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Heating & Cooling » Our Sustainable Home
Browsing Topic: Heating & Cooling

NOW we’re getting toasty

October 13th, 2009

Jerry’s Insulating Co. paid us an unexpected but very welcome visit on Monday. Up until now the roof has been uninsulated and our second floor dropped to 15’C at night (we’ve been bundling the baby in 4 layers at night as he’s not one to keep his covers on).

From what I’ve read on HomeStars, Jerry’s Insulation seems to have a real problem with their spray-foam division, but like others on that site, we were very happy with the guys who came to do our loose-fill insulation for the attic. Professional, friendly, and accommodating. Because our baby needed to get down for his nap at the time they showed up, they rushed in, got the attic done and cleaned up in just 30 minutes.

They did show up without notice, though and we’ll leave that as our one gripe (someone couldn’t have called?). I don’t want to get the story too complicated but someone else was booking the insulation and we were trying for over a week to both rush the job (because it was getting colder at night) and find out when they were coming.

But at least we’re all cozy now (and the baby had no trouble getting down for his nap as soon as they left -whew)!

It’s worth mentioning Foam Comfort again, who are the excellent folks who put in the spray foam in our loft area. It seems they also have been reviewed positively on HomeStars, if interested.

Posted by Colin
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Much Ado About Windows

June 19th, 2009

Generally, I’m not someone who takes any satisfaction from the acquisition of things (a car, new stereo, TV, etc. — they’re mostly just functional, to me).  The arrival of these windows, however, I find deeply satisfying. I feel really good about our windows.

Some background explanation is probably required here.

Rewind about 2 months and you’ll find us talking to the builder about ordering the windows. As with each new product being introduced to the house there were decisions to be made about colour, style, features, etc.  Because of budget restrictions Greg had (at our request) changed from fiberglass to vinyl windows, and had sourced some good quality vinyl windows.

There are areas where reasonable arguments could be made that vinyl is actually the best product for a particular purpose, despite the ecologically unfriendly consequences of manufacturing.

I’m sure you can do your own in depth research so just to hit the highlights: windows seem like an unwise area to be using vinyl because:

  • Seasonal expansion and contraction of the vinyl frame reduces the efficiency of the seals.
  • Vinyl is not a strong material. There are some amazing efficiencies to be gained by using a triple glazed pane, but over time, vinyl will struggle to support even a moderately sized triple-glaze pane.
  • Vinyl has a relatively short warranty period which makes it pretty safe to say, we’d be going through the expense of replacing all our windows much sooner than we’d like.
  • If it must be used, Vinyl is better as an outdoor material because of off-gassing issues. Most of the off-gassing is in the first month or so, but the idea that I’d, say, only be poisoning my 1 year old ‘a little’ isn’t in the least bit reassuring.

If you’ve ever been in a situation where you felt something wasn’t quite right, that’s exactly how we were feeling. Despite the pressure to get the window order in to keep the house build on schedule (which is critically important — construction schedules are the slippiest slopes you’ll come across) we started pushing for more time to do some last minute research.

The research felt somewhat pointless at first because we knew the reality was our project was already over budget. The philosophy used for of every other major component of the house was to select the highest quality product, as long as it paid back in time. Fiberglass windows are exactly such a product… but still have to be paid for in the present.

But then the alternative was to settle for vinyl and that seemed… unsettling.

We went back and reviewed who were the big/established companies in Fiberglass Windows, quality of the products they make, what sort of warranties they offered, etc.

One of our calls found us talking with the very amiable and excellently accented Steven Hall at Fibertec. He had reviewed the window plan I had sent over and prepared a quote for us that was, as we expected, astronomically out of our budget.

He then said something quite interesting: “I know you’re under a time constraint and if this window plan can’t change then there’s not much more I can do for you. But if you’re able spend some time working on this with me, I think we can do much better.”

This is already a long post so I’ll summarize by saying: there was about a week long process of discussion, revision, evaluation, hand-wringing, re-revision, more hand wringing and ultimately the stunning realization that together we had developed a window plan for the house that was:

  • far more sensible than our original design
  • would create a home that was far more comfortable to live in
  • maintained our home’s somewhat stringent ventilation plan (for cooling the house without AC)
  • and was now only “significantly more than we had planned to spend”

But we *could* do it! We could actually get these unbelievable triple-glazed, krypton filled fiberglass windows for our home! We wouldn’t have to poison the planet or ourselves (even if only ‘a little’) and our house would be a much more comfortable place to nestle down in, while the windows ever-so-gradually returned their purchase price (and more) to our pockets.

Fibertec Fiberglass Windows installed in the back windows.

From the moment we committed to buying the windows we felt great about the change. And now seeing them in place I have no doubt it was the right way to go.

Posted by Colin
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Proposed building enclosure

April 21st, 2007

For our initial meetings with contractors Joanne & Alex had put together a list of materials we will likely use in the home’s construction. Here they are:

Below Grade Enclosure

  • Foundation Wall Assembly
    • Clean, Free-draining backfill
    • 2″ Roxul DrainBoard Foundation Insulation
    • Damp-proofing on cement parging
    • 10″ Durisol ICF
    • 3/4″ strapping
    • 1/2″ DensArmor Plus
  • Basement Floor Slab Assembly
    • 4″ Compacted Gravel Base
    • 2″ EPS Insulation
    • 6mil Polyethylene Sheet
    • 4″ Concrete Floor Slab

Above Grade Enclosure

  • Wall Assembley (R40)
    • Fibre Cement Board Cladding
    • 3/8″ Strapping
    • 4″ Polyisocyanurate Insulation
    • 1/2″ ZIP OSB Sheathing
    • 2×6 SPF Framing at 600mm o.c.
    • Cellulose Cavity Insulation
    • 1/2″ Gypsum Board
  • Roof Assembly (R60)
  • Windows and Doors
    • Fiberglass framed, double-glazed, low-e (SHGC < 0.5, VT > 0.5, overall U-value < 2.0 w/m/K), argon filled, superspacer windows
    • Insulated metal-clad wood entry doors

Mechanical / Electrical

  • Space Heating and Domestic Water Heating
    • Source: High-efficiency condensing boiler (high temperature DHW and low temperature space heat) with integral or external heat exchanger.
    • Distribution: Hydronic Radiant Floor Slabs (all floors)
    • Rough-in for future solar pre-heat and power.
  • Ventilation
    • Direct outdoor air system (DOAS) – dedicated ducted supply with Heat Reclaim Ventilation (HRV). Supply points in all bedrooms and living rooms, exhaust from kitchen and bathrooms.

I think the ZIP OSB sheathing is one of the more interesting products to be used in this project. It differs from regular sheathing in that, once installed, creates a perfect water barrier for your home, before siding is even attached. As a result once the sheathing is on, work can actually proceed on the interiors while work continues to complete the exterior shell.

Neat!

Posted by Colin
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Earth-friendly homes and preventative measures

March 31st, 2007

Time has a posted parallel articles on creating earth-friendly homes and changes you can make in your lifestyle to reduce CO2 emmissions and consume less power.

Posted by Colin
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Energuide Energy Ratings

January 3rd, 2007

The government of Canada has an Office of Energy Efficiency (OEE) which, contrary to what you may have come to expect from your government, has a whole lot of truly helpful information to offer!

In particular, they have a library of consumer appliances, complete with their Energuide ratings. They also list available rebates, statistics, regulations, etc. The site doesn’t just deal with valuable information for energy conservation at home, but also for business and on the road.

Well worth a visit if you are concerned about your energy consumption!

Posted by Colin
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Wildly efficient Stirling engines

December 31st, 2006

I first became aware of the Stirling engine when reading about inventor Dean Kamen many years ago. He didn’t talk about the Stirling Engine in detail, but what I did find out was that it is an incredibly efficient non-combustion engine, that is powered by differences in temperature. (e.g. you can buy small a Stirling engine that is powered by the difference in the heat from your hand and the ambient temperature.

Sounds great right? In our home, maybe we could generate heat on the roof, and take cool from the ground and generate some free power, right? As is often the case, the first tip-off that there might be a problem with this logic is that nobody has done so already.

I did a little more research and it seems that unless you can get a heat differential of about 300 degrees Celsius, a Stirling engine practical for powering a typical home would itself need to be about the size of a typical home. Stirling engine size is proportional to the amount of power one needs, and inversely proportional to the heat differential between the cold and hot sides of the engine.

Another problem would seem to be the noise. The seemingly inappropriately named WhisperGen of New Zealand specializes in producing Stirling engine water-heater/power-generator combination units. According to their literature, these devices produce 63dBA of noise (and only a fraction of a house’s power requirements). While that’s quite quiet for a generator, it’s still the volume of a loud conversation, or air conditioner. That’s fine if one is encountering it from time to time, but to have it going in one’s home all the time would likely get a little grating.

It might very well be possible to overcome the heat differential limitation, but given the noise they generate it seems unlikely that Stirling Engines can be a part of any urban sustainable build.

Posted by Colin
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Generating your own solar power seems wasteful

December 8th, 2006

As mentioned previously, we aren’t going to be able to afford solar panels for our house, initially. We are planning space and wiring for them, and are confident solar technology will become quite affordable within a decade. Unfortunately, even our smallish appetite for 350kWh/mo. can only currently be sated by a $25,000 photovotaic array (factoring in the amount of sun we’d receive in Toronto).

But considering 350kWh/mo. only costs $49.221 from Toronto Hydro, I decided to run the numbers on the approximate cost of ownership for solar panels and was very surprised at the result. The disruptive force in the calculations was Bullfrog Power.

Provider Monthly
(25 year span)
Monthly
(35 year span)
Total
(25 year span)
Total
(35 year span)
Toronto Hydro1 $49.22 $49.22 $14,776.00 $20,672.40
Solar Panels3 $146.152 $104.392 $43,844.25 $43,844.25
Bullfrog Power1 $65.52 $65.52 $18,756.00 $26,258.40

Even though I’ve skewed the numbers in support of buying solar panels, that option is still 60% more expensive, for no real benefit to the environment (considering one can buy clean power from Bullfrog).

When I first thought about writing this entry, it was supposed to be about the revolution of distributed power generation that will come with low-cost, high-efficiency solar panels. But now that I’ve run the numbers I don’t see that happening.

A relatively small power generation company like Bullfrog can already sell green power at very reasonable prices. Given the overhead involved in managing one’s own power generation, Bullfrog are in a much better position to take advantage of changes in technology than individual consumers are. When prices drop for individuals, they’ll drop even more for Bullfrog, and other power generation companies.

In fact, companies are just the sorts of long-lived entities that thrive on long term capital investments such as solar panels… when there is actually any profit in it. The fact that no power-generation company is generating with solar (at least not around here) leads me to believe that buying solar panels for home power generation is terrible investment (financially and environmentally). For those living anywhere near an urbanized area, it seems likely there will always be a company able to generate green power with the latest technology far more efficiently than any individual could.

Using solar water heaters in the home still seems like a good idea. (Water can’t be heated ‘cleanly’ by someone else and then piped into your house.) But this also raises a question: If heating our home or water via non-solar means, is it better to do it with less efficient but green electricity, or more efficient but dirtier natural gas? I will have to do a few more of these types of studies on the cost of solar water heaters for tap-water and radiant floor heating vs. electrical heaters.

At the moment, I’m thinking the answer might just be Bullfrog.

FOLLOW-UPS TO THIS POST ARE NOW AVAILABLE (Follow-up 1, Follow-up 2).

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1 Factoring in GST, the cost of power from Toronto Hydro is $13.17+10.3cents/kWh (source).
The total cost from Bullfrog is $13.17+14.1cents/kWh (source).
These numbers are not this simplified at either of these sources. You will have to work through their breakdowns to come to the same numbers.
2 Monthly costs for the solar panel solution is based on being able to borrow money at 5% (which is probably too low) via our mortgage, and paying it down with the rest of the mortgage over 25 years. This seems reasonable as anyone with a mortgage is choosing to spend money on solar panels instead of paying down their mortgage. As such, 5% is the true cost of those dollars regardless of where the money comes from. The 35-year calculation is simply the cost incurred over 25 years, spread over 35 years. These numbers are actually skewed in favor of solar panels because of the generous interest rate used, not factoring in any maintenance over their lifetime, and not including the monthly charges for connecting one’s panels to the grid (which you pay even when you are providing power to it).
3 Solar panel pricing is for the CE20180SB kit from Mr.Solar and converted to Canadian dollars. (source).
Posted by Colin
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Follow-up: Properly sizing mechanical systems

November 22nd, 2006

Follow-up to: Book: The Natural House

Alex was just showing me an article called Smart and Cool ($) that appeared in a 2005 issue of Home Energy magazine.

In summary: Over-sized air conditioners aren’t just inefficient, they can make your house uncomfortable to live in. As I hypothesized about furnaces in the previous post: AC units cool and dehumidify more efficiently, the longer they run.

A heavy-duty AC unit will run in short bursts; not long enough to dehumidify at all because the water won’t have time to run off the cooling unit in the ventilation system. When the AC turns off, but the blower keeps going, the air picks up the small amount of water that had started to collect, and sends it back into the house making it uncomfortably humid.

In contrast, an AC unit that runs all the time eventually adds so much condensation to the cooling coils, that the water drips off and is drained away out of the ventilation system and therefore, out of the air.

When planning your mechanical systems it seems to me that it is actually worse to wind up with a heating or cooling system that is too strong than one that isn’t strong enough.

We aren’t planning to install AC at this point. We think we can keep the house cool by opening windows in the evening to collect cool air, and relying on good insulation and air circulation to keep the house cool through the day. In Toronto’s climate, we find there is only about 1 week every year where our current home (even as badly insulated as it is) is uncomfortably warm. In our new house, we’re hoping we find that to never be the case.

I think people would be amazed at how comfortable they could make their homes if they stopped relying on AC and simply opened their windows in the cool evenings, and sealed their house during the day. In our climate, residential AC really seems like an enormous waste for its limited benefit.

Posted by Colin
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Book: The Natural House, Daniel D. Chiras

November 21st, 2006

The Natural House, Daniel D. Chiras
ISBN: 1-890132-57-8

The first half of this book, while interesting, was dedicated to alternate forms of home construction (cob, rammed earth, straw bale, etc.) that aren’t of much use for our particular project; The city isn’t quite ready to have folks try out these methods in locales where their house can actually fall on another house.

But the second half is chock full of very practical suggestions to keep in mind when designing a house. One suggestion in particular came to mind yesterday, after our furnace received its winter maintenance visit.

“Don’t pay extra to give your heating contractor peace of mind.”

The technician indicated that our 26 year old furnace was putting out 90,000 BTU, whereas our small house probably needed 45,000 BTU “at the very most.”

According to the book (and as was apparently the case when our furnace was bought) most heating contractors will over estimate the amount of heating you need for your home. This happens, if not for the unscrupulous reason that they get to sell you a bigger furnace, because they don’t want your furnace to be unable to adequately heat your house.

But consider this: when have you ever encountered a house who’s furnace couldn’t heat the house? Indeed, it probably stayed off most of the time and came on from time to time to blast the temperature up a couple of degrees and then shut down again.

This can’t be more efficient than a system that runs steadily. To my thinking, a furnace which is the ‘right size’ for your house is one that has to run constantly on the coldest day of the year to keep your house at a comfortable temperature.

And what happens if you have an unusually cold run of weather for your region? It’s not as if the furnace, unable to maintain 22°C will drop to 0°C. If it can’t keep up, it might become 19°C and you’ll have to put on a sweater, or run an electric space heater when and where you need it.

Obviously electric heat is expensive, but just think how much is wasted by running an over-sized furnace every winter, compared with running an electric heater for a few hours on a couple record-breaking cold days in a rare extra-cold year?

But I think I’ve digressed…

The Natural House also covers topics on insulation, window technologies, flooring, non-toxic paints, solar electricity, solar water heating, and much more. It’s a great read for anyone trying to get to the crux of what they need to know about the materials that go into their home.

Follow-up: Properly sizing mechanical systems

Posted by Colin
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Collecting and blocking light

November 7th, 2006

Today I was out measuring the position of existing electrical, water and gas services, in addition to gathering more information about the trees that will shadow our house.Positioning your house and windows to best take advantage of the sun (to capture it in the winter and avoid it in the summer) is one of the easiest ways to improve the efficiency of a home.

All buildings and most trees were already on our survey, but it didn’t include unusual details such as how tall and wide the trees are. This can have a big impact on the amount of light we’ll need to avoid in the summer and somewhat reduce the sun we’ll receive in the winter.

I don’t have any tools to precisely measure tall heights so for the time being I just put a standing tape measure, extended 6′, at the base of various trees and took a photograph. I then counted the number of pixels in the photo that made up the 6′ tape measure, and compared it to the object in question.

The obvious problem with this method is that the tops of the trees are farther away than the bottoms of the trees, so the taller the tree is, the more inaccurate my measurement will be. But it should give us a good estimate.

The attached images illustrate why deciduous trees are useful to have around your property. With leaves, the trees block the sun in the summer. Without, they allow us to gather more heat through our windows.

Elevation of tree across the street Tree coverage to the south-west Elevation of power hookups

Posted by Colin
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