ERV Selection Software — Sizing Energy Recovery the Way the Code Now Demands

Five years ago, Energy Recovery Ventilators were a checkbox on green-rated projects. Today, ASHRAE 90.1 and most regional codes mandate them across a wide swath of commercial buildings — which means every ventilation engineer needs an answer to "what ERV did you select, and why."

What ERV selection actually entails

ERV sizing is a multi-physics problem that catalog-table selection cannot solve cleanly:

Effectiveness across operating conditions. Sensible, latent, and total effectiveness vary with airflow, temperature delta, and humidity. The summer-design number you quote is not the winter or shoulder-season reality.
Pressure drop on both sides. ERV pressure drop hits both supply and exhaust fans — meaning the wrong selection moves the load somewhere it doesn't belong.
Frost control and cross-leakage for cold climates and contamination-sensitive environments (healthcare, labs).
Bypass strategy so you're not recovering heat when free cooling is available.

A real ERV Selection Software handles all four against certified curves, for both wheel and plate-type units.

How MileSoft handles it

The MileSoft ERV Selection tool sits on the same engineering spine as our AHU, FCU, and Chiller selections. Three things matter most:

Multi-condition modeling. You select for design-day, but the tool also reports recovery effectiveness across the full annual bin profile.
Plate vs wheel comparison. Side-by-side TCO comparison for the same project so you can defend the choice to a discerning consultant.
Integration with the broader HVAC tool chain. When the AHU sizing changes, the ERV revisits its selection automatically — no more orphaned components.

The capabilities that matter most

Annual energy modeling that produces a single number an architect can put in front of a green-rating consultant.
Frost-control logic with selectable strategies (face-and-bypass, preheat, modulating) so cold-climate projects don't surprise anyone in February.
Branded submittal package that's audit-ready out of the box.

Where it fits

The natural pairings:

AHU Selection Software — the ERV's job is to make the AHU's job smaller.
Lifecycle Cost Analysis — for the wheel-vs-plate-vs-no-recovery comparison the customer didn't know they needed.

The takeaway

ERV is no longer a niche selection — it's a code-driven, annually-audited piece of every commercial HVAC project you'll touch this decade. Picking from a catalog table means owning the consequences when the actual effectiveness misses the spec sheet.

Book a demo and we'll size the ERV on a real project against your current method. The delta is usually the most expensive number in the conversation.

Frequently Asked Questions

What is ERV Selection Software?

ERV Selection Software sizes Energy Recovery Ventilators using certified sensible, latent, and total effectiveness curves across full annual bin profiles — not just the design-day point — ensuring code-compliant selection and accurate energy savings claims.

When is an ERV required by code?

ASHRAE 90.1-2019 and many regional codes now mandate energy recovery on ventilation systems above a defined airflow threshold in most commercial building types. The specific trigger depends on climate zone and occupancy category.

What is the difference between a wheel ERV and a plate ERV?

Rotary wheels offer higher effectiveness but have minor cross-leakage, making them unsuitable for some healthcare and lab applications. Plate (crossflow or counter-flow) units have zero cross-leakage but lower effectiveness. MileSoft models both types against your project's conditions for side-by-side comparison.

How does MileSoft handle ERV frost control?

The tool models face-and-bypass damper, electric preheat, and modulating preheat frost-control strategies. Each strategy's energy penalty is included in the annual energy model so the lifecycle cost comparison accounts for frost-control parasitic load.

Can ERV selection feed into Lifecycle Cost Analysis?

Yes. MileSoft ERV, AHU, and Chiller selections all feed into the Lifecycle Cost Analysis module, allowing a full central-plant TCO comparison that includes energy recovery as a line item alongside chiller, cooling tower, and AHU energy.

What is an ERV (Energy Recovery Ventilator)?

An ERV is a heat-exchange device in a ventilation system that transfers both sensible heat and moisture between exhaust and supply air streams — reducing the energy cost of conditioning outdoor air by pre-treating it with the energy already in the exhaust.

Is an ERV the same as an HRV?

No. An HRV (Heat Recovery Ventilator) transfers only sensible heat. An ERV transfers both sensible and latent (moisture) energy — making it more effective in humid climates where dehumidification is a significant portion of the cooling load.

Why does ERV effectiveness vary across operating conditions?

ERV effectiveness is a function of airflow ratio, temperature delta, and humidity. The summer-design effectiveness the catalog quotes is different from the winter or shoulder-season value. A selection tool calculates effectiveness across the full annual bin profile for accurate energy savings claims.

What is bypass control in an ERV system?

Bypass control is a strategy that diverts airflow around the ERV core when outdoor conditions are mild enough that direct ventilation is more energy-efficient than recovery — typically in spring and autumn. Selecting the right bypass strategy is part of the energy model, not an afterthought.

How does MileSoft ERV selection connect to annual energy reporting?

The ERV selection feeds directly into MileSoft's Lifecycle Cost Analysis module, which sums energy recovery savings across the full annual bin profile. The result is a single energy-savings number (kWh/year) that can be placed in a green-rating consultant's energy model.