Quick Answer
Elevated areas typically require more BTUs for heating due to lower air pressure and temperature, with a general rule of thumb suggesting an increase of 3-5% in BTU requirements for every 1,000 feet above sea level.
Understanding Elevation’s Impact on BTU Needs
Elevation affects BTU needs for heating by altering atmospheric pressure and temperature. At higher elevations, the air pressure decreases, resulting in a lower density of air. This means that the same amount of heat will dissipate more quickly, requiring more BTUs to maintain a consistent temperature. For example, a propane wall heater rated for 20,000 BTUs at sea level might need an additional 2,000-4,000 BTUs to maintain the same level of heat at an elevation of 3,000-4,000 feet.
Calculating BTU Increases at Higher Elevations
To calculate the required BTU increase, use the following formula: (elevation in feet / 1,000) x (percent increase in BTUs). For instance, at 3,500 feet, the elevation factor would be 3.5 / 1,000 = 0.0035. Assuming a 4% increase in BTUs per 1,000 feet, the required BTU increase would be 0.0035 x 4 = 0.014, or a total of 14% more BTUs. This would translate to an additional 2,800 BTUs for a 20,000 BTU heater.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.