Air handler unit fan installation and control method

Abstract

A method is provided including installing a variable frequency drive unit to drive a previously non-variable air handler fan of an HVAC system. The method includes setting a control strategy for the variable frequency drive. The control strategy includes a drive speed for each mode of the HVAC system. The method includes operating the HVAC system in each mode and monitoring the HVAC system. The method includes adjusting the HVAC system or the control strategy of the variable frequency drive to increase drive speed based on monitoring the HVAC system.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 60 / 796,347, filed on Apr. 28, 2006, the disclosure of which is incorporated herein by reference.FIELD [0002] The present disclosure relates to an air handler unit fan installation and control method. BACKGROUND [0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. [0004] Heating, ventilating and air conditioning (HVAC) systems may generally be equipped with an air handler unit that may control the flow of air. Air handler units may traditionally be non-variable, in that the unit is equipped with a single or two speed fan that may operate at certain fixed or incremental speeds. Because such fans may only operate at either one or two fixed speeds, the fans may not be efficiently controlled to match HVAC system load. Consequently, use of such fans may result in excessive electrica...

AI Technical Summary

Problems solved by technology

Because such fans may only operate at either one or two fixed speeds, the fans may not be efficiently controlled to match HVAC system load.

Consequently, use of such fans may result in excessive electrical energy consumption, excessive cycling of system components, and excessive system component wear.

In a cooling mode, when the air handler fans are operated at slower speeds, less air flow contacts evaporator coils resulting in low evaporator superheat temperatures and a risk of a refrigerant flood-back condition.

Likewise, in a heating mode, less air flow contacting a heating element may result in a high heating element temperature and a risk of a heating element overheating condition.

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