Method of air conditioning

• US 4,319,461 A
• Filed: 12/18/1979
• Issued: 03/16/1982
• Est. Priority Date: 03/28/1979
• Status: Expired due to Term

• Current Assignee: Luminis Pty Limited
• Original Assignee: University of Adelaide
• Inventors: Shaw, Allan
• Primary Examiner(s): Capossela, Ronald C.
• Application Number:
  US06/101,256
• Time in Patent Office: 819 Days
• Field of Search: 62/93, 62/89
• US Class Current: 62/93
• CPC Class Codes: F24F 3/1405 in which the humidity of the air is exclusively affected by contact with the evaporator of a closed-circuit cooling system or heat pump circuit

Abstract

An air conditioning method wherein supply air is introduced into an air conditioned space to maintain a condition of temperature and humidity of air within that space. The invention is characterized in that the air is passed over the cold coil of a dehumidifier both with a low face velocity and a low Reynolds number, resulting in the coil condition curve being compatible with the load ratio line and in turn achieving an energy saving.

This invention relates to a method of air conditioning and has as its main object the conservation of energy as well as the improvement of air conditioning system performance.

Claims

1. A method of conditioning air in a space to maintain a design condition of temperature and humidity of the air within that space by removal of sensible and latent heat from supply air by passing said supply air through a heat exchanger functioning as a dehumidifier, said method comprising:

reducing specific enthalpy by passing said supply air over relatively cold heat exchange surfaces of said dehumidifier and so arranging the face velocity of the air at entry to the dehumidifier to lie between 0.4 and 2 meters per second, the equivalent hydraulic diameter of the compact heat exchanger surface of the heat exchanger (D_e) and the mass velocity of air per unit are (G_m) being such that the maximum Reynolds number of the supply air (D_e G_m /μ

where μ

is the viscosity of the supply air) during its passage over the heat exchanger surface is between 100 and 2000, and maintaining said design condition without reheat but solely by said supply air.

2. A method of conditioning air in a space to maintain a design condition of temperature and humidity of the air within that space by removal of sensible and latent heat from supply air by passing said supply air through a heat exchanger coil functioning as a dehumidifier, said method comprising:

effecting removal of sensible and latent heat solely by passing the supply air through a dehumidifier heat exchanger coil at a face velocity of between 0.4 and 2 meters per second, the equivalent hydraulic diameter of the compact heat exchange surface of the heat exchanger (D_e) and the mass velocity of the air per unit area (G_m) being such that the Reynolds number of the supply air (D_e G_m /μ

(where μ

is the viscosity of the supply air) during its passage over the heat exchanger surface is between 100 and 2000, said coil having such face area that outlet air of a coil of equivalent face but infinite depth would be saturated with moisture.

4. A method according to claim 2 or claim 3 wherein supply air, after having been cooled, to offset a design condition is not subject to reheating to maintain that design condition.

5. A method of conditioning air in a space to maintain a condition of temperature and humidity of the air according to claim 2 or claim 3 comprising:

effecting the reduction of specific enthalpy solely by passing the supply air over a cooling coil at a face velocity of between 0.4 and 2 meters per second and a maximum Reynolds number of the supply air during its passage through the coil of between 100 and 2000, and so relating the air flow rate, the cooling coil size and geometry, and the leaving temperature and humidity that the coil condition curve of a psychrometric chart approximates the inlet condition of a corresponding load ratio line.

3. A method of conditioning air in a space to maintain a design condition of temperature and humidity of the air within that space by removal of sensible and latent heat from supply air by passing said supply air through a heat exchanger functioning as a dehumidifier, said method comprising:

effecting removal of sensible and latent heat solely by passing the supply air through a dehumidifier heat exchanger coil which has sufficient face area that the face velocity is between 0.4 and 2 meters per second, the equivalent hydraulic diameter of the compact heat exchange surface of the heat exchanger (D_e) and the mass velocity of the air per unit area (G_m) being such that the Reynolds number of the supply air (D_e G_m /μ

(where μ

is the viscosity of the supply air) during its passage over the heat exchanger surface is between 100 and 2000, said face area of said coil being such that a continuation of the coil condition curve on a psychrometric chart will intersect the saturation line of that chart.