HM700ADISTKIT
Steam Lines and Condensate Return Instructions
The following instructions must be followed for installation of steam lines for the HM700. Failure to use
recommended material (see Table 1), or failure to follow any other steam line installation instructions will result
in improper operation and could void the warranty. As a best practice, steam hose length should not exceed 20
feet (6.1 m), due to possible excessive condensation, accumulation, and output loss. Always follow the
installation guidelines for long runs of steam hose. See Figures 3–6.
Voltage
110/120V
220/240V
* The use of steam line other than copper, stainless steel tube or the steam line supplied with the humidifier or
this kit will void the warranty and may adversely affect the operation of the humidifier.
* When using copper or stainless steel tubing (other than the supplied tubing), insulation is recommended due
to high temperature safety as well as reduced condensate.
CAUTION
Plumbing to be performed by licensed HVAC
professionals only.
Drain water from humidifier can be very hot. Do
not drain to public sink.
All plumbing work should be done according to
local plumbing code.
CAUTION
Installation
Do not mount in area where freezing can occur.
Do not mount on floor.
Humidifiers produce steam at atmospheric
pressure. No devices which could block
steam output should be connected to the
steam outlet.
Steam lines must be installed so that no
restriction can produce backpressure in the
humidifier.
Regardless of selecting on/off or modulating
control method, HM700 humidifiers must
have a closed circuit across its on/off
security loop control terminal to operate. The
use of a duct high limit humidistat is highly
recommended.
Steam Line Installation
1. The steam hose should only be used on short
steam runs (under 20 feet).
2. Ensure that no condensate produced in the
steam line will remain trapped. Steam naturally
flows upward and condensate naturally flows
downward.
3. Ensure steam line properly supported so that no
sags or dips are present.
4. All bends should be done in large radius 12 in.
minimum. Steam hose will soften when and may
kick if too tight a radius is used which can cause
a blockage and excessive back pressure.
5. Horizontal runs of steam must rise 2 in. per foot
(10º) when flow is going upwards away from the
humidifier, or fall 1/2 in. per foot (2º) when flow
is going downwards away from the humidifier.
33-00160EFS—05
Table 1. Recommended Steam Line Material for HM700 Duct.
Steam Output
Steam
lbs/hr (kg/hr)
Hose
3.85
(1.75)
7/8 in.
7.7
(3.5)
*
Material
MED-L Copper
Stainless
Tube
Steel Tube
0.875 x
3/4 in.
0.049W
Condensate Return Guidelines For
Main Steam Lines
1. Use vertical condensate leg of distributor only.
Do not over-tighten clamp.
2. Condensate traps on steam mains must be
located at all low points in the system, at each
elevation change and or directional change.
3. Horizontal runs of steam must rise 2 in. per foot
(10º) when flow is going upwards away from
condensate trap, and fall 1/2 in. per foot (2º)
when flow is going downwards towards a
condensate trap.
4. In a horizontal run of the steam main,
condensate traps must be located at regular
intervals.
5. The condensate trap itself is a section of piping
connected to the bottom of the main. A full size
tee must be used to create a condensate trap to
allow the condensate to fall away from the steam
flow.
6. Vertical drop of the condensate trap should be
1.5 times the diameter of the steam main but no
less than 12 in.
7. A p-trap should be installed at the bottom of the
condensate trap. The center to center trap
height should be 2 in. greater than duct static
pressure (see Fig. 1).
To return condensate for HM700, insert copper tube
(supplied with equipment) half way into the
condensate opening of the fill cup along with the
spring clamp (supplied with equipment).
Insert the condensate hose into the condensate return
hole at the top of the unit, and over the copper tube.
Fasten in place with the spring clamp.
2
Minimum
Max Static
Airflow CFM
Pressure
115
3.0 in. w.c.
230