HRV vs ERV: Fresh Air in BC Homes, and the Maintenance Both Forget

The Honest Answer Up Front

A heat recovery ventilator and an energy recovery ventilator are the same machine doing the same job with one difference: the core. Both pull stale air out of the wet rooms and push fresh outside air into the living spaces at matched rates, and both run the two streams past each other so the outgoing air warms the incoming air in winter — recovering around 55 to 80 percent of the heat depending on the core and the frost strategy. The HRV core transfers heat only. The ERV core adds a moisture-permeable membrane that also passes some water vapour between the streams. That one membrane is the entire HRV-versus-ERV decision, and we will make it properly in chapter three, because half the internet gets it backwards.

The maintenance answer is identical for both machines and it is short: filters every one to three months, a core inspection and gentle vacuum annually, the exterior hoods kept clear, and one professional deep service a year at $189 that measures what your eyes cannot — airflow against nameplate, motor amps, damper travel, defrost function. A ventilator is a filter, a fan, a core and a control; three of those four are serviceable by the homeowner, and the fourth is where the $189 earns itself.

What neglect looks like, because we meet it weekly in the Step Code subdivisions of Willoughby, East Clayton and Burke Mountain: a machine running at 60 percent airflow on a core felted with drywall dust from year one, filters that were never washed because the manual is in a drawer, and a house that fogs its windows in October while the HRV hums along, technically on, functionally asleep. The fix is almost never a new unit. It is almost always an afternoon.

Why Every New Langley and Coquitlam Home Has One

Ventilators went from specialty equipment to standard issue because of airtightness. The BC Building Code's energy steps — the Step Code tiers that Metro Vancouver municipalities adopted for new construction through the late 2010s and that now underpin the provincial requirements — push builders to seal envelopes to blower-door numbers our grandparents would not have believed. A modern Langley townhome can sit below two air changes per hour at test pressure; a 1970s Coquitlam rancher might sit above ten. Sealed houses are cheap to heat and quiet in the rain, and they also cannot breathe on their own, so the code requires mechanical fresh air — and the heat recovery kind, because exhausting heated air from an airtight house in a Vancouver January is exactly the waste the steps were written to stop.

The practical consequence for homeowners: if your home was built after roughly 2019 in Langley, Surrey, Coquitlam, Port Moody or Abbotsford — or renovated to a permit that required air-sealing — the ventilator is not an optional accessory, it is your lungs. Run it continuously on low, learn its filter schedule, and treat a dead HRV as a genuine indoor-air-quality event rather than a nuisance, because the alternative to its fresh air in a sealed envelope is rising CO2, rising humidity, and window condensation that starts feeding mold by the second October. Our Coquitlam HVAC service area covers the Burke Mountain and Partington Creek builds where we see this newest stock, and the pattern holds from Willoughby to Clayton.

Older homes have the opposite problem, and it is worth one paragraph for fairness: a 1950s Vancouver Special leaks enough that ventilation happens whether you plan it or not. Retrofitting an HRV into an older home is a real and worthwhile project — usually ducted to the wet rooms with the furnace doing distribution — but it is a design conversation, not a bolt-on. If that is your situation, the sizing questions are the same ones we cover in the balancing chapter, and a site visit settles them in an hour.

HRV vs ERV: The Actual Difference, Without the Folklore

Here is the physics, plainly. In winter, the air inside your house carries more water vapour than the air outside — cold air is dry air even at 95 percent relative humidity, which is why North Shore rain somehow dries your house out. An HRV core lets the outgoing stale air warm the incoming fresh air and nothing else: the fresh air arrives warm but dry, and every hour of operation flushes interior moisture outside. That is why HRVs are the coastal-BC default — in a climate where envelopes fight damp eleven months a year, supply air that dries as it ventilates is a feature, not a bug. Big households, daily cooking, showers, a basement suite breathing into the same envelope: the HRV quietly evacuates that moisture load.

The ERV core adds its membrane, and the membrane passes some vapour from the wetter stream to the drier one. In winter, that means the outgoing air gives up heat AND some of its moisture to the incoming air — the house retains humidity it would otherwise exhaust. In summer with air conditioning, the direction reverses and the membrane blocks some of the outdoor humidity from riding the fresh air into your cool house, trimming the latent load on the cooling system. So the ERV is not better or worse; it is tuned for a different humidity problem than the coastal one.

The folklore to ignore: that ERVs are simply the newer, better thing, and that BC homes should upgrade on principle. The honest selection logic runs the other way. House runs damp through winter — fogged windows, musty shoulders-season smells, big family, suite occupancy: HRV, and fix the ventilation rate. House runs dry — static shocks in January, thirsty houseplants, nosebleeds, cracking woodwork, small household in a tight build: the ERV's moisture retention is real comfort. Heavily air-conditioned homes in our humid July-August get a genuine latent-load benefit from the ERV membrane. That is the whole decision, and it is worth having with a technician who carries both cores rather than one who sells one.

The Quarterly Service You Own (Twenty Minutes, Mostly Tool-Free)

The homeowner side of HRV maintenance is genuinely easy, which is why it is so rarely done — nothing about it demands a professional, so nothing schedules it. Open the front panel (most VanEE, Lifebreath and Venmar units unlatch by hand or a single screw), slide out the two filters, and wash them if they are washable foam or replace them if they are media — lukewarm water, a drop of dish soap, air dry fully before they go back. While the panel is open, look at the core behind the filters: if you can see felted dust on the faces, note it for the annual vacuum; if the core faces are visibly mouldy or wet, that is a service call, not a cleaning.

Cadence honestly stated: filters every one to three months — the one-month end for homes with pets, renovation dust, or wildfire smoke weeks in June through September, the three-month end for quieter households. Twice a year, check the two exterior hoods: the intake (usually the one lower or screened) clogs with leaf litter, grass seed, and in late summer the occasional paper-nest wasp; the exhaust hood furs with lint. A thirty-second walk with a screwdriver for the screen keeps both flowing, and a machine starved on its intake side silently loses airflow and recovery efficiency.

Once a year, the core itself comes out — usually two clips or sliders — for a gentle vacuum with a soft brush attachment on the faces only, never a wash unless the manufacturer explicitly allows it (some VanEE and Lifebreath cores are washable in warm water; many ERV membranes are strictly vacuum-only, and washing them is how a $400 core becomes landfill). The full walk-through is in the step-by-step routine at the bottom of this guide, and the payoff is measurable: a clean core at proper airflow recovers up to around 70 percent of the heat a felted one lets march outside.

What the $189 Annual Deep Service Measures

The professional visit exists because the important numbers are invisible. Airflow is the first: we measure supply and exhaust flows against the unit's nameplate at commissioning speeds, because a ventilator can hum along for years while a clogged core, a crushed duct or a failed damper has cut its fresh-air delivery by a third. A house that fogs up or stuffs up with a "running" HRV almost always has an airflow story, and the meter finds it in ten minutes. Motor amperage comes next — the two little fans in these units work long hours, and a motor drawing high amps is a motor arranging its own replacement, which inside the $180 to $650 repair band is a same-visit swap if we catch it before it seizes.

The core gets its professional turn too: a controlled deep clean on washable cores with the manufacturer's chemistry and drying protocol, inspection for the pinhole corrosion that salt-adjacent homes from White Rock to Horseshoe Bay visit on aluminium plates, and on ERV units a membrane check for the tears and fouling that quietly delete the moisture-recovery function while leaving the heat side working. Damper travel, defrost function and the condensate line round out the mechanical list, and the balancing gets verified — which matters more than any other line item in suite homes, and gets its own chapter below.

You receive the numbers in writing: airflow against nameplate, motor amps, recovery temperature readings, and any findings photographed. That report is the same document your builder warranty conversation wants if the unit is young, and the one your insurer quietly appreciates if a moisture claim ever asks what the ventilation was doing. The visit is $189 flat, it pairs naturally with the furnace or heat pump tune-up at $129 in the same truck roll, and the $199 a year maintenance plan wraps both visits with priority booking and 10 to 15 percent off any repair either finds — for a Step Code home with an HRV in its lungs, it is the plan we actually recommend.

Freeze-Up: The Valley Winter Problem Nobody Predicts

An HRV exchanges heat between two air streams, and below roughly -5 to -10 the exhaust side of that exchange gets cold enough that the moisture it still carries can frost the core. Manufacturers handle this with defrost strategies — a recirculation damper that periodically runs house air through the core to melt frost, or a preheater — and in Vancouver proper those strategies almost never engage, which is exactly why nobody here knows about them. The Fraser Valley is different: the arctic outflow events that push Abbotsford, Chilliwack and Mission to -10 and beyond for days at a time put coastal-designed ventilation into its defrost cycle every few hours, and a unit with a failed defrost damper or a worn preheater will ice its core solid overnight in exactly those conditions.

The symptom profile is specific enough to diagnose from the couch: the ventilator runs, but airflow at the registers drops to a whisper through the night, the unit may stop and restart repeatedly, and by morning the intake side of the core — visible when you pull the filters — carries frost or a slick of meltwater that refreezes. A genuinely iced core also risks dripping into the cabinet and tripping the unit entirely. The catch is that by the time a technician arrives at 10 a.m., the outflow has usually eased and the evidence has melted, which is why valley homeowners with this pattern should say the words "defrost cycle" on the phone — it puts the right gauges and the heat gun on the truck.

Prevention is cheap and mostly about location. Intake hoods buried behind snow drifts on a north wall starve the unit and worsen frosting, so terminations get raised or shielded; units in unheated garages and crawlspaces — common in valley builds — get insulated cabinet jackets; and the annual service's defrost test matters more in Chilliwack than in Steveston, where the machine's whole winter job is humidity removal in the rain. If your winter-prep instinct needs an outlet, our winter prep guide slots the HRV check in beside the furnace and the hoses.

Balancing Dampers: The Suite Question Nobody Asks Until It Matters

A ventilator is two fans matched to move equal air: exhaust out, supply in. Balance is set with dampers and grilles at commissioning, and it quietly encodes assumptions about how the house is used. Then life edits the house: a basement suite gets rented in Langley, a mortgage-helper laneway home gets built, a bedroom becomes a grow-adjacent home office, and the exhaust points that were sized for a family of four now serve a family of four plus two adults with their own cooking, showering, breathing schedule. The machine does not know. It keeps moving the air it was commissioned to move, from where it was commissioned to move it.

The failure mode that matters is negative pressure. If exhaust beats supply — a miscalibrated damper, a blocked intake hood, a big kitchen range hood running the house depressurized — the house starts pulling makeup air through every available path: the chimney of the fireplace or water heater, the garage, the crawlspace. Spillage from a gas appliance flue into the living space is the serious version, and Technical Safety BC has spent years educating about exactly this interaction in airtight homes with big exhaust appliances. The everyday version is subtler: suite doors that slam themselves, drafts at electrical outlets in January, and a suite that never clears its cooking smells because the envelope is fighting the ventilation instead of feeding it.

The fix is measurement, not folklore. A properly balanced ventilator runs the house at neutral to very slightly positive pressure, with supply and exhaust flows verified with a flow hood or anemometer at each grille — which is part of the $189 service and takes twenty minutes on a straightforward single-family system. Suite homes get the additional conversation: dedicated exhaust from the suite's wet areas, supply to the common areas, transfer paths that respect both fire separation and privacy, and a CO2 check in the suite bedroom because that is where overnight occupancy tells the truth. If your home grew a suite after its ventilation was commissioned, this single service item is the highest-value hour in this guide, and it pairs with the Langley furnace maintenance visits we run through those same neighbourhoods.

The Failures We Actually See (and What They Cost)

Fifteen years of ventilator calls across Metro Vancouver compress into a short list. First by volume: the clogged core and neglected filters from chapter two — not a failure at all, just scheduled neglect, and the reason a $189 service exists. Second: motor and capacitor failures in the 8-to-15-year window, presenting as a hum with no airflow, an intermittent fan, or the unit's own error light; the motors and caps sit inside the $180 to $650 repair band and are usually stocked on the truck for the common VanEE and Lifebreath lines. Third: damper actuators, especially the defrost damper in valley cold snaps per the previous chapter — a mechanical sticking that shows up as frost or as a unit stuck in one mode.

Fourth: the condensate path. An HRV removes water from the exhaust stream in cold weather, and that condensate drains through a small trap and line — usually to a floor drain, sometimes through an unheated crawlspace in Richmond and Delta builds where it freezes exactly when it is working hardest. A blocked condensate line spills inside the cabinet, corrodes the core rails, and mimics far more expensive failures; clearing and heat-taping the run is a small repair, and a melted-down control board from years of drips is not. Fifth: control-side gremlins — wall controls with failed humidity sensors, dehumidostat wiring nicked by renovation fasteners, and the classic: the unit that has been off since someone flipped the wrong switch at the panel two years ago, which costs nothing and is our favourite diagnosis in the bunch.

What almost never fails: the core itself, unless washed when it should have been vacuumed or corroded by decades of salt air. Aluminium-plate HRV cores are remarkably durable, and even badly neglected ones usually recover with a professional clean. That durability is the honest argument for servicing rather than replacing — a fifteen-year-old HRV with a clean core, fresh filters, one new motor and balanced dampers will outperform a neglected unit half its age, and the math on that swap favours the service every time. When a replacement genuinely is the answer — obsolete parts, a house whose occupancy changed the ventilation math — the honest path is a fresh load calculation and a written quote, not a same-day upsell.

Filters: What Fits, and Why MERV 13 Does Not Belong Here

HRV and ERV filters are not furnace filters, and the distinction saves money and airflow. Ventilator cores are designed around low pressure drop — the two fans are small, efficient, and intolerant of resistance — so the factory filters are typically a coarse washable foam or a low-MERV media in the MERV 6 to 8 neighbourhood, sized to catch the dust that would felt the core while letting the air through. They exist to protect the core, not to clean the house; the air passing through them is a fraction of total airflow, and high-grade filtration belongs on the recirculating system — the furnace or air-handler rack — where hundreds of CFM actually cross the media. Our furnace filter and MERV guide covers that side of the house.

The mistake we meet in the field is upgrading: a homeowner stuffs a MERV 11 or 13 cut-to-fit into the HRV because the smoke-season news cycle scared them, the tiny fans lose a quarter of their airflow against the resistance, and the ventilator now under-ventilates the sealed house it exists to serve — trading real CO2 and humidity control for a token filtration gain on a side stream. If wildfire smoke is the concern, the correct stack is the one our wildfire smoke and indoor air quality guide details: MERV 13 where it counts, on the main system, with the HRV either recirculated or run at reduced fresh-air rates during the worst AQHI days.

Buying filters honestly: note the brand and model of your unit (the label is on the cabinet, and a phone photo outlives the sticker), and buy the manufacturer's washable or media filters rather than generic cut sheets — the fit matters because air bypasses a loose filter the way water bypasses a loose dam. Keep one spare set on the shelf beside the unit; the pairs are inexpensive, and the barrier to a twenty-minute service drops to zero when the filter is already in the house. During smoke weeks, check the filters twice as often — fine ash loads them the way it loads everything else in this climate.

Upgrades: When the Old Box Has Earned a Replacement

Ventilators live fifteen to twenty-five years in this climate — longer than furnaces, shorter than ductwork — and the upgrade decision has honest triggers. Parts obsolescence is the hard one: when the manufacturer no longer stocks the motor or control board for your model, a single failure converts the repair-versus-replace math into replace-only, and we will tell you that plainly rather than hunt salvage parts. Efficiency drift is the quiet one: a 2008-vintage unit recovering 55 percent beside a modern core recovering 75-plus on the same ducts is paying a hidden heating bill every winter, and the delta is measurable with a thermometer at the supply grille on a cold morning. And house changes — the added suite, the finished basement, the heat pump retrofit that altered air distribution — can outrun a unit that was right for the house it met.

The swap itself is one of the gentler projects in HVAC: the duct terminations usually carry over, the cabinet footprint is often close, and the work is a day plus balancing. What we will not do is quote a number before seeing the model, the ductwork and the envelope, because ventilator selection is ventilation-rate math — bedrooms and occupants against the code tables — and the same house can legitimately need two different sizes depending on its suite and its airtightness story. Written quote, load numbers shown, balancing included, and the same commissioning report you would want for any appliance that runs 8,760 hours a year.

The one upgrade we talk people out of most often is the HRV-to-ERV conversion on pure novelty. If your winter problem is damp windows and a house that breathes heavy, the ERV membrane retains moisture and the conversion makes the problem worse; if your winters run dry and staticky, it is a genuine comfort upgrade — chapter three is the whole decision. Either way, the ducts, the hoods and the maintenance routine stay the same, which is the quiet joke of this entire category: the machines argue about a membrane, and the homeowner calendar never notices.

The Whole Category on a Napkin

Sealed the last chapter's threads into the table below, because this category rewards a summary more than most: two machines, one maintenance program, a handful of failure modes, and a small number of decisions that genuinely need a technician in the room.

Read the table with your own house in the first column and honesty in the second, and two patterns emerge that are worth naming. Most HRV problems are not hardware failures — they are airflow problems with a hardware alibi, which is why the same three answers (filters, balance, settings) resolve the majority of the rows. And most of the costs live in the service-visit tier rather than the repair tier: the category is unusual in HVAC for how little of its lifetime budget is parts. That is good news for owners and boring news for parts suppliers, and it is the reason we tell every new-build homeowner the same sentence: the machine you never think about is the one to schedule.

HRV and ERV ownership in BC — the honest one-glance version.

Book It, or Do It This Weekend

This is a category where the homeowner share of the work is twenty minutes a quarter and the professional share is one visit a year, and the gap between done and undone is the difference between a house that breathes clean and a house that fogs, stuffs and grows things in November. If the filters have never been washed since possession, start there this weekend — the routine is written out step by step below, and it requires a screwdriver and a dish rack. If the machine has a history — frosting in the outflow nights, a suite that changed the occupancy math, an airflow that has quietly faded — that is the $189 deep service, and booking it alongside the $129 furnace or heat pump tune-up puts both visits on one truck roll under the $199 a year plan with priority scheduling and 10 to 15 percent off repairs.

For everything ventilator-shaped that is not maintenance — motors, dampers, defrost faults, the balancing conversation — the number is 604-615-2212 and the response runs 30 to 45 minutes in Vancouver, Burnaby and Richmond, 45 to 60 across Surrey, Coquitlam, Langley and Delta, and 50 to 85 minutes out through the valley, with a flat $150 after-hours premium disclosed before dispatch and the $89 diagnostic credited to any completed repair. Ventilation questions are also the least urgent calls in our queue, which makes them the easiest to answer well — use the form below, tell us the unit's brand and model from the cabinet sticker, and we will tell you honestly whether it needs a visit or just a weekend and a screwdriver. The pricing page publishes the flat rates because you should never have to ask twice.