AIR FOR COMBUSTION AND VENTILATION

Continued

6

DETERMINING AIR FLOW FOR HEATER LOCATION

Determining if You Have a Confined or Unconfined Space

Use this work sheet 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 openings, 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 support)

3. Add the Btu/Hr of all fuel burning appliances 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

+

39,000

Btu/Hr

Total

=

 

 

Btu/Hr

79,000

*Do not include direct-vent gas appliances. 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)

79,000

Btu/Hr (actual amount of Btu/Hr used)

The space in the above example is a confined 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 ventilation grills between rooms. See Ventilation Air From Inside Building, page 7.

B.Vent room directly to the outdoors. See Ventilation Air From Outdoors, page 7.

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.

102990

Page 6
Image 6
Desa CGD3930N, CGD3018N installation manual AIR for Combustion and Ventilation, Determining AIR Flow for Heater Location

CGD3018N, CGD3930N specifications

The Desa CGD3930N and CGD3018N are innovative gas heaters that exemplify cutting-edge technology and design in the heating industry. Both models are designed to provide efficient heating solutions for residential spaces, ensuring comfort during colder months while being environmentally conscious.

The CGD3930N is a powerful unit featuring a heating capacity of up to 30,000 BTUs, making it suitable for larger areas. It combines radiant and convection heating methods to ensure even heat distribution throughout the space. This model is equipped with a thermostat for precise temperature control, allowing users to set their desired comfort level easily. One of its standout features is the built-in oxygen depletion sensor, which enhances safety by monitoring the air quality to prevent hazardous conditions.

On the other hand, the CGD3018N, with a heating capacity of 18,000 BTUs, is perfect for smaller rooms or spaces that require consistent heating without excessive energy consumption. Its compact design makes it adaptable for various room layouts. Like the CGD3930N, it also features an adjustable thermostat, ensuring users can maintain the preferred level of warmth. The heater's flameless design provides a safe alternative to traditional heating methods, reducing the risk of accidents.

Both models utilize advanced ceramic burner technology, which enhances combustion efficiency and reduces emissions. This is particularly important as households increasingly seek to minimize their environmental footprint. This technology also ensures that both heaters operate quietly, providing warmth without the disruption of noisy mechanisms.

A significant aspect of the Desa CGD3930N and CGD3018N is their versatility. They can be installed as wall-mounted units or freestanding options, giving homeowners the flexibility to choose the best configuration for their space. The modern aesthetic of both models complements a wide range of interior designs, making them not only functional but stylish additions to any home.

In conclusion, the Desa CGD3930N and CGD3018N are excellent choices for those seeking reliable and efficient heating solutions. With their advanced features, safety measures, and stylish designs, these gas heaters provide warmth and comfort in any residential environment while promoting energy efficiency.