energy efficiency ratio

noun

often capitalized both Es&R

: a number expressing the relative efficiency of an appliance (such as a room airconditioner) that is obtained by dividing the unit's output in BTUs per hour by its energy requirement in watts

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now