Kilowatt costs-whats yours?

[Hulk]

I've been curious 'bout the point of diminishing returns when it comes to insulation, also if/how that point "moves" with energy costs.
We've gone beyond the typically recommended R when adding to the places we can reach - attic/overhead and raised floors.
If we aren't "there" long enough to break even, perhaps the next occupants will get there...

Just looked up what is "U-value"
What’s the Difference Between U‑Value and R‑Value? (vitroglazings.com)
It's a good day then, learned somewhat...

[Bill Kielb]

3 hours ago, Hulk said:

've been curious 'bout the point of diminishing returns when it comes to insulation, also if/how that point "moves" with energy costs.
We've gone beyond the typically recommended R when adding to the places we can reach - attic/overhead and raised floors.
If we aren't "there" long enough to break even, perhaps the next occupants will get there...

Just looked up what is "U-value"

Since I do a bunch of this daily now, the break even will exist as time extends and is influenced by what exists and what is practical. So a big limiter in homes after everything is fairly insulated is glass or windows.  Even good windows are on the order of R-3, or a U value of 0.333 or so. Interestingly air sealing is really important as well but often difficult to do in existing homes.

On a positive note I have been able to install heat pump hot water heaters In the Midwest and save actual money on the utility bills gas vs. electric. First time I can remember - an annual savings now exists. So the new stuff is getting better.

[Mark C.]

I put in argon gas double panes in our new remodeled bedroom (fiberglass frames outside  wood interior )and you can tell the difference besides sun not warming the room thru glass-the room is more quiet and is better insulated . Yes they cost more but I felt well worth that cost.

[glazenerd]

Bill

My windows have LowE argon, with T38 bronze tinting- U factor 0.28. Bronze tinting is for solar gain deflection; but also for privacy. I can see you through the window, but you cannot see me. 

T

[Bill Kielb]

Definitely good windows, triple pane up to about r-5 in reality. Low e, definitely works! This is however still a long way from basic r19 wall framing.

Interestingly if you look at the developed R value of a window it varies significantly across the window pane mainly because of the thermal bridging so center of pane r values are often promoted. Installation requires proper planning in the flashing and counter flashing. The other thing that used to amaze me is traditionally the numbers between reflective and clear coatings were virtually identical when the intuitive expectation was significant improvement for the mirrored.

Still in the end framing requirements limit the performance of the units and they become very expensive on a per sf energy saved basis. Still way nice to have for sure especially in cold climates but eat into the budget quickly and often remain a relatively low r value component of the wall.

[glazenerd]

Bill- in 2005 lumber was cheap: so was insulation. I built with 2x6 walls. Huber came out with the Zip Wall system, including a very effective flashing tape. I had SIU-E run a use verses cost analysis for 19 seer heat pump vs ground source heat pump- it took over 20 years to recoup cost differences. Installed heat pump HW heaters in a couple of houses I built: effective by high maintenance.  I installed an extreme environment 88 gal (dual) electric HW in my house- 4" insulating jacket. So far maintenance free... I retired from home building in 2019: so I do not keep up with new products these days. 

T

[Hulk]

Our home is on a view lot, hence lots of big windows; the main room has four 4x6' along the northwest side. A previous owner had installed vinyl framed fancy film dual pane (perhaps 5/8" between sheets) noble filled retrofits throughout (excepting the second garage - my studio, which has early 80s metal frame dual pane).

We took down the clunky drapes to install "honeycomb" shades, which may bump up the R +1.8 or so, and seem to make a significant difference - raise the shade a few inches in the morning, feel the chill air running out through the gap; it's not, my opinion, just slowing the transfer of heat out the room (we don't need cooling, hardly ever...). The shades also create a dead air space between the window and the room. We mounted the shades so they sit flush with the wall, hence creating a larger dead air space.
Shades also cut down the noise quite a bit.

The master bath and kitchen are at opposite ends, which may be why the designer installed two water heaters. We replaced with one on demand heater with a return loop. Heh, "we" - the plumber did the work, ahem, however, they put foam sleeves on the most visible piping only. I crawled about to rectify that - double foam where room allows, else single, everywhere, even inside the walls. Initially, I'd neglected to cover the hot water piping in the utility closet where the northern end water heater had been. Later, on a winter morning (~40F), stepped into said closet (the door opens to the outside, mind), which was toasty warm! Oooh, time to finish up the hot water pipe insulation, wow. Wow, that hot water pipe radiant heating really works.

Any road, when we bought all the blinds, we figured it would take eighteen years to recoup the outlay, at the current rates. When we bought the on demand gas fired hot water heater, we figured it would take almost twenty years to break even, given the unit lasted that long. I didn't do any figuring on the attic and crawlspace (floor) insulation additions (the house is much quieter; the surf noise, in particular, is much reduced).

Back to pottery then.

[Bill Kielb]

20 hours ago, Hulk said:

The shades also create a dead air space between the window and the room. We mounted the shades so they sit flush with the wall, hence creating a larger dead air space.
Shades also cut down the noise quite a bit.

For excess solar gain, I have had decent economical results with good quality solar film. Although depending on the design of the old window units it may need to be installed on the exterior surface. For pure r value, trapped  air is a thing as well as reducing infiltration to a minimum is very important. 
The seasonally effective application of clear shrink able window plastic is very cost effective and fairly effective at trapping air and really reduces infiltration significantly. 

Way back in the day we had custom magnetic interior storms made up with replaceable desiccant sticks  made for the building below. It was way cheaper than replacing all the window units. Almost forgot about that one. It was extremely effective at the time.

 

[oldlady]

gosh, all this sounds wonderful as i sit here 2 feet from black saran wrap windows on this lovely porch.    thermometer inside is at exactly 60 F inside and my computer tells me it is 55 F outside.  it really is nice on ordinary days.   i even have a long "take a nap sofa" out here.  if the robocalls ever stop.

am wearing a cotton  turtleneck and heavy wool sweater and about to freeze so it is time to go inside and shut the doors.   inside, the original owner replaced the typical florida trailer windows,  thick glass jalousie, with aluminum framed double panes.   fortunately, the porch faces south so it heats up nicely when the sun shines.   when it goes above 85, the drapes keep the debilitating heat from the sun  off the porch enough that i do not have to hold my breath to walk outside.  (you can see why i never plan to move here permanently.)

and that is when i really appreciate the 3 huge trees for their shade.  

[Mark C.]

I installed i  new addition  to studio (early 2000s)  no solar gain filmed windows-the inside heat bounces back in and outside the sun relects heat out.(these where vinyl frames . I liked them so much I put them in new bedroom addition only not vinyl frames but fiberglass frames and added the argon gas to them.

Most of my old studio is single pane salvaged windows from the 60-70s. The studio is insulated well except fro the se old windows-I like them  very much as they add character to the old barn look.

Bill I added solar film to an outbuilding window a few years ago to keep it cool and its been great (one west facing window). My solar inverter is inside that outbuilding

a few other bonus things about the dark silver reflective film is less bird strikes and one cannot see in as well.

[Callie Beller Diesel]

There is a comfort factor to consider as well if you’re looking at upgrading your insulation, and the climate where you live. I don’t know the r value numbers off the top of my head of anything, but I do mind my heating bill, and I can say our usage has gone down with every upgrade we’ve made.

My house is a 1973 build, so I have 2x4 framing and old fibreglass insulation. When we first moved in, we added another 2 feet of cellulose to the attic, and when we refinanced our mortgage 3 years ago, we replaced the aluminum slider windows with double pane argon filled windows. The old bay window in the front of the house didn’t used to open, so we added some louvers. We also replaced the front and back doors with ones that fit properly, and had weather stripping that wasn’t crumbling. We insulated the basement, and that made a big difference too.

After we did the attic, the gas company replaced our meter thinking it was faulty because the heating bill went down so much. 

The windows and doors also made a noticeable difference on our fuel usage. Being able to create a proper cross draft in the summer with the front window being able to open now means we don’t need an air conditioner. No maintenance costs on that, no electricity to run it, no need to buy one in the first place.

Before we did all those upgrades, we spent many a winter with the heat shrink film over the windows while the wind rattled them all night. There’d be ice forming from condensation on the door sills that kept the screen door from being able to close when it got cold.  Now I’m sitting in my kitchen 3 feet from the door in my bare feet in February, warm as toast. And it’s -20 outside.