Sound attenuating shield for an electric heater
AssigneeTrane International Inc.
InventorsFerdy Martinus, William B. Rockwood
Life of this patent
Estimating the term…
Abstract
A sound-abating flow disruptor quiets a PTAC refrigerant system by disturbing the airflow between an energized electric heater and an adjacent fan wheel. In some embodiments, the flow disruptor is a perforated metal plate that attenuates a whistle, which appears to be caused by vortex shedding in the confined area between the energized heater and the fan. In some cases, the heater comprises selectively energizable heating elements of various wattage. The heating elements closest to the fan wheel are the lower wattage ones to minimize the heat near the fan.
Claims26
A refrigerant system, comprising:
- a housing;
- a refrigerant heat exchanger disposed within the housing;
- a fan wheel rotating about an axis, thereby forcing air through the housing;
- an electric heater upstream of the fan wheel and downstream of the refrigerant heat exchanger, wherein the electric heater can be selectively energized and de-energized;
- and
- a sound at a certain peak frequency between 500 and 1,500 hertz emanating from the refrigerant system, wherein the sound at one meter from the axis is no more than 5 decibels louder when the electric heater is energized than when the electric heater is de-energized.
A refrigerant system, comprising:
- a housing defining an inlet and an outlet;
- a fan wheel disposed within the housing and being rotatable about an axis to force air through the housing;
- a refrigerant heat exchanger disposed within the housing;
- an electric heater disposed within the housing, wherein the electric heater is downstream of the refrigerant heat exchanger and upstream of the fan wheel;
- a noise-abating flow disruptor located downstream of the electric heater and upstream of the fan wheel, the noise-abating flow disruptor comprising an outer periphery surrounding an area having a plurality of openings through which air can flow, the air passes sequentially through the electric heater, through the noise-abating flow disruptor and across the fan wheel, and
- a sound emanating from the refrigerant system, the sound at one meter from the axis is no more than 5 decibels louder when the electric heater is energized than when the electric heater is de-energized.
A refrigerant system, comprising:
- a housing;
- a refrigerant heat exchanger disposed within the housing;
- an electric heater disposed within the housing;
- and
- a fan wheel disposed within the housing for forcing air across the refrigerant heat exchanger and the electric heater;
- wherein the electric heater comprises a plurality of selectively energizable beating elements including a higher-wattage element and a lower-wattage element, and the fan wheel is closer to lower-wattage element than the higher-wattage element.
Dependencies are inferred from the claim text.