Aprilaire 700a Installation Instruction

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.

ATTENTION INSTALLER:

READ COMPLETE SAFETY INSTRUCTIONS AND INSTALLATION TEMPLATE BEFORE STARTING

AUTOMATIC HUMIDIFIER MODEL 700

P.O. BOX 1467 • MADISON, WI 53701-1467 • CALL 800/334-6011 • FAX [phone]

INSTALLATION OPTIONS

Typical Installation Alternate Installation

COOLING COILS IN

WARM AIR PLENUM

Aprilaire to
be installed
as shown in
relation to
cooling coils.

WIRING DIAGRAM

(SEE STEP 7 ON BACK AND “HUMIDIFIER CONTROL SAFETY AND INSTALLATION INSTRUCTIONS” FOR DETAILED WIRING INSTRUCTIONS)

90-1099

90-922

90-921

RETURN

RETURN

HOT WATER

SUPPLY

SUPPLY

Orientation of Aprilaire Model 700

to Cooling Coils

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

HUMIDIFIER DIMENSIONS

Width 15

29

⁄32”

Height

(including solenoid valve

and drain spud)

18”

Depth 10

11

⁄32”

PLENUM OPENING

14

3

⁄4”W x 145⁄16”H

WATER FEED RATE

6 gph

ELECTRICAL DATA

120 VAC-60 Hz, 0.8 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 on the furnace jacket.

3. Do not install humidifier 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 the Model 700 power cord to multi-speed
furnace blower motors or blower motors other than 120 VAC.
Premature component failure may result. Use Research
Products Corporation Model 50 Current Sensing Relay.

6. When installing Aprilaire Humidifier Control on a downflow
furnace, ensure blower continues to run after a heat call is
satisfied to eliminate high temperatures from damaging the
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 the supply plenum where static
pressure exceeds 0.4 in. wg.

RISK OF PROPERTY AND EQUIPMENT DAMAGE.

BLANKED OFF

END OF COIL

NOTES

1. The Model 700 is not
suitable for installation
on ducts with horizontal
airflow. Performance
will be reduced.

2. When installing Aprilaire
humidifier on a heat
pump system, use hot
water. The heated
water supplements the
reduced supply air
temperature as added
heat for evaporation.

NOTE:

FOR INSTALLATION IN MANUAL MODE,
REPLACE OUTDOOR TEMPERATURE
SENSOR WITH PLASTIC RESISTOR CASE
AND ATTACH MANUAL FACE PLATE.
SEE “HUMIDIFIER CONTROL SAFETY
AND INSTALLATION INSTRUCTIONS”
INCLUDED WITH EACH HUMIDIFIER.

COMMUNICATION

TERMINALS FOR 8570

THERMOSTAT

24 VAC FURNACE ACCESSORY TERMINALS

(2 VA MINIMUM) OR

24 VAC TRANSFORMER (2 VA MINIMUM)

SHUT-OFF

(SADDLE VALVE)

WATER SUPPLY

120 VAC OUTLET

CONNECT DRAIN

LINE HERE

I-

R

I+

C

24V

ODT

H

NORTH, EAST

OR WEST SIDE

OF HOME

OUTDOOR

TEMPERATURE

SENSOR

ABOVE EXPECTED

SNOW LINE

BROWN WIRES

COMMON

FURNACE

BLOWER

MODEL 50 CURRENT SENSING RELAY
(NOT SUPPLIED) REQUIRED IF 120 VOLT
POWER SOURCE FOR HUMIDIFIER AND
24 VOLT POWER SOURCE FOR CONTROL
ARE POWERED CONTINUOUSLY.

READ COMPLETE SAFETY INSTRUCTIONS AND INSTALLATION TEMPLATE BEFORE STARTING

TEMPLATE MUST BE LEVEL

– TOP –

READ REVERSE SIDE FIRST! READ REVERSE SIDE FIRST!

Figure 1

10006916 B2204052A 04.06

90-923 90-924 90-925 90-926

Figure 2 Figure 3 Figure 4

6

5

7

1

3

9

11

13

12

14

15

8

10

4

2

16

17

90-888

1. Place the humidifier on a flat surface.

Unlatch humidifier cover assembly from base
assembly at the bottom of the cover, lift and
set aside. Pull out the Water Panel

®

evaporator assembly by grasping at the top
and tipping out. (See Figure 1)

2. Using a level, position this template at

least 11⁄ 2 inches above the furnace housing
or cooling coil if applicable, for clearance of
the drain line. Trace around template edges.
When there is insufficient space on the
supply plenum, the humidifier can be
installed on the return duct provided the
humidifier is supplied with hot water. Remove
the template and accurately cut the plenum
opening 14

3

⁄4”W x 145⁄16“H, being careful to

avoid injury from sharp edges.

3. Position the two plastic hooks on the top

of base along the top edge of the plenum
opening. Push base up to engage the two
hooks and sheet metal along the top edge
opening. Push base in and slide down so that
the bottom four hooks engage the sheet
metal at the bottom edge of the opening.
Secure base to opening using top three
screw holes in housing. An additional hole is
provided at the bottom for securing the base
to the plenum. (See Figure 2)

4. While pressing the base against the plenum,

reach through the center opening and turn left
and right swing latches down to secure the
base onto the plenum. (See Figure 3)

5. Reinstall the Water Panel

®

evaporator
assembly into the base, with the bottom of
the scale control insert (5) sitting firmly in the
inside of the drain spud attached to the base.
Push the Water Panel®evaporator assembly
in at the top between the retaining ribs that
hold the assembly in place in a vertical
position. Reinstall cover assembly by hooking
at the top of base assembly and latching at
the bottom.

6. Install the Aprilaire Humidifier Control in

the return duct using the installation
instructions enclosed (see Wiring Diagram,
opposite side). For detailed installation and
wiring instructions, see “Humidifier Control
Safety and Installation Instructions” included
with the humidifier.

7. The Model 700 humidifier power cord must

be plugged into a 120 VAC outlet. Do not use
an extension cord. Do not power 120 VAC
outlet from the furnace blower circuit. The
Automatic Humidifier Control must be
powered from a 24 VAC source connected to
the “R” and “C” terminals on the control. The
24 VAC humidifier wires (brown) must be
connected to the “H” terminals on the control.

CAUTION: Do not connect brown wires to
“ACC” or “HUM” terminals on furnace or
damage to the humidifier could result.

In order for the humidifier to turn on, the
furnace blower must be operating and the
control must be calling for humidity. The
interface between the Model 700 Humidifier
and the furnace to detect blower operation
can be accomplished several different ways:

A. If the humidifier is plugged into a continuously
powered 120 VAC outlet and the control is
powered from 24 VAC “ACC” or “HUM”
terminals on the furnace connected to the “R”
and “C” terminals on the control, then the brown
wires from the humidifier can be connected
directly to the “H” terminals on the control.

B. If the humidifier is plugged into a 120 VAC
outlet that is powered only when the furnace
is on, then the humidifier control can be
powered by a constant 24 VAC source
connected to the “R” and “C” terminals on
the control, and the brown wires from the
humidifier can be connected directly to the
“H” terminals on the control.

C. If the humidifier is plugged into a
continuously powered 120 VAC outlet and the
control is powered from a continuous 24 VAC
source, then a Model 50 Current Sensing
Relay (not included) must be installed in the
humidifier circuit. (Brown wires connected to
“H” terminals on control.)

8. Tap into water supply line with the saddle

valve furnished. See instructions on saddle
valve package. The humidifier will function
with cold, hot, softened or unsoftened water.
The use of service hot water (140°F MAX.)

and constant blower operation will provide
maximum evaporative capacity. When

installing humidifier on heat pump system,
humidifier must be supplied with service
hot water.

NOTE: The saddle valve is designed to be
fully opened or closed. Do not use it to
regulate water flow.

9. Connect tubing from the saddle valve to

the inlet side of the solenoid valve using 1⁄ 4”
O.D. copper tubing (not furnished).

DOUBLE WRENCH TO PREVENT LEAKING!
(See Figure 4)

10. Drain spud is designed to accept

1

⁄ 2” I.D.
plastic hose (not furnished). Run drain line
from drain spud to floor drain. CAUTION: If

hose clamp is used, do not overtighten, drain
spud could crack. Be sure drain line has
continuous slope. NOTE: Do not sweat or
directly attach metal drain line to fitting. Do
not use solvent type adhesives when
connecting plastic drain line, since damage
to fitting could result.

11. Open saddle valve completely and turn

on furnace. Turn up humidifier control so that
humidifier will turn on. Allow humidifier to run
until water is observed coming out of the
drain line. Check to see if humidifier and
saddle valve are watertight. Check operation
to make sure that all electrical components
function properly by utilizing humidification
system check-out section in the “Humidifier
Control Safety and Installation Instructions”.
Set humidifier control to recommended level.

FURNISHED ITEMS

Automatic Humidifier Control

Automatic Humidifier Control

Installation Sheet

Saddle Valve

Humidifier Installation Template

Mounting screws

(sheet metal screws)

Water supply line (1⁄4” copper)

Drain line (1⁄2” I.D. hose)

Low voltage wire

Model 50 Current Sensing Relay

(if required)

ITEMS NOT FURNISHED

IMPORTANT! Be sure owner’s manual containing instructions for operation

and warranty information is given to owner in order to avoid unnecessary calls.
Warranty is void unless humidifier is installed by qualified heating and air conditioning
contractor due to possible misapplication of product.

PARTS LIST

1. Front Cover

2. Base

3. Orifice Plate

4. Motor Mount Bridge

5. Scale Control Insert

6. Water Panel Evaporator

7. Water Distribution Tray

8. Fan Blade

9. Motor

10. Motor Mount Gasket

11. Circuit Board

12. Power Cord

13. Strain Relief Bushing

14. Solenoid Valve

15. Connector Plug

16. Feed Tube

17. Nozzle

NOTE: BEFORE LEAVING THE
JOB SITE, MAKE SURE:

1. Saddle valve is fully open.

2. All plumbing connections are
watertight.

3. Humidifier functions properly.