I’ll Take Residential HVAC for $1000, Alex.
By Corey McCloskey, Customer Response Team Representative
This HVAC component has risen in prominence over the last decade,
and is a major contributor to energy savings, interior air quality, and
also assists in controlling humidity within your home.
What is a heat recovery ventilator?
You tell me.
My cue card says heat recovery ventilator, so I’ll give you your thousand
Bucks, but I have no idea what that means.
Dude, you’re Alex freaking Trebek. You know everything!
Dude, I’m a game show host. Although I do have a degree in philosophy.
And I’m super sweet. It’s my turn to ask the questions!
What have we got for him, Johnny? A heat recovery ventilator, or HRV, is an additional component to a conventional forced air HVAC system, and serves a variety of purposes in your Cedarglen home. Included with the Energuide 80 package, this non-descript looking box in your mechanical room ties in to the return air portion of your HVAC system, and recovers heat from the air already circulating throughout your home and transfers it to the fresh air the unit is drawing from outside. It’s also ventilating stale air from the interior to the exterior. See what I did there? HRV!
Truth be told, these guys have been a mainstay in our homes for the better part of a half-decade, which was well before energy code revisions or climate change accords, which kind of makes us cool before it was cool. Why do something that, technically, still isn’t required in energy code, you ask? Let’s take a step back in time, and check out Alex’s first home in Sudbury, Ontario, way back in 1940.
Like a submarine with a screen door, this house would have been LEAKY, and I’m not talking about rain. This was essentially the time when the building envelope was born but, as you might recall from visits to your grandparents’ old shack, it was still bloody hot in the summer and bloody cold in the winter, but it beat living in an uninsulated house. Enter the forced air furnace. Eventually, people started figuring out that they were wasting a lot of money on fuel by basically heating the outside in the winter. Over the subsequent decades, we made the building envelope better, our homes got tighter, and we lived happily ever after…
Ever try to blow air into a pop bottle? You’re liable to burst something but, more significantly to this blog, it’ll fog up and smell like whatever was going on in your mouth the last time you ate. Put the lid back on the bottle, and it stays that way for a very long time. Think of that bottle as a house, complete with impeccable building envelope details and sprayfoamed rim joists and cantilevers, and add cooking, bathing, pets, offgassing VOCs from the Scotchgard on your Costco furniture, to the breathing you and your family are already doing 24 hours a day, seven days a week. I’d like to solve the puzzle, Pat: WE HAVE AN AIR QUALITY ISSUE.
HRV Air Flow Diagram, courtesy of Lennox
So we made everything better and, naturally, made everything worse, at the same time. The HRV addresses all of the above. As this handy diagram illustrates, cool, fresh air from outside your home mixes with the warm, stale air which has already circulated through the HVAC system, on its way out. Blower fans within the unit, in conjunction with air dampers within the ducting itself, precisely balance air flow, and that cube in the middle of the diagram is an aluminum core, which is kind of like the opposite of the radiator on your car.
Excessive humidity from the clothes hanging in your basement is expelled (or condenses and drains away from the unit), along with the burned toast smell lingering in your kitchen from breakfast, but let’s talk about energy savings. You’ve already paid to heat your home once. As the stale air passes through the core, the aluminum fins absorb some of the heat. When the fresh air from the outside passes through, it’s heading towards the furnace, so why not pre-heat that air with the air you’ve already warmed up?
There’s your energy savings right there, to the tune of 84% sensible effectiveness. What does that mean? That means the air your furnace is pulling in at 0 degrees Celsius goes through the HRV and hits your furnace at 17.6 degrees, and it costs you less to heat it the rest of the way to the toasty 21 degrees you have your thermostat set at. The HRV is just another feature of Cederglen’s Energuide 80 package, so stop by a showhome and check one out for yourself.
Have a great weekend,