Redo of Blower Door Test

Posted on by kent

Way back in 2015 before we moved into the house we completed a Blower Door Test. Check out my previous post for a more thorough breakdown of the testing and our rationale for decisions/assumptions. Briefly though, a Blower Door Test assesses the airtightness of a building – basically, how leaky/drafty a building is. It probably goes without say but an eco house should not be drafty. Drafy = bad. Airtightness is rated based on “air changes per hour a 50 pascals of pressure” (ACH). Typical construction in Canada these days reaches about 3 ACH. The Canadian R2000, our high-efficient energy standard, is 1.5 ACH. While the Passive House standard is the most ambitious and rigorous target of 0.6 ACH. These days, pretty much anyone shooting for an energy efficient target has their eyes on the Passive House standard – even if not building a true Passive House per se.

Although that was the ultimate target, when we were building and modelling the house, we’d shot for a modestly ambitious goal of 0.8 ACH (again my prior post for the background information). I was only aware of a handful of houses that had been able to reach 0.6 ACH in Canada and much less that had ever done so in Saskatchewan. Anyways, when we’d originally run the Blower Door Test in 2015 we’d ended up hitting 0.72 ACH – meeting our goal. We were happy with that.

Still after we’d tested, Howard, who ran the test, speculated the results were perhaps not entirely accurate and he’d suggested running the tests again. But one thing led to another and we got busy, life happened and we sort of forgot about doing it again…

That is until this past Spring. I’d written in my last post about having issues with 2 of our exterior doors needing to be replaced due to bowing of the frames (increasing leakiness). When we replaced these we’d also decided to add cam locks to all of the doors to increase the seal and prevent any potential bowing in the future. Surprisingly, we had noticed almost immediate improvement in the comfort of the house. It’s strange but when you have such an energy efficient house any slight deviations from it (that you may not ever perceive in a standard home) become blatantly obvious.

Also, which I did not write about, but around the same time I realized that the locking mechanism on one of our windows was not working at all – basically the window would close but it did not lock (also increasing leakiness). When the service technicians came out to replace the doors, they fixed the locking hardware of this window as well. We asked them to check all of the other windows when they were here and they recognized that a couple of the other windows were not totally centred (several of our windows had to be site glazed, i.e. glass installed in the frames on site as they were too big to ship with the glass in the frame). So they fixed those as well.

I started to think back to the Blower Door Test. I wondered how much tighter our house was now that these issues were fixed? I mean, we actually noticed a perceptual physical change in the airtightness of the house. It felt different, better. How could that not correlate to some change in the actual air leakage values?

I contacted Howard again and asked if he would like to come repeat the test. I was cautiously optimistic about the potential to actually reach 0.6 ACH – the Passive House standard. But I was not going to hold my breath.

IMG-2876

The testing took about an hour or so and I was anxiously awaiting the results.

Drum roll…

The air leakage rates for the house were:
Depressurization: 0.56 ACH
Pressurization: 0.61 ACH
Total: 0.58 ACH

That’s right. We hit the 0.6 ACH Passive House benchmark! Might have been 3 years in the making but we made it. I’m so pleased with the results.

Granted back in 2015, as I said, there really weren’t that many houses that hit the 0.6 ACH Passive House benchmark. There are more houses since that are reaching this standard and I couldn’t be happier that we can now put ourselves in that fairly elite category as well. It makes me very proud of the house and all the people that have worked to reach that level of efficiency.

Processed with VSCO with a6 preset

 

Year 2: Solar Tracking and Energy Use for 2017

Posted on by kent

Last year, I’d been very pleased with the house’s first year performance, but after analyzing the numbers, I’d thought there was still room for improvement.

Processed with VSCO with b1 preset

With a few tweaks and utilizing our wood stove a bit more, I was looking forward to seeing how we did for 2017 compared to our first year. Let’s find out!

For completeness sake, below are some key stats from my previous 2016 blog post about our energy modelling and actual use:

HOT2000 Predictions:

Annual Space Heating Energy Consumption: 7159 kWh

Annual Domestic Hot Water (DHW) Energy Consumption: 3409 kWh

Annual Appliance Energy Consumption: 8760 kWh

TOTAL = 19,328 kWh/year

PHPP Predictions:

Annual Space Heating Energy Consumption: 7584 kWh

Annual DHW Energy Consumption: 3974 kWh

Annual Appliance Energy Consumption: 11,310 kWh

TOTAL = 22,868 kWh/year

PV Array Predictions (6.2 KW)

PHPP Estimation: 7321 kWh/year

Solar Installer’s Estimation: 9300 kWh/year

Also:

For interest, according to Stats Canada website’s most recent 2011 home energy use data, a Saskatchewan home consumes an average of 30,555 kWh/year (110 GJ), of which electricity for appliance use is 8889 kWh/year (32 GJ).

2016 ACTUAL TOTALS:

Actual Solar PV Generated = 8189 kWh

Actual Household Energy Consumed = 19,000 kWh

Actual Total Energy Used (consumption – PV) = 10,811 kWh

We did pretty darn good in 2016, actually coming in under the estimated values with the exception of the higher end of the solar production (though that is the manufacturer’s estimates so probably these are the “best case scenario” numbers anyway).

So how did we do for 2017?

2017 ACTUAL ENERGY CONSUMPTION AND PV GENERATION:

January: Solar generated = 250 kWh vs. Energy Use = 2979 kWh

  • A dramatic difference no doubt. But I was not surprised given I had 2016 to compare, it’s January in Saskatchewan after all. Still our energy use was less than the previous year (by almost 400 kWh) so we were off to a good start.

February: Solar generated = 378 kWh vs. Energy Use = 1258 kWh

  • This is when I did my experiment. We kept the boiler set at 65°F and tried to burn wood as much as possible. There was a more than 50% drop in energy use (electric) from 2016.

March: Solar generated = 695 kWh vs. Energy Use = 1652 kWh

  • Pretty much the same as 2016. We kept the boiler set a bit high at 68°F (65°F is too cool first thing in the morning!). But it was starting to get warmer this month. Note that we used over 400 kWh more this month then February – due to less wood heat, even though the outdoor temperatures were rising.

April: Solar generated = 736 kWh vs. Energy Use = 1125 kWh

  • April kind of sucked. It was cloudy and not very Spring-like at all. Many days were around the freezing temperature still.

May: Solar generated = 1143 kWh vs. Energy Use = 840 kWh

  • Hot month and hit the net positive energy production one month early as a result.

June: Solar generated = 1092 kWh vs. Energy Use = 708 kWh

  • It was a hot and dry month and I watered the garden nearly every day which uses a fair bit of electricity to run the water pump at the river.

July: Solar generated = 1112 kWh vs. Energy Use = 575 kWh

  • It was really hot again in July. Only 2 or 3 days of rain all month.

August: Solar generated = 982 kWh vs. Energy Use = 643 kWh

  • Almost completely opposite weather to 2016, which was extremely rainy. This month was HOT and DRY.

September: Solar generated = 744 kWh vs. Energy Use = 662 kWh

  • Finally started to become seasonal temperatures in September. But still remained Net Positive for energy use.

October: Solar generated = 555 kWh vs. Energy Use = 771 kWh

  • Last October (2016) was terrible – snowing on October 4th. This October was more normal and as such, our energy use was 50% less than 2016 (1478 kWh). I did turn the boiler on for the basement heat, but not on the main level.

November: Solar generated = 234 kWh vs. Energy Use = 1569 kWh

  • It snowed on November 1st and stayed snowy and cold until the last week of the month when it got above freezing and melted a lot of the snow off.

December: Solar generated = 291 kWh vs. Energy Use = 2229 kWh

  • December was extremely cold again with several days of -40°F. Good fun. But still used way less energy then 2016 (almost 600 kWh less!) despite it being a similar month weather-wise.

ACTUAL TOTALS:

Actual Solar PV Generated = 8212 kWh (Comparison 2016 = 8189 kWh)

Actual Household Energy Consumed = 15,011 kWh (Comparison 2016 = 19,000 kWh)

Actual Total Energy Used (consumption – PV) = 6799 kWh (Comparison 2016 = 10,811 kWh)

Shheeeet! That’s good! I was pleased about 2016, but 2017 was awesome. That’s a 4012 kWh reduction of our electrical energy use from the previous year. And at $0.12/kWh that works out to a $481 saving for the year.

Granted we burned more wood this year than last. I’d estimate we burned around 3/4 cord of wood in 2017 compared to about 1/3-1/2 cord in 2016. But at $250 per 1 cord that’s still a good savings. My February experiment had the biggest single month change with mostly burning wood. I have no idea how to factor in the equivalent energy. Obviously it’s not zero. Maybe another post if I find some information on it.

Even so, almost every month we improved from the prior year. I think part of that was us getting used to the functioning of the house and getting our house thermostat temperatures dialled in better at least in the winter. As for why it was still less energy use in the summer months, well, I’m not sure?

Our solar generation was almost identical to the 2016 which was good to see.

My favourite comparison though is to the Canadian home average of 30,555 kWh/year. At 15,011 kWh, our house used 50% as much energy, while factoring in solar use, it’s at 78% less energy use then the average house. High fives!

Also we were again, way under the predictions of both the HOT2000 (19,328 kWh/year) and the PHPP (22,868 kWh/year), which is pretty sweet. Again, I have to wonder how close we would have come to meeting the Passive House standards had we made sure to reach the 0.60 ACH airtightness benchmark…

Processed with VSCO with b1 preset

Speaking of airtightness, in January (2018) we made a few changes to our doors to try and get a better seal.

I wrote in the “everything is perfect” article how we’d had issues with bowing of two of our three doors from Duxton. I’ve been really happy with the service of Duxton and they’ve been out to our house a few times now to tweak and make some changes to help optimize our house’s performance this past year. But the doors had been a problem since the beginning with not getting a great seal on top and bottom corners. In an apparent airtight house, leaky doors is not something you want. Due to the bowing of the door frames, Duxton offered to replace the doors at no charge. Still, we had some issues with getting a really tight seal even after replacement.

Duxton now offers multi-point locking doors which, like it sounds, have multiple latches that create an extra tight closure. Unfortunately, I didn’t know they were available at the time or they actually weren’t available yet when we ordered our original doors, either way a deadbolt with one single 1″ contact in the middle of 6.5′ tall door, inherently doesn’t create an optimal closure. So what were our options? We did chat with Duxton briefly about pulling out the doors and retrofitting them with their multi-point doors, but the labour and extent of work to do so was going to be terribly extensive. Instead, we went with a simpler option: cam locks.

IMG_6133

We had them install two of these low profile cam locks on each of the doors: one at the top and one at the bottom. Immediately we’ve noticed a difference. The house felt… snugger. We’ve also noticed a significant improvement in the heat retention of the house overnight. It does not cool off nearly as quickly at night, even on the -40°F/C nights. It’s tempting to have another blower door test done as I’m certain there has been a fairly dramatic improvement with this simple fix. I wonder how much under 0.72 ACH we’d be now…

It’ll be interesting to compare the above numbers with 2018. I’m not expecting as dramatic a change from this past year as I’m not going to burn as much wood – just what is comfortable for us. But I think the change in airtightness will have really positive effect. We will see.

The February Experiment: Heating with Wood Fire

Posted on by kent

After writing my last post, and happily confirming that our house had exceeded our expectations for energy use for 2016, I’d made the comment: “Based on the predicted numbers, the heating energy likely accounts for about 50% of our overall energy use. Makes me wonder too how much better we could do if we burned wood a bit more often?”

I’d written that without thinking about what that would mean too much. But after re-reading my post I got thinking, ‘Hmm… what if we did burn wood more?’

We tended to keep the thermostat around 70°F in the winter, which was comfortable, but would still allow us to have a wood fire on occasion and warm the house up to 73-74°F. It’s not that we really needed it, we just liked it. The in-floor hydronic heat can certainly meet our heating requirements. But we’d figured the wood stove would always be our back-up heat in the event of a prolonged power outage or in extremely cold weather. BUT – what if we flipped it and tried a little experiment? Make the wood stove our primary heat source and our in-floor heat the back-up. I’d also received our most recent bill from the power company which advised that our electrical rates had gone up 3% for 2017…so…

Impressively, my wife was game for the idea too. So, on February 1st, we turned the boiler way down, to 65°F, and started loading the wood stove.

My objectives for the month were:

  1. To determine if we would love/hate or be impartial to the need to fill the wood stove in the morning and night.
  2. To determine if we would be comfortable with the house temperature we could maintain.
  3. To determine how much electrical energy we could save by using wood as our primary heat source.

First off, I love our wood burning stove from Morso Denmark. And I love fire. Who doesn’t really? Isn’t their something primordial about sitting around a crackling fire with friends and family? We’d had it a mandatory requirement from day one of the house planning that we would have a wood burning stove in the main living space.

fire2

I’d only ever seen one house with the stove in front of the windows and I think it is a brilliant spot. It doesn’t obstruct our view during the day, but at night the fire gives a nice focal point to the room. This placement also allows it to be viewed from the kitchen, dining room and living room and extend it’s heat range to the bedrooms on the main floor.

We have a wood nook directly opposite the wood stove that is 24″x84″x20″ which contains the mess and also adds another interesting feature to the room.

living1

But enough about design and aesthetics (although I do want to write about that again sometime), let’s talk about function.

My goal was to keep the house around 69°-72°F during the day and a bit cooler at night while we slept.

The month of February was an interesting temperature mix. The first week was stupid cold (-30 to -40°F/C). But then typical for SK, it warmed up to above freezing temperatures for mid-month and then dropped to seasonal temperatures for the last week (-15°C or 5°F). This made it actually a very convenient month to test the wood heat giving us a fair bit of variety.

The first week (very cold week) we burned through the entire wood storage nook. This was surprising to me as I’d only filled it twice the entire winter beforehand! We were going to use up some wood. Basically what I would do is start a fire when I got up (it was good reason to get up and not to hit the snooze button too). The house temperature was around 66°F or 68°F most mornings. I’d get it hot, then load it up and turn the damper down before work. Passive solar gain would keep the house reasonably warm during the day and when we’d get home the house was usually about 69°F. We’d start the fire again and keep it burning until we went to bed, usually trying to get the house temperature up to around 74°F. Again, I’d load up the stove and turn the damper way down before tucking in.

I actually didn’t find this nearly as much work as I thought I would. In fact, I liked it quite a lot. Certainly it’s more work then just getting up and doing nothing, but it really wasn’t bad.

By the second and third weeks, we were in our groove, and the outside temperature was mild. We used half as much wood and the house stayed above 70°F most days and nights, which was higher then we’d had the boiler set at before.

In the last week, we used a bit more wood again, but it didn’t seem like much work. I ended up loading the wood nook three times for the month in total.

We had pine, tamarack, maple and poplar wood that we burned for the month. The pine and tamarack had been what we’d mostly been using for the winter. It’s a soft wood, but has high BTU output, so it burns hot, and also burns quickly. It’s good for a quick warm-up if the house is cooler, but it doesn’t give that prolonged slow burn you might want at night time. It does however burn clean, not giving off a lot of smoke and ash. Maple is a bit better for the prolonged evening slow burn given that it is a hardwood. While the poplar, well, it’s crap. I regret burning it. It’s a dirty wood, very smoky and lots of ash. It’s BTU output is crap too. Oh well. Now I know.

wood

OK so for objectives #1 and #2, I realized that I was generally impartial to the work of loading the stove. We loved the wood heat though. It was comforting and, in fact, most days the house was able to stay above the typical 70°F temperature we’d had the boiler set at previously, which was a nice bonus. Some of the really cold days when you’d wake up to 66°F inside were a bit uncomfortable for the first few minutes until the wood stove got things warmed up. Also, I didn’t really want to be in bare feet on the concrete floors. Even though the house would be warm, we generally would wear slippers.

Now, the big question was, was the extra time/effort worth the energy savings?

This was something that I was most interested in and there was no way to know for sure until I checked out power at month’s end. I’d had the data from 2016 so it was easy to compare the numbers. Based on my notes from February 2016, it was a similar month in terms of average temperature, however as you will see, there are some significant differences. I’m fairly confident that a direct comparison from February 2016 to February 2017 is reasonable. So what did the numbers show? Let me tell you:

February 2016: Solar generated = 553 kWh vs. Overall Energy Use = 2706 kWh

February 2017: Solar generated = 378 kWh vs. Overall Energy Use = 1258 kWh

First off, I was shocked at the overall energy use! It was a massive drop from the previous year. That’s a 64% drop in electrical energy! Wow. I  really did not expect that. And as you can see it’s not like we had an especially sunny month by any means, the solar generation was actually one-third less than last year so we weren’t even getting much passive solar heating.

Needless to say, I was very pleased with these results. When I crunched the numbers a bit more, the cost savings were $177.00 (1448 kWh x $0.12224/kWh)! In a single month. That’s awesome.

Roughly taken over the course of an entire winter that could be upwards of $1000/year in energy savings if we burned wood regularly. And now, well, I’m seriously considering doing just that…

fire3

 

How Were Our Energy Predictions? An Analysis of the First Year Energy Use: Solar and Energy Performance

Posted on by kent

bwhouse

We had spent a lot of time planning and designing a house that would be energy efficient, aesthetically pleasing, and cost effective. This is a fine balance to try to find. However, it really is a big guessing game until you actually live in the space and track it’s performance. You can run all of the computer programs you want, but you really don’t know how things will be until you’re in and living your normal life.

We had installed PV solar panels on the house to combat some of our energy use with the hope that someday we could work towards a Net Zero home, but this too, seemed to be a big guess as to how well it would perform.

In the planning and designing stages of the house we ran a couple different energy models on the house. The first is called the “HOT2000” program. “HOT2000 is an energy simulation and design tool for low-rise residential buildings.  This software is widely used across Canada to support program, policy and regulatory development and implementation.  HOT2000 is developed and managed by the Office of Energy Efficiency at Natural Resources Canada” (NRCAN). It was originally designed for use with the R2000 energy efficiency program, which was an early promoter of green home building in Canada.

We later used the Passive House Planning Package (PHPP), which is now the widely used software program for building highly efficient homes worldwide.

My intent with this article is to report the varying predictions of the these two programs, as well as our predicted solar generation, and also to show our actual energy use for the year of 2016 – our first full year in the new house. I’ll also report some considerations and possible options for the future.

1: PRE-BUILD ENERGY MODELLING

I had been very curious about this when we were in the early stages of planning the house. Most of what I read was the predictions of various homes, but I’d only come across one house that actually tracked and reported its energy use – that being the Mill Creek Net Zero House in Edmonton, AB, Canada. Which, although using exceptionally little energy, did not meet it’s net zero target. That being said, it was very close.

I fully did not expect our home to be anywhere close to net zero, but we hoped that over the next number of years we could gradually build our solar panel array (as costs come down) to eventually reach our goal.

OK, let’s get to the numbers:

HOT2000 Predictions:

Annual Space Heating Energy Consumption: 7159 kWh

Annual Domestic Hot Water (DHW) Energy Consumption: 3409 kWh

Annual Appliance Energy Consumption: 8760 kWh

TOTAL = 19,328 kWh/year

PHPP Predictions:

Annual Space Heating Energy Consumption: 7584 kWh

Annual DHW Energy Consumption: 3974 kWh

Annual Appliance Energy Consumption: 11,310 kWh

TOTAL = 22,868 kWh/year

PV Array Predictions (6.2 KW)

PHPP Estimation: 7321 kWh/year

Solar Installer’s Estimation: 9300 kWh/year

So obviously there are discrepancies between the HOT2000 and the PHPP. Although their prediction of Heating and DHW are quite close, surprisingly the Appliance use was significantly different. Also, surprising was the discrepancy in the solar predictions – I was a bit disconcerted by the drastic difference of 2000 kWh/year!!

For comparison’s sake, according to Stats Canada website’s most recent 2011 home energy use data, a Saskatchewan home consumes an average of 30,555 kWh/year (110 GJ), of which electricity for appliance use is 8889 kWh/year (32 GJ).

Drum roll please.

… Actually first, some clarifications. All I have is our actual overall energy use. I cannot separate out Heating vs. DHW vs. Appliances unfortunately, although this would be interesting. The following information is taken from the solar panel’s generation and the Electrical meter. I tracked each month and have recorded it below.

OK, now the drum roll.

solar

2. ACTUAL ENERGY CONSUMPTION AND PV GENERATION:

January: Solar generated = 315 kWh vs. Energy Use = 3323 kWh

  • Yikes! I was a pretty worried when I saw this. That being said, January was very cold and has very short, dark days (-20° to -30°Celsius most days. We kept the house around 71°F).

February: Solar generated = 553 kWh vs. Energy Use = 2706 kWh

  • February is always a cold month. Although you can see the solar was getting a bit more sunlight already as the days lengthened.

March: Solar generated = 603 kWh vs. Energy Use = 1716 kWh

  • This was getting a bit better still. I lowered the house temperature to 69°F. It was getting warmer outside and more solar gain.

April: Solar generated = 979 kWh vs. Energy Use = 1385 kWh

  • April was warm and sunny. Nice spring weather. Started to not need the in-floor heat on at all during the day, but still ran it during the night.

May: Solar generated = 960 kWh vs. Energy Use = 1029 kWh

  • Almost net zero for the month. It was a very nice month. We were running our river pump frequently to water new grass, which I think increased energy use quite a lot.

June: Solar generated = 1434 kWh vs. Energy Use = 989 kWh

  • Net Positive in a big way. Beautiful month. Obviously the longest days of the year.

July: Solar generated = 956 kWh vs. Energy Use = 511 kWh

  • The first two weeks of July were cloudy and rainy which is unusual for July.

August: Solar generated = 950 kWh vs. Energy Use = 645 kWh

  • This month was very rainy as well, which again, isnot normal. Usually August is very hot.

September: Solar generated = 778 kWh vs. Energy Use = 611 kWh

  • Cool and cloudy. I replanted grass seed and was running the river pump a lot again.

October: Solar generated = 315 kWh vs. Energy Use = 1478 kWh

  • October sucked!! 315 kWh is the same as January! It snowed on October 4th. We had to turn the heat back on. There were only 2-3 sunny days all month.

November: Solar generated = 390 kWh vs. Energy Use = 1750 kWh

  • Cloudy month, but had some mild days mid-month with above freezing temperatures. Still, we generated more solar in November then October, which should not happen.

December: Solar generated = 229 kWh vs. Energy Use = 2857 kWh

  • Shortest days of the year and extremely cold (-40°F). What do you expect?

ACTUAL TOTALS:

Actual Solar PV Generated = 8189 kWh

Actual Household Energy Consumed = 19,000 kWh

Actual Total Energy Used (consumption – PV) = 10,811 kWh

3. DISCUSSION

I’m extremely pleased with these numbers! I’ve been waiting for two and a half years to know what our actual energy use would be.

We actually used less overall energy then was predicted by both the HOT2000 (19,328 kWh/year, although it was close) and a LOT less then PHPP (22,868 kWh/year), which is surprising that it was so off… It makes me wonder how close we would be to meeting the Passive House standard given the actual energy use is 3868 kWh less then it predicted… Hmm. Maybe we should have tried to hit that airtightness target of 0.6 ACH after all. Oh well.

Nonetheless, the overall energy use of 19,000 kWh is very good (and such a nice round number too!). We did not do anything different in terms of our behaviour except to just be smart and not be wasteful. I still baked bread every weekend and we used our larger appliances just like we normally would. We have two refrigerators and two deep freezers in the house. All the lights are LEDs. We try to hang our clothes to dry. We used our wood stove occasionally, maybe 2-3 times per week, but mostly just for ambiance and occasionally on the extremely cold days. That being said, based on the predicted numbers, the heating energy likely accounts for about 50% of our overall energy use. Makes me wonder too how much better we could do if we burned wood a bit more often?

As for the actual solar PV generation (8189 kWh), it pretty well split the difference between the installer’s predicted 9300 kWh/year and the PHPP prediction of 7321 kWh/year. I think this past year was on the cloudier side for sure. We had a lot of rain in the Spring and even more in the Fall, which is very unusual. Followed by an extremely early snowfall which seriously cut into our PV generation (see October – brutal). It probably would be closer to the installer’s prediction on a typical year (will have to see what 2017 brings).

Still based on the actual numbers, our solar panels did cover nearly 45% of our overall energy use for 2016. We would however need to double our solar panels (add another 6.2 KW array) to meet Net Zero with consistency year to year. Who knows, maybe in the coming years the costs will drop more and perhaps government incentives will increase. One can hope.

Comparing our house to the average Saskatchewan home consumption of 30,555 kWh, we did very well. Using 37% less energy then the average home. And when you take into account the solar energy generated that drops us further to using 65% less energy then the average house! Sweetness.

Considering that we are completely on electric energy, it makes sense to make the house as energy efficient as possible. The cost of electricity for us is $0.12224/kWh (while cost for natural gas power is about $0.04/kWh equivalent), which works out to an electricity bill of $1321.54/year (10,811 kWh x 0.12224). We do however have to pay a basic service fee of $32.61/month (even when we are net positive in a month) which sucks and then 5% tax. That brings our absolute costs for the year to $1798.50/year or $149.88/month, which is about half the cost of our previous homes power and electricity bill. I’m ok with that.

throughthetrees

This post was updated on March 4, 2017. 

Solar panels – Good for the environment, good for your wallet

Posted on by kent

It wasn’t enough for us to simply reduce our carbon footprint through building a super-insulated eco-house. We wanted to come as close to eliminating our footprint completely by working towards a net zero standard. The house envelope, airtightness, passive solar design, and thermal mass of the house, would all have the effect of reducing our energy consumption by 75-80%. The rest of our energy for heating, domestic hot water, and appliances was purely electric based, with the exception of our wood burning stove. We have no natural gas to our property – and to be honest, even if we did, we would not have hooked it up. Burning fossil fuels for energy, despite it’s current affordability, is not a clean energy source nor is it sustainable. Still, despite what some people say, electricity – at least in Saskatchewan – is not sustainable nor is it clean either. Our electricity comes from a power plant that uses a combination of coal and natural gas. Really, in one of the windiest and sunniest places in the world, you’d think we should be able to have some capacity to utilize renewable energy sources. Unfortunately, this is often a top-down decision in the government and sadly, both our provincial and federal governments are heavily financed through their strong ties to the oil and gas industries in this country (no matter how much of a downturn there has been in the markets over the past year) and there is no sign of this changing anytime soon

Until such a time that the collective elite decide to recognize the need to shift away from non-renewables, it will continue to be left to the grassroots movements and local homeowners to decide if they care enough to make a commitment to renewable energy – despite the upfront costs of doing so.

But these times are changing. No longer is it purely a decision of environmentalism. Now the argument of the economics of renewable energy can be made. Let me present this in layman’s terms (as I am, of course, a layman myself).

Our projections for electrical energy consumption:

Estimated yearly energy use (DHW, appliances, heating) = 14,508 kWh (including regular wood stove use for heat)

Cost per kWH hour of electricity in Saskatchewan = $0.1456

Our projected electrical costs per year = 14,508 x 0.1456 = $2,112.36/year or $176.03/month

We worked with a company in Saskatoon, called MiEnergy, in sizing a choosing which solar array system would best suit our needs. We decided to purchased a 6.2 kW PV array. There was the option to upgrade to the 9.3 kW system but we felt that this would definitely be oversized for us at this point. The 6.2 kW system will be slightly under-sized but we can always add on more panels at a later date if we so choose.

6.2 kW system delivers an average of 775 kWh/month = 9330 kWh/year on average

That provides us an immediate saving of $1358.45 per year ($113.20/month) in energy costs. Expanded over the course of a 25 years this delivers $33,961 in electrical savings at the current electrical rates. (I found an interesting article on the energy outlook in the U.S. – there has been a $0.04 cent rise per kWh from 2003 to 2013. Extrapolating that, conservatively, over the next 25 years we should expect an upwards $0.08-0.10 rise per kWh. That equals between $0.22-0.24/kWh. The projections from MiEnergy pegs the 30 years saving at $58,067).

If you take the cost of the PV panels and roll this into a 25 year mortgage at a current 3.19% interest, this only costs a meagre $110/month. So essentially instead of giving $113.20/month (currently, which will increase) to the government to cover our extra electrical bill, we will invest $110/month towards the PV panels on our mortgage. After 25 years, they are paid for and we have money in our pocket (not to mention the fact that we’ve saved 233,250 kWh of energy from being generated at a polluting power plant). That’s a win for us and for Mother Nature.

IMG_3047

If you want the facts and economics only, then disregard the story that follows. Of course, I wish my post, could be that short and simple. But as I’ve learned with building the house – something always goes wrong – no matter how bizarre, stupid or impossible it might seem…

The above photo is the after shot. After I received the phone call at 6pm on a Friday night from Saskpower (the electrical company) asking why a large steel beam had been driven directly through their power line?

“Uh… I don’t… know?”

You see there is this thing called: “Call Before You Dig.” It’s a free service that most places have that asks that you please call them to mark your underground power and gas lines before digging so that you don’t kill, maim, electrocute or otherwise dismember yourself. Unfortunately, as we learned that night, it is not a perfect service.

The solar company had called and had the power line (note, the singular word: line) marked a couple of days before the planned installation. Unfortunately, there were in fact, two power lines running into our transformer, one from our neighbours place to ours and the other running from ours to about 60 houses over the next number of miles. Well, you guessed it, they hit the one running to the 60 houses (that was not marked), knocking out their power for the next 8 hours. Oopsy.

IMG_3040When I showed up to the house, you could see the one line that was marked (as it was prior) with the solar panel racking system 4-5 feet away, then you saw where they had discovered the 2nd line, lying directly underneath the 2nd row of racking (not previously marked). The Saskpower guys though were very good, they realized it was not the fault of the solar company, nor mine, the line simply had not been marked by the Call Before You Dig people. They were just glad that no one had been hurt. They were able to restore power to the 60-odd houses that had been affected and the next day they were back out to splice and move our newly rediscovered power line.

(Incidentally, this was a total blessing, had they actually marked both power lines previously, we would not have been able to put the solar panels where we had wanted them. We would have been forced to find another, less ideal spot a much greater distance away).

By the way, we have had a number of people ask us why we did not choose to utilize a solar thermal system for water heating. Basically, it was because of this article and this article on Green Building Advisor.

Is Passivhaus Appropriate for a Cold Canadian Climate?

Posted on by kent

This is something I’ve been wrestling with since we decided on building a super-insulated, highly energy efficient home. And really this is something that I think a lot of builders, architects, and designers of eco- and green homes have been debating about since the Passivhaus concept came to North America in the past few years. When we initially got going on our project I was pumped on the possibility of ‘not needing an active heating system’ – as Passivhaus enthusiasts have touted their homes on. However, that really is not quite true.

Although many of these Passivhaus homes in Europe don’t necessarily use a boiler or furnace as we do in Canada, they do still technically require some way of heating. Often that is a heating coil attached to the existing ventilation unit that warms the incoming ventilated air. For our house, the possibility of using such a system simply made no sense. Passivhaus often justifies some of its standards on “user comfort.” Certainly I agree that user comfort is critical, however, in order to meet some of the rigorous standards of Passivhaus, people have tended to sacrifice comfort to meet the certification. For example, in our project, indeed, we could have used this method of heating as a secondary option, but it would not be sufficient to meet all of our heating needs despite the super-insulation. Furthermore, we need a thermal mass (concrete floor) to take advantage of the solar gains to cut down on our heat load. Those of you who have walked around on a cold concrete floor know that this is pretty uncomfortable (as a physiotherapist, I cannot count the number of people I see who complain about knee, back and foot pain due to walking on concrete floors at work). That being said, a warmed concrete floor is very pleasant, and strangely comfortable. Given that we wanted a concrete floor for both thermal mass and aesthetics, it made no sense to me not to use in-floor hydronic heat. In this case, we had to choose user comfort over Passivhaus standards.

Another major criticism of Passivhaus standards is both the annual energy consumption and annual heating/cooling consumption standards. These standards are very strict at 120 kWh/m.sq./yr and 15 kWh/m.sq./yr. I’ve previously written about these as well. But is this actually possible to attain in a very cold Canadian climate? Indeed this has been shown to be possible in a handful of projects in Canada. But not that many. Why is that? Recently we’ve run our numbers through the HOT2000 software, which is a Canadian software for energy efficient homes to calculate energy consumption. It’s not as thorough as the PHPP Passivhaus software, but it’s pretty good, and a lot cheaper to have done.

Ok so here are our numbers:

House size 1240 sq.ft (main floor) + 1240 sq.ft (basement) = 2480 sq.ft of treated floor area = 230 m.sq of total treated floor area.

Estimated Annual Space Heating Requirement: 7159 kWh / 230m.sq. = 31.13 kWh/m.sq/yr

Estimated Annual Electrical Space Heating (minus expected wood stove use): 2342 kWh / 230 m.sq. = 10.18 kwh/m.sq/yr
Estimated Annual DHW Heating: 3409 kwh
Estimated Annual Appliance: 8760 kWh
TOTAL ENERGY CONSUMPTION: 19,328 kWh / 230 m.sq = 84.04 kWh/m.sq/yr
First let me explain a couple things. One, we expect to use our wood stove a lot in the winter. I love a wood fire, there is something incredibly comforting about watching wood burn. Two, I do think that the annual appliance use is on the high side and I would also argue that our total space heating is also a bit high when comparing it to the Mill Creek NetZero house, an eco-house project using the same wall system in a similar climate. Nonetheless, let’s give these numbers some context:
Our House Projected Annual Space Heating = 31.13 kWh/m.sq/yr
Our House (minus wood stove heat) Annual Space Heating = 10.18 kWh/m.sq/yr
vs.
Passivhaus Annual Space Heating Standard = 15 kWh/m.sq/yr
Ok, so you can look at the comparison numbers I’ve provided above for Passivhaus and the average Canadian home versus our place at 31.13 (overall heat requirement) and 10.18 (electrical space heating requirement). Both of these numbers are A LOT less than the Canadian average. I’ll use the 31.13 number because it is the highest possible use we would need in an extremely cold year without using any wood heat. That is 77.3% less than the average house in Canada! Pretty awesome! And yet, it is twice as high as the Passivhaus standard!!
I’ll remind you that we are using the following: R100 ceiling, R56 above grade walls, R32 below grade walls and R32 under slab insulation. We are also having significant south glazing and minimal north glazing. We will be installing the highest efficient fiberglass windows and we expect the airtightness of the house to meet the Passivhaus standard of 0.60 air changes per hour at 50 pascals. So, WTF?
The bottom line here is that Saskatchewan is a lot friggin’ colder than Germany. The number of heating degree days in Germany in 2014 was 3100. The number of heating degree days in Saskatoon in 2014 was 6035. Well, that’s about twice as much, which would account for our need for twice the heating load – makes sense! Therefore, I have a hard time understanding how the standards of German Passivhaus can be applied to a very cold Canadian climate.
If we look at the overall Total Energy Consumption (84.04) however we are actually significantly lower than the Passivhaus standard of 120. This begs the question of, in Germany, what is accounting for the 105 kWh/m.sq/yr difference of energy if not for heating? Is their appliance and hot water use that much higher? Or is this particular standard higher to account for the larger homes and buildings that are typically built with Passivhaus? (This brings up another criticism of Passivhaus penalizing smaller homes. Check out this article for an exhaustive list of criticisms of Passivahus in North America. Passivhaus US and Canada have recognized the limitations of the European standards and are taking steps to try to modify these to be appropriate in North America. However at this time, the standards are still up for debate).
Anyways, what do these numbers really mean, except to compare apples (Germany) to oranges (Saskatchewan)? We weren’t going to be pursing Passivhaus certification anyways (at an approximate $10,000 price tag for certification, I’d rather put that money into solar panels). But I think it provides an interesting discussion. In the end we will be building a highly efficient, super-insulated house that will consume about 75-80% less energy than the average Canadian house. We truly won’t know our overall energy consumption until we actually live in the house so all of these numbers are a bit arbitrary.
Yes, you can build a “true” Passivhaus on the prairies, but you’d be looking at making huge financial investments and sacrificing comfort to meet the standards.
I’m reminded of a discussion I had with a local energy efficient home builder recently. He said: “Anyone can build an extremely energy efficient house with enough money. But to build one on a budget, now that is something impressive.”
In the end, we are building on a budget, which should come in at or below the cost of building your average stick framed house and our energy bills (100% electric) should be in the range of $100/month. I think I can live with that.