BPM Motors in Residential Gas Furnaces: What are theSavings?

Conference · Fri May 12 04:00:00 EDT 2006

OSTI ID:889624

Lutz, James; Franco, Victor; Lekov, Alex; Wong-Parodi, Gabrielle

Residential gas furnaces contain blowers to distribute warm air. Currently, furnace blowers use either a Permanent Split Capacitor (PSC) or a Brushless Permanent Magnet (BPM) motor. Blowers account for the majority of furnace electricity consumption. Therefore, accurate determination of the blower electricity consumption is important for understanding electricity consumption of furnaces. The electricity consumption of blower motors depends on the static pressure across the blower. This paper examines both types of blower motors in non-condensing non-weatherized gas furnaces at a range of static pressures. Fan performance data is based on manufacturer product literature and laboratory tests. We use field-measured static pressure in ducts to get typical system curves to calculate how furnaces would operate in the field. We contrast this with the electricity consumption of a furnace blower operating under the DOE test procedure and manufacturer rated conditions. Furnace electricity use is also affected by operating modes that happen at the beginning and end of each furnace firing cycle. These operating modes are the pre-purge and post-purge by the draft inducer, the on-delay and off-delay of the blower, and the hot surface ignitor operation. To accurately calculate this effect, we use the number of firing cycles in a typical California house in the Central Valley of California. Cooling hours are not considered in the DOE test procedure. We also account for furnace blower use by the air conditioner and stand-by power. Overall BPM motors outperform PSC motors, but the total electricity savings are significantly less than projected using the DOE test procedure conditions. The performance gains depend on the static pressure of the household ducts, which are typically much higher than in the test procedures.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE. Assistant Secretary for Energy Efficiency andRenewable Energy. Office of the Deputy Assistant Secretary for TechnologyDevelopment. Office of the Building Technologies Program
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 889624
• Report Number(s): LBNL--59866; BnR: BT0400000
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
AIR CONDITIONERS
BLOWERS
BPM Motor Gas Furnace Furnace Electricity
CALIFORNIA
CAPACITORS
DUCTS
ELECTRICITY
ENERGY EFFICIENCY
FURNACES
GAS FURNACES
HOUSEHOLDS
MANUFACTURERS
MOTORS
PERFORMANCE
PERMANENT MAGNETS