The "value of insulation"

Thought I would post this for the "non believers", "those in denial", but more importantly for those of you who I unfortunately see posting as living in a drafty "whatever", who think that more BTU's is the answer to all your heating woes. The last group can be helped, the first two are lost causes. Destined to forever live in the cold & complain about it. My apologies for the length of the post, details matter as I hope you will come to appreciate when you have time to digest this post & relate it to your own situation.

We finished a shop for a customer in Oct - Nov. Thought I would share with you some of the details of construction as well as the results in required heating of the building.

Size: 60'x40'x12' high walls. So 2400 sq ft of floor space & 28,880 cu ft of space in the structure.

Const type: concrete grade beam on concrete ribbon footing with 2" high density foam on inside face of grade beam.
: concrete slab on grade with 2" high density foam under entire floor.
: tubing in floor, 12 zones - 200 sq ft/zone.
: ext walls 2"x6"x16" O.C. 3/8" O.S.B. sheathing on exterior. Tyvek house wrap. Vinyl siding. R19 fiberglass. 6mil vapor barrier. 3/8" O.S.B.interior sheathing.
: Doors: one 16'x10' O.H. door, R20 foam core. Two 8'x10' O.H. doors, R20 foam core. Two man doors 36"x80", R20 foam core.
: Windows: Four 5'x5', R4.8 dual pane vinyl.
: Roof: 2"x4" engineered 4/12 pitch, high heel trusses 24" O.C. Fiberglass reinforced asphault shingles. 13" R50 blown in cellulose in attic.

There is nothing special about this type/method of construction, actually most of it is min code here. The customer let me know in advance that the budget was tight on this one, so nothing fancy please just good solid work. Christmas was coming soon & all that. As usual the devil is in the details. So here are some non minimum code details that matter.

On each plug, switch, fixture, etc in an insulated cavity I install a vapor barrier hat (standard code requirement here). On this job there were over 30 on both the interior face, exterior face, as well as the ceiling. When the walls are sheathed I foam them in so I gain back as much R value as possible. Having an R19 reduced to an R9 by installing a switch is not a loss I am willing to accept (you shouldn't either). We also foam all doors & windows as well as small gaps in the framing, no point trying to fit a 2" wide piece of 5 1/2" thick insulation in, easier & better to foam it. Also we NEVER twist, compact, pinch or otherwise force insulation in any cavity. It is called friction fit for a reason, it should always be 1/2" bigger than the space it is going into, no more no less. It is not called force it, crush it, shove it, kick it or I hate doing this so lets just get it in so I can do something else insulation. Vapor barrier deserves attention as well, we seals all penetrations/seams first with acoustic sealant then with const tape (red "tuck" tape here) helps keep the acoustical sealant out of electrical boxes etc. We never cover the vapor barrier until we are satisfied with the work. No half measures.

Long & short of it is after some (minor) attention to detail, we are satisfied with the quality of the job & the results they should yield. So job is done & we leave.

3 weeks later I receive a call from the customer about trouble he is having heating his shop. As I am driving out I have all sorts of hydronic problems racing through my head & I am preparing to try & trouble shoot them, turns out that those thoughts were a waste of my time, (it wasn't the hydronics at all).

The customer is already in the shop waiting for me to arrive, so I go in (I notice that it is cooler than I thought he would be keeping it) & I immediately think that OMG the high end mod/con boiler that I had recommended, install by the contractor I had recommended has failed (awful thought & remember hydronics were not the problem) so I ask what seems to be the problem? He points to a 750 watt electric heater he has running on the floor, smiles & states that he was able to keep the shop at 5-7 C (41-44.6 F) during the -30 -35 C (-22 -31 F) cold snap we had (it lasted 7 days). No other working source of heat in the shop, except for his daughters two bunnies 3-4lb each, that his wife had insisted that he rescue from a very hungry looking weasel.

So with the heat sources stated above he was able to achieve a 35-42 C (63-75.6 F) increase in temp (not bad at all).

Almost forgot: the trouble he said he was having heating his shop:, turned out to be that he could not justify to his wife installing a mod/con nat gas boiler in the new shop as he was sure the cost (electric) of operating the boiler, pumps, ZVs etc would exceed the cost of running the 750 watt electric heater.

On the upside he did get the OK from his wife to spend the 10K they had budgeted for the boiler & install on boy toys for his new shop.

Hope this helps some of you too see the "value of insulation". Not just how much you put in but how you put it in as well. Details matter.

No Fo: You are absolutely right, infiltration is in my opinion more important than R value. If you dont address infiltration successfully it really doesn't matter how much R value you put in as the great outdoors is coming in through all the cracks & forcing the owner to heat it to maintain some semblance of comfort (a losing battle for sure).

bigburner: agree the ROI is so much faster on proper insulation & methods, no way any heating system can compete with the speed of that ROI.

Birdman: there are some newer products on the market for chinking logs, these will expand to fill voids as the logs age, shrink, crack etc; they also have a higher R value than traditional chinking materials. Worth some www. time IMO. I will let you know if I stuble across them again. Try searching for expandable chinking. IIRC they were a foam based product that had a faux wood grain finish on them.

Greg H: ROFL, yes high output bunnies indeed. They were both black, maybe black haired bunnies hold more heat & release it after the sun is down. Maybe the daughter is feeding them high output lettuce. ;-)

Como: Yes below 10 btu/sq ft is doable even in my neck of the woods. The newer net zero homes are coming in around 5btu/sq ft. So yes the industry is improving. This structure has 2 windows & 1- 8x10 OH door in south wall. 1 window & 1 man door in east & west walls. North wall has 1- 8x10 OH door & 1- 16x10 OH door. Doors were manufactered 1.5 hrs away in Edmonton, commercial door BTW due to 10' height. About $220 more for the 8' door than the standard big box R5 door when you add the cost of the extra panel to get 10' high. (Very competitive industry). Gotta love the results that high density closed cell foam yields. Well worth it IMO. Lighter than you might imagine, 1 man could do the 8' door easily. Did the www. thing & you have them south of 49 as well. Joints between panels are double ship lap design with a neoprene seal on both laps (really tight) when you apply the standard amount of down pressure on the door with the door opener. I have never had an owner complain about the door upgrades I always suggest after they are in. They like it warm ;-) & realize with the ever increasing cost of fuel that they will save money for as long as they own it. Heating bills like this one dont hurt resale value either. I think the kids will make out like bandits this Christmas with that extra 10K. Maybe a toy for Mom & Dad too. BTW thickest door I have ever installed was a commercial R40 & you dont want to know how much that cost. Big mobile equipment repair shop 3 equipment repair bays (drive thru) 30'wide x 16'high doors (dozers come in with the blades on) & 1 wash bay. You dont open those with a 1/2 hp motor. :ahhh: They are warm & happy though, manager tells me he has paid for those doors plus the extra installation costs 5 times over with the money he has saved on gas bills. Thats in 5 years so 100% payback per year. Not bad at all. See it pays not to heat the great outdoors

Woodchip: agree 100% ; rubbish work is so easy to spot & costs the owner nothing but money in the long run.

Glad to see I got some members thinking long term comfort/cost rather than short term savings that really are not saved past the first few heating bills.

Just thought I would post an update for those that are interested:

We should be coming out of this cold snap here on thursday (according to the forecast), during the past 10 days we have been between -25C & -30C (-13F -22F).

So I took a trip out to my new "high output bunny" farmers shop this last weekend to see how the shop temps had been. Wondering what his comfort level was now that all the ooooo ahhhhh nice newness should have worn off.

He had setup thermometers in 5 locations in his shop, these had a daily high & low temp guage as well, that he was recording & resetting each day (I think he was trying to prove to his wife that he needed that mod/con nat gas boiler I had recommended) ;-) .

Unfortunately for him the shop had stayed between 5 - 8 C (41 - 46.4 F), during that 10 day stretch.

So I dont think a boiler is in his immediate future, at least not until his wife goes on holidays & leaves him at home (alone). Hard to sneek a boiler in without being seen. :lol: ESP when she is watching & knows full well what his intentions are

On the upside as I tried to point out to him (while he pined for the boiler she wouldnt let him have) the building is perfoming well & he should have a good long.....low cost relationship with it

Relationship with the wife may cool off considerably if he does sneek that boiler in though.


BTW Como he did hang onto the extra $$$$$ but for nefarious reasons. (He really wants that boiler). Maybe he should sneek in a small refrig unit to cool the building down first then say "see I told you, I need the boiler"!! ;-)

Just trying to plan ahead for the poor guy.

Como:

Wish I had a better knowledge of thermo dynamics so I could offer you an explanation (along with graphs & tables). To demonstrate, the physics involved. AFA thermo dynamics goes, in this situation I feel it is straight air to air conduction or the lack thereof, that is driving the equation. I feel that most of the energy in the building is not lost probably due to the much lower delta T's involved, as the building has no significant heat source. ie. it is closer to outside temp than it would be with an operating boiler in it.

AFA solar gain is concerned there should be some through the west window (maybe at this time of year) as well as the two windows in the south wall. Any sunlight would fall on the concrete floor thereby introducing other factors into the equation as well.

Building is very tight. Close to zero air infiltration. I had recommended a mech building air make up in conjunction with the mod/con nat gas boiler as I felt it could become a sauna so to speak with higher building temps due to the lack of air exchange with outside.

In short I feel that if he were to bring the boiler online & up to say the 60s for building temp there would be a far more significant heatloss as the pressure in the building would increase along with the temperature thereby driving the heat out of the building in any way it could. In the absense of that "driving force" most of the heat is retained. At least IMO. Maybe one of the engineers on the board can offer a more "enlightened" explanation.