insulating my hotwater pipes

[Rafael]

Hey all,

My tankless water heater is in a crawl space that gets pretty cold during the winter (we're in San Francisco, so that means the 40s, but sometimes it can get into the 30s). Since they're pretty long, I thought it made sense to insulate them.

I found what appear to be pretty good instructions online at:

http://www.leaningpinesoftware.com/hot_water_pipes.shtml

The author has convinced me that the foam pipe insulation is the way to go, and that it's worth the cost of going with the thicker product to get as much R value as I can.

My only question is how to deal with the multiple sizes of piping I have. The piping seems to have multiple branches and multiple sizes. Can anyone tell what sizes I have, based on the following pictures? Also, can anyone tell me if the various markings on the piping are normal? I'm a first-time home owner and still have a lot to learn.

Any guidance would be much appreciated.

Raf

 

[Terry]

1/2" pipe with be 5/8"
3/4" pipe will be 7/8"

Insulation is normally bought for the OD of the pipe.
Your pipes won't freeze in the crawl space there, but you will have more hot water.

 

[Sponsor]

 

[Tom Sawyer]

Yes, rule of thumb is that for copper pipe add 1/8 to the nominal size.

1/2"=5/8"
3/4"=7/8"
1"- 1-1/8" and so on

 

[Rafael]

Thanks to both of you for the quick replies. I'm such a newbie that I'm not even sure if the pipes I have are 1/2 inch or 3/4 inch (or both). Looking at the pictures, can anyone tell?

 

[hj]

The larger pipes are 3/4" and the small ones are 1/2".

 

[Geniescience]

space is big; use Larger Amounts of Insulation !

You have lots of space that no-one else has, so use it.

Go ahead and buy the tube surround thingies if you wish.

Then add more of Anything that will trap air and also be airtight on the surface. Your goal is to prevent the kind of air movement that is invisible and imperceptible to you. Here is an Example: wrap fiberglas batts and then large sheets of plastic. Here is another Example: expanding foam.

But, think not of any specific product. Think of trapping air.

 

[Rafael]

space is big; use Larger Amounts of Insulation !

You have lots of space that no-one else has, so use it.

Go ahead and buy the tube surround thingies if you wish.

Then add more of Anything that will trap air and also be airtight on the surface. Your goal is to prevent the kind of air movement that is invisible and imperceptible to you. Here is an Example: wrap fiberglas batts and then large sheets of plastic. Here is another Example: expanding foam.

But, think not of any specific product. Think of trapping air.

Did you intend to put links in your post? I'm very interested in preventing the kind of air movement you mention, but I don't see either of the examples you refer to.

 

[Geniescience]

Know principles.

If I get too specific about principles to learn about, you or anyone else could feel that I'm talking down to you.

Here we go: Go to wikipedia and read a lot about "heat transfer"

No links to products. It's not a product that you want. It's an understanding of a concept. Focus not on the thing to buy, but on the method that will make ANY reasonable material (even something free from your garbage bin) into a great insulator.

http://en.wikipedia.org/wiki/Insulation

http://en.wikipedia.org/wiki/Heat_transfer

Since you have many inches of free space, use it In Any Way to Trap Air so that it is trapped in small bubbles and does not move. Another E.g. bubble wrap. If you used a filter material like fiberglas batts, you have to enclose it with an air barrier like a sheet of plastic (or several).

I hope you do not expect a recommendation of a specific kind of batt or foam. That is not helpful.

Any Product will do, if you ensure that air is trapped and does not move through it.

There is no shortage of people who will point you to A Single One Product.
I'm being far far more helpful to you.