Advantages:

• Gas is an efficient heat source, and it saves you money compared to electricity.
• Gas burners are capable of much higher temperatures than electric elements.
• Faster recovery means more hot water per hour than same-size electric.
• Direct-vent and power-vent models are available for hard-to-vent applications.
• Variety of sizes (30 to 75 gallons) to fit most household applications.
• Most units do not require electricity to operate.
• No need for special 240-volt wiring or isolated electric circuit.
• No heating elements to short, burn out, or replace (their average life is 2-3 years).
• Instantaneous models available for hot water-on-demand applications.
• Stands and drain pans are available for certain installation needs.
• Temperature controls allow settings for personal comfort and energy-saving "Vacation Setting".

Proper Sizing of Natural Gas Water Heaters:

To determine the proper size of water heater, you need to know the total amount of hot water that will be required to satisfy all of the hot water uses at the peak hour of demand. This can be determined by reviewing the following chart and totaling the estimated gallons needed at the time of highest usage:

Major hot water users

Estimated gallons of hot water consumed per use

Clothes Washer

10-12 gallons (warm wash/cold rinse)
20-25 gallons (warm wash/warm rinse)
Up to 30 gallons (hot wash/warm rinse)

Bath

15-20 gallons

Shower

10-15 gallons (3 gallons/minute)

House Cleaning

5-12 gallons

Automatic Dishwasher

5-15 gallons/load

Hand dish washing

4 gallons/load

Food Preparation

3-5 gallons

Hair shampoo

4 gallons

Shaving

2 gallons

Hand Washing

1-2 gallons

Note: The estimates above take into consideration the fact that hot and cold water will be mixed for many of the uses listed.

Calculate the peak hourly demand by adding the total amount of gallons for all hot water users that might be in use at the peak demand time. Use the first hour rating on the available water heaters to select units that will satisfy the peak hourly demand.

Natural Gas Versus Electric: