installing foam insulation around heat pipes?

[Mr_Accord]

I'm going to be installing foam insulation around the main heating pipes coming from my oil fired hot water tank. My question is I have read on several websites which offer good instruction on how to properly do this and they mention that if you are using a gas powered water heater not to install the foam all the way to where the copper piping connects with the tank itself you should leave a few inch of bare pipe because it is close to the flute or exhaust pipe and that area gets hot and could be a fire hazard. As for an electric heater they say its alright but they don't mention anything about furnace oil heating tanks unless gas and oil are considered the same, but as for mine I don't have a flute just a direct connecting exhaust pipe that is also shared by my oil powered furnace and when running the area around the top of the water tank does get warm but not very hot. Should i install the foam all the way to the tank of leave a few inch bare?

Thanks

 

[SuperDave456]

I'd do more research if you have questions.

I have a gas water heater. My father has electric.
The electric water heater you can wrap with insulation to your heart's content. Nothing external gets hot enough.
Although you might want to leave access panels open so that you can service them.

On my Gas water heater things get HOT around the flu. There is some insulation on the pipes, but wrapping the heater in one of those insulated blankets would be difficult. You don't want to mess with the draft for the pilot light.

That pilot light is the only thing that you will want to consider.

Other than that if the pipes only get Warm then I would insulate as much as humanly possible. If the pipes did get hot I would look for some high temp tape, like the real aluminium duct tape, wrap the pipes with that then go over that with insulation.
The idea is to keep the heat in the pipe until it gets to its destination.

FYI, I live in Texas and have no idea how you guys survive up there.

 

[Al]

If the pipe you are insulating has water in it the water will conduct a lot of the heat away on the underside of the insulation. If there is no external heat source that actually heats the outside of the insulation I don't see how there could be a problem.

If you are concerned... a small amount of un-inslated pipe in the area won't affect things much. Especially if there is heat radiating on that part of pipe.

 

[duaneb9729]

just keep your foam 6 to 8" from the flu piping, or anything combustable for that matter.

 

[JustinH]

I don't see much benefit in insulating the copper pipes that come off the water heater.

The only benefit I would see is if your water heater is located in an area that is exposed to the elements. This is not common where I'm from. Water heaters are in the basement that is at least semi heated.

The blankets that go over the entire water heater are not recommended by any water tank manufacturer, as they are a fire hazard. Putting those foam wraps over the copper will be a fire hazard if you position the foam too close to the flue, or it slips down there somehow.

I also wonder if with condensation that will weaken the pipe or damage it somehow with the sleeve being on the pipe?

It seems like a good way to not save any money anyways. Its 10 degrees out here today, and the only difference in my water heater performance is it takes a few seconds longer to get hot water to the tap first thing in the morning. Would I save a few seconds worth of hot water by insulating those pipes?

I have a 10 year old 40 gallon gas water heater, it costs about $20 per month to run at the hot setting, plus whatever water runs.

I had noticeable difference this winter by putting in a $900 Ruud 80% furnace, that puts out half the BTU's as the old 1970's furnace. Much more efficient, and keeps the house warmer. The gas bills are about 45-50 percent what they were last year, and I keep the house at a higher temp.

 

[sciphi]

My apartment has an unheated basement. Wrapping the hot pipes as far as I could made a difference in how fast we got hot water into the shower, and to the kitchen sink. I was also able to turn down the temperature, and still have water that was plenty hot enough.

Keep in mind, that's in an otherwise unheated basement that's basically heated by the hot water heater flue. It's probably 40*F down there right now.

It made a difference for me. As anything, YMMV.

 

[Mr_Accord]

Alright thanks guys I think I will just leave a few inchs bare away from the exhaust pipe

 

[JHZR2]

Leave a few inches. I cut my insulation at an angle near the flue to help provide spacing.

Also make sure you have a ground line from inlet to outlet.

 

[JustinH]

Originally Posted By: JHZR2
Leave a few inches. I cut my insulation at an angle near the flue to help provide spacing.

Also make sure you have a ground line from inlet to outlet.


Do you mean to connect a ground from one water pipe to another one right at the water heater? What would the purpose of this be?

The cable company put a ground on one of my water inlets to ground their equipment, but I have never seen running the inlet to the outlet with a ground cable.