Venting For Condensing Application - Camus Hydronics MFH060 Installation, Operation And Service Manual

7.6

VENTING FOR CONDENSING APPLICATION

When supplied with the optional condensing cartridge, the MicoFlame is 95% efficient (category II or IV
appliance) which requires the use of a special venting system fabricated from AL29-4C material. Only
venting components listed by a nationally recognized testing agency may be used.
This appliance may be installed with conventional, sidewall or vertical venting. Conventional vented
appliances operate with negative pressure in the vent pipe and require a special vent adapter to increase
the flue outlet diameter. Sidewall and vertically vented appliances operate with positive pressure in the
vent pipe and may be directly connected to the flue outlet without the use of an increaser.
Consult the vent pipe manufacturer's instructions for minimum clearances to combustible material for vent
components. In the absence of instructions, the minimum clearance to combustible material is six inches.
Consult vent pipe manufacturer's instructions for proper method of sealing vent pipe sections and fittings.
In the absence of instructions, make sure that pipe and fittings are clean by swabbing with alcohol. Use
Dow Corning 736 or 732 RTV, Polybar # 500 RTV or Sil-bond 4500 or 6500 to seal vent pipe. Do not use
other sealants or adhesives except as expressly permitted by vent manufacturer's instructions.
Consult vent pipe manufacturer's instructions for vent system assembly. Follow vent pipe manufacturer's
instructions if those instructions differ from this section.
Conventional Venting
Multiple condensing appliances may be vented into a common chimney. The chimney must be lined with
AL29-4C and a single acting barometric damper must be provided for each appliance.
A qualified professional using a proven vent-sizing program with input of accurate operating parameters
must properly calculate sizing of the venting system. In applications where flue gas temperatures are
lower than can support a Category II with conventional negative draft, it will be determined at the venting
design stage that a positive pressure will be developed in the vent. It will then be necessary to either
provide separate vents as for Category IV, or to provide an extractor at the chimney outlet in order to
maintain a negative draft in the chimney and allow common venting.
Approval of the installation will be at the discretion of authorities having jurisdiction.
The chimney must be protected from down drafts, rain and debris by using a listed chimney cap.
Sidewall and Vertical Venting
The maximum vent length is 50 equivalent feet. Vent pipe may be run through a vertical or horizontal
chase provided that minimum clearances to combustible materials are maintained.
The vent termination location is restricted as follows:
Minimum 12 inches above grade plus normally expected snow accumulation. Or 7 feet above grade if
located adjacent to public walkways. Do not install over public walkway where local experience indicates
condensation or vapor from the appliance creates a nuisance or hazard. Minimum 3 feet above any
forced air inlet located within 10 feet of vent termination. Minimum 4 feet below, 4 feet horizontally or
above any door window or gravity air inlet. Minimum 4 feet horizontally from electric meters, gas meters,
regulators and relief valves. Use appropriately designed thimbles when passing through combustible
walls or roofs. Install fire stops where vent passes through floors, ceilings or framed walls. The fire stop
must close the opening between the vent pipe and the structure. Locate vent terminal above combustion
air intake terminal (if used) and no closer than 2 feet vertically or horizontally. Vertical venting requires
flashing and a storm collar to prevent moisture from entering the structure. Vertical vent termination must
be at least 2 feet plus the expected snow accumulation above the roof penetration height.
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