Aprilaire 445, 440, 224, 112, 760 User Manual

READ AND SAVE THESE INSTRUCTIONS

Includes Safety, Operating and Maintenance

Instructions and Warranty

TABLE OF CONTENTS

PAGE

Introduction ................................................Inside Front Cover

Principle of Operation ............................................................1

Operating Instructions

•Automatic Humidifier Control............................................3

•Manual Humidistat ............................................................5

Effect of Water Characteristics ..............................................6

Annual Maintenance ..............................................................7

Annual Summer Shutdown ....................................................7

Periodic Preventative Maintenance .......................................8

MAINTENANCE INSTRUCTIONS

Models 558 & 550 ..............................................................9

Models 568 & 560 ..............................................................9

Models 768 & 760 ............................................................10

Model 440 ........................................................................11

Models 448 & 445 ............................................................11

Reservoir Pump Sections .............................................12

Models 350 & 360 ............................................................13

Models 110 & 112 ............................................................14

Models 220 & 224 ............................................................15

Limited Warranty..................................................................16

Replacement Record ............................................Back Cover

HUMIDIFIERS

The Best Cure For Dryness

®

®

FOR MODELS 768, 760, 568, 560, 558, 550,

448, 445, 360, 350, 110, 112, 220, 224, & 440

OWNER’S MANUAL

WARNING! 120 volts may cause injury from

electrical shock. Disconnect power and shut off
water supply before servicing.

CAUTION!

Sudden operation may cause
personal injury or property damage. Turn
humidistat or Automatic Humidifier Control,
to “OFF” or lowest setting before servicing

Replacement Water Panel evaporators are available from your installing con­tractor or from most other local heating and air conditioning contractors in
your area. However, if you still have difficulty in obtaining a replacement Water
Panel evaporator, use the dealer locator in our web site (www.aprilaire.com)
or look in the Yellow Pages under Humidifying Apparatus or Heating & Air
Conditioning Contractors.

© Research Products Corporation 2000

INTRODUCTION

Thank you for your recent Aprilaire®Humidifier
purchase. We sincerely appreciate your business and
are pleased to add your name to our growing list of
customers. With this purchase, you have invested in the
highest quality equipment currently available. Research
Products Corporation is the largest manufacturer of
whole house humidifiers, air cleaners and fresh air
exchangers and is a recognized leader in the heating
and air conditioning industry today.

Please be assured that in addition to product quality,
we are also committed to unit performance as well as
customer satisfaction. Your unit will require periodic
maintenance to assure you of continued fine performance.
Please proceed as shown on page 7 to obtain service
parts and/or replacement Water Panel

®

evaporators.

Now, please take a few minutes and read the
appropriate section of this booklet. This will familiarize
you with the benefits you will receive from the equip­ment you just purchased and help you understand the
routine maintenance that will be required. Be sure to
register your warranty with us for our records and your
protection. You may do so by returning the Warranty
Information Card to us, or you can register online at:
www.aprilaire.com/warranty.

I. PRINCIPLE OF OPERATION

With your purchase of a humidification system, you have
invested in a humidifier that operates on the evaporative
principle – nature’s own way of adding moisture – and will
provide the proper relative humidity all during the heating
season. It is very possible that you have questions concerning
your new humidifier – questions on what it can do for you, and
what you should do to receive maximum benefits from it. This
booklet is intended to help you do exactly that.

Nature, in producing an invigorating comfortable April day,
combines just the right temperature and the right amount of
moisture. Aprilaire Humidifiers employ the same principle, with
refinements, to give you the proper relative humidity for maxi­mum allowable comfort all winter long.

The important considerations in the evaluation of a humidifier
are Positive Control, Sufficient Capacity, Trouble-free
Performance and Minimum Maintenance. The operating
principle of your Aprilaire provides all of these advantages.
Here, briefly, is the method:

The Aprilaire Humidifier (except the Models 350 and 360) is
installed to operate in conjunction with the furnace blower
motor. When the humidistat or Automatic Humidifier Control
calls for humidity and the blower motor is operating, water flows
to the distribution pan located at the top of the unit. The water is
uniformly distributed across the width of the pan and through a
scientifically designed system of outlets. It flows by gravity over
the Water Panel

®

evaporator, the heart of the unit. Dry, hot air is
moved through the moisture-laden Water Panel evaporator
where the evaporation takes place. The now humidified air
carrying moisture in vapor form (nature’s own way) is circulated
throughout the home.

The Models 350 and 360 use service hot water (140°F maxi­mum) for its heat source, as heat is needed for evaporation.
While the water going to the unit is hot, the flushing water to the
drain will be cold. The heat is extracted during the evaporation
process.

The correct water flow is determined by an orifice
equipped with each drain type unit. When the unit is operating,
there will be a small, steady stream of water to drain, which
flushes away most of the trouble-causing minerals. Do not

use the saddle valve to regulate the water flow. It is designed to
be completely opened or closed. The minerals and solid residue

®

Your

Humidifier

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not trapped by the replaceable Water Panel evaporator are
flushed down the drain. The drain also eliminates the problems
caused by stagnant water. This is the most effective and least
expensive method to dispose of trouble-causing minerals.

There are some homes where drain facilities are not accessi­ble or available. For these situations, or where high water
hardness is not a problem, specially designed Aprilaire
Humidifiers, Models 448 and 445, are available, incorporating
a water recirculating system.

Capacity is high because an average-size home (10,000 cu. ft.)
requires the addition of approximately 9 gallons of water
per day to maintain

35% relative humidity when the outside
temperature is 20°. The smallest Aprilaire Humidifier under most
operating conditions, has this humidifying capacity. Trouble­free performance and minimum maintenance are assured by
the design features of the Aprilaire Humidifier. All unit hous

ing
parts that come in contact with water are non-metal and will
never rust

or corrode. Neither heat nor water will affect them

under normal operating conditions.

The Water Panel evaporator, designed especially for uniform,
high evaporation, and the Scale Control Insert also efficiently
traps mineral deposits which are often the cause of damage to
working parts in ordinary humidifiers. No “white dust” can be
distributed throughout the living quarters. The Water Panel evap­orator is the heart of the unit and must be in good condition to
assure high capacity trouble-free performance. It should be
changed annually.

The granular coating in the bottom of the distribution tray is
designed to provide equal distribution of the water to each of the
openings assuring an even flow of water over the Water Panel
evaporator. Do not clean the mineral scale off the bottom of the
water distribution tray at the end of the humidification season.
The scale itself provides an excellent track for the water to follow.
This is actually what we try to simulate with the synthetic coating
in the bottom of the tray. If the coating is removed, it is not necessary
to purchase a new distribution tray or upper housing. You can
accomplish the same uniform performance by applying a small
amount of liquid dishwashing detergent over the entire lower surface
of the water distribution tray. This will allow the water to flow
evenly through each of the openings, provided, of course, the
unit is level in order to achieve maximum capacity.

There are many humidifiers on the market. They all add
moisture . . . with varying degrees of efficiency. None, however,
can provide the features, design, and performance incorporated
into your Aprilaire Humidifier.

II. OPERATING INSTRUCTIONS

Automatic Humidifier Control: (Manual humidistat-see pg 5)

Your Automatic Humidifier Control is installed in the cold air return.
During the first heating season, your Automatic Humidifier Control
needs to be set initially to match your home’s condition. Please
follow these steps when adjusting your control (refer to Figure A).

1.Turn the dial setting knob to “5,” which is within the normal
range. During the next 24-48 hours it may be necessary to
adjust the dial for more or less humidity, depending on your
personal comfort and home’s requirements. Refer to the
“Operation Guide” (Table 1).

2.During the coldest portion of the first heating season, minor
adjustments may be necessary. This is dependent upon
your individual home construction, refer to the “Operation
Guide” (Table 1).

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(Table 1) Operation Guide

Condition Solution

Condensation on windows Reduce the setting on the control dial

by 1 increment.

Lack of humidity Increase the setting on the control dial

by 1 increment.

Humidifier does not operate Turn dial to “Test.” Make certain furnace

blower is operating and furnace is calling
for heat. If unit still doesn’t operate, consult
a heating contractor.

Humidifier won’t shut off Turn dial to “Off.” If unit continues to

operate, consult a heating contractor.

Test mode System operation is checked by setting the

knob to “Test.” Make certain furnace blower
is operating and furnace is calling for heat.
Humidifier will operate for one minute.

Off

7

6

5

4

3

2

1

T

e

s

t

N

O

R

M

A

L

Humidity Level

(Figure A)

The relative humidity in your
home will now be accurately
controlled to meet your needs
and should not need further
adjustment during future
heating seasons. Make note of
the dial setting in the event you
temporarily move the knob
when performing annual
maintenance of the Aprilaire
Humidifier.

Your Aprilaire Automatic Humidifier, is a high precision system
that will accurately maintain the relative humidity in your home.
For every 1º change in outdoor temperature, the control will
automatically adjust the indoor relative humidity (RH) by 1⁄2%.
If you would like to determine the RH in your home, follow
these steps:

1. Determine the outdoor temperature.

2. Activate the furnace blower by setting your thermostat fan

switch to the “On” position, or setting your thermostat to a

higher temperature.

3. Turn the control dial setting to the “Off” position. Then,

slowly turn the dial clockwise until you hear the solenoid

valve “click on.” Next, slowly turn the dial counter

clockwise until you hear the solenoid valve “click off.” At

this point, make note of the dial setting.

4. Locate your dial setting on Table 2. Follow the dial setting

to the right until it intersects with the current outdoor

temperature. This is the relative humidity in your home

under existing conditions.

5. Return the thermostat and the control to their original

settings.

The Automatic Humidifier will accurately control the humidity
in your home to a maximum of 45% RH and a minimum of
10% RH. The values of outdoor temperature and dial settings
may fall in between or outside of the listed values in Table 2. In
these cases, you can only approximate your home’s actual
indoor RH.

As an example, if the outdoor temperature is 20º F, and, following step 3, the
humidifier turns off at “5” on the dial range, then the RH in your home is 35%.

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(Table 2) % Relative Humidity Guide

-10 0 10 20 30 40

1 101010152025

2 101015202530

3 101520253035

4 152025303540

520253035 40 45

6 253035404545

7 303540454545

Outdoor Temperature (ºF)

Dial Setting