The U.S. Department of Energy funded research of small-duct, high-velocity heating and air conditioning systems in two separate low-load, new construction homes. One is a cold climate home located in Pittsburgh, PA and the other in Fresno, CA, a warm climate. IBACOS Research was the company that conducted the testing.
IBACOS provides building product and material evaluation and development services to leading manufacturers who provide products for high performance homes.
Their research found several interesting items in regards to the Unico System when compared to conventional HVAC systems in new construction homes such as these.
- Duct leakage of the Unico System was measured at just over 1 CFM of leakage over 100 sq. ft. of conditioned space. 2012 International Energy Conservation Code (IECC 2012) requires duct leakage to meet or be less than 4 CFM per 100 sq ft of conditioned space.
- With the motor running at low speed, which is normal field operating conditions, the air handler was found to be highly efficient, using only 0.2W per CFM. A marginally inefficient system will operate at approximately .5W per CFM.
- Whole-house average air temperature stratification is rarely greater than 3°F from floor to ceiling when supply air outlets are properly selected and located to engage the whole volume of room air and appropriate return air strategies are implemented.
- In these homes, the Unico System duct work only required 4" drop in ceiling height. Bringing conventionally sized duct work into conditioned space represents a significant challenge to conventional production home builders. In fact, 52% of builders polled in this research said that a 12" drop in ceiling height, which is what is required for conventional duct work to be located in the conditioned space, would affect the sales and marketing of their homes.
- Because of the cost of materials to lower the ceiling, or install bulkheads to accommodate the duct work in a conditioned space, the research showed that the small-duct, high-velocity system costs up to 17% less to install than a traditional ducted system.