 125W/m. White paint reduces radiation by >90% = 5W/m Heat loss from one inch insulated pipe = 10W/m Re: How to insulate cold water pipes to stop wasting cold water? 7Oct 08, 2009 10:08 pm spring_chicken This has been bugging me since we moved into our house 5 years ago! For about 20 metres, the cold water pipes run along the length of the outside of the Western wall, at around knee-height. This wall gets very very hot in summer. So in summer the pipe is heated by the sun, and the water inside is very hot - in fact, it is hotter than the water coming from the hot water tank!!! So to get water we have to run the cold water tap and waste about 15 seconds' worth of water. It's so hot that, on a summer's day, if I want cold water within about 5 minutes of the last time I opened the cold water tap, I have to run the cold water tap for another 15 seconds until the hot water runs out. It's a *huge* waste of water. There's no problem at all on cool or cold days. I was thinking of insulating the length of pipe that runs along the western wall . . . but have no idea if it's possible, or how to go about it, or what to use. I have seen pipe insulation at harware stores but it's all black or grey dense foam so it seems to me like it's designed to keep heat in the pipes. Is that sort of insulation also going to work to stop the baking sun from heating the water in my pipes? Any advice or suggestions gratefully received!!! Thanks in advance, everyone. You can fix the problem by preventing the sunlight from falling on the pipe. Try it first, just bend some cardboard and slip it over the pipe on a sunny day... run your tap until the water is cold, then wait 10 mins and run it again. When you are convinced, then get some aluminium angle and fit it like a shelf above the pipe. Or get some zinc anneal sheet bent into a "Z" shape to be even more effective. The pipe will then only reach the ambient temperature in the shade. Ed "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Re: How to insulate cold water pipes to stop wasting cold water? 8Dec 14, 2009 12:50 am spring_chicken So to get water we have to run the cold water tap and waste about 15 seconds' worth of water. It's so hot that, on a summer's day, if I want cold water within about 5 minutes of the last time I opened the cold water tap, I have to run the cold water tap for another 15 seconds until the hot water runs out. It's a *huge* waste of water. You could save water by catching that first 15 seconds of hot water in a jug, then leave it on the counter or stick it in the fridge, and next time you need water you won't need to run the tap. Built with Sw1tch H0mes >Build thread< House status 15/12: Gates and A/C finally installed! Sep 09 Bought block, Dec 09 Engaged builder, Jul '11 Moved in Re: How to insulate cold water pipes to stop wasting cold water? 9Dec 17, 2009 10:14 am I have the same problem of pipes running thru the roof without insulation. The cold water gets so hot it almost burns. Then the cold water comes through. Our 6m high Cathedral ceiling has 0 insulation, just plaster, wrap and tiles as far as I can tell. Wife likes the exposed beams, I hate the $600 per month heating bill,… 0 11762 Building Standards; Getting It Right! Thank you for the generous offer. I need to get the plumber out to give me an explanation. As mentioned I haven't seen any rain water discharge from pipes 1& 3. It… 7 10805 Depends how much direct sun it gets. Is there any shading (eaves or trees)? If the sun hits a window directly it doesn't matter too much if it's double or single… 1 12647 |