adding insulation to steam boiler

TCR_2

You guys are no fun. You're like my plumber who refused to install the boiler until I put a clean-out door at the base of the chimney! 50 years without a way to remove the soot sure accumulated a lot of crud! Right up to the point where the stack entered the chimney!!! I've lived here three years and sure am glad I decided to replace the boiler. Yikes...

He was absolutely correct of course and safety is at the top of the list. He installed a probe LW cutoff and auto feeder in addtion to Peerless's standard float type cutoff. Hartford loop is done properly...

Dow Chemical makes a reflective product (Thermax, 4x8 sheets, 0.5"-2.0" thickness options) that has a max temp rating of 250*F. Because it "reflects" it works differently than regular insulation (ie, fur coats). If I build a three-sided box with an air gap next to the sheetmetal jacket it should keep a majority of the heat in the boiler, be easily removed for servicing, etc.

I'll see what Peerless has to say about the concept and let you know.

Thanks for your thoughts.

TCR_2

adding insulation to steam boiler

As you guys already know the site is excellent and without a doubt the best source for information. Thanks!!!

A great heating guy replaced my ancient steam boiler with an oil fired Peerless EC/ECT 3 section. He went with Peerless because the twin 2" steam outlets were the same size as the 2" main in my little bungalo houme (7 raditors, 54,000 sf radiation). My oil company tuned it up and said the Efficiency test at 86.25% which was better than some new HW boilers the tech has seen.

My question: has anyone added extra insulation "around" a new boiler? I was thinking of building a box of the 1" rigid panels with the reflective side facing in to the boiler. Peerless's insulation seems minimal and the boiler raditates a lot of heat the cold basement. I would probably only cover the back, sides, and top and leave the front basically open.

PS. Getting the plug out of the second steam opening on the boiler required laying it on its back and standing on a 6 ft. pipe added to the 4 ft. pipe wrench. They sure put those plugs in tight!!

Thanks.

Ken_40

I urge you...

to CAREFULLY unscrew the cabinet panels, look in the void between the block and the cabinet and determine how much 3 1/2" fiberglass insulation you could "pack" in the voids, without compressing the 3 1/2" into 2 or less (compressing the insulation will reduce the R-value, almost in direct proportion to the percentage from the "original" 3 1/2" R-11 would [roduce.

Get "unfaced" (pure 3 1/2" thick, no paper or foil on EITHER side) and carefgully place it where needed.

We have done this where the boiler room was already warm - before the boiler was ever fired and have reduced radiation by well over half. Be neat and carefully cut around piping holes, and take your time. The end result will be very effective.

A before, during and after picture would be great!

If you have to buy kraft paper insulation, simply peel off the paper. The tar like mastic they use to attach foil and/or paper facing to FG is flamable and smells when heated.

I hope I am correct when I assume both the supply and returns are all insulated already?

TCR_2

insulating new steam boiler

Ken,

I'll see if I can get a digital camera for the before and after. When we moved the boiler into the basement we took off everything but the front jacktet. I noticed there was not a lot of room for much more than the 1" of factory insulation. In some areas there was empty space so I will take your suggestion and fill those spaces carefully with unfaced insullation. Because I am an "ex-solar" guy who believes in insulation, I thought adding the reflective rigid foam around the boiler (with a 1" air gap between the insulation and the metal jacket of the boiler) would significantly reduce the heat loss and consequently speed up delivery of steam when the T Stat calls for heat.

To make a rough test of my idea I placed a 2' by 2' panel of 1/2" rigid reflective foam behind the back of the boiler and the back panel DOES stay significantly warmer longer.

The supply lines are insulated but the returns are not. I was thinking about insulating the return lines and will follow your suggestion and insulate them with fibreglas.

Feel free to post any other thoughts.

Thanks again...

TCR

Ken_40

I don't know...

Something about covering a steel, nicely painted boiler jacket with additional insulation on the outside, seems a bit like wearing shoes with rubbers on in the house. Can be done, but looks sort of dorky - and, to what end? If 2" is good, 4 more is better?

I think the look and insulation we are discussing will be more than adequate for your purposes. If for some reason, you still feel obliged to go further, knock yourself out.

FG insulation on the returns is a home run.

Stay in touch.

Christian Egli_2

Dress in layers, mothers say

Why bother wearing layer upon layer of marginally heat stopping clothes when just one layer of fur coat does the trick?

People nowadays no longer sport a mink coat and so they are forced into the politically correct layers of polyester, urethane, poly fill and nylon. Just not the same visual effect.

What I'm thinking of is to undress your boiler from it's fiberglass underwear and trade it in for a more beefy thermal insulation. Such things exist and are available from industrial furnace suppliers.

Options

Low density calcium silicate boards (the marinite and such); pearlite in bulk; vermiculite in bulk; rockwool; fiberfrax wool; cast in place insulting cement; paintable ceramic coatings; plaster even... the choices are endless.

I imagine furring the jacket on the inside with a layer of calcium silicate boards and then stuffing all the gaps with vermiculite would be something worth doing. You need to slow all the air movements already within the jacket, or else, it's not worth much to just pile layers of fiberglass on the outside of the boiler box. Then add external layers of fiberglass boards and such with thickest layers on the top panel.

I would stay away from any flammable material such as urethane foam in direct contact with the boiler jacket - because of the fire hazard.

Sometimes boilers loose their water while they keep on firing; everything can then get very hot and if the safety limit does not abort the whole thing, the boiler jacket itself will get cooking - possibly to the point of igniting a flammable plastic. I've seen such appliances with burnt and warped sheet metal jackets just because it all got very hot inside. Saving a bit of fuel is not worth burning down the home.

We go through a lot of the calcium silicate stuff, it's phenomenal, it's what protects the space shuttle on earth reentry. It's amazing, you can handle chunks of the material with bare hands while it is cake-baking hot: it is so good at stopping heat transfer, it doesn't let your fingers get burned.

That's now one heck of a customized boiler... check codes, insurances and manufacturers for approval.

I've always been intrigued by olden pictures of automobile drivers wearing the heaviest fur coats. Was it because no one had figured out to put a top on the car, or was it because everyone complained the coats were too hot to roll up the windows?