HRV vs ERV: Commercial MVHR and ERV Fresh Air System FAQ for Dealers

I handle commercial HRV/ERV and air recuperator orders for Napoleon dealers and contractors. Eight years now. I have personally made and documented six significant mistakes, totaling roughly $18,400 in wasted budget, rework, and rush freight. Now I maintain our team's pre-check list. Here are the questions I get every week.

If you have ever ordered a heat recovery ventilation system and found out at commissioning that the ratings did not match the job, you know the sinking feeling. This FAQ is for you.

Is an HRV the same as an ERV?

No. An HRV heat recovery ventilation system transfers sensible heat only. An energy recovery ventilator transfers sensible heat plus moisture. That difference matters in commercial HVAC. In 2019, I assumed 'same airflow, same result' and swapped an ERV for an HRV in a restaurant makeup air package. The space had high winter humidity from dishwashing and laundry. The HRV could not manage the latent load. Not ideal. We added dehumidification and controls. Cost: $3,200. Per ASHRAE 62.1-2022, you still need to meet ventilation rates, but the standard does not let you ignore moisture. So specify ERV when latent recovery is required. Specify HRV when you mainly need sensible recovery and the space is dry. And remember: 'air recuperator' is often a generic translated term. Ask whether the spec actually wants moisture transfer.

When should you specify an ERV instead of an HRV?

Specify an ERV when your building has a real latent load or a humid climate. Think high-occupancy spaces, restaurants, laundries, natatoriums, and buildings where winter dryness or summer humidity causes complaints. The ERV fresh air system can recover moisture in winter and help reject incoming humidity in summer. That is basically a two-for-one on the ventilation load. I learned this the hard way in 2019, as noted above. Then again, ERVs are not magic. They need proper frost control, drainage, and filter maintenance. In very cold climates, check the frost control strategy. In dirty exhaust streams, check cross-leakage and filtration. If your project is a dry, cold building with simple sensible recovery needs, an HRV may be simpler and cheaper to maintain. Bottom line: size and select based on psychrometrics, not on the acronym.

What does 'commercial MVHR' mean in North America?

MVHR stands for mechanical ventilation with heat recovery. It is common in UK and European specs. In North America, people usually say HRV, ERV, or energy recovery ventilator. I assumed 'commercial MVHR' meant the same voltage, controls, and certifications as a US ERV. Didn't verify. Turned out the submittal had 230V/50Hz components, different duct connections, and no AHRI 1060 listing for the exact configuration. We caught it before shipment on eight units. Re-engineering added three weeks and $4,200. Expensive lesson. So translate the term first. Then verify voltage, frequency, static pressure, controls protocol, and certifications for your market. 'Air recuperator' is another translation trap. It can mean plate HRV, rotary enthalpy ERV, or something else. Trust me on this one: get the core type in writing.

How do you size an ERV HVAC system for commercial projects?

Start with required outdoor airflow from ASHRAE 62.1-2022 or your local code. Do not start with the unit's nominal CFM. Then calculate external static pressure at design airflow. Include filters, dampers, ductwork, heat recovery core, and any heating or cooling coils. In 2021, I approved 12 ERV fresh air systems based on catalog 'max CFM.' At 0.4 in. w.g. external static, actual airflow was 18% below design. The building failed commissioning air balance. Rebalancing and adding boosters cost $6,800. What I mean is that the catalog number is not the installed performance. Ask for fan curves at your real static pressure. Check temperature exchange effectiveness and latent effectiveness at winter and summer design conditions. Also confirm the unit can handle the required airflow at the available power and control sequence. If the fan curve does not reach your design point, the project will find out at commissioning.

What certifications should I check before ordering?

For HRV/ERV performance, check the HVI Certified Products Directory and AHRI Standard 1060 listings. As of March 2025, HVI is still the first place I check for airflow and energy performance at published conditions. For commercial code, ASHRAE 62.1-2022 and ASHRAE 90.1-2022 drive ventilation and energy requirements. Local code may be stricter. I once assumed a submittal sheet was enough. The authority having jurisdiction asked for certified ratings at specific static pressure. We did not have them for that configuration. One-week delay. So before you promise a delivery date, verify certification listing, voltage, controls protocol, filter access, and installation orientation. Then verify current requirements at the official source, because codes and listings change. If you have ever had a submittal rejected for a missing rating, you know why I keep this checklist.

What is the biggest ordering mistake with commercial MVHR and ERV fresh air systems?

Assuming 'same specifications' means identical results across vendors. In September 2022, I ordered 10 ERV fresh air systems using another vendor's spec sheet as a template. I assumed airflow, static pressure, and control sequences were apples-to-apples. They were not. Two vendors rated airflow at different external static pressures. One included filters in the rating. One did not. The result was a mismatch across 10 units, $5,100 in controls rework, and a very uncomfortable call with the contractor. The lesson: build a line-by-line comparison. Airflow at ___ in. w.g., temperature exchange effectiveness, latent effectiveness, power draw, filter pressure drop, and controls. Do not assume. Verify. That one habit has caught 47 potential errors in the past 18 months. It is boring. It works.

How do I avoid balance and commissioning problems?

Design for commissioning before you order. Specify balancing dampers, pressure taps, and a controls sequence that reports airflow or fan speed. Then require a factory or field commissioning checklist. I went back and forth between two ERV units for two weeks on a 40,000 sq ft office project. Unit A offered higher nominal airflow. Unit B had better low-static performance and simpler balancing. On paper, A made sense. But my gut said B. We chose B because the duct layout had more resistance than the initial estimate, and B held airflow at 0.6 in. w.g. That decision saved us from a repeat of the 2021 rebalance. Honestly, the first cost was not the main issue. The cost of fixing air balance after ceilings are closed is the issue. If you have ever watched a contractor chase airflow with a ladder, you know exactly what I mean.

Is an 'air recuperator' the same as an HRV?

Usually, 'air recuperator' is a generic or translated term for a heat recovery ventilator. But not always. Some suppliers use it for an ERV. Some use it for a plate HRV. Some use it for a rotary enthalpy wheel. In 2020, I assumed 'air recuperator' meant an HRV with a plate core. The submittal came back with a rotary enthalpy wheel—an ERV—with different frost control and cross-contamination characteristics. It was actually a better fit for the humid climate, but it changed the controls and maintenance plan. We had to revise the O&M manuals and train facility staff. So ask for the core type: plate, rotary enthalpy, or membrane. Then confirm latent recovery, frost control, and cross-leakage. The term alone tells you almost nothing. If you are comparing commercial MVHR options, make the supplier spell out the core and the certified performance.