# How Much Propane Does a 20,000 BTU Heater Use?

A 20,000 BTU heater is a powerful heating appliance that can effectively warm up a medium-sized room or space. However, the amount of propane it consumes can vary depending on several factors, including the runtime, efficiency, and the specific usage patterns. In this comprehensive guide, we’ll dive deep into the technical details and provide you with a step-by-step DIY approach to understanding the propane consumption of a 20,000 BTU heater.

## Technical Specifications

### Propane Consumption Rate

• A 20,000 BTU heater uses approximately 0.25 gallons of propane per hour (20,000 BTU ÷ 80,000 BTU/gallon)
• This means that a 20,000 BTU heater running continuously for 24 hours would consume around 6 gallons of propane

### Runtime on a 20# Propane Tank

• A standard 20# propane tank has approximately 430,000 BTU of total energy
• Assuming a 20,000 BTU heater is running at full blast, the 20# tank can last for around 6 hours (430,000 BTU ÷ 20,000 BTU/hour = 21.5 hours)
• However, the actual runtime may vary depending on the heater’s efficiency and the tank’s fill level

### Daily Propane Consumption

• A 20,000 BTU fireplace that runs for 30 minutes every hour or 12 hours a day would use approximately 2.62 gallons of propane per day
• This calculation is based on the formula:
((MINUTES PER HOUR × 24) ÷ 60) × BTU LOAD) ÷ 91,500) = GALLONS PER DAY
Where:
• MINUTES PER HOUR is the number of minutes the heater runs per hour
• BTU LOAD is the BTU rating of the heater
• 91,500 is the energy content of a gallon of propane in BTUs

## DIY Approach

### Calculating Propane Consumption

To calculate the amount of propane used by your 20,000 BTU heater, you can use the following formula:

((MINUTES PER HOUR × 24) ÷ 60) × BTU LOAD) ÷ 91,500) = GALLONS PER DAY

1. Determine the number of minutes per hour your heater runs (e.g., 30 minutes per hour)
2. Multiply the minutes per hour by 24 to get the total minutes per day
3. Divide the total minutes per day by 60 to get the hours per day
4. Multiply the BTU load of your heater (20,000 BTU) by the hours per day
5. Divide the result by 91,500 (the energy content of a gallon of propane in BTUs) to get the gallons of propane used per day

### Estimating Runtime on a Propane Tank

To estimate the runtime of a propane tank with your 20,000 BTU heater, you can use the following formula:

TOTAL TANK BTU ÷ (BTU LOAD × HOURS PER DAY) = DAYS OF RUNTIME

1. Determine the total BTU capacity of your propane tank (e.g., 430,000 BTU for a 20# tank)
2. Multiply the BTU load of your heater (20,000 BTU) by the number of hours per day it runs
3. Divide the total tank BTU by the result from step 2 to get the estimated number of days the tank will last