Weil-McLain CGA25SPDN manual Exhaust fans and air movers, Motorized air dampers

GOLD CGa Gas-Fired Water Boiler — Boiler Manual

FREE AREA of openings — the minimum areas given in this manual are free area (equals the area, length times width of opening, after deduction for louver obstruction).

Use the free area information provided by the louver manufacturer. When this information is not available, assume:

ss7OOD LOUVERSV ˆASSUME FREE AREA IS OF TOTAL SO THEHACTUALLAREA of each opening with wood louvers would be 5 times the required free area.

ss-ETALTLOUVERSV ˆASSUME FREE AREA IS OF ACTUAL AREAESOOFOR WOOD louvers, the actual area of each opening must be 1.67 times the required free area.

Single air opening option 7

A single combustion air opening can be used in lieu of the two-opening options on page 10, provided:

Clearances from boiler to walls

ss4HEHBOILER MUST HAVE CLEARANCES OF AT LEASTATHOSEOSHOWNOIN &IGURE A page 7.

Opening must be directly to outside

ss4HEHOPENINGNMUST CONNECTNDIRECTLY TO THEHOUTDOORS OR TO AASPACE THAT communicates directly to the outdoors (not to an interior space).

s4HEHAIRICANABE PROVIDED THROUGHOAADIRECT OPENINGNOR THROUGHOA HORIZONTAL or vertical duct.

Opening placement

ss 4HEHTOP OF THE AIR OPENING MUSTABE WITHINP INCHESGOF THE CEILING

Opening size

ss4HEHFREE AREA OF THEHOPENINGNMUST BE AT LEASTAEQUALUTO THEHSUMMOF THEH area of all equipment vent connectors in the space, and . . .

ss4HEHFREE AREA OF THEHOPENINGNMUST BE AT LEASTASQUARE INCH PER 

"TUHR INPUT RATINGPOF ALL EQUIPMENT LOCATED INATHELSPACE

Exception for large spaces 7

.O COMBUSTION AIRIOPENINGS ARERNEEDED WHEN THEHBOILER AND OTHERRAP-

pliances) are installed in a space with a volume AT LEASTA CUBICBFEETEPERE "TUH of all installed appliances, provided:

ssTHEHBUILDINGDMUSTSNOTOHAVE UNUSUALLYYTIGHTGCONSTRUCTION (see defini- tion, this page)

ssALLLCLEARANCES AROUND THEHBOILER MUST MUST BE NO LESS THAN SHOWNWIN

Figure 1a, page 7.

To determine if the space is large enough to qualify:

ss !DDDTHE TOTALEINPUTOOF ALL APPLIANCESTIN -"( S OF "TUH 

ss-ULTIPLY THIS NUMBER TIMESM TO DETERMINERMINIMUMIROOM VOLUME

ss %XAMPLE &OROAATOTALTINPUTPOF -"(" "TUH  MINIMUMM volume is 50 x 100 = 5,000 cubic feet. At a ceiling height of 8 feet, the space must have at least 5,000 ÷ 8 = 625 square feet (25 feet x 25 feet, for instance).

Part Number 550-101-009/0107

Unusually tight construction

5NUSUALLYUTIGHTGCONSTRUCTION MEANSAPER !.3) :  buildings in which:

a.Walls and ceilings exposed to the outside atmo- sphere have a continuous water vapor retarder with a rating of 1 perm or less with openings gasketed, and . . .

b.Weather-stripping has been added on openable windows and doors, and . . .

C #AULKING OR SEALANTS ARERAPPLIEDLTO AREASESUCH AS joints around windows and door frames, between sole plates and floors, between wall-ceiling joints, between wall panels, at penetrations for plumbing, electrical, and gas lines, and in other openings.

For such construction cases, if appliances use inside air for combustion, PROVIDE AIRIOPENINGS INTO THEHBUILDING FROM OUTSIDE. Size and locate these openings per the appropriate case in &IGURE   OR  on page 10.

Exhaust fans and air movers

The appliance space must never be under a negative pressure, even if the appliance(s) are installed as direct vent. Always provide air openings sized not only to the dimensions required for the firing rate of all appli- ances, but also to handle the air movement rate of the exhaust fans or air movers using air from the building or space.

Motorized air dampers

If the air openings are fitted with motorized dampers, electrically interlock the damper to:

ss0REVENTVTHEHBOILER FROM lRINGIIF THEHDAMPER IS NOTO fully open.

ss3HUT THEHBOILER DOWN SHOULD THEHDAMPER CLOSEODUR- ing boiler operation.

To accomplish this interlock, wire an ISOLATED CONTACT (proving the damper open) in series with the thermo- stat input to the boiler. The boiler will not start if this contact is open, and will shut down should it open during operation.

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