Mesker Hollow Metal Door Energy Efficiency
It's important to determine your steel door energy costs.

At Mesker, you'll save on your heating and cooling costs by considering the thermal rating of hollow metal
door cores. A good core choice means you'll benefit from continual savings without adding to the original
cost of your hollow metal doors. Mesker has the information you need to figure how door cores affect your
energy costs. The graph below gives you an idea of which cores are more energy efficient. To estimate your
cost savings, you'll need to approximate the number of days you'll be using your heating during each
season. Your energy supplier also has helpful information to help you calculate your hollow metal door and
frame energy efficiency.
Using the cost of energy per 100,000 BTU from the graph above and the "U-Factor" information from the
table below, you can begin zeroing in on your energy cost per season when using a particular hollow metal
door core. Although figuring your summer cooling costs is a bit more complicated, many electric utility
engineers use this method to estimate local energy costs. Essentially, to determine your specific BTU loss,
take the square footage of your door (length times the width), multiplied by the U-Factor, multiplied by the
Degree Days, and multiplied by 24. The formula for determining your unit cost each season is kilowatt input
per ton of output, multiplied by the estimated hours of full load cooling, multiplied by the cost of a kilowatt
hour, multiplied by the difference between the desired temperature inside and the outside temperature,
multiplied by the square foot of your door's surface, multiplied by the "U-Factor" for your hollow metal door,
and divided by 12,000 (BTUs per ton).

Door Summary Chart
To learn more about building standards and guidelines for energy efficiency, we suggest you go to, the website of the "American Society of Heating, Refrigerating and Air-conditioning
Engineers." Hollow metals doors can help improve your energy efficiency.