Saturday, March 20

• Seminar: 10am to 12:30pm
• Tours: 2pm to 4pm

Seminar: Designing and Owning a NetZero Energy Home

• Grant MacEwan University, CN Theatre Rm. 5-142, 105 St. Building at 105 St. and 105 Ave
• Peter Amerongen (builder), Gordon Howell, P.Eng. (solar engineer), Conrad Nobert (Mill Creek homeowner)
• Seminar and tours: No need to register. Cost: free

Open House Tours - see ideas you can use on your own house

• energy- and water-efficient construction and appliances reduce space heat by 65%, hot water by 75%, and
  electricity use by 50% for upgrade cost of less than $20,000. All electric. No need for natural gas line.
• air and water heat recovery, LED lighting, rainwater harvesting, passive solar, active solar, solar electricity
• sustainable materials, healthy indoor air quality, eco-landscaping, net zero emissions

Myles Kitagawa is my favourite Edmonton-based environmentalist. He articulates an intelligent, realistic vision for where we need to go as a society.

Myles works full-time, for very little money, to improve Alberta’s environment and to mitigate the impacts of humanity’s destructive activities. Watch the above video to get a feel for how well Myles understands the issues, and how much sense his approach to solving our problems makes.

Myles is the executive director of the Toxics Watch Society of Alberta, a livejournal blogger, and an occasional contributor to this website.

My family and I will be showing our support for local food tonight at City Hall (6 o’clock). Council will be discussing a plan for future land use. The Greater Edmonton Alliance (GEA) has influenced the plan so that it includes provisions to protect high quality farmland that is within city limits.

I hope that GEA is also arguing against the plan’s ridiculous idea that 75% of future growth should occur as urban sprawl (discussed more here). Anyone who has witnessed the many vacant lots and underutilized spaces in the city’s core can tell that there is plenty of room for growth/revitalization without ANY more urban sprawl.

Anyway, GEA has it right on local food. That’s why we’ll be joining a few hundred other concerned citizens to pack city hall tonight.

The Bricor Hand-Held Showerhead only uses 4.2 litres (1.11 gallons) per minute

I've never needed a reason to conserve water. Simply knowing that half of the world’s population lives without easy access to it is enough to make me grateful for my easy life.

Other than gratitude, the reasons to conserve water are excellent:

• Carbon Dioxide: Saving 1000 litres (one cubic metre) of water averts the emission of 1.75 kg of carbon dioxide (source).
• Cost: Water costs me about $2.64 per 1000 litres to deliver and treat.
• Cost Again: Water is very expensive to heat.
• Contamination: When I use water in my house, it returns to the North Saskatchewan river more contaminated than if I had left it there.
• Water Security: Our glaciers are melting. We may one day be water insecure, so having infrastructure in place to reduce its use is a good thing.

Toilets account for roughly 1/3 of our water use. In the Mill Creek Net Zero Home we installed dual-flush toilets.

Our Toto Dual-Max toilets “get the job done” while keeping water use to a minimum.

We decided on Toto Aquia Dual-Max toilets because they reportedly worked well, and our plumbing supply company stocked them. So far, so good.  read more... »

Earths General Store has reopened at 9605 – Whyte Avenue (across from the Humpty’s), its new, bigger and better location. EGS was the flagship of the Edmonton environmental scene in the early 1990s. It remains the main hub of conscious green living in Edmonton. If you want to get connected to Edmonton’s environmental community, EGS is the place to be.

In its new location, the store has expanded from its role as retailer, coffee roaster, bookstore, and information provider to included groceries and an expanded line of offerings.

EGS now sells food!

One of the things I’ve always loved about the store is that Michael and his staff have done “the research” for me. At most other stores, you have to constantly be on the lookout for green washing and gouging. At EGS, you can relax and trust that whatever you’re buying is truly the greenest, healthiest choice.

I’m thrilled that EGS has stepped into the role of green grocer. Stop in and check it out. Here are some more pictures of the new space:  read more... »

Email from Conrad Nobert to Bob Heath, Peter Amerongen and Rob Dumont:

Hi guys,

Well, we've pushed just about every boundary that there is to push in this
house. We have squeezed every damn piece of energy out of each component,
but there is one potential gain left that I can think of.

We're gearing up to purchase window coverings for the main floor south
windows and the second floor library. We want them for privacy and to block
out light when the space is getting drenched with it. Hunter Douglas has a
product called "duette architella". It is a honeycombed horizontal blind
that apparently has three air spaces in it. They claim that it adds R4.
Even if it's R2, that's a huge gain for the winter nights. My question is,
how can moisture possibly not build up behind these things? I would
appreciate any insights that you might have.

Thanks,

Conrad

Answer from Bob Heath

Hi Conrad,
   Thanks for bringing this up as it is something that I have already been
thinking about and would have eventually asked you about.
   If  you were to get a true R4 from the window covering, that would be close
to the R value of a south window (R5) so the temperature of the inner window
surface would be about halfway between the room temperature and the ambient
temperature. At -30C ambient temperature, the inner window surface would be
at about -5C which is going to condense and freeze any moisture in the air.
The only way I can see that this would not occur is if there is not a tight
seal around the window covering which would allow warm room air to circulate
at the inner window surface and warm it to above the dewpoint. This, of
course, would mean that the effective R value of the window covering was not
R4. If you could get an airtight seal with your window covering, then only
the moisture trapped between the window and the window covering would be
available to condense and freeze and this might only be enough to lightly fog
the window, but getting that airtight seal with a moveable window covering
would be difficult. R2 would leave your inner window surface above freezing,
but you would likely still get condensation depending on the RH, and hence
dewpoint, of your room air.
   I did an experiment in my old house last winter. I cut a piece of  2"
styrofoam to fit tightly in my kitchen window which was roughly 2 feet
square. In the morning after a very cold night I had a very thin film of
frost on the window. I suspect it was thin both because of the tight seal
which only allowed the small amount of moisture, trapped against the window
when I installed the styrofoam, to freeze and also the fact that I did not
have a humidifier on my furnace so the RH of the house air was very low
(probably 10% or less). In my case the R10 of the 2" of styrofoam was much
higher than the double-paned window, so the inner window surface temperature
was probably around -20C.
   Unfortunately, it seems that the only solution to this problem is to have
the insulation on the outer window surface. Exactly the same reason why the
rule of thumb is that at least 2/3 of your wall insulation should be outside
your vapour barrier (think of your inner window surface as your vapour
barrier).
B.

Answer from Peter

These are good insights, Bob.
The COG R value of the south windows is 5.7. With the 1/3 - 2/3 rule 
of thumb ( I wonder where that came from.  +20C minus -40C = 60C ; 
20C- 0C = 20C which 1/3 of the total difference, but we can get 
condensation on the glass with no interior insulation if the RH is 
high enough.) we could go up as high as R 2.75 without concern.
  I think  we should just try it. R2.75 would make a decent 
difference. The total annual heat loss from those south facing windows 
is about 3500 kWh per year. Increasing the total R value to 8.5 for 
1/2 the time ( might be optimistic)  would save over 1100kWh per 
year.  ( 16607kWh/year x 22% south window heat loss x R5.7/R8.5x.5 of 
the time)
We need to figure out how to simulate the effect of an R 4 blind 
without spending a bunch of money.
Oops. I need to redo those numbers. I just remembered that   Hot2000 
is already assuming some kind of R1 window covering. Corrected for an 
assumption that we already have R1  window coverings, the potential 
saving goes down to about 700kWh per year. Still nothing to sneeze at.
Peter Amerongen

Answer from Rob Dumont

Hello from a previous user of interior insulation.
1. The lower corner of the windows are the coldest spots, and it does not take much interior insulation to cause condensation.
Assuming an interior temperature of 20 C and a relative humidity of 30% in winter, the dew point for that interior air is about 2 C.
If the humidity goes up to 50%, the dew point is about 9 C.
Any point on a window that is colder than 2 C will have condensation if  the RH is 30%, and any point on a window colder than 9 C will have condensation if the RH is 50%. (The dew point is the temperature at which a given sample of air will start to condense.)
2. Back in the 70s I had a small house with lots of south windows. I experimented with interior rigid insulation on the windows.
Some observations:
You need a very tight air and vapour barrier on the warm side of the insulation. I did not have either, and condensation would readily form on the window. I used a 2 inch thick piece of beadboard as the insulation. The windows were double glazed sealed units with an R value of about R2. Even more condensation would form on the window when the insulation was removed, as the warm, moist air could then, unimpeded, hit the window.  The condensation would run onto the sill. I actually got quite sick from the mold that grew on the lower corners of the windows. Never again.
3. A friend used rigid insulation on the inside of his windows and the rigid insulation was left on during a sunny day. The inner window cracked from the temperature stress. My windows did not crack because they were tempered glass (patio door pieces.)
4. I very strongly doubt that an interior curtain can have an R4 value. Convective air leakage around the perimeter of the curtain will readily move air past the sides, top and bottom of the curtain and dramatically lower the R value.
5. I do think that exterior insulation is a possibility. However, Harold Orr put it in perspective for me. An exterior door mounted on the outside of the window has a materials cost of about $200 and probably about $50 worth of labour to install and weatherproof. At $250 the cost is about $14 per square foot, and that would not include the cost of any actuator to allow the exterior insulation to be controlled from indoors. We did have a house in Saskatoon that used a sliding shutter on the south side with barn door hardware. It worked all right, but the sliding shutter used a lot of valuable real estate on the south wall. See the attached photo.
6. In Europe exterior shutters are very common. Roll-up shutters are seen a lot in Germany. I don't know the R value but they do provide some R value and also sun control.  
If one could come up with a low cost shutter that didn't cause moisture problems...
Hope this is of value.
Rob Dumont

The temptation has always been there for eco-house builders. It’s those damn windows; they are just so useless once the sun goes down. There must be some way to insulate them once they no longer need to be seen through, right?

Moisture

The answer is yes, but not cheaply. The biggest problem is moisture. If you insulate a window from the inside without a perfect air seal between the heated space and the cavity between the window covering and the window, moisture-laden air will flow into said cavity. When that happens, the moisture will condense on the window. Take it from green building pioneer Rob Dumont:

Back in the 70s I had a small house with lots of south windows. I experimented with interior rigid insulation on the windows. Some observations:

You need a very tight air and vapour barrier on the warm side of the insulation. I did not have either, and condensation would readily form on the window. I used a 2 inch thick piece of beadboard as the insulation. The windows were double glazed sealed units with an R value of about R2. Even more condensation would form on the window when the insulation was removed, as the warm, moist air could then, unimpeded, hit the window.  The condensation would run onto the sill. I actually got quite sick from the mould that grew on the lower corners of the windows. Never again.

R Value

We felt compelled to buy window coverings as soon as we moved into the Mill Creek NetZero Home  read more... »

Mill Creek NetZero Home, December 15, 2009, 14:00.

As we approach the winter solstice and the three-month anniversary of our moving in, we continue to learn about our new house. These observations are mostly qualitative, because we don’t have the rest of our solar modules up, and we haven’t set up monitoring equipment yet. We are tentatively planning to remove the door of our wood stove on July 1st, 2010  and then monitor the house’s energy use for a year.  read more... »

Mill Creek NetZero Home Heat Recovery Ventilator

I heard a story once about a man who built a house using insulated concrete forms (ICFs). While I don't advocate their use in general, ICFs have some distinct advantages (certainly over conventional construction). The primary of these advantages is supreme air tightness. ICF homes (those that are built with ICFs from top to bottom) can achieve hourly air change rates of 0.2. In contrast, the Mill Creek NetZero Home has an airtightness measurement of 0.36 ACH, which is really amazing for a wood-framed house.

So back to this guy who built the ICF house. He apparently wasn't aware of how air tight his house was, or at least the consequence of that air tightness. Six months after he moved in, he had to rip all of the drywall out because it had rotted. He had built a house as tight as a plastic bag, and forgotten a critical aspect: ventilation.  read more... »