The launch of the R2000 program in the 1980s landed on its face because of issues related to humidity and air quality but it didn’t have to be that way. With the Ontario Building Code poised to make Heat Recovery mandatory in ventilation systems, will Ontario unwittingly get a black eye for doing the right thing?
With CO2 levels rising both in the house and in the atmosphere, the province of Ontario has finally taken small steps to implement higher building energy efficiency for 2017 in the Ontario Building Code. As part of those requirements in SB-12, the province is mandating special ventilation equipment be installed in each new house that will, for the first time, make heat recovery part of the ventilation system. Prior to this, ventilation systems largely consisted of crude and wasteful exhaust only ventilation systems that would grind away in the background forcing air out of the house, typically through one large principal bath exhaust fan, and pulling fresh air indiscriminately in through building envelope leaks.
Like it or not, houses are getting more air tight and that’s a good thing for energy efficiency and comfort, especially if you have a fully ducted Heat Recovery Ventilator (HRV) and the home owner appreciates why its important. Unfortunately, most homeowners don’t know much about their ventilation systems much less how to operate and maintain them. Adding insult to injury, HRVs are poorly understood by building official and builders alike.
Pulling the Plug on Loud
In my years of energy auditing, there’s a direct relationship between noise and machine use. The more noise a machine makes, the less likely occupants are to use said machine, even if their health depends on it. Loud kitchen exhaust ranges over gas stoves in homes tend not to be used and ditto loud bath fans; even if the mould on the wet window frames is screaming for fresh air and a tighter grip on humidity control.
The irony is that homes are getting more quiet indoors as they become more air tight and better insulated. These significantly quieter new homes tend to make small noises from mechanical equipment sound louder. As a designer, if you’re thinking of cheaping-out on the ventilation system be forewarned; the system may be get unplugged and the home owner will suffer.
In a 3 month span, I found two homes in the municipality of Toronto, each less than 1km from the Humber River, that had disastrously installed HRVs (See photos below). Both systems were permitted by the municipality and it’s reasonable to infer that both systems were inspected and given the green light by the municipality.
The province would be wise to push ventilation system literacy onto homeowners so they don’t poison the air they breath and technical training at the very least for building inspectors as well as designers and HVAC technicians. A bit of training on why its preferable to have low sone ratings on ventilation equipment and fully ducted systems might help too.
As for the designer of the home or the mechanical system, you’ll be mandated to have heat recovery so make the house tight to ensure the HRV earns its keep. Further, consider having these “lungs of the house” commissioned not only to catch issues in this budding industry but also tune the systems so that each room gets the designed quantity of fresh air that the occupants deserve.
West of the Humber
Composite image of the wall where penetrations from left to right are: white DHW exhaust, black sump drain pipe, white furnace exhaust, white furnace intake, brown HRV Intake, white DHW intake, brown kitchen exhaust, brown HRV exhaust, brown clothes dryer, grey gas meter and hose bib. A good distance from pollutants is minimum 6′ and the HRV intake is sucking in dangerous polluted air.
Indoors, the HRV has issues of its own; no condensate drain connection!
East of the Humber
BEFORE: Granted, this combined HRV and forced air unit isn’t common, it doesn’t take a rocket scientist to figure out that only one (un-insulated) pipe going to to the HRV is wrong.
AFTER: Now we have two pipes with a bit of insulation on them; lower – stale air exhaust, upper – fresh air intake.
BEFORE: Of the 6 possible circular and two backwall knockouts, only one (blue), is connected as exhaust – but where does it get it’s air from given that neither of the two back knockouts are open either. It’s a dead end.
AFTER: Now each quadrant has a knockout open for circulation! Of the 6 possible circular knockouts, now two are open (blue). As in previous picture, one’s connected as exhaust the other an intake. The left quadrants are now open at the top (circular, black) and bottom back wall polygon hole.