AprilAire 700 Whole-House Fan Powered Evaporative Humidifier
MODEL 700 FEATURES:
- HUMIDITY FOR HEALTH: AprilAire Humidifiers can help you maintain optimal humidity in your home which has been shown to reduce the incidence of respiratory infections and symptoms related to allergies and asthma by minimizing the formation of bacteria and viruses.
- HUMIDITY FOR COMFORT: Balance your humidity to preserve your home and protect its occupants from dry air issues like static shock and chapped skin.
- PROTECT YOUR HOME: Preserve your home and any contents susceptible to damage from changing humidity or dry conditions.
- BUY WITH CONFIDENCE: This humidifier was designed and manufactured in the USA by AprilAire—the inventor of the whole-house evaporative humidifier, and the leader in Indoor Air Quality since 1954.
- ONBOARD CONTROL SENSOR: Automatically turns on the HVAC fan to measure the relative humidity inside the ductwork and from all parts of the home. Turns on the humidifier whenever the measured humidity drops below the set point.
- CONVENIENT CONTROL: To monitor and adjust the humidity with a high-contrast digital screen.
- WHOLE-HOUSE HUMIDIFICATION: For Ducted HVAC Systems.
- FULL COVERAGE: For tightly constructed homes up to 5,300 square feet, with a capacity of 18 gallons per day.*
BENEFITS:
Our fan-powered, duct-mounted humidifier adds balanced humidity to your whole home. The fan pulls air directly from your furnace, moisturizing the air before returning it to the air ducts to be dispersed throughout your home.
INCLUDED IN THE BOX:
- Model 700 Humidifier
- Model 60 Digital Automatic Humidistat
- Model 35 Water Panel
- 24VAC Transformer
- Outdoor Temperature Sensor
- Saddle Valve
- Installation Instructions
What "Fan-Powered" Actually Means — and Why It Matters
The Key Difference from the Model 400
The AprilAire 400 (bypass humidifier) relies entirely on your furnace's own blower to push air through the water panel — meaning it only humidifies while your furnace happens to be running for heating. The Model 700 has its own dedicated fan, pulling air directly from the furnace and pushing it through the water panel independently of whether your heating system is actively calling for heat. This is a meaningful distinction: it means the 700 can maintain consistent humidity levels even during mild weather when your furnace cycles infrequently — a common gap with bypass-style humidifiers.
Why This Enables Greater Coverage
The added fan is also why the Model 700 covers more square footage than the 400 — up to 5,300 sq. ft. at 18 gallons/day, compared to the 400's 4,000–5,000 sq. ft. at 17 gallons/day. By actively forcing air through the water panel rather than relying on passive furnace airflow, the 700 can achieve more consistent evaporation and output regardless of furnace cycling patterns, making it a better fit for larger homes or homes with more demanding humidity needs.
The Onboard Control Sensor: Smarter Activation
Rather than only responding to a wall-mounted humidistat reading, the Model 700's onboard control sensor actively triggers your HVAC fan to sample humidity from air pulled throughout the ductwork — giving a more representative reading of your whole home's actual humidity level rather than relying on a single fixed sensor location. When that measured humidity drops below your setpoint, the system automatically activates.
What's Included and Why It Matters
The complete kit — including the Model 60 Digital Automatic Humidistat, Model 35 Water Panel, transformer, outdoor temperature sensor, and saddle valve — means this is a fully specified system rather than requiring separate component sourcing. The included outdoor temperature sensor is particularly important: like other AprilAire automatic models, it allows the system to adjust target humidity based on outdoor conditions, since the ideal indoor humidity setpoint shifts with outdoor temperature to avoid window condensation in colder weather.
Model 400 vs. Model 700: Which Fits Your Home?
| AprilAire 400 (Bypass) | AprilAire 700 (Fan-Powered) | |
|---|---|---|
| Air movement | Relies on furnace blower | Dedicated onboard fan |
| Coverage | Up to 4,000–5,000 sq ft | Up to 5,300 sq ft |
| Capacity | 17 gallons/day | 18 gallons/day |
| Best for | Standard homes, furnace runs frequently in season | Larger homes, or homes needing consistent humidity regardless of furnace cycling |
| Included sensors | Indoor humidity | Indoor humidity + outdoor temperature + ductwork sampling |
If you're unsure which model fits your home's size and furnace usage pattern, our technicians can evaluate your specific setup — see also the AprilAire 400 for smaller or standard homes, or the AprilAire 800 Steam Humidifier for the fastest, most precise response regardless of furnace or HVAC fan operation at all.
Professional Installation Matters
Because the Model 700 includes multiple components — humidistat, water panel, transformer, outdoor sensor, and saddle valve — that all need to be correctly wired and plumbed together, professional installation ensures the full system performs as designed. Our licensed HVAC technicians will:
- Mount the fan-powered unit and connect it to your furnace's ductwork
- Install the saddle valve and connect the water supply line
- Wire the transformer, Model 60 digital humidistat, and outdoor temperature sensor
- Configure the onboard control sensor and set your target humidity range
- Test fan activation and humidity response independent of furnace heating cycles
Frequently Asked Questions
Does the Model 700 run even when my furnace isn't heating?
Yes — because it has its own fan, it can pull and humidify air independently of whether the furnace is actively producing heat, unlike bypass models that rely entirely on furnace airflow.
How is the outdoor temperature sensor used?
It allows the system's digital control to automatically adjust the target indoor humidity level based on current outdoor temperature, helping prevent window condensation in colder weather while still maintaining comfortable humidity.
Is the Model 700 harder to install than the Model 400?
It has more components (fan, additional sensors) than the simpler bypass Model 400, so professional installation is especially recommended to ensure everything is wired and configured correctly.
High-Capacity Fan-Powered Evaporative Humidification for Ultimate Winter Comfort
The Aprilaire 700 Whole-House Fan-Powered Evaporative Humidifier is a premium, high-output climate control solution engineered to combat bone-dry indoor winter air by delivering maximum moisture throughout spacious homes up to 4,200 square feet. Unlike standard passive humidifiers that rely solely on furnace airflow, the Aprilaire 700 features a built-in internal fan that actively draws heated air through a wet water panel, evaporating up to 0.75 gallons of moisture per hour. Installed directly onto your furnace or air handler ductwork, it introduces perfectly balanced humidity into your heating airstream, eliminating static electricity, soothing dry nasal passages, and protecting your home's fine hardwood floors, cabinetry, and wooden furniture from winter cracking. Call our certified HVAC specialists at (224) 754-1984 for expert humidifier installation, water line hookup, or annual service:
Built-In Fan-Powered Delivery: Features an internal heavy-duty fan that forces warm air directly through the water panel, maximizing moisture output regardless of furnace size.
Massive High-Capacity Output: Delivers up to 0.75 gallons of water per hour, making it one of the most powerful residential evaporative humidifiers on the market.
Protects Hardwoods & Fine Woodwork: Maintains ideal relative humidity levels (35% to 45%) to prevent expensive wood flooring, doors, and furniture from shrinking or splitting.
Automated Digital Control: Pairs with an intelligent digital humidistat that monitors outdoor temperatures to adjust indoor humidity automatically without window condensation.
Low-Maintenance Operation: Requires only a simple annual water panel replacement to keep the system running at peak performance year after year.
Aprilaire 700 Technical Specifications & Performance
Designed for clean, professional installation on residential furnace supply or return plenums:
Technical Parameter Feature & Specification Details Operational Advantage Manufacturer & Model Aprilaire Model 700 Fan-Powered Humidifier Premium high-capacity residential evaporative humidifier. Capacity & Coverage Up to 0.75 gallons per hour (Homes up to 4,200 sq. ft.) Maximum moisture output for large homes and open floor plans. Blower Technology Built-in Fan-Powered Motor Forces active evaporation independently of furnace airflow. Duct Compatibility Mounts easily on warm air supply or cold air return ducts Flexible installation configuration for any furnace layout. Control System Automatic digital humidistat with outdoor sensor Prevents window frosting by regulating humidity based on outside weather. Replacement Part Aprilaire #35 Water Panel / Evaporator Pad Quick, straightforward annual maintenance.
Key Benefits of Upgrading to an Aprilaire 700 Humidifier
Integrating an Aprilaire 700 fan-powered humidifier into your home infrastructure delivers immediate health and financial rewards:
Superior Winter Humidity Coverage: Actively forces moisture through large homes where standard passive humidifiers struggle to maintain adequate humidity levels.
Enhances Winter Health & Immunity: Proper indoor humidity keeps mucous membranes moist, reducing susceptibility to cold viruses, sore throats, and airborne germs.
Eliminates Static Shocks: Stops annoying static electricity buildup on carpets, clothing, and blankets during dry winter months.
Lowers Heating Costs: Humidified air feels warmer at lower thermostat settings, allowing you to turn down your furnace and save on winter utility bills.
Our Step-by-Step Aprilaire 700 Installation Process
Furnace Plenum & Layout Assessment: Evaluating your heating duct configuration to determine the optimal mounting position for the fan-powered humidifier chassis.
Plenum Cutting & Unit Mounting: Cutting a precise template opening in the sheet metal duct and securely mounting the humidifier housing with airtight seals.
Water Supply & Drainage Plumbing: Connecting a copper or PEX water supply line with an inline valve and routing the drain tube to a floor drain or condensate pump.
Electrical & Low-Voltage Wiring: Connecting the internal fan power and wiring the digital automatic humidistat and outdoor temperature sensor to your HVAC system.
System Commissioning & Testing: Testing water flow, verifying proper blower activation, checking fan operation, and running final leak checks.
Frequently Asked Questions: Aprilaire 700 Humidifier
Q: What is the difference between the Aprilaire 700 and standard passive humidifiers?
A: Standard passive humidifiers rely entirely on your furnace blower to push air through the water panel. The Aprilaire 700 features a built-in electric fan that actively forces air through the pad, resulting in significantly higher moisture output for larger homes.
Q: Will this humidifier cause window condensation in the winter?
A: No, provided it is installed with the included automatic digital humidistat. The sensor monitors outdoor temperatures and automatically adjusts indoor humidity levels to prevent window frosting and condensation.
Q: How often do I need to change the water panel inside the unit?
A: We recommend replacing the evaporative water panel (Aprilaire #35) once a year (at the start of each heating season) to ensure maximum moisture output and mineral control.
Q: Can the Aprilaire 700 help protect my hardwood floors and furniture?
A: Yes. Dry winter air causes wood to shrink, crack, and warp. Maintaining a stable relative humidity between 35% and 45% with the Aprilaire 700 protects your flooring, doors, and wooden furniture from splitting.
At AprilAire, our mission has always been to make homes healthy through intuitive design and professional-grade solutions—because healthy homes are the foundation for healthy people, families, and communities.
With multiple locations throughout North Shore and Northwest suburbs of Chicago, Illinois, Emergency Plumbing offers promt and professional plumbing services.
Are you looking for a reliable plumber near me in the Arlington Heights, Bannockburn, Barrington, or surrounding areas?
Our local plumbing company offers expert services, catering to all your needs. Whether you're in the heart of Buffalo Grove, the serene streets of Deerfield, or require an emergency plumber in Des Plaines or Elk Grove Village, we are here to help. Our plumbing contractors are well-versed in the unique plumbing systems of Glencoe, Glenview, Hawthorn Woods, and Highland Park.
For those in Highwood, Hoffman Estates, or the quaint town of India Creek, our team guarantees prompt and efficient service.
Residents of Inverness, Kildeer, Lake Bluff, Lake Forest, and Lake Zurich can also rely on our expertise. We extend our services to Long Grove, Mettawa, Lincolnshire, Mount Prospect, Mundelein, Northbrook, and Palatine.
Need a plumber in Prospect Heights, Ravinia, RiverWoods, Rolling Meadows, Vernon Hills, Wauconda, Wheeling, Wilmette, or Winnetka? Look no further! As a trusted plumbing contractor, we ensure that your plumbing issues are solved quickly and efficiently, keeping your home or business running smoothly.
