Download Engineering Specification

Herrtronic MD Series Electrode Steam Humidifier
15781 HUMIDIFIERS
PART 1: SCOPE
1. Furnish a humidification system for the project known as _____________________.
2. Operation of the system shall be controlled automatically to maintain _____%R.H. at ____°F with
a tolerance of ±_____%R.H.
3. Warrant the system to be free from defects in materials and workmanship for a period of two
years from date of shipment. (Except for the replaceable steam cylinder).
4. Provide (1) owner's manual to cover installation, startup, operation, maintenance & diagnostics of
unit.
PART 2: PRODUCT
1. Furnish a self-contained electrode steam humidifier having a capacity of ____lbs/hr with electrical
characteristics of _____VAC/Ph./Hz. The humidifier shall be capable of operating on water with a
conductivity of 100-1500 micromho. The equipment shall be supplied per the schedule on the
drawings. The humidifier shall be Model MD_-__ as manufactured by Herrmidifier.
2. Units shall have a replaceable sealed steam cylinder with zinc plated electrodes with a published
cylinder life based on incoming water conductivity.
3. Water make-up system shall include inlet strainer, solenoid valve with flow regulator, and fill tee
with built-in air gap to prevent back siphoning.
4. Drain system shall consist of a solenoid valve, with shielded core dry operator.
5. Unit(s) shall have terminal connection points for all line and low voltage (control) connections. A
system on/off switch shall be externally available.
6. The unit(s) will utilize one of the following humidity control systems (shown with corresponding
input method):
A. On/Off (Humidistat)
B. Proportional (Transmitter or signal-ohms, VDC, mADC)
C. Proportional + Integral (Sensor or signal - VDC , mADC)
The control mode is integral with the Herrtronic MD unit. The input devices shall be:
A. Control input device (or signal) ____
B. High limit humidistat _____ OR
Proportional high limit device (or signal) _____
Note: This enables modulating control systems to adapt the capacity setpoint in
response to varying psychometric conditions - i.e., VAV systems, applications
with high percentages of outdoor air, etc.
C. Air proving switch _____
7. An integral microprocessor control, monitor and diagnostic system. The microprocessor shall:
A. Sense water conductivity and adjust water level and output capacity.
B. Include an LCD display -- (2) lines, 20 alpha/numeric characters per line -- to monitor
system operation/performance.
Note: Only parameters pertinent to the specific humidity control system shall be
displayed.
C. Provide programmable set points with built-in default values for simplified startup. Only
set-points pertinent to the control mode are accessible.
Note: Certain set-points shall be password secured to prevent tampering.
D. Provide adjustable drain tempering capability.
101 McNeill Road  Sanford, NC 27330  Phone: (919) 775-2201  Fax: (919) 777-6399
www.herrmidifier-hvac.com
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E. Provide "fault" sensing and display the type of fault. Certain faults shall result in system
shutdown. Other faults reflect a potential maintenance problem and allow the unit to
continue operation.
F. Provide visual indication (LED) of:
 Cylinder Full (Red)
 Power (Green)

Fault (Red)
G. Network communications with slave units. (up to 29 units) The master shall be capable of
providing operational information on any of the slave units individually.
A door interlock switch shall prevent operation when the access door is open.
Enclosure to be 18 gauge steel and powder-coat painted to prevent against corrosion with
lockable cylinder access door.
Electrode wiring shall be connected with a nut to prevent loosening of the connection. (Friction
connections are not acceptable).
A steam distribution system consisting of:
A. Stainless steel steam distributor pipe(s) with integral pitch OR
Room Distribution Unit (RDU) with adjustable speed control
Note: The supply air blower shall operate approx. 15 minutes after humidifier unit
shutdown. Steam input shall be thru the bottom or back of the unit. The RDU
shall be remote/unit mounted. Supply voltage and control input shall be provided
by the humidifier.
B. ____ft. of EPDM steam hose OR
____ft. of insulated copper pipe shall be provided for connection between the unit and the
steam distribution system
Note: The system operates at atmospheric pressure. Maximum duct static
pressure 5" (MDM units) or 7" (MDS and MDD units).
Multiple cylinder humidifiers (Series MDD, over 100 Lbs/Hr) will have separate fill and drain
provisions. These units shall be capable of common or independent control. Each cylinder shall
have a separate microprocessor control.
PART 3: INSTALLATION
The installing contractor shall assume responsibility according to the installation manual, specifically:
1. Application within system limitations.
2. Mounting recognizing required clearances.
3. Provide water supply (including softened water) in accordance with pressure and conductivity
criteria. Hot water shall not be applied.
4. Provide cylinder and unit drains.
5. All wiring shall be in accordance with applicable sections of national, state and local electrical
codes. The contractor shall provide and install external over-current protection and install system
wiring in accordance with the manufacturer’s requirements.
Herrtronic MD Systems are manufactured by:
Herrmidifier,
101 McNeill Rd.
Sanford, NC 27330
101 McNeill Road  Sanford, NC 27330  Phone: (919) 775-2201  Fax: (919) 777-6399
www.herrmidifier-hvac.com