Pop the wall open to insulate the steam pipe or not?

agurkas

As pipe insulation is coming in, I am replacing the old 1/2" stuff with 1 1/12" and infrared camera is putting a smile on my face. You can barely see insulated pipes while 1/2" stuff is baboon butt red.

That all said, in some area, since I am working on redoing those rooms, I have no problem opening up the wall a bit by the pipes going up to 2nd floor. Big question is: worth the trouble to insulate those pipes or not?

Really hoping that as I replace the insulation at least on the exposed pipes, the steam will finally dry up and I will no longer see spitting vents by the rads.

JStar

It only makes sense for pipes in outside walls. If they are in interior walls, the lost heat is usable.

Mark N

Agurkas, dry steam is produced right at the boiler. It is the moisture content of the steam, should be no more than 2%. Are you seeing the boiler water level dropping quickly because the steam leaving the boiler is pulling water with it? The header should remove this water from the steam. The rad vents may be spitting because the rads are being vented to quickly, the steam entering doesn't allow the water to drain. The rad is pitched wrong, or the rad valve is not opened completely. The condensate from the steam condensing in the mains should be going down either the dry return or the wet return. From what I remember your boiler is oversized. The increase in the velocity of the steam because of this might be causing the spitting.

vaporvac

It is also possible that those interior lines were insulated when the house was built unless the system was put in later.

agurkas

vaporvac, house was built in 30s and added on to in 50s.They definitely were not thinking insulation.

vaporvac

Hmmm. OK. MY house was built in 1914 and ALL steam piping including runs and returns and interior wall piping was insulated. It's plaster on brick so no insulation there, but the pipes themselves were completely covered. However, I'm sure you seen inside your own walls, but I just thought to throw it out there..

I also wanted to know if you had tried the IR with oft suggested 1" insulation. I have'nt ordered mine yet and am torn which was to go given the $$$ difference.

agurkas

vaporvac,

Capes were built without common standard. There isn't much consistency. What you find in one, you won't in another. You could have two houses built in the same year, same style, same town, and it would have very different materials/techniques used.

The Seek Thermal camera has been great. Considering Home Depot wants for 3-day rental of lesser resolution FLIR same as buying Seek Thermal, I chose to buy. As you can see in the picture below, I got a lot of work to do in the basement.

P.S. Spend the $ on 1 1/2" stuff. There are two online places that sell it. One is about 25% cheaper than the popular one here.

ChrisJ

What prices did you get on 1 1/2" vs 1" thick at the other place? At buyinsulationproducts.com 1 1/2" is about twice the cost and I feel a lot of the heat lost via the piping ends up in the home in most situations anyway so I can't see ever getting a return on that.

agurkas

We can't discuss prices here. Compare buyinsultation folks and expressinsulation.com. There are members here who bought from both of those places.

I got a complex spreadsheet from one of the members here, where I plugged in heating days, per therm costs (which in New England are averaging $1.5 in the winter), and couple other variables. In the end 1 1/2" was a no brainer. 1" was just not good enough of ROI and not worth it.
Remember, that you are also going to spend considerable time putting up all that insulation. Better yet, instead of spending all that money on elbows and Ts, learn the mitering technique (Youtube has videos), and saved material costs will also look and perform better. I got the hang of it after 3rd elbow.

ChrisJ

I may be mistaken, but we are not suppose to discuss pricing regarding having work done or prices given by different contractors etc. I don't think Mr Holohan or anyone else has ever had a problem with discussing prices of materials available from different retailers.

agurkas

Expressinsulation runs about 25% cheaper, with shipping included, at least for the quantity of stuff I got. I did scour Ebay and ended up getting a good deal on insulation for my 1" pipes. For the other sizes I am getting the stuff from Expressinsulation people.

KC_Jones

Thanks for the tip I will be buying insulation early next year (tax return money) I will have to take a look at the expressinsulation. And I THINK Chris is correct if it's just pricing of online retailers I don't think that is a problem. Labor costs for contractors is what is primarily banned. My best understanding anyway.

David Nadle

Shipping is a huge component of insulation cost. If you can find a local supplier and pick it up yourself it might be worth it. One of the big online suppliers is in West Paterson, NJ, but I forget which one.

Agurkas, I know you played around with that spreadsheet but the whole point of it was to demonstrate that the choice between 1" and 1.5" was anything but a "no-brainer."

agurkas

David,
Definitely not a no-brainer. But with per therm cost going steady at $1.5 per and my yet to be wrong financial advisor pegging the price to go hire, because fraking is becoming less and less welcome (he has clients, who make money off those land leases), it is safe bet to assume we are going to be seeing $2+ per therm. So extra $100-$200 gets you ROI much much sooner than one might think.

ChrisJ

I still feel a lot of the heat lost ends up in the home anyway. It has to.

Bob Bona_4

I hear you Chris J, but it's a race to get the steam to the rads before condensation. Don't want that happening on the way to them.

David Nadle

I think insulating steam mains is not primarily about ROI or even efficiency. In many cases it's about preventing water hammer. ChrisJ is right, you can't consider heat lost to a conditioned basement as a total loss. Insulating can also help keep a conditioned basement from getting too warm.

The relative or marginal utility of pipe insulation is not dependent on operating hours or fuel costs. If a bare 2" pipe loses 168 Btu/ft-hr and a 1" insulated pipe loses 23 Btu/ft-hr, you can say the 1" insulation has a utility of 145 Btu/ft-hr. But a 1.5" insulated pipe loses 18 Btu/ft-hr. So the marginal utility of 1.5" insulation is just 5 Btu/ft-hr or 3.4% better than 1".

In other words, by choosing 1.5" insulation over 1" you are paying about 1.7x the cost for 3.4% more performance. The caveat is that installation labor is the same, and when you factor that in the difference in total cost between installing 1.5" and 1" may not matter much to you.

agurkas

David,
I would love to see you create a post about this. Cliff notes version for us mere mortal homeowners.
Even for a guy like me, who is constantly in spreadsheets, what you had was heck of a complex thing without a primer on how to think about it.

And yes, I was looking through how long it would take to install AND another variable of it being easier to miter and cut scoop out some insulation to accommodate the elbows and Ts, if you have more material to work with. In a way I do wish I spent bit more and got 2" stuff. It is not that huge of a difference even for 2900 sq ft house.

P.S. I have uninsulated basement and I don't plan to finish it anytime soon (really don't want my taxes to go up), so insulating the pipes is important in my case.

David Nadle

I think my last comment is the "Cliff notes" version. Why you would consider 2" pipe insulation at 2% marginal utility and not be putting the money into air sealing and insulating your rim joist instead is perplexing.

agurkas

David, air sealing and insulating rim joist is covered by our Nstar in our state. I am getting that done in about two weeks. My total cost: $600 :-) That includes all new attic insulation, air sealing all over the house, and longish list of other stuff.

Re. 1" vs 1.5" vs 2". Even if it is marginal, I live in a town that is bit obsessed with energy conservation. I know there is grandfathering in play, but you know those inspectors. Easier to tell them to scram with 1.5" stuff.

Maybe when I do siding on my house, I may go super-insulation route. There is a utility program for that too.

TheRooster

I am just going to chime in here with my 2¢..

I am also just a mere homeowner but I also chose to go with the 1.5" insulation. I did it not because of the extra R value, but because I could use the mitering technique and still have about an inch of insulation at the T's and elbows.

Granted, I could have saved money if I went for the 1" insulation but I would either have to buy all the fiberglass joint covers or just use rock insulation and ASB tape (which would look horrible). For me, it made sense, I am about 3/4 the way through the insulation job and it really looks great.

Also, about the steam condensation in the pipes..
Before the insulation, I never witnessed my boiler building any pressure. Now that the pipes are only partially insulated, I actually have seen my 3psi gauge finally climb to the 1.25psi mark. This tells me that the system is filled with steam (plus some extra for pressure) and the steam is not condensing faster than steam can be produced.

agurkas

TheRooster, you explained my point so much more eloquently!

ChrisJ

@TheRooster‌

I heat my house currently with around 1/4 of an ounce of steam pressure. Not sure why you would interpret pressure climbing to more than a pound as a good thing? I removed my 3 PSI gauge as it was useless but may install it with a valve just to test my Pressuretrol yearly to make sure it still works as a safety device. At 4 ounces my system gets forced into hold mode for 10 minutes to allow steam to condense and the radiators to cool a little as this only happens when all vents are shut and radiators are full.

I'm currently in the process of finishing insulating my returns. Dry returns are done but I want to do something with the wet return.

ChrisJ

Forgot to mention, I do like the mitering idea.

agurkas

Ever since I saw pictures of properly done insulation with mitering technique, I could not bring myself to do those PVC elbows. It is more work, but results are well worth it. And it did not take that long to get at least half-decent at it. Though I am sure pros can get it done at 10X the speed with 100X less cursing :-)

ChrisJ

When I insulated my piping in the crawl spaces, especially the tight crawlspace that I barely fit in I didn't do any cursing but I did do a lot of laying there feeling sorry for my self and pondering the universe.

This is a before and after of the worst crawl space though I still have not done the elbows yet. That may not look that tight but in all honesty I'm fat, and for me it's tight. The before picture everything is soaked because someone had drilled an 1/8" hole in it to drain condensate as it was pitched wrong. Lovely conditions to work in not to mention the bag of lime that was in the way. We all know how great lime is to roll in when you're all wet.

David Nadle

ChrisJ, the before/after picture was superfluous. You painted quite a word picture!

agurkas

So I went outside to scope out how visible on IR camera are the steam pipes. Well, those on the exterior wall cause at least 6 degree difference in surface of the siding. And that is with 40 degree weather outside. So I have my answer what I need to do with three branches. Fortunately I was planning to pop those walls open anyway to re-run some electrical.

agurkas

David Nadle said:

The relative or marginal utility of pipe insulation is not dependent on operating hours or fuel costs. If a bare 2" pipe loses 168 Btu/ft-hr and a 1" insulated pipe loses 23 Btu/ft-hr, you can say the 1" insulation has a utility of 145 Btu/ft-hr. But a 1.5" insulated pipe loses 18 Btu/ft-hr. So the marginal utility of 1.5" insulation is just 5 Btu/ft-hr or 3.4% better than 1".

In other words, by choosing 1.5" insulation over 1" you are paying about 1.7x the cost for 3.4% more performance. The caveat is that installation labor is the same, and when you factor that in the difference in total cost between installing 1.5" and 1" may not matter much to you.

So if I am calculating right, at the historically typical $1.5 per therm cost of gas, each foot of 2" bare pipe costs 1 cent per foot each day heating day and 30 cents per average month. But considering in my place 2" mains are bit under 100 feet, so that is ~$30 per month.
At 1.5" we are looking at that number dropping to ~$3
So at ~$9.30 per section we are looking at rough ROI of roughly one year.
For argument sake we were planning to do work ourselves anyway and our hour is $0.

TheRooster

ChrisJ said:

I heat my house currently with around 1/4 of an ounce of steam pressure. Not sure why you would interpret pressure climbing to more than a pound as a good thing?

Right now my 3psi gauge only climbs when the system is full of steam, the needle doesn't move off the pin for the first 20min of the cycle.

What I was trying to say was, before insulating, the gauge barely moved which I interpreted as a leak in the system. If all the main and rad vents are closed, pressure has to build, makes sense right? So what I was actually seeing the whole time was the steam condensing faster than the boiler could make steam. I think Dan said in his book that steam takes 1700 times more space than water, so condensate must be 1700 times smaller than steam, right?

I don't have a vaporstat to cut the burner before it gets above 1psi but maybe next years project, who knows. What I do know now is that the pressuretrol will cut off the burner where before my boiler would just run and run until the thermostat was satisfied. Less burner time = less oil = money in my pocket. So that's why I viewed climbing pressure as a good thing

TheRooster

ChrisJ said:

When I insulated my piping in the crawl spaces, especially the tight crawlspace that I barely fit in I didn't do any cursing but I did do a lot of laying there feeling sorry for my self and pondering the universe.

This is a before and after of the worst crawl space though I still have not done the elbows yet. That may not look that tight but in all honesty I'm fat, and for me it's tight. The before picture everything is soaked because someone had drilled an 1/8" hole in it to drain condensate as it was pitched wrong. Lovely conditions to work in not to mention the bag of lime that was in the way. We all know how great lime is to roll in when you're all wet.

This is probably the funniest thing I read in a long time. Back in my days as an electricians apprentice, I spent many hours pondering the universe in crawl spaces.

KC_Jones

ChrisJ said:

When I insulated my piping in the crawl spaces, especially the tight crawlspace that I barely fit in I didn't do any cursing but I did do a lot of laying there feeling sorry for my self and pondering the universe.

My spot was always laying on my back under my '72 Ford, still is actually. Why am I here, what does it all mean....why do I like old cars again? lol

agurkas

After insulating at least 2/3 of my mains, I am totally happy with decision to spend on 1.5" insulation vs 1". Having extra "meat" in the insulation for all those Ts, elbows, and unions has been invaluable. Coarsely sharpened steak knife - best tool for the job.

That all said, near boiler insulation work, if you had plumber use lots of unions, elbows, reducers, etc all in tight space - that is what separates us DYIers from pros. Ugh.

ChrisJ

agurkas said:

After insulating at least 2/3 of my mains, I am totally happy with decision to spend on 1.5" insulation vs 1". Having extra "meat" in the insulation for all those Ts, elbows, and unions has been invaluable. Coarsely sharpened steak knife - best tool for the job.

That all said, near boiler insulation work, if you had plumber use lots of unions, elbows, reducers, etc all in tight space - that is what separates us DYIers from pros. Ugh.

You had someone do your piping for you?

agurkas

You know what I meant. And coffee has not kicked in yet, so I get a pass on this one.

ChrisJ

I tried to give you an LOL and an agree on that, but you can only have one I guess.

agurkas

Vents not spitting water. Now that alone was worth a facefull of spiderwebs for several hours while installing the insulation. Radiators also felt much hotter for some reason.

ChrisJ

Hotter would indicate increased pressure which is not necessarily a good thing.

However I don't know what is worse, losing excessive heat into an unconditioned space or running higher pressure.

Mad Dog_2

I've found that Insulation to a steam system is the cherry on a sundae. In and of itself, it not going it's not going to make dry steam and will often not compensate for underfired burners, undersized and oversized piping. After, I get everything squared away with a problem, then, and only then will I reinsulate. Mad Dog

agurkas

Mad Dog, spitting valves main is about 100 feet plus 2 rads on 1st and 3 on 2nd floor. Keeping that steam from condensing before getting to the rads was my huge headache. Half inch crumbling insulation and naked elbows and Ts in vented crawlspace, where majority of that main went - atrocious waste of energy.

Jeff_H

I am in the process of insulating my steam pipes (I'm going to go with either 1" or 1.5" thickness and most of the pipes I need to insulate are 2" pipes). I tried looking for videos explaining the mitering technique for elbows (and there is something similar for tees), but could not find anything. Would someone be able to share a link?

Thanks!