Carrier 58DXT Operating Instructions Manual

Also see for 58DXT: User's information manual Service and maintenance instructions

Contents

Carrier 58DXT Operating Instructions Manual Manual pdf 5 page image

The requirements for combustion and ventilation air depend uponwhether furnace is located in a CONFINED or UNCONFINEDspace.UNCONFINED SPACEAn unconfined space must have at least 50 cu ft for each 1000Btuh of input for all appliances (such as furnaces, clothes dryer,water heaters, etc.) in the space.For Example:58DXT FURNACEHIGH-FIRE INPUTBTUHMINIMUM SQ FTWITH7-1/2 FT CEILING63,000 42084,000 560105,000 700If the unconfined space is constructed unusually tight, air forcombustion and ventilation MUST come from either the outdoorsor spaces freely communicating with outdoors. Combustion andventilation openings must be sized the same as for a confinedspace as defined below. Return air must not be taken from theroom unless equal or greater amount of air is supplied to the room.CONFINED SPACEA confined space is defined as a space whose volume is less than50 cu ft per 1000 Btuh of total input ratings of all appliancesinstalled in that space. A confined space MUST have provisionsfor supplying air for combustion, ventilation, and dilution of fluegases using 1 of the following methods.NOTE: In determining free area of an opening, the blockingeffect of louvers, grilles, and screens must be considered. If freearea of louver or grille design is unknown, assume that woodlouvers have a 20 percent free area and metal louvers or grilleshave a 60 percent free area. Screens, when used, must not besmaller than 1/4-in. mesh. Louvers and grilles must be constructedso they cannot be closed.The size of the openings depends upon whether air comes fromoutside of the structure or an unconfined space inside the structure.1. All air from an unconfined space inside the structure requires2 openings (for structures not usually tight):a. Each opening MUST have at least 1 sq in. of free area per1000 Btuh of total input for all equipment within theconfined space, but not less than 100 sq in. per opening.(See Fig. 3 and Table 2.) The minimum dimension of airopenings shall not be less than 3 in.b. If the building is constructed unusually tight, a permanentopening directly communicating with the outdoors shall beprovided. (See item 2 below.)c. If furnace is installed to obtain return air is taken directlyfrom hallway or space adjacent to furnace, all air forcombustion must come from outdoors.2. Air from outside the structure requires 1 of the followingmethods:a. If combustion air is taken from outdoors through 2 verticalducts, the openings and ducts MUST have at least 1 sq in.of free area per 4000 Btuh of total input for all equipmentwithin the confined space. (See Fig. 4 and Table 2.)Fig. 3—Confined Space: Air for Combustion andVentilation from an Indoor Unconfined SpaceA93387RETURNAIR6″ MIN(FRONT) †SUPPLY AIRVENT THROUGH ROOF(CATEGORY I)1 SQ IN.PER 1000BTUH* IN DOOROR WALL12″ MAX1 SQ IN.PER 1000BTUH* IN DOOROR WALL12″ MAXINTERIORHEATEDSPACE* Minimum opening size is 100 sq in. withminimum dimensions of 3 in.† Minimum of 3 in. when type B-1 vent is used.UNCONFINEDSPACEFig. 4—Confined Space: Air for Combustion andVentilation from OutdoorsA93388DUCTS TOOUTDOORS1 SQ IN.PER 4000BTUH *RETURNAIR VENTTHROUGHROOF(CATEGORY I)DBACE1 SQ IN.PER 4000BTUHDUCTTOOUTDOORSSUPPLY AIR1 SQ IN.PER 2000BTUH*DUCTSTOOUTSIDE12″ MAX12″ MAXCONFINEDSPACE12″MAX12″MAX1 SQ IN.PER 4000BTUH *OUTDOORS1 SQ IN.PER 4000BTUH *1 SQ IN.PER 2000BTUH*12″ MAXUse any of the followingcombinations of openings:A & B C & D D & E F & GNOTE:*Minimum dimensions of 3 in.FG5