Aprilaire 500 SERIES - User Manual

FURNACE
BLOWER MOTOR
MODEL 50
CURRENT
SENSING RELAY
(IF REQUIRED)
24 VAC FURNACE
ACCESSORY TERMINALS
OR TRANSFORMER
(10VA MINIMUM)
SHUT-OFF
(SADDLE VALVE)
WATER SUPPLY
YELLOW
24V SOLENOID
VALVE WIRES
IMPORTANT
USE 120 VAC POWER SOURCE OTHER THAN FURNACE MOTOR
CIRCUIT. HOWEVER, THE TRANSFORMER CAN BE POWERED
OFF THE HOT 120 VAC LINE BEFORE IT ENTERS THE FURNACE.
• DO NOT WIRE TRANSFORMER INTO FURNACE BLOWER CIRCUIT.
IMPORTANT
WHEN MODEL 50 CURRENT SENSING RELAY IS USED:
• WIRE MODEL 50 CURRENT SENSING RELAY INTO
24 VAC HUMIDIFIER CONTROL CIRCUIT ONLY!
DO NOT INSTALL IN TRANSFORMER PRIMARY CIRCUIT.
CONNECT DRAIN LINE HERE
COMMON
HI
LO
YELLOW
WIRES
G
Y
W
C
R
THERMOSTAT
110 VAC
R
C
W
Y
G
FURNACE
OUTDOOR
TEMPERATURE
SENSOR FOR
AUTOMATIC
MODE
NORTH, EAST
OR WEST SIDE
OF HOME
ABOVE EXPECTED
SNOW LINE
CONTINUOUSLY POWERED
24 VAC TRANSFORMER
PROVIDED WITH HUMIDIFIER
CONNECT TO
HOT WATER SUPPLY
CONNECT DRAIN
LINE HERE
OUTPUTSINPUTSPOWER
GWCRHHODT GfA
ADHC TERMINAL STRIP
B
RE AD CO MPL ETE SAFETY INSTRUCTIONS AND INSTALLATION TEMPLATE BEFORE STARTING INSTALLATION
This product must be installed by a qualified heating and air conditioning contractor. Failure to do so could result in serious injury from electrical shock.
This product must be installed in compliance with all local, state and federal codes.
Proper humidification and humidity control also requires that the home be constructed in accordance with local codes and good building practices.
ATTENTION INSTALLER:
MODEL 500 SERIES HUMIDIFIER
The Model 500 and 500M Aprilaire can be
installed on either the supply or return
plenum of a forced air handling system and
is easily reversible for installation with
right hand or left hand bypass duct
connections. The humidifier dimensions
and serviceability must be considered
when selecting the best location for the
humidifier. Here are 2 examples of many
types of installations.
RESEARCH PRODUCTS CORPORATION • P.O. BOX 1467 • MADISON, WI 53701-1467 • CALL 800/334-6011 • FAX 608/257-4357
RETURN
SUPPLY
S
RETURN
R
SUPPLY
S
Horizontal
Upflow
90-120790-1510
90-1079
WARNING
1. ELECTRICAL SHOCK HAZARD.
Disconnect electrical power to the
furnace before starting installation.
Failure to do so could result in
serious injury from electrical shock.
2.
SHARP EDGES HAZARD. Sharp
edges may cause serious injury from
cuts. Use care when making plenum
openings and handling ductwork.
3.
RISK OF SCALDING. Water
temperature over 125°F can cause
severe burns and scald instantly.
Shut off the hot water supply before
disconnecting or tapping into any
hot water supply line.
SPECIFICATIONS
H
UMIDIFIER DIMENSIONS
Width (including solenoid valve): 15
5
⁄8”
Height
(including drain spud): 13”
Depth
: 10
1
⁄4”
BYPASS DUCT OPENING
6” diameter
PLENUM OPENING
9
1
⁄2”W x 9
1
⁄2”H
WATER FEED RATE
3 gph
ELECTRICAL DATA
24 VAC-60 Hz, 0.5 AMP
CAUTION
1. Do not install humidifier where freezing temperatures
could occur. The water line could freeze and crack
causing water damage to the home.
2. Do not install humidifier or bypass connection on the
furnace jacket.
3. Do not install humidifier or bypass connection on a
plenum face where the blanked off ends of the cooling
coil will restrict air movement through the humidifier.
4. Do not set humidity level above recommended or to
recommended level if condensation exists on inside
windows of any unheated space, as condensation
damage may result. Excess humidity can cause
moisture accumulation which can allow the possibility
for mold growth in the home.
5. Do not connect Model 500 or 500M transformer
to blower motor wiring. Premature component
failure may result.
6. When installing Humidifier Control on downflow
furnace, ensure blower continues to run after a
heat call is satisfied to eliminate high temperatures
from damaging the Humidifier Control.
7. Do not install humidifier where water pressure
exceeds 125 psi, since damage to the humidifier
may result. Follow codes in effect concerning
pressure reduction.
8. Do not install humidifier on systems with
greater than 0.4 in. wg pressure differential
between supply and return plenums.
RISK OF PROPERTY AND EQUIPMENT DAMAGE.
INSTALLATION OPTIONSRECOMMENDED WIRING DIAGRAMS
(SEE STEP 7 ON BACK AND “HUMIDIFIER CONTROL SAFETY AND INSTALLATION INSTRUCTIONS” FOR DETAILED WIRING INSTRUCTIONS)
Model 500M
MANUAL CONTROL
Model 500
DIGITAL HUMIDIFIER
CONTROL
NOTE
When installing the Aprilaire humidifier
with the Aprilaire Digital Humidifier
Control or on a heat pump system, use
hot water. The heated water supplements
the reduced supply air temperature as
added heat for evaporation.

Summary

Aprilaire Model 500 Series Humidifier Installation Guide

Installer and Code Compliance

Requires qualified contractor installation and adherence to all local, state, and federal codes.

Critical Safety Warnings

Covers electrical shock, sharp edges, and scalding hazards during installation.

Equipment Protection Precautions

Avoid freezing, improper plenum placement, high humidity, and incorrect wiring to prevent damage.

Recommended Wiring Diagrams

Details recommended wiring diagrams for humidifier and control system setup.

Humidifier Specifications and Options

Provides dimensions, duct/plenum openings, water rate, electrical data, and installation types.

Humidifier Installation Steps and Controls

Humidifier and Bypass Duct Installation

Step-by-step instructions for preparing and mounting the humidifier and bypass components.

Manual Humidifier Control (Model 500 M)

Instructions for mounting the manual control in return duct or on a wall.

Digital Humidifier Control (Model 500)

Instructions for mounting the digital control on the return duct with sensor placement.

Plumbing and Water Connections

Guidance on connecting the water supply via saddle valve and drain line.

Final Operation Check and Job Site Completion

Ensuring all connections are secure, water-tight, and the unit functions correctly before leaving.

Overview

1. Function Description
2. Usage Features
3. Maintenance Features

The Aprilaire Model 500 Series Humidifier is designed to provide proper humidification and humidity control within a home, working in conjunction with a qualified heating and air conditioning system. This device is intended for installation by a professional contractor to ensure compliance with all local, state, and federal codes, as well as good building practices.

Function Description:

The primary function of the Aprilaire Model 500 Series Humidifier is to add moisture to the air within a home, thereby maintaining a comfortable and healthy humidity level. This is achieved by evaporating water into the forced air system, which then distributes the humidified air throughout the living space. The humidifier operates by drawing water from a supply line, distributing it over a Water Panel® Evaporator, and then allowing the furnace blower to pass air through the moistened panel, picking up humidity. Excess water drains away, preventing mineral buildup within the system. The humidifier can be controlled either digitally (Model 500) or manually (Model 500M) to set and maintain the desired humidity level. It is designed to integrate seamlessly with existing HVAC systems, utilizing the furnace's operation to facilitate humidification.

Usage Features:

The Aprilaire Model 500 Series Humidifier offers several features that enhance its usability and adaptability to various home environments:

• Installation Flexibility: The humidifier can be installed on either the supply or return plenum of a forced air handling system. Its design allows for easy reversal, accommodating both right-hand and left-hand bypass duct connections. This flexibility ensures that the humidifier can be optimally placed given the specific layout of the HVAC system and available space.
• Control Options:
  • Model 500 (Digital Humidifier Control): This version features a digital control that can be mounted on the return duct. It includes an outdoor temperature sensor for automatic mode operation, allowing the system to adjust humidity levels based on external conditions for optimal comfort and to prevent condensation. The digital control provides precise management of humidity.
  • Model 500M (Manual Humidifier Control): This version offers a manual control that can be mounted either on the return duct or on a wall in the living space. Users can manually set the desired humidity level using a knob.
• Bypass Damper: An integral bypass damper allows for seasonal adjustment. The damper handle can be set to "WINTER" (open) for humidification during the heating season and "SUMMER" (closed) when humidification is not needed, or when the cooling system is in operation.
• Water Source Versatility: The humidifier can function effectively with cold, hot, softened, or unsoftened water. However, using hot water (up to 140°F max) is strongly recommended, especially when paired with the Digital Humidifier Control or a heat pump system. Hot water supplements the reduced supply air temperature, providing added heat for more efficient evaporation and maximizing evaporative capacity. A saddle valve is provided for tapping into the water supply line.
• Safety Mechanisms: The system is designed with safety in mind, including recommendations to disconnect electrical power during installation, use caution with sharp edges, and shut off hot water supply to prevent scalding. Installation guidelines also advise against placing the humidifier in areas prone to freezing or where water pressure exceeds safe limits.
• Integration with HVAC System: The humidifier is designed to operate in conjunction with the furnace. It requires the furnace to be on and the relative humidity (RH) to be below the set-point of the control for humidification to occur. This ensures that humidified air is distributed efficiently throughout the home via the existing ductwork.
• Drainage System: A dedicated drain line is required to manage excess water and prevent mineral buildup within the humidifier. This ensures continuous, clean operation and prolongs the life of the Water Panel® Evaporator.

Maintenance Features:

The Aprilaire Model 500 Series Humidifier is designed for relatively straightforward maintenance to ensure long-term performance:

• Water Panel® Evaporator: The Water Panel® Evaporator is a key component that requires periodic replacement. The manual indicates that the cover can be easily removed by pressing top and bottom tabs, allowing access to pull out the feed tube and remove the Water Panel® Evaporator assembly. This design facilitates quick and simple replacement of the panel, which is crucial for efficient humidification and to prevent mineral accumulation.
• Scale Control Insert: The system includes a scale control insert located at the bottom of the Water Panel® Evaporator assembly, which sits in the drain spud. This insert helps manage mineral deposits, and its design allows for easy inspection and cleaning or replacement as part of routine maintenance.
• Drain Line: The humidifier requires a 1/2" I.D. hose for the drain line, which should have a constant downward slope and be free of kinks. Regular checks of the drain line ensure proper water flow and prevent blockages that could affect humidifier performance.
• Accessibility for Servicing: The overall design prioritizes accessibility for servicing. The cover removal process is simple, and internal components like the feed tube, water distribution tray, and Water Panel® Evaporator are easily accessible for inspection, cleaning, or replacement.
• Professional Installation and Service: While some maintenance tasks are user-friendly, the initial installation and any complex servicing are intended to be performed by qualified HVAC contractors. This ensures that the system is correctly set up and maintained, preventing potential issues and preserving warranty validity. The manual emphasizes that the warranty is void if the humidifier is not installed by a qualified contractor.
• Owner's Manual Importance: The importance of providing the owner's manual, which contains instructions for operation and warranty information, is highlighted. This empowers homeowners with the knowledge needed for basic operation and understanding maintenance schedules, reducing unnecessary service calls.

Aprilaire 500 SERIES Specifications

General

Capacity	12 gallons per day
Coverage Area	Up to 3, 000 square feet
Voltage	24 V
Installation	Professional installation recommended
Control	Automatic or Manual
Warranty	5-year limited warranty
Mounting Location	Duct-mount