Code and Performance Path

We’re almost one year into the new Ontario Building Code Supplementary Standard SB-12 Energy Efficiency requirements and this article by Gord Cooke which was originally published in Better Builder Article, October 2016 is a great summary of the trends emerging from the changes.

In my article for the last issue I mentioned that the draft of the Ontario Building Code Supplementary Standard SB-12 Energy Efficiency requirements for January 2017 had come out. Well in the ensuing weeks, the final version of SB-12 for 2017 has been made public and there are some compelling trends to discuss. First, the number of prescriptive packages is down reflecting the fact that it is getting tougher to find significant, cost effective incremental energy improvements through simple changes to insulation levels or mechanical equipment specifications. Second, there is a not so subtle mention of air tightness, with the supporting documents of SB-12 hinting that in future code iterations air tightness testing will be mandatory.read more

HVAC Choices for “Zero Energy” Homes

Eveyone has asked the question “So what kind of HVAC system do you put in a house that is supposed to, at the end of the year, use ZERO energy?” at one time or another. This article by Gord Cooke, which was originally published in Mechanical Business, September 2014, answers that question in detail…

Well, of course, that may sound like an oxymoron and at least isn’t a very fair question. But it is worth considering the optimization of HVAC options for what has been referred up till recently as Net-Zero energy homes. The nomenclature may be changing due to an initiative by the Department of Energy in the US. In looking at better ways to communicate the value proposition of homes that, on average, only use as much as they are able to produce themselves on site, they are considering the term Zero Energy homes. Lets not get caught up in this article in the long debate as to exactly how to define “zero energy”; does it include all energy use, big screen TVs, long showers, should it be carbon neutral, should it include power or fuel transmission losses? Moreover, I am not talking about the in-the-woods, off-grid, earth-berm house that has a little wind mill. I want us to consider the thousands of more mainstream zero-energy homes that are being built across North America this year. In this regard allow me to hint simply at some of the HVAC option considerations that we have been going through generally at our company working with five mainstream builders who are this year building Zero Energy homes in Ontario and specifically decisions I have been wrangling with for my own new modest cottage that is now under construction.read more

Furnace Sizing Professionalism

Now that the fall season has rolled around, the cooler temperatures are a good reminder to brush up on all things related to furnaces. This article by Gord Cooke, which was originally published in Mechanical Business, March  2017, outlines how “we as an industry, particularly contractors, salespeople and designers, need to recalibrate the way we think about furnace sizing.”

One of the people I work with was recently shopping around for a replacement furnace in his older home and had a local HVAC contractor come to his house to quote the job. After walking around with a tape measure and calculator for 5 minutes the salesman announced that the house would require at least a 60,000 btu unit. He acknowledged that a 50,000 BTU/hr unit, like the one that was being replaced, would probably do the trick, but seeing as the contractors brand of choice only came only in 40, 60 or 80 increments, he defaulted up to 60,000 BTU/hr. My colleague raised concerns about this size recommendation, as the 50,000 BTU/hr mid-efficiency unit being replaced had always seemed to be short-cycling. The salesman assured him that he would be ‘rolling the dice’ going with a smaller unit, reassuring him that he’d been sizing and selling furnaces this way for almost 20 years… etc., etc.read more