A high-capacity whole-house large bypass evaporative humidifier featuring a built-in damper for seamless seasonal changeover. The AprilAire Model 600 delivers up to 17 gallons per day (GPD) of moisture distribution for homes up to 5,000 sq. ft. Built with an integrated bypass damper that eliminates the need for field-installed duct dampers, the Model 600 allows homeowners to switch between Winter humidification and Summer cooling modes with a single rotary dial. Equipped with the Model 60 Automatic Digital Humidifier Control and outdoor temperature sensor, the unit continuously modulates humidity output to protect hardwood floors, cabinetry, and interior architectural finishes across Canadian heating seasons.
Technical specifications
| Warranty | 5 year warranty Source: AprilAire warrantyWarranty is provided by the manufacturer under its own terms. See the source link for full details. |
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Key features
- Built-in bypass damper — integrated rotary damper switches effortlessly between Winter and Summer positions without requiring separate duct damper hardware.
- High evaporative capacity — delivers 17 gallons per day, providing comprehensive whole-home humidity coverage for residential floor plans up to 5,000 sq. ft.
- Automatic digital humidity control — includes Model 60 digital controller and outdoor temperature sensor to dynamically balance humidity and prevent window moisture.
- High-efficiency Model 35 Water Panel — expanded aluminum matrix with porous ceramic coating ensures uniform water flow and maximum moisture evaporation.
- Reversible bypass duct collar — 6-inch round bypass duct collar mounts on either the left or right side of the chassis for flexible equipment pad installation.
Sizing guide
| Tight construction (modern building code, 0.5 ACH) | Up to 5,000 sq. ft. (465 m²) |
|---|---|
| Average construction (typical residential, 1.0 ACH) | Up to 2,500 sq. ft. (232 m²) |
| Loose construction (older heritage structure, 1.5 ACH) | Up to 1,500 sq. ft. (139 m²) |
Specifications
| Manufacturer | AprilAire |
|---|---|
| Series | 600 Series Evaporative Bypass |
| Model / SKU | 600 |
| Equipment type | Whole-house large bypass evaporative humidifier |
| Evaporative capacity | 17 Gallons Per Day (GPD) @ 120°F plenum temperature |
| Coverage (tight construction) | Up to 5,000 sq. ft. (465 m²) |
| Coverage (average construction) | Up to 2,500 sq. ft. (232 m²) |
| Coverage (loose construction) | Up to 1,500 sq. ft. (139 m²) |
| Integrated bypass damper | Built-in rotary damper (Winter / Summer settings) |
| Humidifier control included | Model 60 Automatic Digital Humidifier Control |
| Outdoor temperature sensor | Included (digital proportional reset) |
| Replacement water panel | Model 35 Water Panel |
| Bypass duct connection | 6 in. round duct collar (reversible left or right) |
| Plenum opening dimensions | 14-3/4 in. W × 14-5/16 in. H (375 × 364 mm) |
| Unit dimensions | 15-5/8 in. W × 15-7/8 in. H × 10-1/4 in. D |
| Electrical rating | 24 VAC, 60 Hz, 0.5 A |
| Transformer included | 120 VAC to 24 VAC, 10 VA Class 2 Transformer |
| Water feed rate | 3 Gallons Per Hour (GPH) |
| Water supply connection | 1/4 in. O.D. copper tubing with compression fitting |
| Drain hose connection | 1/2 in. I.D. flexible tubing to floor drain or pump |
| Water supply temperature | Cold or service hot water |
| Certifications | UL rated, AHRI Guideline F compliant |
Before you buy
- Requires an existing or field-cut 14-3/4 in. by 14-5/16 in. opening on the warm air supply plenum or cold air return duct with 6-inch bypass ductwork.
- The Model 60 Automatic Digital Control must be mounted on the cold air return duct at least 6 inches upstream of the bypass connection for accurate humidity sensing.
- Mount the outdoor temperature sensor on an exterior wall facing north or east out of direct sunlight using standard 18/2 low-voltage wire.
- Ensure the built-in damper knob is set to "WINTER" during the heating season and rotated to "SUMMER" when central air conditioning is active.
- Annual replacement of the Model 35 Water Panel is recommended at the start of every heating season to maintain rated 17 GPD output.
Questions about bypass ducting or seasonal damper operation? Contact our technical team for assistance.
Frequently asked questions
Which water panel does the Model 600 use?
The Model 600 uses the standard AprilAire Model 35 evaporative water panel, featuring an aluminum honeycomb core with a porous clay coating.
What ductwork connections are needed for installation?
The unit requires an opening on the supply or return duct (approx. 10 in. wide by 12.75 in. high) and connects via a 6-inch round bypass metal duct pipe to the opposite plenum.
Does the Model 600 feature an integrated bypass damper?
Yes. The built-in bypass damper can be set to Winter (open) during the heating season and turned to Summer (closed) when the central air conditioning system runs.
What electrical power is needed?
The unit includes a 24 V AC water solenoid valve powered by a 120 V to 24 V 10 VA step-down transformer.
How does the automatic control prevent condensation on windows?
The Model 60 digital controller continuously monitors outdoor air temperature and reduces indoor relative humidity as outdoor temperatures drop, preventing window sweating and drywall moisture damage.
What drain requirements exist for the Model 600?
The unit features a 1/2-inch drain outlet spud that connects to flexible vinyl tubing routed with continuous fall to a floor drain or sump pit.
Can this humidifier be installed with a heat pump system?
Yes. When installed with a heat pump, plumb the humidifier to the domestic hot water line and configure the blower activation mode to maximize moisture transfer.
How is the humidifier maintained?
Replace the Model 35 water panel annually, clean the distribution tray of lime deposits, inspect the solenoid valve strainer, and clean the drain tube.
Documents
- AprilAire 600 Series Whole-House Evaporative Humidifier Specification Sheet (PDF)
- AprilAire Canada All Products Specification Reference Guide (PDF)
- AprilAire Model 600 Humidifier Owner's Manual (PDF)
Specifications compiled from official AprilAire 600 Series Whole-House Evaporative Humidifier Specification Sheet (Lit. No. 382) and 600 Series Owner's Manual (B2209190). All specifications subject to manufacturer verification. View AprilAire 600 specifications (PDF).
Installation & Safety Notice: Bypass humidifiers must be installed on supply or return ductwork with proper water supply, drain line, and transformer wiring per AprilAire instructions.
Common questions
Is installation included?
No. AVL Shop sells equipment only. Installation is done by an independent licensed contractor that you hire.
How is freight charged?
Freight cost is included in your written quote before you pay.
What warranty does this product have?
The manufacturer warranty applies. Where we have the manufacturer’s exact wording, it is shown in the Warranty row of the specifications on this page, with a link to the source.
How do I get a quote?
Use Request a quote on this page and send the model and your city or postal code.