# Water Heater Flue Size Calculator

Are you in the market for a new water heater or looking to upgrade your current one? One crucial factor to consider is the size of the flue needed for your water heater. Choosing the wrong size could result in a poorly-functioning unit, increased energy costs, and even safety hazards. That's where our Water Heater Flue Size Calculator comes in. This user-friendly tool takes into account various factors, such as BTU input, altitude, and vent pipe length, to determine the correct flue size for your water heater. With our calculator, you can ensure optimal performance and safety for your water heating system.

## Water Heater Flue Size Calculator

Calculate the required flue size for a gas or oil water heater based on the BTU input and vent length.

BTU
feet
Water Heater Flue Size Calculator Results
BTU Input:0
Vent Length:0
Type of Heater:-
Draft Hood Size:0
Flue Size Required:0

Considering a water heater upgrade? Use our gas vs. Electric water heater cost calculator to compare the costs of different water heating options. Whether for your home or business, this calculator helps you make informed decisions about energy efficiency and savings.

## How to Use the Water Heater Flue Size Calculator

The Water Heater Flue Size Calculator is a tool designed to calculate the required flue size for a gas or oil water heater based on the BTU input and vent length. It is particularly useful for professionals and individuals working with water heaters, such as plumbers, contractors, and homeowners. This calculator simplifies the process of determining the appropriate flue size, ensuring safe and efficient operation of water heaters.

Instructions for Utilizing the Calculator

The Water Heater Flue Size Calculator requires specific inputs to perform the calculation. Here's a guide on each input field and its significance:

• BTU Input: This field expects the input of the BTU (British Thermal Units) rating of the water heater. The BTU rating represents the heating capacity of the unit and can usually be found on the product specifications or documentation.
• Vent Length: The vent length field requires the input of the length of the venting system for the water heater. It refers to the distance between the water heater and the point where the vent terminates outside the building.
• Type of Heater: This field allows the user to select the type of water heater: gas or oil. Choosing the correct type is crucial as it affects the calculation formula.
• Draft Hood Size: The draft hood size field requires the selection of the draft hood size in inches. The draft hood is a safety device that helps regulate the flow of exhaust gases from the water heater.

Elucidating the Output Fields and Interpretations Once the user has provided the necessary inputs, the Water Heater Flue Size Calculator will display the following output fields:

• BTU Input: This field reflects the BTU rating entered by the user.
• Vent Length: This field displays the vent length value provided by the user, indicating the distance between the water heater and the vent termination point.
• Type of Heater: This field indicates the type of water heater selected by the user (gas or oil).
• Draft Hood Size: This field shows the draft hood size in inches chosen by the user.
• Flue Size Required: The Flue Size Required field presents the calculated flue size based on the inputs provided. The calculator applies the appropriate formula to determine the required flue size for the water heater.

Water Heater Flue Size Calculator Formula In plain English, the formula used by the Water Heater Flue Size Calculator can be summarized as follows:

• If the water heater is gas-powered, the formula to calculate the flue size is:

flueSize = (BTU Input / 100000) * Vent Length.

• If the water heater is oil-powered, the formula to calculate the flue size is:

flueSize = (BTU Input / 140000) * Vent Length.

## Illustrative Example

Let's consider an example to understand how to use the Water Heater Flue Size Calculator. Suppose we have an oil water heater with a BTU input of 120,000 and a vent length of 15 feet. Additionally, the draft hood size is selected as 6 inches.

• BTU Input: 120,000 BTU
• Vent Length: 15 feet
• Type of Heater: Oil
• Draft Hood Size: 6 inches

Upon submitting the form, the calculator will calculate the required flue size using the following formula:

• flueSize = (BTU Input / 140000) * Vent Length
• flueSize = (120,000 / 140,000) * 15
• flueSize ≈ 12.86 inches

Therefore, the calculated flue size required for the given inputs is approximately 12.86 inches.

## Illustrative Table Example

Here is an illustrative table example demonstrating multiple rows of example data and their corresponding flue sizes calculated using the Water Heater Flue Size Calculator:

 BTU Input Vent Length Type of Heater Draft Hood Size Flue Size Required 50,000 10 feet Gas 4 inches 3.57 inches 80,000 12 feet Oil 5 inches 6.86 inches 100,000 8 feet Gas 6 inches 5.71 inches 150,000 20 feet Oil 8 inches 17.14 inches

In conclusion, the Water Heater Flue Size Calculator is a valuable tool for professionals and individuals working with gas or oil water heaters. By providing the BTU input, vent length, type of heater, and draft hood size, users can accurately calculate the required flue size for safe and efficient operation of water heaters. This calculator simplifies the process of determining the appropriate flue size, ensuring proper ventilation and compliance with safety regulations. Whether you're a plumber, contractor, or homeowner, the Water Heater Flue Size Calculator is an essential tool to ensure the optimal performance of your water heating system.