Aprilaire 112 - User Manual

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Maintenance Instruction2 pages

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Summary

Operating Instructions

Automatic Humidifier Control

Instructions for setting and adjusting the Automatic Humidifier Control for optimal home humidity.

Manual Humidistat

Guidance on setting and using the manual humidistat for effective humidity control.

Effect of Water Characteristics

Annual Summer Shutdown

Automatic Humidifier Control Shutdown

Procedure for summer shutdown of humidifiers using Automatic Humidifier Control.

Manual Humidistat Shutdown

Procedure for summer shutdown of humidifiers using a manual humidistat.

Periodic Preventative Maintenance

Maintenance Instructions Models 558-550-568-560

Maintenance Instructions Models 768-760

Maintenance Instructions Model 440

Maintenance Instructions Models 448-445

Reservoir Pump Sections

Detailed cleaning and maintenance for reservoir and pump sections of specific models.

Maintenance Instructions Models 350-360

Maintenance Instructions Models 110-112

Maintenance Instructions Models 220-224

Service and Water Panel Replacement Record

Summary

Operating Instructions

Automatic Humidifier Control

Instructions for setting and adjusting the Automatic Humidifier Control for optimal home humidity.

Manual Humidistat

Guidance on setting and using the manual humidistat for effective humidity control.

Effect of Water Characteristics

Annual Summer Shutdown

Automatic Humidifier Control Shutdown

Procedure for summer shutdown of humidifiers using Automatic Humidifier Control.

Manual Humidistat Shutdown

Procedure for summer shutdown of humidifiers using a manual humidistat.

Periodic Preventative Maintenance

Maintenance Instructions Models 558-550-568-560

Maintenance Instructions Models 768-760

Maintenance Instructions Model 440

Maintenance Instructions Models 448-445

Reservoir Pump Sections

Detailed cleaning and maintenance for reservoir and pump sections of specific models.

Maintenance Instructions Models 350-360

Maintenance Instructions Models 110-112

Maintenance Instructions Models 220-224

Service and Water Panel Replacement Record

The Aprilaire Humidifier is a whole-house humidification system designed to integrate with your existing heating and cooling system to provide optimal indoor air comfort, particularly during the heating season. It operates on the evaporative principle, mimicking nature's way of adding moisture to the air.

Function Description

The primary function of the Aprilaire Humidifier is to maintain a desired level of relative humidity in your home. It works by introducing moisture in vapor form into the air circulated by your furnace blower. For most models (excluding 350 and 360), the humidifier operates in conjunction with the furnace blower motor. When the humidistat or Automatic Humidifier Control calls for humidity and the blower is running, water flows to a distribution pan at the top of the unit. This water is then uniformly distributed over a Water Panel® evaporator. As dry, hot air passes through this moisture-laden Water Panel, evaporation occurs, and the now humidified air is circulated throughout your home.

Models 350 and 360 utilize service hot water (up to 140°F) as their heat source for evaporation. While hot water enters the unit, the flushing water to the drain will be cold, as heat is extracted during the evaporation process.

A key design feature is the use of an orifice in drain-type units, which ensures a small, steady stream of water to the drain. This continuous flushing helps remove trouble-causing minerals, preventing them from accumulating and causing damage. This method also eliminates problems associated with stagnant water. For homes without drain access or where water hardness is not an issue, Models 448 and 445 incorporate a water recirculating system.

The humidifier is designed for high capacity, capable of adding approximately 9 gallons of water per day to maintain 35% relative humidity in an average-sized home (10,000 cu. ft.) when the outside temperature is 20°F. All water-contacting housing parts are non-metal to prevent rust and corrosion. The Water Panel evaporator is specifically designed for uniform, high evaporation and, along with the Scale Control Insert, efficiently traps mineral deposits, preventing "white dust" from being distributed throughout the living spaces.

Usage Features

The Aprilaire Humidifier offers both Automatic Humidifier Control and Manual Humidistat options for managing humidity levels.

Automatic Humidifier Control: Installed in the cold air return, this control system is a high-precision system that automatically adjusts indoor relative humidity (RH) by ½% for every 1° change in outdoor temperature.

Initial Setup: During the first heating season, the control needs to be set to match your home's conditions. Users are instructed to turn the dial to "5" initially and then adjust it over 24-48 hours based on personal comfort and home requirements.
Adjustments: Minor adjustments may be needed during the coldest parts of the first heating season, depending on home construction.
Operation Guide (Table 1): Provides solutions for common issues like condensation on windows (reduce setting), lack of humidity (increase setting), humidifier not operating (turn to "Test" mode, ensure furnace blower and heat are on), and humidifier not shutting off (turn to "Off").
RH Determination: Users can determine the current RH by following a specific procedure: determine outdoor temperature, activate the furnace blower, turn the control dial to "Off" then slowly clockwise until the solenoid valve "clicks on," then slowly counter-clockwise until it "clicks off," noting the dial setting. This setting, combined with outdoor temperature, can be cross-referenced with the "% Relative Humidity Guide" (Table 2) to approximate indoor RH.
Control Range: The Automatic Humidifier will accurately control humidity between a maximum of 45% RH and a minimum of 10% RH.

Manual Humidistat: This control can be installed in the living area or cold air return.

Anticipatory Adjustment: Users must anticipate drops in outdoor temperature and reduce the setting accordingly to prevent excessive condensation. For example, if the outdoor temperature is 20°F (recommended 35% RH) and expected to fall to 0°F, the setting should be reduced to 25% several hours prior.
Recommended Settings (Table 3): Based on extensive research, these settings balance comfort with protection for the home, as excessively high RH can cause damage (e.g., condensation/frost on windows).
RH Determination: To determine actual RH, turn the dial to a lower setting, then slowly reverse until a "click" is heard, and read the RH on the dial.
Operation Check: To check operation, set the humidistat above the click point, ensure the water saddle valve is open, and power is supplied. For most models, the furnace blower must be operating. After several minutes, reduce the setting below the click point; the unit should shut off.

Additional Information:

Fireplace Dampers: Keep fireplace dampers closed when not in use to prevent humidity loss.
Indoor Moisture Sources: Be aware that activities like clothes drying, cooking, and showers can increase indoor RH, potentially causing condensation on cold surfaces. Ventilation may be needed to dissipate excess moisture.
Water Characteristics: The humidifier can use hot, cold, hard, or mechanically softened water. Hard water residue is primarily calcium and magnesium, while softened water residue is softer and fluffier. While hard water may extend Water Panel life, the panel is typically changed annually regardless. Drain-equipped models effectively flush most solids away.

Maintenance Features

Regular maintenance is crucial for the Aprilaire Humidifier's efficient and safe operation. This includes annual and periodic preventative maintenance.

IV. Annual Maintenance: For optimal performance, the Water Panel evaporator should be replaced annually.

Replacement Sources: Users can contact their installer, heating and air conditioning dealer, use the "Dealer Locator" on www.aprilaire.com, or look in the Yellow Pages under "Humidifying Apparatus" or "Heating & Air Conditioner Contractors."

V. Annual Summer Shutdown: For models 220, 224, 440, 445, 448, 550, 558, 560, and 568:

Close the bypass damper (if provided).
For Models 445 and 448, empty the reservoir.
Automatic Humidifier Control: No control adjustment needed; simply shut off the water supply by closing the saddle valve.
Manual Humidistat: Turn the humidistat to "Off" and shut off the water supply by closing the saddle valve.

VI. Periodic Preventative Maintenance: This section details the cleaning and inspection of components, particularly the in-line water strainer and orifice, which are present in all models except 448 and 445.

General Inspection and Service Instructions (for models with in-line strainer and orifice):

Disconnect electrical power to the furnace and shut off water supply.
Disconnect the water line at the inlet compression nut.
Remove the in-line strainer from inside the inlet fitting (using a small nail or wire).
Flush the in-line strainer clean or replace it (Part No. 4004).
Replace the in-line strainer and reconnect the inlet water line (using a double wrench to prevent leaking).
Disconnect the water line at the outlet compression nut.
Remove the orifice from the copper or plastic tube and ensure the small opening is unplugged.
Replace the orifice and reconnect the outlet water line (using a double wrench to prevent leaking).
Turn on water supply and reconnect electrical power to the furnace.

Specific Maintenance Instructions for Models (558, 550, 568, 560, 768, 760, 440, 448, 445, 350, 360, 110, 112, 220, 224): These sections provide detailed, step-by-step instructions for disassembling, cleaning, and reassembling specific components for each model series. Common steps include:

Water Panel Evaporator Assembly: Removing the front cover, feed tube, and evaporative assembly.
Distribution Tray: Removing the black plastic distribution tray, scraping out calcium deposits, and cleaning "V" notches. Crucially, do not scrape off the granular coating from the bottom of the tray, as this aids in even water flow. If removed, a small amount of liquid dishwashing detergent can be applied to simulate this effect.
Water Panel Evaporator and Scale Control Insert: Sliding out the Water Panel evaporator from the Scale Control Insert, cleaning the insert frame by twisting/flexing or using a putty knife, inspecting the Water Panel, and replacing it annually (with the colored spot up).
Drain Hose: Removing the drain hose, bending and flexing it to loosen internal calcium deposits, and flushing it with water under pressure.
Reassembly: Reinstalling components in reverse order, ensuring proper fit and connections.
System Operation Check: Verifying the humidifier operates correctly after maintenance by adjusting the humidistat/control and ensuring the furnace blower is running.

Models 448-445 Reservoir Pump Sections (Additional Maintenance): These models require more frequent cleaning (every 30 days during heating season) of the reservoir, hose, pump, and float.

Reservoir Cleaning: Loosening the retainer knob, lowering the reservoir, emptying water, removing the partition and liner, cleaning/replacing the liner, and reassembling.
Hose Cleaning: Disconnecting, flexing to loosen scale, flushing with water, and cleaning the nozzle.
Pump Cleaning: Removing the pump impeller cap, cleaning scale from the cover and impeller with a dull blade, cleaning the flow control with a 5/32" bit, and reassembling.
Float Cleaning: Cleaning scale off the float and arm mechanism with a dull blade, and working the arm to dislodge buildup.
Motor Oiling: Disconnecting water lines and humidistat leads, removing the motor cover, and applying two drops of SAE 20 oil to specified oil holes.
Reassembly: Reinstalling motor cover, reservoir, water connections, top cover, humidistat/control leads, and checking unit operation.

Models 110-112 and 220-224 (Specific Disassembly/Reassembly): These models involve removing "Z" clips and closure clips to separate the unit halves for access to internal components for cleaning and Water Panel replacement. Oiling the motor is also specified for Models 110-112.

The manual emphasizes that proper installation by a qualified heating and air conditioning contractor is essential for warranty validity and optimal performance. A "Service and Water Panel Replacement Record" is provided at the end of the manual for tracking maintenance history.