What’s the Difference Between HRV and ERV?

An HRV (Heat Recovery Ventilator) transfers heat from outgoing stale air to incoming fresh air, while an ERV (Energy Recovery Ventilator) does the same and also moves moisture. Understanding the difference between HRV and ERV systems is the first step to choosing correctly. 

In a cold climate like Nova Scotia, an HRV is usually the default fit, unless your home runs dry all winter, in which case an ERV is worth a closer look. In this guide, we walk through how both systems work, who each one's right for, and how to make the call for your specific home.

What Is an HRV (Heat Recovery Ventilator)?

An HRV works by swapping stale indoor air for fresh outdoor air while capturing the heat from the outgoing air and transferring it to the incoming air. The two air streams never actually mix; they pass through a heat exchanger core that transfers heat.

The result: you get fresh air coming in, but it's already been pre-warmed by the outgoing air. In a cold Halifax winter, that's a big deal. You're not blasting cold outside air straight into your home every time it ventilates.

HRVs are particularly well-suited to cold, dry climates. They move heat, but they also move moisture out. If your home tends to be humid (think: condensation on windows, lingering bathroom moisture), an HRV is often the right call.

HRV quick summary:

• Recovers heat from exhaust air

• Reduces indoor humidity

• Best for cold climates with higher indoor moisture levels

• Great fit for newer, tightly sealed homes

What Is an ERV (Energy Recovery Ventilator)?

An ERV does everything an HRV does, but it also transfers moisture between the two air streams, not just heat. So instead of pushing humidity out with the exhaust, an ERV holds some of it back.

This is useful in climates with very dry outdoor air, such as extremely cold winters or hot, dry summers. An ERV helps prevent your home from getting too dried out when you're ventilating.

ERV quick summary:

• Recovers both heat and moisture

• Maintains indoor humidity levels

• Better for dry climates or homes that struggle with low humidity in winter

• More common in milder or variable climates

How HRV and ERV Systems Work

Both systems follow the same three-step process:

1. Exhaust stale indoor air

2. Capture the energy from that outgoing air

3. Precondition the incoming fresh air before it reaches your living space

In winter, that means pre-warming cold incoming air. In summer, both systems help reduce the load on your air conditioning by pre-cooling incoming hot air.

The real difference comes down to one component: the heat-exchange core.

	HRV Core	ERV Core
Material	Sealed aluminum or polymer	Desiccant or semi-permeable membrane
Transfers heat	✓	✓
Transfers moisture	—	✓
Winter behaviour	Exhausts excess indoor humidity	Retains moisture; prevents air from getting too dry
Summer behaviour	Exhausts heat	Blocks humid outdoor air from entering

The airflow path between the two systems is nearly identical, but the core material is what separates them.

HRV vs ERV: Side-by-Side Comparison

The difference between the two systems becomes clearest when you lay them out side by side across the factors that actually matter to a homeowner deciding between HRV and ERV.

Criteria	HRV	ERV
Moisture transfer	Heat only, no moisture exchange	Heat AND moisture exchange
Best climate fit	Cold, dry climates (most of Canada, northern US)	Mixed-humidity or hot-humid climates
Best season performance	Excellent in winter; neutral in summer	Strong year-round in variable climates
Ideal home humidity profile	Homes with excess moisture (occupants, cooking, plants)	Dry homes or those with low winter humidity
Energy efficiency	High, recovers 70–80% of heat energy	High, recovers heat and latent energy
Typical installed cost	~$1,200–$2,000 (CAD)	~$1,400–$2,500 (CAD)
Maintenance requirements	Filter cleaning every 1–3 months; annual service	Filter cleaning every 1–3 months; annual service
Operating noise level	25–50 dB depending on fan speed	25–50 dB depending on fan speed

Which System Is Right for Your Home?

The honest answer depends on where you live and how your home manages moisture.

If you live in a cold climate like Nova Scotia, your home was built in the 1990s, and every winter your family's skin dries out, and you're running a standalone humidifier in the bedroom, that's a home losing moisture through normal air exchange. An ERV would help retain more of it without adding extra equipment.

Flip that situation: same cold climate, but you have a large family, frequent cooking, and your basement runs damp in shoulder seasons. That home already produces plenty of moisture, and an HRV is the right call to exhaust the excess rather than retain it.

Ultimately, the choice comes down to a single question: Does your household need to lose moisture or hold onto it?

Here are the four decision factors, per guidance from Natural Resources Canada:

1. Climate Zone: Cold, dry climates point toward HRV. Mixed-humidity or milder climates point toward ERV.

2. Home Age: Pre-1970 homes are naturally leaky and may not need moisture retention. Post-1977 airtight homes benefit more from ERV moisture management.

3. Household Moisture Profile: High-occupancy homes with frequent cooking and indoor plants produce excess moisture, and HRV helps exhaust it. Dry homes benefit from ERV retention.

4. Existing HVAC: Running a whole-home humidifier already? An HRV pairs well with it. No humidifier? An ERV can reduce your reliance on add-on equipment.

Choose an HRV if:

• You're in a cold Canadian or northern US climate

• Your home is already humid from occupants or cooking

• You have an existing whole-home humidifier

Choose an ERV if:

• Your home runs dry in winter

• You live in a mixed or humid climate

• You want to reduce reliance on separate humidification equipment

How Colgrove Air Can Help

We install HRV ventilation systems for Halifax-area homeowners, and we won't oversell you on something your home doesn't need.

When you call us, you're talking directly to a technician, not a call centre. We'll ask the right questions about your home, your current setup, and what you're actually dealing with: humidity issues, stale air, and condensation on windows, before making any recommendations.

HRV installation also pairs really well with a new heat pump. If you're already investing in a heat pump for heating and cooling efficiency, adding proper ventilation at the same time rounds out your home's comfort system in one shot. Check out our heat pump installation services to see how the two work together.

We service the full Halifax Regional Municipality and surrounding communities. If you're not sure which system your home needs, give us a call at (902) 830-1676. As your trusted HVAC contractor in Upper Sackville, we'd rather answer your questions up front than have you guess.

Final Words on the Difference Between HRV and ERV

Both HRV and ERV systems are sound investments for any modern airtight home. The right choice almost always comes down to your climate and your home's moisture balance, and now you have the framework to make that call with confidence. If you're not sure which system is right for your home, we're happy to talk it through. We actually answer our phone.

Contact us today! We're happy to help you figure out what your home actually needs.

Key Takeaways

• HRV: Recovers heat and removes moisture; best for cold, humid climates, which cover most of Nova Scotia.

• ERV: Recovers heat and moisture. Better for dry homes or milder climates.

• For most Halifax-area homes: An HRV is the more common recommendation, but your home's specific conditions matter.

• Not sure? Give us a Colgrove Air. We'll talk it through with no pressure and no sales pitch.