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Smart Evaporator Fan

IP.com Disclosure Number: IPCOM000011383D
Publication Date: 2003-Feb-14
Document File: 3 page(s) / 43K

Publishing Venue

The IP.com Prior Art Database

Abstract

The current invention uses an evaporator fan, 1, that contains an embedded microcontroller. The microcontroller is responsible for controlling the motor speed. Attached to the fan is a sensor, 3, capable of sensing the temperature of the air that the fan is moving, 2. Also attached to the fan is a sensor (i.e. current), 5, that can indicate the ON/OFF state of the refrigeration system compressor, 4 (i.e. when placed in series with the compressor motors, 6, power supply). The embedded microcontroller is capable of reading the attached sensors, 3 and 5, and controlling the fans output speed. An algorithm based on the logic in table 1 is programmed into the microcontroller. The algorithm will keep the fan running at a high speed (may be optimized for a given cabinet design) while the compressor motor is in the energized state. The fan will reduce its energy consumption by runnig at a low speed (may be optimized for a given cabinet design) as soon as: 1) the compressor motor turns off and, 2) the air being pushed through the evaporator remains cold enough to cause freezing within the heat exchanger (temperature may be optimized for a given evaporator design). When the air temperature rises high enough to prevent freezing on the evaporator the fan can be turned off completely, further reducing energy consumption.

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Smart Evaporator Fan

Explanation of invention:

The current invention uses an evaporator fan, 1, that contains an embedded microcontroller. The microcontroller is responsible for controlling the motor speed. Attached to the fan is a sensor, 3, capable of sensing the temperature of the air that the fan is moving, 2. Also attached to the fan is a sensor (i.e. current), 5, that can indicate the ON/OFF state of the refrigeration system compressor, 4 (i.e. when placed in series with the compressor motors, 6, power supply). The embedded microcontroller is capable of reading the attached sensors, 3 and 5, and controlling the fans output speed. An algorithm based on the logic in table 1 is programmed into the microcontroller. The algorithm will keep the fan running at a high speed (may be optimized for a given cabinet design) while the compressor motor is in the energized state. The fan will reduce its energy consumption by runnig at a low speed (may be optimized for a given cabinet design) as soon as:

1)      the compressor motor turns off and,

2)      the air being pushed through the evaporator remains cold enough to cause freezing within the heat exchanger (temperature may be optimized for a given evaporator design).

When the air temperature rises high enough to prevent freezing on the evaporator the fan can be turned off completely, further reducing energy consumption.

Table 1

Fan Speed Logic Table

Compressor
State

On

On

Off

Off

Evaporator Air Temperature

< 32°F

> 32°F

< 32°F

> 32°F

Fa...