Insulate convector enclosure?

crash2009

The stairs up to the 3rd floor finally caved in.  We had been skipping tread 3 and 4 for some time.  The saws-all, and a 5 lb sledge, knocked them down quite quickly.



On the up-side I finally got to see the backside of a convector, and I am looking for some insulating ideas.  Anybody ever insulate one of those?  I was also planning to insulate the runout to the convector and the riser to the 3rd floor.

Brad White

When you say

insulate the enclosure, do you mean the back side to reduce the back-loss?

I have to imagine so.



Also that offset riser looks like asbestos and I would be 99% certain it is, if concealed for long enough for the stairs to collapse around it. Is it still accessible?



I would also suggest that you be sure the piping is not leaking- there is not a lot that will make an interior stair rot and collapse except moisture and what more likely source than a pipe leak?

crash2009

Just 16 screws and I am back in

1-Yes, I wanted to insulate the enclosure to prevent back-loss.  It seems that the back-loss, and or that poorly insulated riser are over-heating the stairway area.  I don't know exactly what temp that area is but it kinda feels like near 80.

2-Yes accessable, I built the stairs with removeable riser and step so I can get back in there.

3a-Leak, The shower above the stair leaked and caused the stair to warp and collapse.  It has remained dry since repairing the shower leak. 

3b-Re- possible steam leak, Wouldn't the understair have been humid if there was a steam leak? Shouldn't I have felt wet wood when I did the demo? 

3c-I have repacked 8 valve stems, and 3 radiator unions this winter.  Sight-glass reports that I am leak free at present.

Brad White

All good

and understood. You probably do not have a steam leak for the reasons you stated. Sounds like you have a plan.

crash2009

Yes, I have somewhat of a plan

I just needed to know what kind of rigid insulation I should use on the back of the enclosure.

Brad White

Given

steam temperatures, I would shy away from the foam types unless you can get at least a half-inch of air space AND the insulation is faced with foil. This distance applies to the heated element. If the enclosure has a sheet metal backing, foam is fine.



If direct contact with the element is unavoidable,  use rigid fiberglass board insulation. You may have to call a local mechanical contractor and pick up a piece as scrap. Get enough thickness to fill the plane.

crash2009

I was hoping

 to have a little space between the convector itself and the back of the enclosure.  I just went up and checked.  The convector fins are tight against the back wall of the enclosure.  So I guess the sheet of 2" plain foam that I have in stock is out of the question.  I will have to go down to the mechanical insulation supplier and get something for high temp.  Thanks Brad, 

Brad White

Another thought or two.

Do I assume correctly that the convector is on an interior wall abutting the staircase? In other words, the bathroom backs on the staircase?

If so, why not insulate the stud bays with low pressure foam? Or is the recess the full depth of the studs? I think that is more likely.



I would expect the finned element to be tight to the enclosure, this is to prevent air bypass around the element. If it is just a bit of back loss you are seeking, half-inch Armaflex sheeting above the element would do a lot of what you are asking. Just keep the insulation about an inch above the element and carry it up and into the top.



In the scheme of things, the amount of back-loss to an interior space is not so great, especially with the sheet metal cover and a fractional air space to the wall finish. On an outside wall the losses are much greater.

crash2009

see pic 2 above

interior wall abutting the staircase?  Yes

recess the full depth of the studs?  Yes

see pic 2 above, I have drawn on it in red.  This is the backside of the convector housing.  I was thinking about just cutting a piece of rigid insulation, 2" R10-R15 and fastening it to the wall studs that surround the enclosure.  I have to go under the stairs anyway to insulate the riser to 3rd floor and the runout to the convector.  Yes this is an inside wall, but the amount of heat that radiates from the back of the convector and the 3rd floor riser is too much for the small space of the stairwell and the 3rd floor hall.  It is so geat that it is melting the snow off the roof. 



Maybe most of the excess heat is coming off the 3rd floor riser, and not the back of the convector.  This riser is 1st from the boiler then straight up.

Brad White

Nice building

Where is it located?

Thanks for clarifying.

I can see a need for roof insulation to avoid those ice dams. My optimistic side says that the heat would be welcome if the stair well were exterior, but obviously my wishes are easily and appropriately trumped by your experience -you live with it, I do not!



Can you fur-out the wall by an inch to get an overall layer of insulation along that surface? Just a half-inch of polyiso board and gyp board as a fire barrier cover. One thought.

Dave in QCA

Nice Job on the Stairs!

Looks like you have work on all fronts!  It is looking good and a wonderful old brick house!

Regarding the insulation, Like Brad said, I would focus on getting that steam pipe insulated well.  As far as the back of the convector, I am very squeemish with most of the foam board products.  Many of them have the warning right on the product, that to meet building codes for fire resistance, the product must be covered compeltely with a layer of sheetrock.  That tells me that the stuff will burn like heck, and I prefer to not put it in my home.  Probably best choice is that fiberglass board.  Of course, you could add an extension to the 2x frame that surrounds that convector, and put in fiberglass batts.  If you can find the fiberglass boards, that would be the quickest!



I imagine that you have continued to enjoy the propert operation of your boiler after getting the new gas line in.  How has it been going on that front?

crash2009

Dave

Its been going pretty good with the new gas line.  Had to put in a vaporstat to offset the oversized boiler, Mike told me to turn down the anticipator from 1.2 to 1.0.  You know the routine, first you don't have enough, then you got too much.  I am new at this stuff.  Takes time to iron out the wrinkles. 

From the look of the ice-dam, I am getting too much heat to the upper S/E corner.  The rest of the house is same as the t-stat top to bottom.  I think I will also pull the Danfoss TRV out of that upper corner, and adjust it so the tenant is unable to get 85 F, in his room.  That likely is part of the problem too.  I seem to remember the Danfoss info said something about installing a tamper proof limiter.  So for now I'll insulate under the stairs, and lower the Danfoss, and slow the venting, then hopefully next winter I get a "Its too cold in here"  complaint from that upper room.  

Mike Kusiak_2

Anticipator setting

Have you noticed any difference in the length of the thermostat cycles since you reduced the anticipator setting? I believe your gas valve only draws 0.4 Amp, so you may be able to reduce the setting a bit more if you haven't any change in cycle length.



Do you have any foil faced fiberglass insulation that they use for insulating HVAC ducts? You might try that for insulating the back of the convector. I have a roll of it and find it comes in handy for all sorts of uses.

crash2009

Mike

When the anticipator was at 1.2, the off times were about twice as long as the on times.  20 ON, 40 OFF, 20 ON.  We haven't had the same weather as in early February, but if I had to approximate, I would say, the boiler is on a bit less and off a bit more, something like 18 ON, 42 OFF, 18 ON. 

What are you using to record your on and off times?  I have noticed your charts from time to time, and thought "what a great idea" and "what a great time and ink saver"

crash2009

Thanks,

 the other side of the house looks a bit better.  We are in Ann Arbor Mi 48104.  I might throw in a suspended ceiling over those stairs to cut down on heat loss.  That area of the home is really a sows ear.  It should be torn down and done right, but for now the roof is not leaking, so it stays as it is for now.



I think you have come up with something that will work.  I could fasten a piece of 5/8 drywall to the back of the enclosure, then use any kind of rigid foam.  I have some fire-rock left over from the boiler room ceiling job.

Mike Kusiak_2

Lascar thermocouple datalogger...

Is what I have been using. Has a thermocouple temperature probe which can be inserted into the flue pipe. The increase in temp shows when the boiler is firing.



This is the same logger that JPF321 uses for his measurements. You just plug it into the USB port of your computer to download the data, and the included software generates the graphs. Works great for monitoring firing times and you can zoom in and expand any portion of the graph for detailed timing info. 



http://www.testequipmentdepot.com/lascar/dataloggers/elusbtc.htm

Steve_175

Use the foam

you have. Rip some strips of wood to build out the existing frame work to hold the foam off the back of the convector. I would make the strips 1/2-3/4" thick X the width of the exposed framing. Tape the foam to the new strips with aluminum tape like they use on boiler ducts.

Brad White

It is a gem

I am guessing it was built between 1890 and 1900, 1892-93 as a finer guess. How did I do? A keeper for sure.

crash2009

Wow! you know your architecture

  The city building department has it pegged at 1894.  What details gave away the age? 

Brad White

Dang! Off by one year?

Well, OK, I do have a fair eye for architecture, thanks!



The house I grew up in had similar details and was built in 1892. It was a Chateau style with what I called "Rapunzel turrets" and lots of nooks to hide in with a book.  Houses up and down my street (Beacon Street in Brookline, MA), dated from the same period. Bays, corbels, keystone lintels, the use of local stone and certain brick colors.



The porch spindles and brackets are also of that period, late Victorian, Eastlake with some English manor touches. Also the plaster and lath back-side looked familiar.

crash2009

When I was under the stairs

 taking pictures, I was surprised to see that the bathroom wall was constructed with metal lathe.  The rest of the house is wood lathe.  Was it common to use metal lathe in the bathroom in 1894 or do you think they were added in more recent years?

Dave in QCA

Steam heat, cast iron radiators, and the love of Historic Architecture!

Brad, I am impressed too!  I thought I was the only a architecture nut on here!  I love the ingenuity that was used to very inventively create something that was new at its time, and truly astounding.  The same thing for architecture applies to steam heat.  They were cranking out one invention after another, from steam traps, to sub-atmospheric vapor at 160F.   WOW! 



I think it would be really nice, if folks who post their boiler projects would also post pictures of the outside of the building.  It makes it all the more interesting!



Here is a great link that might be interesting.  It is a photo series of houses designed by George F. Barber, of Knoxville, TN.  He pioneered the mail order architecture business.  http://www.flickr.com/photos/11769785@N05/show/with/3966098907/ 

click on "show Info"  and it will give information about the building, etc. as the slide show plays.

There are a couple of nice shots of American Radiator, Rococo pattern.

Enjoy!

Dave in QCA

Later.....

Crash, the metal lathe is a later remodel project.  They didn't have convectors in 1894 either.  Is your ceramic wall tile old, or a recent project.  I would guess that there was a major bathroom remodel, and they used the metal lath at that time.  My guess on that would be the 1930s or 1940s, although it could be earlier.

crash2009

I suspected

 the metal lathe would be more recent.  Thanks for the confirmation.  It looks pretty old.  I suppose I could date it from the design of the toilet which appears to be the same age as the tile.

No convectors in 1894 huh.  The runout to the convector looks like an add-on.  I can imagine the sales man saying "from now on this will be the warmest room in the house". 

I was just looking at the photo-link you sent, so far the Greenman is my favorite.  I sure would not want to be the painter.  I watched a friend of mine paint one of those old beauty's.  Stripper, neutralizer, primer-bondo-primer, then sand and paint.  He will be working on it again this summer.  Restoration is very time consuming.

crash2009

Thanks Brad, Dave, Steve, Mike.

It just occured to me that I left this thread as a loose end.  I try not to do that but it looks like I forgot to thank you guys for your assistance.  Thank-you!  As it turned out, my little insulation project turned into a month long renovation, next thing I knew it was spring, and it was time to go fishing. 



Any way, once I got under there, and was asessing the situation, I realized that the ceiling tiles in the first floor kitchen were the only thing separating the kitchen from under those stairs.  My insulation prioritys quickly changed to fire safety.  If there had ever been a fire in the kitchen, the flames would have lit this whole house up, right through the middle.  So, I ended up building a fire break under there.  Then insulated the steam line.  I didn't do anything at all to the back of the convector cabinate.  While I was at all that I decided to cleanup that whole section of the house from the bottom of the second floor stairs to the end of the third floor hall.  I will throw in some carpet in there once I know for sure the leak is not coming back.  I might have to replace the third floor shower.



The fire break has created a posative impact (so far) on the heating chemistry of the home.  The overheating of the third floor has been reduced, the first floor is warmer now, and the southwest corner of the bomb shelter is warmer too. 

Dave in QCA

thanks for the update

Thanks for the update and refreshing my memory of a conversation a while back