All Air from Outdoors

Outdoor fresh air can be provided to a confined area either directly or by the use of vertical and horizontal ducts. The fresh air can be taken from the outdoors or from crawl or attic spaces that freely communicate with the outdoors. Attic or crawl spaces cannot be closed and must be properly ventilated to the outside.

Ductwork must be of the same cross-sectional area as the free area of the opening to which they connect. The minimum dimension of rectangular air ducts cannot be less than three inches.

The size of each of the two openings is determined by the method in which the air is to be provided. Refer to Table 3 to calculate the minimum free area for each opening. Figures 6, 7, and 8 are typical examples of each method.

Louvers and Grilles

In calculating free area for ventilation and combustion air supply openings, consideration must be given to the blocking effect of protection louvers, grilles, and screens. These devices can reduce airflow, which in turn may require larger openings to achieve the required minimum free area. Screens must not be smaller than 1/4” mesh. If the free area through a particular design of louver or grille is known, it should be used in calculating the specified free area of the opening. If the design and free area are not known, it can be assumed that most wood louvers will allow 20 - 25% of free area while metal louvers and grilles will allow 60 - 75% of free area.

Louvers and grilles must be locked open or interconnected with the equipment so that they are opened automatically during equipment operation.

Keep louvers and grilles clean and free of debris or other obstructions.

Table 3

Minimum Free Area of Permanent Openings for Ventilation and Combustion Air Supply - All Air from Outdoors Only.

Based on the total BTUH input rating for all gas utilizing equipment within the confined space.

Opening	Minimum Free Area	Reference
Opening	Per Opening	Reference
Source	(sq. in.)	Drawing
Direct to	1 Square inch per 4000	Figure 6
outdoors	BTUH
Vertical ducts	1 Square inch per 4000	Figure 7
	BTUH
Horizontal ducts	1 Square inch per 2000	Figure 8
	BTUH

Example: A water heater with an input rate of 50,000 BTUH using horizontal ducts would require each opening to have a minimum free area of 25 square inches.

Minimum free area = 50,000 BTUH x 1 sq. in. / 2000 BTUH = 25 Sq. Inches.

*These openings connect directly with the outdoors through a ventilated attic, a ventilated crawl space, or through an outside wall.

Consult the local codes of your area for specific ventilation and combustion air requirements.

	Gable vent
	to outdoors
	Install above
	insulation
Confined	Outlet
Space	air to attic
	1 Sq. inch per
	4000 BTUH
Alternate	Inlet air
Alternate	from the
Air Inlet	crawl
	space
1 sq. inch per	Open
4000 BTUH	Foundation
	Vent

Figure 6

All Air from Outdoors; Inlet Air from Ventilated

Crawl Space/Outlet Air to Ventilated Attic

	Gable vent
	to outdoors
	Install above
	insulation
Confined	Outlet air
Confined	to attic
Space	1 Sq. inch per
	4000 BTUH
	Inlet air duct
	1 sq. inch per
	4000 BTUH

Figure 7	12” maximum
All Air from Outdoors
Through Ventilated Attic

	1 sq. inch
	per
	2000 BTUH
Confined	Outlet
Space
	Outdoor
	Air Ducts
	Inlet

Figure 8	1 sq. Inch
All Air from Outdoors	per
Using Horizontal Ducts	2000 BTUH

192906, BFG1F4034T3PV, BFG1F4034T3PV 7K, 195102, 211456 specifications

The Whirlpool BFG2H4040T3NOV E and BFG1J4040T3NOV 5K are high-efficiency gas water heaters that cater to the needs of modern households with their cutting-edge technologies and features. Engineered with the latest advancements, these models ensure optimal performance, energy efficiency, and user convenience.

One of the standout features of the Whirlpool BFG series is its robust build quality. Both models are designed with a cylindrical stainless-steel tank that enhances durability and longevity. The insulation used in these heaters minimizes heat loss, ensuring that water remains hot for an extended period while reducing energy consumption. This characteristic not only saves on utility bills but also contributes to environmentally friendly practices.

Additionally, the BFG2H4040T3NOV E and BFG1J4040T3NOV 5K incorporate smart technology that simplifies the user experience. The thermostatic control allows homeowners to set and maintain precise water temperatures according to their preferences, providing comfort and convenience. Furthermore, these models are equipped with a high-efficiency burner system that maximizes the heating process, ensuring that hot water is readily available when needed.

Safety is a significant focus of Whirlpool's design philosophy. The BFG series features advanced safety mechanisms including a flame arrestor that prevents combustion incidents, along with a built-in pressure relief valve. These safety features offer peace of mind for users, ensuring worry-free operation in everyday use.

Moreover, the Whirlpool BFG model line is designed with installation flexibility in mind. They can be seamlessly integrated into various home designs, whether residential or commercial. The compact nature of these heaters allows for space-saving installations while delivering high output efficiency.

The BFG series also emphasizes user serviceability with clear instructions for maintenance and troubleshooting, enabling homeowners to address common issues effectively without requiring professional assistance. This aspect further enhances the overall ownership experience, making these water heaters an excellent choice for energy-conscious consumers.

In summary, the Whirlpool BFG2H4040T3NOV E and BFG1J4040T3NOV 5K stand out in the market due to their exceptional durability, advanced technology, safety features, and ease of installation. With their energy-efficient design and user-friendly functionality, these gas water heaters provide the perfect solution for families seeking reliable hot water solutions.