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How to Make it Air Tight: Move the AB Outside!

There’s no trick to making buildings air tight; pick the least penetrated sheet good either on the inside or preferably the outside of the building and seal everything to it. It’s that simple folks! Check out the image below:

 

Exterior Air Barrier

Portland Maine’s Jesse Thompson‘s got it figured out; put the air barrier on the OUTSIDE and seal everything to it! See the window bucks on the right; the pans are flashed! In the above, the insulation ideally will be placed tight against the air barrier. If you think this house won’t look groovy, you’re wrong, check out the rendering below. Canadian carpenters; take note.

I hope the house above will have overhangs added for protection of windows, doors and walls from the elements. Admittedly adding framing lookouts in situ is tougher than to build rake walls on the ground, but either way, this house has made air sealing very simple. The electricians and plumbers can drill away inside and it won’t affect the air barrier.

P1040481 (Medium)

The taping festival goes on in Ontario and it’s 2016. We know better, stop with the 6mil poly masquerading as an air barrier. Let the poly be what it’s supposed to be; a vapour barrier only! Then put your air sealing efforts outside where you won’t have to air-seal a million holes around framing, wires and plumbing penetrations. Besides, the OBC says if the above poly is the AB, the seams need to be clamped.

 

The other great advantage of sticking the air barrier, hopefully with shingle-style lapped seams, to the sheathing is that no air can travel under the fabric air barrier and its substrate. Tack on the vertical furring strips for the drainage layer and it makes for a durable air barrier. So if you’re considering making your indoor 6 mil the air tight layer, give us a call, we’ll show you why your building won’t perform optimally.

For the record, the blue house above will look like this when completed:

Thompson Kaplan Arch

If you were thinking the house wrapped in blue Henry VP100 was going to look square, think again; this rendering is what Kaplan Thompson Architects have in mind for their build. Fresh, contemporary and very appealing.

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What are the Feds doing for Building Efficiency?

“Budget 2016 proposes to provide $128.8 million over five years, starting in 2016–17, to Natural Resources Canada to deliver energy efficiency policies and programs, and maintain clean energy policy capacity. These resources will support improved energy efficiency standards and codes for products, buildings, industry and vehicles, and further the development of a legislative framework for offshore renewable energy projects.” reads the fed’s website, but if you’re wondering what the fed’s are proposing in their new budget for building energy efficiency, it’s a sea change from the last regime.

But as Elizabeth May says “… but when comparing Budget 2016 with the last Liberal budget – from former Finance Minister Ralph Goodale in 2005 – this one misses the mark on climate action,” said Elizabeth May, leader of the Green Party of Canada.”

Green Party Secretary Dan Palmer goes on to say “The 2005 budget offered a fully formed climate action plan, including eco-energy rebates for homeowners, substantial funding for provinces to act to address the climate challenge, rebates for the purchase of energy efficient vehicles, and a carbon pricing scheme through a complicated carbon credit approach. The 2016 budget contains none of these measures.”

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The Ground Source Heat Pump: SB-12′s Silver Bullet or Hail-Mary Pass?

Since 2012, for the well-to-do who want to build a new house anywhere that’s not serviced by a natural gas line in Ontario, the decision making process for custom homes with lots of glass eventually whittles down to installing a Ground Source Heat Pump (GSHP). But is the GSHP a Silver Bullet or a Hail Mary pass when it comes to SB-12′s distorted view of energy efficiency?

Heat pumps are brilliant machines and unlike the electric baseboard heater which converts electrical energy directly into heat, a heat pump uses electrical energy to “move” heat. A GSHP moves heat from the ground into the house in winter time but in summer time, it pumps the heat out of the house back into the ground. The same with an Air Source Heat Pump (ASHP), except that an ASHP moves heat from the air in the house to the air out outside. Because heat pumps move heat instead of generating heat, they are up to 3 times as efficient in their use of utility-based electricity.

It’s that last point that has many new home owners with GSHP in Ontario feeling the sting. As electricity prices keep going up, any GSHP that happens to run on auxiliary heat the during utility’s peak prices, will see a massive spike in heating cost. Remember, time of day use varies from 8.3¢ per kWh to 17.5¢ per kWh and at twice the price, it doesn’t take long. Imagine filling your car’s gas tank during rush hour for $2 a litre as opposed to filing up off-peak for only $1 a litre; when would you shop?

Putting aside Henry Gifford’s contention that “heat pumps actually use more fossil fuel than a furnace or boiler” one cannot deny that their exact energy performance isn’t always cut and dry. There are many factors that go into designing and installing a GSHP system and it should be known that identical systems installed in 2 different locations by different installers and used by a different occupants with different lifestyles will have an impact on the performance of the GSHP.

For example, did you know that some loop fields need to be “recharged” with summer-time heat and actually depend on the occupant using the AC to pump heat back into the ground or risk running out of stored heat the following winter? Did you know that a GSHP system’s loop length is something not to be be trifled with and that it needs to be purged with a very high powered pump when commissioned? Commissioned? Yes, your installer should provide you with a Commissioning Report. You’ll also need a very large electrical panel; 60A for the pump, 60A for the auxiliary heat (read: electric resistance heating).

Where the vagaries of GSHP systems seem to be given short shrift is in the Ontario Building Code. SB-12 relies on old energy modeling software used to calculate “compliance” to building codes and gives the GSHP with electrical resistance backup accolades that might not always be deserved given the potential for variance in their mechanical components, geological fields, occupant lifestyle and control parameters.

Remember, if you’re going to install a GSHP, get it commissioned per link above but first have an expert energy modeler help you reduce your loads. Not all software is equal and you may want to follow many of the Passive House principles to help you design with thermal comfort in mind. If installing lots of thermally weak components like windows, don’t cheap out; invest in high performance windows that are sized to benefit the occupant’s comfort and compliment your HVAC system. We’re also looking forward to the 2017 version of SB-12 that will see the adoption of new more powerful and specialised software – WUFI Passive -  that can help the design community avoid thermally weak envelope designs by calculating interior surface temperatures of window frames and exterior walls to avoid drafty feeling rooms and windows condensation.

Remember, don’t paint yourself in a glass corner; if you have large wall(s) of glass in a given room, the room should be thermostatically controlled and zoned independently to optimize comfort. Finally, if you’re betting on the Hail-Mary pass, heed Peter Yost of GBA words “Ground-source heat pump systems work great if you have an expert installer, for both the above- and the below-grade work, and you stick with the leading manufactured systems. Play with either or both of these and you are playing with fire.”

 

 

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Compliance VS Performance Energy Simulations

As change to the energy performance of proposed buildings goes through the meat grinder of the legislative process, we’re keeping our fingers crossed that the Ontario legislature brings meaningful change as they, rightly, slap consumers with higher electricity costs – albeit still substantially lower than EU rates. As a special to the Globe and Mail, John Lornic wrote two columns a few days ago focusing on the issues highlighted by Ted Kesik “a professor at the University of Toronto, [who] says the condo developers have exploited a loophole that allows them to erect towers clad in one of the least energy-efficient materials: glass.”

The sad truth is, it’s not just the high-rise sector that exploits energy simulation or modeling loopholes. The energy modeling loopholes also apply to the low-rise residential sector and BlueGreen Group is starting to see the fruit of the 2012 OBC changes in the volume of complaint calls from luxury homes, often with substantially more than 22% window to wall ratio. These well-to-do homeowners want to know what can be done to their new home to make the rooms more comfortable or figure out why their Ground Source Heat Pump is always running on auxiliary electric resistance as opposed to drawing from the bore field causing electrical bills in winter in excess of $2000. A $2000 monthly electrical bill isn’t chump-change, even for a rich guy.

Lornic touches on the Compliance concept in his second article saying “Despite all the political rhetoric about emissions reductions, if you want to build a really efficient home, you can’t rely on the code – you need to hire specialists to design it.” As we blogged a few days back about the myriad changes to SB-12 proposed for 2017, we wish more would have been done but hope at the very least that the proposed changes stick.

The proposed 15% increase in overall energy efficiency might just mean that serious changes to the building envelope and significantly better windows get installed – which by the way are still getting short shrift from building inspectors who rarely check that installed window performance is in compliance with what was promised in the Energy Efficiency Design Summary. For that matter, there are countless windows being installed TODAY that are NOT ENERGY RATED!

Compliance energy modeling differs from Performance energy modeling in that it only seeks to satisfy the bare minimum requirements building code. Compliance is the absolute minimum required by the code and it’s often calculated by a quirky piece of software – HOT2000written before the iPhone was available.

Whereas, performance energy modeling seeks to minimize utility bills and if the professional doing the energy modeling has a good grasp of building science, they bring comfort into the equation too by using more modern software like WUFI Passive. This is where the confluence of field experience and a deep understanding of how energy models or simulators work.

Just because an energy model says its OK, it still doesn’t trump common sense when designing a building and our diagnostic business is confirming that builds merely ‘complying’ with the code have some new home owners VERY frustrated. Some have been allowed to pain themselves into a glass corner, some were promised the Ground Source Heat Pump was a silver bullet.

Either way, if you’re an architect or design build firm, drop compliance energy modeling like a hot potato; it’s a liability to your reputation. Hire experts that do performance energy modeling and who can help you detail your building envelope to produce a home your client will be both comfortable paying the utility bills or lounging by a large window on a cold blustery day.

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Proposed Changes to SB-12 are Posted

Kyle Anders of Mindscape Innovation wrote a great blog piece highlighting the proposed changes to OBC’s SB-12. The following is an excerpted quote from their great monthly news letter:

The Ontario Ministry of Municipal Affairs and Housing (MMAH) is working to finalize the next version of the Supplementary Standard SB-12 (2017). SB-12 is the standard that Ontario home builders (i.e. for Part 9 buildings) must use to meet the minimum energy efficiency design requirements of Part 12 in the Ontario Building Code.  This SB-12 update will include more stringent energy efficiency requirements for new homes, in order to achieve the mandated target of 15% energy savings versus the current standard.  This is the first major SB-12 update since its inception in 2012, and it will come into effect for all permit applications after December 31st, 2016.  MMAH is requesting input from key stakeholders in the building, design, manufacturing and municipal government sectors to help finalize this standard, and has provided the following documents:

1) Draft MMAH SB-12 (2017) Version

2) Background Document and Comment Form

Anyone who cares about the future energy efficiency and cost effectiveness of new homes in Ontario should pay attention to this and have their voice heard on the issue.

 

Key Changes Proposed for 2017 Version

  • 15% Energy Efficiency Improvement: Each SB-12 package is designed to be 15% more energy efficient than current SB-12 packages, based on an ‘average’ home.
  • Fewer Packages: To reduce redundancy of unused packages in the current version, the proposed number of prescriptive packages will be less, e.g. 6 instead of 13 for the scenario of Zone 1 – Natural Gas.
  • Now in Metric! Metric thermal values are now included in addition to imperial.  Metric continues its slow and steady march to global domination
  • Effective Thermal Resistance: Minimum thermal performance values for various assemblies are now listed in both nominal and effective.  This will give a boost to buildings that use exterior continuous insulation, well the actual performance of the entire assembly, including thermal bridging through the studs, is recognized.
  • Mandatory Heat Recovery Ventilators: Heat Recovery Ventilators is proposed to be mandatory across all packages, in order to facilitate better indoor air quality in airtight homes.
  • Credit for Reduced Air Leakage: Recognition for demonstrating increased airtightess of the building envelope with a blower door test has been added.  Improved airtightness can be used as a substitution for various insulation upgrades.
  • Drain Water Heat Recovery (DWHR) Tradeoff has Been ‘Discreetly’ Removed: While MMAH doesn’t specifically indicate this in the list of proposed changes in their Backgrounder document, the proposed SB-12 (2017) update has been scrubbed of all traces of DWHR: where builders currently have the option of being credited for including DWHR by trading off another upgrade, they will no longer have this option under the drafted SB-12 (2017) update.
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Retrofitting Vintage Homes for Energy Efficiency

A presentation by Greg Labbé in April 2014 on retrofitting vintage home for energy efficiency. He talked about basic building science, brick houses, movement of heat energy and moisture in and out of the house, air barrier and water barrier, house foundation, ventilation, insulation and testing of the houses. The talk was presented at the Annette Street Public Library in Toronto.

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Missed Last Week’s Event? We Got You Covered!

If you missed last weeks High Performance Meets Boots on the Ground Event held at our office, we can’t give you the networking part, but here’s the complete technical part. Enjoy!

 

 

 

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BGG gives a Talk at the PBC AGM

Passive Buildings Canada recently posted a presentation we gave at their fall 2015 AGM.  The talk covered the latest findings based on our testing and field observations.

Here it is in all it’s unexpurgated glory!

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Quoting a Job: Think you Got it Hard?

I marvel at the late English steeplejack, Fred Dibnah, who’s work was highlighted a number of years back by the BBC’s Made in Britain. I’ve always loved to listen to Fred ramble on as he goes about his work at high altitudes with little to no protection.

Here, he can be seen painstakingly putting up a series of maybe 20 ladders just to inspect the chimney so he can prepare a quotation for services. So the next time you complain about the effort it takes to put a quotation together, have a look at this wonderful short:

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Building Details: Air Sealing Chimney Penetrations

Getting a good air seal around chimneys – be it masonry or metal – is always challenging. Although the details could be more clearly defined, I was happy to stumble on Natural Resources Canada’s following detailed drawings in the latest version of Keeping The Heat In:

fig5-4_e_2

Though in concept good, there are two clarifications the illustrator needs to more clearly define. It would be nice to know if the ceiling flange (labeled ‘fire stop’) connects to the outside face of the chimney or the outside face of the radiation barrier. Also, the detail showing the detail showing the air and vapour barrier needs to be clarified, it just shows up.

fig5-3_e_3

Here too the illustrator should show a bead of acoustical sealant on the cut away for clarity. This detail relies on dimensional lumber to carry the air seal, so where cross-cut, sealant or tape needs to be applied.

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