| Airflow capacity | 50 CFM 80 CFM 110 CFM 150 CFM
1 CFM equals approximately 0.472 L/s. | Airflow is reported in cubic feet per minute and should be evaluated using the stated HVI-certified rating rather than the motor’s free-air output. | Ask for the certified airflow value, test report reference, operating voltage, frequency, and whether the rating is for a complete installed fan assembly. | Compare fans at the same certified airflow point. A higher nominal motor capacity does not automatically mean higher delivered airflow. |
| Bathroom sizing reference | For bathrooms up to 100 square feet, a common sizing rule is approximately 1 CFM per square foot, subject to local code and installation conditions. | HVI testing provides a standardized performance reference; it does not replace room-specific ventilation design or local building requirements. | Request the supplier’s sizing guidance, recommended duct length, duct diameter, and performance data at representative static pressure. | Use room size, occupancy, shower frequency, duct layout, and climate together when selecting airflow. |
| Sound rating | Sound is commonly stated in sones.
Lower sones indicate quieter operation. | HVI sound testing provides a comparable loudness rating when products are tested under the applicable stated conditions. | Request the certified sone rating at each published airflow setting and confirm whether the rating applies to the complete fan, not only the motor. | Do not compare a low-speed sone rating with a high-speed airflow rating. Match the sound and airflow settings before making a decision. |
| Certified performance label | HVI Certified Airflow Sound Energy | An HVI certification mark indicates that the published performance data has been evaluated through the relevant certification program requirements. | Request a current certification listing or directory reference, model number, rated airflow, sones, and any certification limitations. | Distinguish between independently certified ratings and manufacturer claims described only as “tested to” or “complies with.” |
| Static-pressure performance | Actual airflow decreases as duct resistance, bends, grilles, dampers, and termination resistance increase. | A free-air or zero-resistance rating may not represent installed performance. Test conditions and pressure points must be reviewed. | Request an airflow-versus-static-pressure curve, test pressure, duct configuration, and recommended maximum equivalent duct length. | The supplier with the strongest installed-airflow data is generally easier to evaluate for real projects than one providing only a free-air figure. |
| Airflow control | Single speed Multi-speed Variable speed | Each selectable speed should have its own airflow and sound data if performance claims are made for multiple operating modes. | Request certified airflow and sone values for low, medium, and high settings, plus control compatibility and wiring diagrams. | Multi-speed products should be compared using the operating mode intended for the target bathroom, not only the maximum setting. |
| Continuous ventilation suitability | Continuous-duty use requires a motor, thermal design, controls, and product documentation intended for extended operation. | HVI airflow and sound ratings describe measured performance; they do not by themselves confirm suitability for every continuous-duty application. | Request the duty classification, operating-hour guidance, motor thermal protection details, and warranty conditions for continuous operation. | For residential and hospitality projects, confirm that the product is designed for the proposed schedule and control strategy. |
| Humidity or occupancy control | Manual switch Humidity sensor Motion sensor Timer | Controls can change operating duration and energy use, but sensor accuracy and control behavior are separate from HVI airflow and sound testing. | Request humidity trigger range, timer settings, sensor location, minimum run time, calibration method, and replacement-part availability. | Evaluate the control system separately from the fan performance label to avoid treating convenience features as certified airflow performance. |
| Energy information | Energy use is normally reported in watts or watts per CFM, depending on the product documentation and efficiency program. | Energy data should be reviewed together with certified airflow and sound values. Low wattage alone does not prove adequate ventilation. | Request input power at each speed, standby power for electronic controls, power factor where relevant, and the energy test method used. | Compare efficiency at an equivalent delivered airflow and operating mode, rather than comparing wattage without airflow context. |
| Electrical compatibility | Common market requirements include:
100–120 V 50/60 Hz 220–240 V 50 Hz | Electrical configuration does not change the meaning of an HVI rating, but an incorrect voltage or frequency can invalidate the intended operating condition. | Request rated voltage, frequency, current, wiring method, regional plug or hardwire configuration, and approved replacement components. | Specify the destination market before quotation. Do not assume a 100–240 V input range unless it is explicitly stated on the product documentation. |
| Duct connection | Typical residential connection sizes include:
3 in 4 in 5 in 6 in | Duct diameter and resistance directly affect delivered airflow and sound. The connection size should match the tested or recommended installation configuration. | Request connection diameter, duct material guidance, adapter details, backdraft damper information, and equivalent-length limitations. | A larger duct or lower-resistance route can help preserve installed airflow, but the complete system still needs correct design and installation. |
| Moisture and installation location | Bathroom fans should be suitable for the intended damp or wet-location application according to the applicable regional electrical and building requirements. | HVI performance certification is not a substitute for electrical safety approval or location-specific installation approval. | Request the product’s location rating, installation instructions, required clearances, ceiling or wall installation limits, and regional safety approvals. | Confirm both performance certification and safety compliance before approving a model for a specific country or project type. |
| Outdoor discharge | Bathroom exhaust should normally discharge outdoors through an appropriate termination rather than into an attic, ceiling cavity, or interior space. | Incorrect termination can increase resistance, reduce airflow, raise noise, and contribute to moisture damage even when the fan’s laboratory rating is acceptable. | Request compatible roof or wall termination options, damper type, weather-resistance details, and installation limits for cold or humid climates. | Compare the complete exhaust path, not only the fan unit. Installation accessories can materially affect final performance. |
| Documentation package | Data sheet Installation manual Test report Wiring diagram | Complete documentation enables buyers to verify airflow, sones, energy data, test conditions, and installation assumptions. | Require model-specific documents with revision dates, ratings, dimensional drawings, spare-parts information, and certification references. | Prefer suppliers that provide traceable, model-specific records instead of generic product brochures. |
| Warranty and service support | Warranty periods and service terms vary by supplier, product series, market, and installation conditions. | Warranty information is not an HVI test result, but it supports long-term evaluation of the product and supply program. | Request warranty duration, motor coverage, labor exclusions, claim process, minimum order quantities, lead time, and spare-parts availability. | For global projects, assess technical support and replacement-part logistics in addition to the initial purchase price. |
.svg)
