Insulating hot water pipes

Hello everyone,
Winter is just around the corner, and I'm trying to find a way to make my water heater perform better than it did last year.
First off, it seems a bit too small for my family (50 gallon for 4 people). However, in addition to that I have hot water pipes coming out of the heater to the bathroom and the kitchen, and I'd say there is at least 6-7 feet of bare copper pipes (before they enter the walls) in this first floor closet. The closet gets cold in winter. Not too much, but I think 60F degrees is probably what it stays at for couple of months. I wonder if it adds to our poor heater performance? Do you think water can loose much temperature going through 6-7 feet of copper pipes? What materials one uses to insulate the pipes? And, lastly, should the heater itself be wrapped into some sort of a thermal insulation blanket to improve its performance?
Thanks for all your feedback and ideas!
Cheers! D. -------------------------------------
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It depends.
Re size: depends on t-stat setting and timing/temp/flow-rate of showers. To better accomodate users: low-flow heads, shorter showers, lower temp at head, higher t-stat setting at heater.
Re insulation: my experience is that more is better, as far as you can go, especially in what might be uninsulated/unheated area. Copper is a great conductor. Insulation can greatly reduce temp drop at head between showers.
HTH, J
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Have you cleaned the tank? I flush mine every 6 months. Water here is hideous. Once you think the tank is flushed, then drain the tank and then remove the drain valve. It just screws out. Screw in a piece of 1/2 inch pipe with a 5/8 hose attached. Refill and check the hose end. I usually get some bigger chunk out this way. You will see what I mean when you pull the installed valve out.
Insulating the pipes is easy and pretty cheap. Benefit is ??? for 6-7 feet. Insulating the water heater might be a waste of time depending on the ambient temp of its location. If the heater is subject to outside temps then yes. It would help some. The top and upper 1/2 of the tank is all that is needed to be insulated. Careful if you have an gas heater.
You might consider raising the thermostats up 10-15 degrees. Them bumps on the outside of the tank are where they are located. Careful there is 240v inside there. I set my electric heaters, top element 5 degrees less than the bottom one.
Water heater work on temp rise. So the colder the incoming water the longer it takes to raise the water temp. Winter the ground is colder so the water takes longer to heat.
A long time ago I had a house with 5 people, and a 30 gallon water heater, gas. I limited the kids to 10 minutes and staggered them over a couple of hours. The youngest liked baths so he got 15 minutes. Actually he used less hot water than his siblings. I had the water heater set on max from the second day we lived in the place. I also installed a low flow shower head for the children. We always had to wait for the dinner dishes to run when wifey went to bed. I showered before bed and the wife was a morning person. It worked, and yes there were times when we just had to wait a few minutes.
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My family of four has done fine for 20 yrs without any problems so perhaps it's a use issue. The low-flow shower heads help as does a diverter on each of the sinks. This allows you to set your water temp on the faucts and then you flip a lever which stops the water flow right at the spigot. That way you don't have to let the water keep running while you shave or wash dishes, etc. I have found them hard to find of late, but it looks like an aerator with a 'U' shaped wire lever stick out the one side. I have seen them on specialty sites on-line.
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The water in the pipes will cool, but the heat it gives off help heat the closet. It is not a "loss", but used as part of the home heating.

No, not much t all.

Older heaters are helped a lot. Newer heaters have pretty good insulation.
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Edwin Pawlowski wrote:

Hi Edwin,
Thank you for the insight. My heater seems to be about 5 years old (I bought this house 1.5 years ago), and it has that yellow "Energy Facts" label, so I would guess it may already be a pretty efficient one. So, the verdict would be: it's just too small for the size of the family?
Cheers! D. -------------------------------------
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Edwin Pawlowski wrote:

Ed is exactly right -- but you might have an electric hot water heater and a 90% eff gas furnace so you want to heat with your furnace where practical.

You can figure this sort of question out. Let the ambient temperature be 60 degrees F, a hot water temperature of 130 degrees. That means you lose 48 Btu/ft-hr of 3/4" bare copper. 7 feet of pipe would be 336 Btu/hr. If you ran your hot water for 1 hour per day that would be 122724 Btu/yr or about as much energy as is in a gallon of gasoline per year tops (unless this section of pipe stays hot while you are not running the hot water at the tap).

You can buy special pipe insulation with a slit that fits nicely over the pipe -- but any insulating material will do. Just be sure that the insulation doesn't allow free air flow around the pipe.

An insulation blanket always helps -- but do a back-of-the-napkin calculation to determine if it is worth your time and it probably isn't on a gas heater.
Hope this helps, William
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On 7-Oct-2005, rcdd_at_teledatasystems_dot snipped-for-privacy@foo.com (DA) wrote:

If it's electric, that's probably small. If it's gas, it may be fine. Gas water heaters recover faster and can be sized smaller. YMMV.
Low-flow shower heads can help if everyone wants to take a shower around the same time.

If you want to improve the efficiency of the water heater, then you should insulate these pipes. More than that much would not be useful, as the heat from the water heater is lost in the first few feet of copper pipe. That will also reduce by a couple of seconds how long you wait for hot water when you turn on the tap.
You can get foam insulation specifically for water pipe at Home Depot or similar improvement stores. It's usually black with peel and stick adhesive. Usually 3 or 4 foot lengths and in several different inside diameters to match common copper pipe sizes.

That's debatable. The manufacturers and especially the energy suppliers say it's unnecessary. Some folks say that for gas heaters, it's dangersous if done wrong. However, It makes some sense that more insulation means keeping the heat in longer. Whether it's cost effective is another story.
Mike
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"If you want to improve the efficiency of the water heater, then you should insulate these pipes. More than that much would not be useful, as the heat from the water heater is lost in the first few feet of copper pipe. That will also reduce by a couple of seconds how long you wait for hot water
when you turn on the tap. "
So, the water is back to ambient temp after running through the first few feet of pipe? If that were the case, you'd never get hot water. And it isn't going to make hot water show up any faster, except in the case where it's reused within a reasonably short period, before it cools off again. But, for example, first thing in the morning, it's still going to take just about the same amount of time to get hot water with or without insulation.
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On 7-Oct-2005, snipped-for-privacy@optonline.net wrote:

No the water will return to ambient temp if it sits in the pipe for a while.

It will reduce by the amount of time taken to empty the pipe that has been insulated. That isn't great, but the amount of water wasted while folks wait for hot water represents a significant fraction of the total amount of water wasted in homes.
Mike
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In a short while, with no flow... 20' of 3/4" pipe with C = 3.8 lb of water and 4 ft^2 of surface might have a thermal conductance G = 1.5x4 = 6 Btu/h-F, so the time constant RC = C/G = 0.63 hours, ie the water would cool from 120 to about 70+(120-70)e^-1/0.63 = 80 F in 1 hour in a 70 F room.

True, if there were no flow :-)

The important energy savings and faster hot water might come because the water heater keeps the first few feet of pipe warm by warm water convection, even with no hot water usage. You might feel the pipe in the morning, before any usage, and keep insulating it until the end of the pipe emerging from the insulation no longer feels warm.
Nick
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One potential problem insulating a gas heater is blocking vents for exhaust or incoming air.
In the summer, you want to keep the heat in the heater and not waste it. in the winter, the heat is going into the room that is part of the house that you are heating anyway. It is not lost at all, but may not be the most cost effective way of heating your house.
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DA wrote:

It is not costing you much heat. Unless you use hot water through that pipe often, it is going to loose all the excess heat anyway, it might take a few hours rather than 10 minutes, but the end result will be the same. Don't feel too bad however as much of that heat will find it's way back into your home.

Only if it is a very old heater. All the ones made in recent years are insulated to start with. While additional insulation will help, it will not help that much. Again, that heat that it looses is lost into your home, so if you stop it, then your furnace will just need to take up the slack. During the summer the reverse is true the heat it gives off must be removed by the A/C costing your more then. Still not likely all that much.

--
Joseph Meehan

Dia duit
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you didn't mention if the WH is gas or electric. If electric, you may have one of the heating elements (there are two) that is failed or so mineral coated that it very inefficient. I've had a number of them where the top element is OK and the bottom one is dead, and for small consumption, you can't even tell there's a problem. Bill

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