| 摘要 |
A system (40) and method for providing a gas-fired heating system with improved thermal efficiency includes modulating a quantity of combustion air flow to a combustion mixture in response to a measured change in fuel-gas pressure using a DC (e.g., brushless) motor (42) to drive a combustion air blower (44). A pressure transducer (48) in a manifold (50) transporting fuel-gas into the combustion mixture outputs a signal (52) proportional to the measured pressure to the motor. The motor speed and thus the resultant quantity of combustion air flow are modulated in proportion to the quantity of fuel-gas to the mixture. Accordingly, a constant fuel-gas to combustion air ratio is maintained. The system and method may further provide for adjusting the output signal to accommodate measured intake air temperature, and/or measured atmospheric pressure in order to maintain a constant, good thermal efficiency (preferably ‰¥ 80%) regardless of air temperature and altitude at the system's installation location. |
