Aprilaire 500 Bypass Humidifier – 12 Gallon/Day
The Aprilaire 500 is a furnace-mounted bypass humidifier that adds up to 12 gallons of moisture per day into your home’s forced-air system. Its manual humidistat runs only when indoor humidity drops below the set point. It draws 24VAC power from the furnace, so no separate electrical circuit is required.
Price: $550 CAD, installation included.
Aprilaire 500 Bypass Humidifier – Supplied & Professionally Installed by 4Most Energy
The Aprilaire 500 is a high-performance, furnace-integrated bypass humidifier built for whole-home humidity control in forced-air systems. Rated for up to 2,800 sq ft, it draws its 24VAC control power from the furnace transformer and distributes moisture through the existing supply plenum and ductwork. Humidistat control cycles output to hold indoor relative humidity at the set point, which matters most in Ontario from November through March, when cold outdoor air carries little moisture and furnace operation pulls indoor humidity down.
Equipment alone does not guarantee performance. Output depends on correct bypass duct configuration, plenum connection, cold-water supply and drain routing, furnace airflow, and humidistat placement. These are the variables that determine whether a humidifier runs efficiently or wastes water and creates condensation issues on windows and framing.
4Most Energy supplies the Aprilaire 500 and manages installation through factory-trained, certified installers across the Greater Toronto Area (GTA) and Ontario. Installation covers the steps that determine real-world results: confirming the unit is matched to the home’s size and construction, mounting it to the supply plenum with the correct bypass configuration, connecting the water supply and drain, and commissioning the humidistat. Work follows manufacturer instructions and the Ontario Building Code requirements that apply to HVAC and plumbing connections.
Homeowners searching for bypass humidifier installation Toronto, furnace humidifier replacement GTA, or Aprilaire 500 installation Ontario will be working with a single supplier and installer. For a licensed HVAC technician near me, 4Most Energy’s installation team handles the full job, from site assessment to final commissioning.
Warranty: Manufacturer parts warranty: 5 years. 30-day money-back guarantee on equipment.
Get a Free Installation Quote
Installation requires a site assessment before quoting. Answer these questions and a 4Most Energy specialist will confirm sizing and schedule a free site visit:
- Do you have an existing bypass or whole-home humidifier? If yes, what brand and model is it?
- What is the make, model and approximate age of your furnace, and is it an upflow, downflow or horizontal unit?
- Is the supply plenum accessible, and is there a cold-water line and floor drain within reach?
- What is the approximate square footage and number of storeys, and is the home newly built, renovated or older?
- Is the existing system a high-velocity system?
Replacement Option
This unit is designed to replace older bypass humidifiers installed on the supply plenum of a forced-air furnace. It fits most bypass setups and installation situations using the included flexible bypass duct and mounting. It is not recommended for high-velocity systems. Replacement is not a like-for-like swap with air conditioning or heat pump equipment, so confirm fit against the specific unit being removed.
Features
- Evaporative bypass design: Water is distributed across an evaporative pad and moisture is carried into the supply air by the furnace blower.
- 12 gallons per day capacity: Rated output for whole-home humidification through the forced-air system, for homes up to 2,800 sq ft.
- Manual humidistat control: Runs output only when indoor humidity falls below the set point, which limits over-humidification and wasted water.
- 24VAC furnace-powered operation: Draws control power from the furnace transformer. No separate power circuit.
- Compact footprint: Mounts beside the furnace and does not require ceiling or wall space in living areas.
Included with the unit: humidifier, water valve, manual humidistat, new evaporative pad, and flexible bypass duct.
Note: This is the simple model. It has no outdoor sensor and no display.
Specifications
| Specification | Value |
|---|---|
| Brand | AprilAire |
| Series | 500 |
| Operation mode | Evaporative (bypass) |
| Daily capacity | 12 gallons/day |
| Rated coverage area | Up to 2,800 sq ft |
| Electrical | 24VAC, furnace-powered |
| Controls | Manual humidistat |
| Parts warranty | 5 years |
| Weight | 8 lb |
| Dimensions (W × D × H) | 10.25 in × 15.63 in × 13 in |
Variations: Single model listed. No size variants.
Warranty and Maintenance
Coverage: 5-year manufacturer parts warranty.
Registration: Register the unit with the manufacturer after installation using the serial number on the unit.
Maintenance requirements:
- Replace the evaporative pad at the interval specified in the owner’s manual.
- Inspect and clean the water distribution tray and float assembly annually.
- Confirm the drain line is clear and the water supply shutoff is accessible.
- Check humidistat setting against the season, lowering output in mild weather to avoid window condensation.
Sizing Guide
- Home square footage and volume: The Aprilaire 500 is rated for up to 2,800 sq ft. For larger homes, a steam humidifier is recommended instead.
- Air-tightness: Newer, well-sealed homes lose less moisture and need less output than older, drafty homes.
- Furnace airflow: The humidifier must sit on a supply plenum with adequate airflow to distribute moisture. Not recommended for high-velocity systems.
- Winter climate: Ontario winters with sustained sub-zero temperatures create the greatest humidity deficit. Winter indoor air is typically very dry, and Health Canada guidance commonly cites an indoor relative humidity range of 30–50%.
Installation Process
- Enquiry: Submit the installation form or call 4Most Energy.
- Site assessment: Installer visits the home to confirm furnace model, plenum access, water supply, drain and home size. This visit is free.
- Quote: Written quote with equipment, labour and any required parts.
- Scheduling: Installation booked once the quote is accepted.
- Installation: Unit mounted to the supply plenum with bypass duct connection; cold-water supply and drain connected; 24VAC wiring completed.
- Commissioning: Humidistat set and system tested under load. Homeowner shown controls and maintenance schedule.
- Follow-up: Warranty registration assistance and maintenance reminders.
FAQs
Does the Aprilaire 500 need its own electrical circuit?
No. It draws 24VAC control power from the furnace transformer.
How much water does it use?
It is rated at up to 12 gallons per day. Actual usage depends on the humidistat setting, furnace run time and home conditions.
Will it cause condensation on my windows?
Only if the humidistat is set too high for outdoor conditions. Lower the setting during mild weather and in cold snaps.
How long does it last?
7–10 years with proper use and timely maintenance.
Can you replace my existing humidifier?
In most cases, yes. Send the make and model of your current unit and we will confirm fit. The unit is not recommended for high-velocity systems.
What if my home is larger than 2,800 sq ft?
A steam humidifier is recommended for larger homes.
