Variable refrigerant flow (VRF) air conditioning and related methods

Abstract

Disclosed is an improved variable refrigerant flow (VRF) air conditioning (AC) unit that eliminates the need to run refrigerant lines into the spaces being cooled or heated while providing the benefits and energy savings of a VRF system. Suitably, the disclosed VRF AC system can connects multiple condensate drain pans via one pipe then uses gravity to drain condensation from the condenser coils. Further disclosed is a VRF AC system that provides the required minimum outside air as an integral part of the system. Finally, disclosed may be a VRF AC system that has an economizer to use outside air to cool inside air if the outside air temperature is lower than the inside air temperature.

I claim: 
     
         1 . A variable refrigerant flow heating ventilation and air conditioning apparatus comprising:
 a platform  1100 ;   an external condensing unit  1200 ; and,   a venting box  1300 , said venting box featuring:
 an outside air damper  1310 ; 
 a filter bank  1340 ; 
 a supply air fan and motor assembly  1351 ; 
 a plurality of cooling units  1390 ; 
 a supply air opening  1350  that is defined by a plurality of ducting pathways between said plurality of cooling units and a corresponding plurality of zones within a building; 
 a return air opening  1360  that is defined by another plurality of ducting between said plurality of zones within the building and venting box  1300 ; 
 an exhaust fan and motor assembly; 
 an exhaust vent  1370 ; 
   wherein said supply air fan and motor assembly  1351  is configured to (a) pull air through the outside air damper, and said filter bank and (b) drive air through said supply air opening along of said ducting path ways to said zone;   wherein each of said plurality of cooling units is separately controlled according to a setting that corresponds to the associated zone;   wherein said exhaust fan and motor assembly is configured to pull air from said plurality of zones and exhaust said air from the exhaust vent.   
     
     
         2 . The variable refrigerant flow heating ventilation and air conditioning apparatus of  claim 1  further comprising a drain defined by the manifolding together of a drain pan from each of said cooling units. 
     
     
         3 . The variable refrigerant flow heating ventilation and air conditioning apparatus of  claim 1  wherein drainage of condensate from said cooling units is accomplished by said drain. 
     
     
         4 . The variable refrigerant flow heating ventilation and air conditioning apparatus of  claim 3  wherein said drainage flows via the force of gravity. 
     
     
         5 . A method of conditioning air in a building with at least two zones to be cooled comprising the steps of:
 Locating a venting box and a condenser unit on a rooftop of the building;   Wherein said venting box features;
 an outside air damper to allow ambient air to enter said venting box, 
 a supply air fan, 
 a first evaporation coil; 
 a second evaporation coil; 
 a first ducting pathway from said first evaporation coil to a first one of said two zones to be cooled; 
 a second ducting pathway from said second evaporation coil to a second one of said zones to be cooled; 
 an exhaust air opening, 
 an exhaust fan, and, 
 an exhaust vent; 
   circulating refrigerant between the condensation unit and the evaporation coils;   forcing air into the venting box through the outside air damper via said supply air fan;   forcing a first portion of the air over the first evaporation coil so that said first portion of said air is conditioned to a first temperature;   forcing a second portion of the air over the second evaporation coil so that the second portion of air is conditioned to a second temperature;   delivering said first portion of the air to the first one of said zones to be cooled via operation of the supply air fan;   delivering said second portion of the air to the second one of said zones to be cooled via operation of the supply air fan;   forcing the first and second portions of air through the exhaust opening and the exhaust vent via said exhaust fan.   
     
     
         6 . The method of  claim 5  wherein the first evaporation coil has a pan for collecting moisture from the first evaporation coil, wherein the second evaporation coil has a second pan for collecting moisture from the second evaporation coil, and wherein the first pan and second pan are manifolded together into a single drain. 
     
     
         7 . The method of  claim 6  further comprising the step of draining moisture from said drain. 
     
     
         8 . A system for conditioning air in a multi-unit building comprising:
 a rooftop condensation unit;   a rooftop venting box comprising a single supply air fan for circulating air and for providing air over a plurality of evaporation coils, wherein each of said plurality of evaporation coils is in fluid communication with a single unit of said multi-unit building; and,   a drain that is in fluid communication with all of said plurality of evaporation coils, where said drain operates via the force of gravity to remove moisture from said plurality of evaporation coils.