Energy saving environmental chamber temperature control system

Abstract

A method and apparatus for controlling the temperature of an environmental chamber by controlling the flow of refrigerant, the number of compressors and fans as necessary to produce and preserve precise temperature conditions within the chamber which uses less energy than available systems.

Description

[0001] This application claims Priority 2 Provisional Application No. 60 / 655,486 filed Feb. 23, 2005.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates generally, but is not limited to Controlled temperature chambers as often used in Bio-Medical Research, Pharmaceuticals, Teaching Universities and any other operation requiring special constant temperature needs within a confined space or chamber, often called “Environmental Rooms” or “Cold Rooms”. [0004] 2. Background of the Invention [0005] Medical Research and other Bio-Medical functions are often done in cold (4° C.) or warm (37° C.) rooms. Other frequently used applications are −20° C. and +25° C. As technology over the years has become increasingly precise, the need to have closer temperature control tolerances, faster recovery rates, and wider ranges of operation has impacted Environmental Room design. [0006] To insure close temperature control, quick recovery from door openings, higher ...

AI Technical Summary

Benefits of technology

[0009] This invention, (the Green Room), is a method and apparatus for adjusting and maintaining the desired temperature within an Environmental Room while reducing the power to produce the required cooling as compared to conventional Environmental Room systems and standard cold storage mechanical equipment. This is accomplished with a special HVAC system capable of operating at low power / capacity levels when the internal environment is within temperature specs and instantly supply more capacity when needed while maintaining the critical research or storage environment within the chamber. Refrigeration system redundancy is achieved by the ability of the controller to determine within seconds that either the primary system is off or the chamber load has exceeded its capacity and can turn on the secondary mechanical system before the internal temperature of the chamber has only changed by a few tenths of a degree.

[0011] First is the basic design of the heat exchangers. Both the primary and secondary refrigeration systems can be incorporated into a single evaporator and condenser heat exchanger assembly, each with two individual refrigerant circuits. The circuiting of the evaporator and condenser coils is done in such a way that when operating as a single system, the evaporator and condenser both operate as though they have much larger heat exchangers resulting in more efficient operation of the primary compressor. This is accomplished by interlacing the heat exchanger circuits. While interlacing the circuits is beneficial, it is not essential to still achieve substantial energy savings.

[0014] Third, the controller can cycle the airhandler fans on and off depending on phase of operation. When the chamber is cooling, a minimum of cubic feet per minute of air must pass over the heat exchanger for it to operate efficiently. When the temperature is satisfied and the compressor is turned off or is idled, the fans cannot be cut off because the temperature uniformity within the chamber must be maintained. The chamber does not require as much circulation when the temperature is satisfied so some of the fans in the airhandler can be cut off or slowed to reduce power consumption. Generally, fan power is being consumed within the chamber and adds to the total heat load of the chamber. Reducing evaporator fan power saves energy twice, once to not run the fan and again to not have the cooling system remove the heat generated by the fans had they not been turned off.

Problems solved by technology

This increased size and capacity has resulted in increased power consumption.

There is currently no manufacturer of environmental or cold storage rooms with a Leed Rating.

Images