Energy reducing retrofit method for a constant volume HVAC system
US8515584B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2009 |
| Grant date | Aug 20, 2013 |
| Priority date | — |
| Expiry date | Sep 7, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B30/90
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
An energy-reducing method and apparatus for retrofitting a constant volume HVAC system, with or without an economizer, that provides heating, cooling, and ventilation to occupants within a building space. The present invention includes the introduction of a programmable logic controller and variable frequency drive (VFD) that takes control of the existing fan, heating, cooling, and optional economizer operation. The controller is programmed for the reduction of fan speed in the heating and cooling modes. The reduction of the fan speed in the ventilation mode when the 100% operation is not needed saves significant energy of the existing constant volume HVAC system where the fan motor is designed to run 100% of the time. The fan speed may be further reduced upon a reduction in sensed occupancy levels of the space, such as with a CO2 sensor. Additionally, the fan speed may be reduced in the heating and/or cooling mode to further reduce energy consumption. The controller may also be programmed and equipped with sensors to allow simultaneous mechanical compressor cooling and economizer free cooling operation, for the operation of the economizer in response to the monitoring of outside a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.