Desa Tech CGN20TA Continued, Owner’S Manual, Fresh Air For Combustion And Ventilation, Example

Models: CGN20TA

1 24
Download 24 pages 27.88 Kb
Page 5
Image 5
Continued

OWNER’S MANUAL

FRESH AIR FOR COMBUSTION AND VENTILATION

Continued

DETERMINING FRESH-AIR FLOW FOR HEATER LOCATION

Determining if You Have a Confined or Unconfined Space

Use this worksheet to determine if you have a confined or unconfined space.

Space: Includes the room in which you will install heater plus any adjoining rooms with doorless passageways or ventilation grills between the rooms.

1.Determine the volume of the space (length x width x height).

Length x Width x Height =

__________ cu. ft. (volume of space)

Example: Space size 20 ft. (length) x 16 ft. (width) x 8 ft. (ceiling height) = 2560 cu. ft. (volume of space)

If additional ventilation to adjoining room is supplied with grills or open- ings, add the volume of these rooms to the total volume of the space.

2.Divide the space volume by 50 cubic feet to determine the maximum Btu/Hr the space can support.

_______________ (volume of space)

÷50 cu. ft. = (Maximum Btu/Hr the space can support)

Example: 2560 cu. ft. (volume of space) ÷ 50 cu. ft. = 51.2 or 51,200 (maximum Btu/Hr the space can sup- port)

3.Add the Btu/Hr of all fuel burning ap- pliances in the space.

Vent-free heater __________ Btu/Hr Gas water heater* ________ Btu/Hr Gas furnace _____________ Btu/Hr Vented gas heater _________ Btu/Hr

Gas fireplace logs ________ Btu/Hr

Other gas appliances* +

___ Btu/Hr

Total

=

___ Btu/Hr

Example:

 

 

 

Gas water heater

40,000

Btu/Hr

Vent-free heater

+ 20,000

Btu/Hr

Total

= 60,000 Btu/Hr

*Do not include direct-vent gas appli- ances. Direct-vent draws combustion air from the outdoors and vents to the outdoors.

4.Compare the maximum Btu/Hr the space can support with the actual amount of Btu/Hr used.

__________ Btu/Hr (maximum the

space can support)

__________ Btu/Hr (actual amount of

Btu/Hr used)

Example: 51,200 Btu/Hr (maximum the space can support)60,000 Btu/Hr (actual amount of Btu/Hr used)

The space in the above example is a con- fined space because the actual Btu/Hr used is more than the maximum Btu/Hr the space can support. You must provide additional fresh air. Your options are as follows:

A.Rework worksheet, adding the space of an adjoining room. If the extra space provides an unconfined space, remove door to adjoining room or add ventila- tion grills between rooms. See Ventila- tion Air From Inside Building, page 6.

B.Vent room directly to the outdoors. See Ventilation Air From Outdoors, page 6.

C.Install a lower Btu/Hr heater, if lower Btu/Hr size makes room unconfined.

If the actual Btu/Hr used is less than the maximum Btu/Hr the space can support, the space is an unconfined space. You will need no additional fresh air ventilation.

Continued

104190

5

Page 5
Image 5
Desa Tech CGN20TA installation manual Continued, Owner’S Manual, Fresh Air For Combustion And Ventilation, Example