US 6,684,653 B2 · Air-conditioner and air-to-air heat exchange for closed loop cooling

Abstract

Closed loop cooling is provided by means of a mechanical air conditioner combined with an air-to-air heat exchanger. Three basic modes of operation maximize cooling while minimizing energy consumption, depending on ambient air temperature. In the first mode the air-to-air heat exchanger or economizer provides all required cooling to a closed circuit enclosure air stream, transferring heat to the cold ambient air stream. In the second mode the air-to-air heat exchanger precools the closed air circuit stream using moderate temperature ambient air, in the same manner as in the first mode, followed by further removal of heat by passing enclosure air through refrigeration condenser coils. The heat taken in at the evaporator is transferred to the ambient air stream as it passes through a condenser coil after passing through the heat exchanger. In the third mode, only the mechanical air conditioner provides cooling, transferring heat from the closed circuit enclosure air stream to the evaporator after which it is transferred in the condenser to ambient hot air that does not pass through the air-to-air heat exchanger. A fourth heating mode can be employed if necessary under extremely cold conditions. A system of dampers and controls provides the alternate modes of cooling.

Claims19

Dependent claims

An enclosure cooling system comprising:

a cooling unit having a compressor, a condenser, an evaporator, a fan for recirculating enclosure air, a fan for circulating ambient air, an air-to-air heat transfer economizer, and means for controlling air flow;
control means for operating said compressor, said fan for recirculating enclosure air, said fan for controlling ambient air and said means for controlling air flow;
said control means has a first sensor for sensing the air temperature within said enclosure and a second sensor for sensing the temperature of ambient air;
an enclosure air flow path from within said enclosure, past said fan for recirculating enclosure air, through said air-to-air heat transfer economizer, through said evaporator, and back into said enclosure;
an ambient air flow path independent from said enclosure air flow path from outside said cooling unit, through said cooling unit and back outside said cooling unit;
said means for controlling air flow has an enclosure inlet air damper and an enclosure outlet air damper;
said control means opens said enclosure inlet air damper and said enclosure outlet air damper whenever said first sensor for sensing air temperature within said enclosure indicates an enclosure air temperature at or above a maximum set temperature.

4 more elements

An enclosure cooling system comprising:

a cooling unit having a compressor, a condenser, an evaporator, a fan for recirculating enclosure air, a fan for circulating ambient air, an air-to-air heat transfer economizer, and means for controlling air flow;
control means for operating said compressor, said fan for recirculating enclosure air, said fan for controlling ambient air and said means for controlling air flow;
said control means has a first sensor for sensing the air temperature within said enclosure and a second sensor for sensing the temperature of ambient air;
an enclosure air flow path from within said enclosure, past said fan for recirculating enclosure air, through said air-to-air heat transfer economizer, through said evaporator, and back into said enclosure;
an ambient air flow path independent from said enclosure air flow path from outside said cooling unit, through said cooling unit and back outside said cooling unit;
a first ambient air flow path from outside said cooling unit passes through said air-to-air heat transfer economizer and past said fan for circulating ambient air before passing back outside said cooling unit.

3 more elements

An enclosure cooling system comprising:

a cooling unit having a compressor, a condenser, an evaporator, a fan for recirculating enclosure air, a fan for circulating ambient air, an air-to-air heat transfer economizer, and means for controlling air flow;
control means for operating said compressor, said fan for recirculating enclosure air, said fan for controlling ambient air and said means for controlling air flow;
said control means has a first sensor for sensing the air temperature within said enclosure and a second sensor for sensing the temperature of ambient air;
an enclosure air flow path from within said enclosure, past said fan for recirculating enclosure air, through said air-to-air heat transfer economizer, through said evaporator, and back into said enclosure;
an ambient air flow path independent from said enclosure air flow path from outside said cooling unit, through said cooling unit and back outside said cooling unit,
said cooling unit has a heater;
said enclosure air flow path from said enclosure passes through said heater before returning back into said enclosure;
said control means activates said heater whenever said first sensor indicates enclosure air temperature to be at or below a minimum set temperature and said second sensor indicates said ambient air temperature to be below the minimum set enclosure air temperature.

5 more elements

Dependencies are inferred from the claim text.

Air-conditioner and air-to-air heat exchange for closed loop cooling

Life of this patent

Air-conditioner and air-to-air heat exchange for closed loop cooling

Life of this patent

Abstract

Claims19