Monthly Archives: January 2011

bau biologie, vapor-open envelopes, and hygric capacity

air transport vs moisture transport

Bau Biologie

vapor-open exterior sheathing discussion — the no-foam approach

vapor-open assemblies

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Filed under erik-green, passive house, superinsulation, zero energy home

VS: home heating — heat pumps vs wood (or solar)

There are many in green circles — superinsulated/zero energy home/passivhaus circles — who think that heating with electricity (ideally with an air-source heat pump) is the ideal way to heat a house with solar electric (PV) panels on the roof (well, or yard). Example link

As someone with a house that is exactly that, let me chime in.

Heat pumps: PROS
1. No hole needed in house for exhaust or air intake
2. No air-quality or safety concerns since no burning of wood or fossil fuels in the house
3. Math is easy if you are trying to be net-zero. If everything is electricity, then there is no complicated math to do converting gallons of propane or cords of wood burned into KWh. (not much of a reason)
4. Now you have AC too. OK, so you saved a few bucks. Window ACs are only $80 though. And you house probably doesn’t need much more than one of those. Really.
5. No baseboards taking up space. But there are other approaches (forced hot air and such) to deal with that.
6. Quiet inside. Wow, very very very quiet. No furnace, furnace fan, or boiler making a racket. (Aside: And no humidifiers in winter… thanks to the tight superinsulated house part…)
7. Electricity tends to be price-stable vs the price of propane and heating oil which seems to whip-around a lot.
8. Usually a bit cheaper to install vs a “central” system esp in a very small house. But add in the price of the HRV or ERV stuff if you have that too.
9. Point source: I list “point source” below as a con too. Some like point source heat since it allows zoning, getting cozy by the “fire” and such. Flip side to everything.
10. Future safe. Electricity can come from many primary sources.

Heat pumps: CONS:
1. Can be a bit loud outside (well not LOUD, but there is a fan running, like for central air-conditioning, all winter) So if you are noise sensitive maybe there is a quieter heating approach? Not sure what qualifies as the quietest. Radiant floor heat?
2. PVs should not be thought of as anything more than an offset in my opinion. Don’t think of that electricity your panels made as yours. Who cares WHO uses it. The point is to reduce CO2/greenhouse gases overall. In other words, if you make electricity, dump it into the grid for your neighbor to use, and burn some wood to keep warm instead, then you are ahead (in my eyes) of someone using that electricity directly to heat their house with a heat pump.
3. In very cold areas, you will need either a HYPERHEAT model that keeps up with sub-0F temps, or some back up (maybe electric space heaters). Most other air-source heat pumps drop their output by a lot when it is VERY cold.
4. Power outages. You will have no heat. Now, that might not matter as much, because your superinsulated house has a certain amount of “passive survivability” built into it with all that insulation, but if we are talking comfort here, then grab a wood stove or a propane heater needing no electricity to run. There are a few!
5. “Non-traditional” Looks: Some might think they are ugly. I don’t mind them. Just different. And controls. Our Mr Slim one has a “remote” vs a traditional thermostat. And the model we got doesn’t control all 4 internal heads. So like a house with zoning, you have to walk around and set each individually.
6. Point source: We have 4 of these inside “heads”. One on a wall on each floor (basement, 1st, 2nd, 3rd (attic)) But there is not heat/coolth pumping into every last room. Doesn’t matter much, but bedrooms are a little cooler — 5F? Coldham/Rocky Hill study seems to say. Ask google.

Wood: PROS
1. Local
2. Carbon neutral
3. Ambience
4. Simple technology (especially if not pellets and not catalytic)
5. No electricity needed (heat when power outages)

Wood Stoves: CONS
1. Lugging stuff
2. Might be difficult to vent properly in a very tight house. Indoor Air Quality risk. Especially with a pellet stove which loses electricity.
3. Even the smallest pellet stoves will overheat some houses that are superinsulated. But big whoop. Run it on thermostat-mode. And open the window if you must!
4. Particulate pollution. You might live pretty near other people or in a town or city that prohibits wood burning.
5. Related… Gotta know what you are doing. (slow-burning, smoldering wood stove fires pollute like crazy and smell up the neighborhood.)

Solar Thermal Heating: MIGHT BEAT WOOD IF…
1. You have sun
2. You have a spot to put the solar thermal panels and a HUGE 1000 gallon tank in your basement
3. You have already done energy efficiency fixes — insulation, CFLs, etc. (see
4. CON: Up front cost is going to be higher than the wood (at least a pellet stove vented out the side of a house) unless you are a DIY person (see

Prius: PROS (W/holistically speaking, maybe this is a better place to start…)
1. Do the calculations in KWh. If you cut the number of gallons of gas you use in half by driving a hybrid or electric car, how much is that in KWh?
2. Energy Independence: coal and nukes (for making electricity) are “local” to the US, vs gasoline comes mostly from other countries. Propane is 90% from US. Natural Gas is ???
3. Use as a backup generator for house

So what would I do?
Well right now we use an air-source heat pump to heat our almost passivhaus ZEH. But I hope to do more solar-thermal heating in the future. 5 days of storage would get you to 97% solar “if cloudy days are like coin flips”. And the no-electricity propane heater is intriguing, especially for a little backup. Check back in a year!

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Filed under contrarian, erik-green, erik-VS, futuresafe, heating with wood, homesteading, house, HVAC, passive house, simple, solar, superinsulation, zero energy home

Under the microscope

We agreed to let Fraunhofer add little sensors to EVERY plug in our house. It’s a pilot program that Lawrence Berkeley National Laboratory is running Miscellaneous and Electronic Loads Research. It will report usage every 10 seconds from every plug back to the interweb via UDP

I am trying to imagine what useful information could come out of this for the greater good, and I can’t quite come up with anything. Perhaps they will be able to use the detailed data to disambiguate data coming from a single smart-meter on a house. (like Google Powermeter) In other words, being able to tell “oh, that’s the fridge coming on” vs “oh, someone turned on a light” or “that’s the dishwasher”. Who knows.

On a personal level, I probably won’t learn anything… but that’s totally fine, I am happy to help! I have pretty much figured out anything I wanted to know via a Kill-a-watt and the eMonitor/TED 5000 approach of “circuit” level monitoring.

I suspect it would be better to “follow the money”. I bet people (in New England at least) spend a lot more heating and cooling their house than they do on phantom loads from electronics and leaving lights on.

Both are worth doing I guess. Like Gary did with his “half” plan.

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The Best Magazine Articles Ever

No patience for overwritten nonfiction books? Perhaps some of these magazine articles will be of interest.

The Best Magazine Articles Ever
The Top 25 Articles — Based on the number of times an article is recommended

There could (of course) be a website (with LIKE/DISLIKE buttons, comments, voting/etc) devoted to this topic instead of this “hand-made” list. But there is some value in someone’s (Kevin Kelly’s in this case) editorial control over it of course.

To this list I would add just about any newspaper or magazine article that later became an entire book. Usually one can probably just read the article. The book is probably overwritten.

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exporting Yahoo Notepad notes using iMacros

Instead of waiting to see if Yahoo accidentally deletes my old Yahoo Notepad notes (no API or sync or export tool that I am aware of!) — when they transition to the “All New” interface they just emailed me about — I snagged the iMacros Firefox add-on and made a little loop to grab them and save them locally. Phew!

1. get iMacros
2. make the folder to dump the notes into
3. tweak as you wish to name files differently and then save as an .iim i nthe same spot as all the samples.
4. PLAY (LOOP). Which works great, but after 40 iterations, Yahoo seems to lock you out for an hour with an unexplained error code -100. So each time you re-run just up the SET LOOP line to 41, 81, 121 etc.


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DAVID BROOKS — What would he think of Sudbury Valley School?

“[S]he [Amy Chua] is not really rebelling against American-style parenting; she is the logical extension of the prevailing elite practices. She does everything over-pressuring upper-middle-class parents are doing. She’s just hard core.”

“I have the opposite problem with Chua. I believe she’s coddling her children. She’s protecting them from the most intellectually demanding activities because she doesn’t understand what’s cognitively difficult and what isn’t.”

ARTICLE LINK: Amy Chua Is a Wimp (and don’t forget to click on the Comments…. Highlights tab … “There is a middle way between these two extremes.”)

Actually, I think it’s like any duality… it’s both easy and hard to be a kid with a parent like the “Tiger Mother”… easy because you don’t have to choose (freedom is difficult)… hard because playing the piano or doing math problems for hours and hours against your will is not fun!

So I think David Brooks would think SVS is interesting in that it is the true opposite of the parenting and educational approach the Tiger Mother took. High standards, but standards that come FROM WITHIN each person, not from their parents.

See also:
Sudbury Valley – the Easiest School or the Hardest? (a written version of this talk was also published in the SVS Journal, Volume 40, Number 1, Fall 2010)
Stupid white man criticizes smart Chinese woman
Gender & the Brain: A New View (Chua has 2 girls, so it made me think… what if she had boys?)
Video Games Boost Brain Power, Multitasking Skills
(also depression?) (and childhood obesity?)
– Organic Intelligence, Toy Story and “What Did You Do In School Today?” (SVS Journal, Vol 40, Num 1, Fall 2010)
– A longer Brook’s article on this same theme: “The meal was delightful, but it [a first date] was also a rigorous intellectual exam that made the S.A.T. seem like tic-tac-toe.” ARTICLE LINK: “the Composure Class” (seems partially an attempt to followup on his BOBO word from 2000 but bear with him! Good description of attachment parenting “Thanks to his mom’s attunement, he became confident that if he sent a signal it would be received. Later in life, his sense of security enabled him to go out and explore the world.”)

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Filed under alternative education, communication, creativity, Sudbury Schools and Sudbury Valley School

Nothing In Life Is As Important As You Think It Is

Psychologist, Princeton; Recipient, 2002 Nobel Prize in Economic Sciences

Focusing Illusion
“Nothing In Life Is As Important As You Think It Is, While You Are Thinking About It”

Education is an important determinant of income — one of the most important — but it is less important than most people think. If everyone had the same education, the inequality of income would be reduced by less than 10%. When you focus on education you neglect the myriad other factors that determine income. The differences of income among people who have the same education are huge.

Income is an important determinant of people’s satisfaction with their lives, but it is far less important than most people think. If everyone had the same income, the differences among people in life satisfaction would be reduced by less than 5%.

Income is even less important as a determinant of emotional happiness. Winning the lottery is a happy event, but the elation does not last. On average, individuals with high income are in a better mood than people with lower income, but the difference is about 1/3 as large as most people expect. When you think of rich and poor people, your thoughts are inevitably focused on circumstances in which their income is important. But happiness depends on other factors more than it depends on income.

Paraplegics are often unhappy, but they are not unhappy all the time because they spend most of the time experiencing and thinking about other things than their disability. When we think of what it is like to be a paraplegic, or blind, or a lottery winner, or a resident of California we focus on the distinctive aspects of each of these conditions. The mismatch in the allocation of attention between thinking about a life condition and actually living it is the cause of the focusing illusion.

Marketers exploit the focusing illusion. When people are induced to believe that they “must have” a good, they greatly exaggerate the difference that the good will make to the quality of their life. The focusing illusion is greater for some goods than for others, depending on the extent to which the goods attract continued attention over time. The focusing illusion is likely to be more significant for leather car seats than for books on tape.

Politicians are almost as good as marketers in causing people to exaggerate the importance of issues on which their attention is focused. People can be made to believe that school uniforms will significantly improve educational outcomes, or that health care reform will hugely change the quality of life in the United States — either for the better or for the worse. Health care reform will make a difference, but the difference will be smaller than it appears when you focus on it.


There are 163 of these at . Here is Kevin Kelly on Embracing Failing and The Importance of Negative Results. which was interesting to read after the NYer article recently about the decline effect (due to “selective reporting”).

See also:
The Experiment Driven Life – Think, Try, Learn
Cheating in Science (part 2)
Sudbury Valley School

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VS: electricity vs propane — New England style

1 gallon of propane is $2.80 right now on avg in the US says the web.

If you assume 90% efficient boiler or furnace, that is how many KWh of heat delivered to the house?

1 gallon of propane has ~91500 BTU = 26.82 KWh * 90% efficient = 24.13 KWh delivered for $2.80


So how much does that amount of heat cost with an air-source heat pump if you pay $0.15/KWh and assume a COP of 2? (being very conservative… our seasonal avg COP is supposedly 2.7 I think I estimated once using Canadian (cold) figures from service manuals)

24.13 KWh / 2 COP = 12.065 KWh * $0.15/KWh = $1.81

Even if you are heating with straight resistance electricity (no heat pump trickery), the cost is only $3.62 (vs $2.80 for propane). Not bad, $-wise.

1. The propane would be much greener since electricity from power plants is very dirty in the northeast. IOW, the carbon/KWh heat delivered is 3 times higher due to inefficient power plants using fossil fuels. Better to use the fossil fuel directly.
2. If you are in a warmer climate, the math for the heat pump is even better, since you COP will be 3+.
3. If you can use zoning (heating one room) with an electric heater, you will probably be ahead (in both $ and green) vs central-heat using propane.
4. Wood heat or solar beat everything.

Next week: electricity vs heating oil

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Filed under contrarian, energy, erik-green, erik-VS, heating with wood, HVAC, simple

Picasa Users — use tags and only tags!

I know the people/faces feature in Picasa is seductive, but JUST SAY NO! The data is stored in a specialized Picasa database on your hard drive which doesn’t work perfectly in my experience. (Whereas “tags” are stored *in the images themselves* in a standardized way — IPTC — and cannot be lost/mangled!)

It has been my experience (as well as many others — ask Google) that this Picasa-only method (for labelling faces) is flawed in the following ways:

1. Using one shared photo collection amongst many home computers (say on a NAS) is difficult if you rely on special features of Picasa (or iPhoto I assume). Not impossible, but only for extreme power-users. If you ignore most of the fancy features of Picasa and stick with tags, you should be ok.

2. Many people have experienced problems with picasa losing track of their database (and hence all of their face data). I believe there might be ways to “get it back” — again, ask Google — but you really don’t want to go thru this nightmare!

So.. just stick with hitting “Ctrl-T” and adding tags for the people or other labels you’d like to add. Captions are safe too. Those are stored in the image file too! Or if tags scare you too, add the data to the file name!

Yes, I know you will lose the cool feature where you outline the face allowing you to visually see 100s of your kid’s face in a collage, etc. But I bet you will be able to add that back in in some future year pretty easily — the faces tool in Picasa and other photo apps will only get better and better. And you’ll have already tagged many of your photos so you’ll be half way there.

Wanna test it? Add some tags to a photo, then go look at the image file in Windows Explorer or Mac Finder and view properties. Your tags (and/or caption) will be there! Search works great in Windows too (as well as Picasa). Just click “search file contents” and your tagged images come right up! You can even make the tags visible in the results. It’s an optional column in Windows. And you can of course add tags right in Windows. Picasa just makes it easier.

Cool! Simple! And future safe!

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A few wintertime utility bill stats

Here is our spending* for the last month (mid Dec to mid Jan) in our almost passivhaus here in Massachusetts:

$25: hot water (it’s probably a little less than that because my home office is on the same circuit)
$138: heating (mini split heat pump)
$6.50: HRV (fresh air)

OK, so if we have 4-5 months as cold as the middle of winter (this past month)**, that would be ~$600 for heating for a year. This compares very favorably with a recent newly constructed house we lived in which we probably paid $2000/year or so to heat AND we were freezing our tail off at that price. To stay as comfortable as we are in this almost passivhaus, I can only assume our bills would have been $500 or $1000 higher. And this house probably has more usable space. So we pay probably at least 5 times less in heating bills. Just a guess. We’ll see what the numbers are.

And for hot water for a year that’s $300/year. (And we should probably be net-zero for the year, so that is 100% solar hot water, net.) So as I’ve mentioned in a previous post, that is much better than a typical thermal solar hot water system which is often more like 50-60% solar fraction for the same price. (Solar Today reference coming) We’ll see how we’re doing after a full year! (We moved in in June, so it’s only been 7.5 months so far.) But see***

*Assuming $0.20/KWh (which is actually high compared to our current utilities actual rates, but is probably about what it costs for “green” electricity — this is what we paid at National Grid for “GreenUp” — 100% from wind and small hydro

**One could also estimate a year of heat based on the number of HDD we had during the last 30 days vs the total estimated for a year. And that would give you your multiplier, instead of my guess of 4.5. Using for example. And use base 68F to be fair, unless you really do keep your house at 65F!

***I think one flaw in my reasoning is that it might not cost so much for a traditional system if one upsizes the system so you can get to nearly 100% and I bet the heat pump will not last as long as the 50 years I’ve heard reported for flat plate collectors (reference coming soon). Who knows. You can’t beat my system for simplicity!

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Filed under energy, erik-green, passive house, superinsulation, zero energy home