Category Archives: green

“When we do complex roofs in high snow load areas like ski resorts we typically have the roof deck act as the air control layer and provide a high level of thermal resistance at the roof deck (either rigid insulation directly above the roof deck or high density spray foam directly under the roof deck – and then we provide an over roof creating a vented space over the top of the entire assembly. In essence we created a vented unvented roof hybrid. An unvented primary roof assembly with a vented over roof.”

from comment#53 here:

Lstiburek’s Rules for Venting Roofs
You need an airtight ceiling, lots of air flow, plenty of soffit vents, and deep insulation at the attic perimeter

Awesome awesome article on insulating roofs.

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NRJ (energy)

We came home to a HOT house after an afternoon out at a picnic. It was probably only a sunny 80F today. Forgot what that felt like after living in superinsulated splendor for 3 years. :-)

So that got me pondering the MASS-SAVE proposal for insulating (some) of our house — The walls. And part of the attic. Areas that can be done easily with either cellulose or foam board. It’s something like $5000+ for which their is a $2000 subsidy. Plus I believe an option for a 0% loan. With an estimated payoff of something on the scale of 5 or 6 years.

But as an exercise, I think it’s important to consider what that $3000 (after rebates and tax credits) could pay for in other energy-savings or green-house gas reductions:

1) Pellet stove
2) More solar PV panels
3) The up-charge on buying a hybrid like a prius vs a civic or something like that.
4) A nice trailer to make grocery-shopping by bike easier perhaps
5) Windows/doors upgrades — not all, just some

Probably a good deal of insulation wins in dollars. Certainly it wins in comfort. And our IAQ would clearly be better with some better air-sealing of our attic.

This is also a reminder to go back to basics for a moment with a simple heat-loss calculator like Marc Rosenbaum’s excel or’s web app. I have some similar “payoff” numbers from Mass-Save, but better to do it myself to really get it.

**NRJ is a fun way to say Energie in French. Since recall… a J sounds more like G in English.
And click the speaker to hear it.

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low-flow showerheads review

Over at the wirecutter they write in their article about showerheads: “If you go less than 1.5 gpm you’re going to have to spend so much time in the shower rinsing off that you will waste more water than if you didn’t.”

That’s totally not true (in my experience). We have been very happy with our 1.0 gpm Bricor and that includes the resident with VERY LONG AND THICK hair. No complaints. At all.

It’s also probably news to the 140 people giving this 1.25 GPM showerhead (Niagara Earth Massage) a 4.5 out of 5 star rating at Amazon. It’s also a cheap experiment, since it’s less than $10.

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Filed under erik-green, green, shopping, stuff

On electric cars…

“Once consumers get used to the charge-at-home ritual, the pilgrimage to the gas station will very quickly feel as inconvenient as rewinding the VHS tape and driving it back to Blockbuster.” LINK:

One caveat with electric cars is that in the winter when it is very cold, you have to use the battery to heat the cabin. Apparently new models (like 2013 LEAF) are getting heat pump heaters which will be 2-3 times efficient at heating.

BTW, Saw my first LEAF today at… the Whole Foods parking lot in Andover.

My sense is a plug-in hybrid would be most practical for the new few years, but at some point I bet the full-EVs will take over.

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New to me: look how low on the list the US is. ” In 2007–2008, the Gallup Poll surveyed individuals from 128 countries in the first comprehensive study of global opinions.”

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Concealed duct indoor units for air-source mini-splits**

idea 1) Add a single zone minisplit that directly feeds 3 rooms with only 1-zone via tiny duct runs. Mitsubishi and Fujitsu both have these. I think the indoor unit might fit in the ceiling of a closet and losing 8 inches might be acceptable? The idea being that we could then turn off the “central heat” completely on cold nights and during the day. $2000?

idea 2) Much cheaper — thicker down comforters, sweaters, fleece, hat, my 100W electric panel under-desk (vs 1500W space heaters) with blanket for a sort of “homemade Kotatsu”. The problem is that fingers still get cold and it’s more flexible and more comfortable to not bundle.

idea 3) Some combo of the above.

idea 4) pellet stove or wood stove. Problem being that it would be mainly heating the big common space so getting heat to the office/bedrooms would be tricky.


**Main goals are: 1) save $ and 2) KISS (Keep it simple, stupid) and 3) reduce carbon

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Well, the almost passive-house/almost net-zero Stow house sold in a week to a smart buyer who got a great deal. And we’ve already moved (to the 1958 split level mentioned earlier).

I’m missing…
– the warm basement (my office)
– the quiet HVAC (the new house has a typical forced-hot-air system)
– the even temps (both room to room, and time of day)
– those huge window sills!
– the attic playroom
– the very quiet location (far from highways and other major roads)

There are some nice things about our new place too though (the main one being that we are 3 or 4 minutes to the kids school) so we save lots of time/money/CO2 each day on that.

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CFLs time has passed

I won’t be buying any more CFLs (compact fluorescent light-bulbs). Time for LEDs!

CFL problems:

1. CFLs apparently often leak UV!!! — 2013 NIH report:
2. CFLs usually don’t last NEARLY as long as claimed (in my experience) especially in down-facing applications where they get especially hot
3. Cleanup of broken ones is a pain (worrying about mercury)

So that’s enough for me to jump ship to LEDs now that they are starting to be almost reasonably priced.

Excellent: Philips 409904 / 423343 Dimmable AmbientLED 12.5-Watt A19 Light Bulb (good Amazon availability)

Also excellent is a similar one from CREE. Not sure Amazon has a good stock of them, but I think HomeDepot has them.

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It’s payback time…. insulating a 1958 split-level house

We’re moving soon to a “normal house” built in 1958, and that means beginning to ponder what heating-system, insulation and air-sealing projects to embark on.

My go-to blogger will be Marc Rosenbaum:

Here’s what we will be working with. The house is a split-level with 4 different living levels all separated by half-flights.

My first thought is that the way to go is to get a pellet-stove installed in the main living area. There’s a good central spot for one. The house is currently heated with a forced-hot-air (FHA) furnace with smallish “high-velocity” ductwork. But my guess is that in the winter it probably heats up the basement level like crazy, which is a waste since we won’t use that much. So like with our pellet stove in our previous Shutesbury, MA house** (and with Marc in his post above), getting point-source heat (a pellet stove) directly on the living floor will make a lot of sense. It will effectively limit the amount of space we are heating.

(**Our basement in Shutesbury definitely got down to at least 45 if not 40 sometimes. And we still ran the FHA occasionally. Nice.)

Other obvious things will be to improve the insulation on the 3 attic hatches. (as in… add insulation and air sealing. There is none now!)

And generally go nuts with cellulose in the attic.

And ponder what to do about the rooms above the 1 car garage since there is probably no insulation in those floors. Or basically none.

Payback will be an important consideration.

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Filed under about the house, erik-green, green, insulation

Our oil problem

“Our oil problem is not that “we’re running out.” Our oil problem is that we’re producing so much of the stuff that we are changing the planet’s climate.”
— David Frum, ‘Peak oil’ doomsayers proved wrong

True on climate, but the commenters at the article have it right:

“[W]e are extraordinarily blessed with a moment of respite to temporarily postpone the extremely difficult economic environment brought on by the decline of abundant oil….but it is only temporary, and we would be wise to use this moment to prepare ourselves.”

My comments: Keep bringing on the bikes, insulation, and solar. :-)

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Filed under energy, energy-efficiency, erik-green, green, solar