10 Best Energy Efficient Air Conditioners to Keep You Cool Without Raising Your Bill

4. Della 048-TL-WAC6K -- Compact and Feature-Packed

Della isn't as well-known as some other brands, but this model punches above its weight. The 6,000 BTU output is ideal for small to mid-sized rooms, and it boasts digital controls, sleep mode, and a timer --- all features typically found in higher-priced units. Energy efficient and easy to install, it's a great pick for tech-savvy renters.