Bubba Moore

Bubba Moore

Technical Services Manager
Southeast District

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Humidi-MiZer® Adaptive Dehumidification Systems – 48-50 TC/HC Packaged Units

Packaged rooftop units are being used in many applications today not only for cooling but for comfort and humidity control. Indoor space humidity levels can be increasingly difficult to control depending on the time of year, location and the ability of the equipment to provide flexible operations to meet indoor part load, sensible and latent load requirements. Carrier’s Humidi-MiZer® Adaptive Dehumidification System is designed to meet these requirements. The Humidi-MiZer® unit’s will respond based on the temperature and humidity requirements as sensed in the space. This is achieved by a thermostat with a built in humidity sensor (thermidistat) or a separate thermostat with a humidistat.

The Humidi-MiZer unit’s operational flexibility to maintain year round indoor comfort and humidity levels is due to its three operational modes and the controls that help achieve it. There is a liquid line solenoid valve and a discharge gas solenoid valve that open and close to direct refrigerant depending on the operational mode of the Humidi-MiZer unit.

The cooling mode provides sensible and latent cooling from the evaporator coil. During the cooling demand only the liquid line solenoid valve is de – energized and open(NO), the discharge gas solenoid valve is closed (NC). In the cooling mode only the system performs like any other package A/C unit.


Normal Mode Operation

These Humidi-MiZer units transition from cooling to subcooling mode as humidity rises in the space which is determined by a thermidistat or a humidistat device. This subcooling mode will cause the liquid solenoid valve to energize causing the valve to close and redirect all hot liquid refrigerant to flow in to the Humidi-MiZer coil. Where it is exposed to cold supply air flowing through the evaporator coil. The liquid is subcooled to a temperature close to the evaporator leaving air temperature. As the subcooled liquid leaves the Humidi-MiZer coil it passes through a thermostatic expansion valve (TXV) causing the liquid to drop to a lower pressure. The TXV does not have a pressure drop great enough to change the liquid to a two phase fluid, so the liquid is directed into a fixed metering device at the evaporator coil.

The liquid enters the evaporator coil at lower temperature than in normal cooling mode. The increased subcooling causes the evaporator coil temperature to decrease, thus increasing the unit’s latent cooling effect (up to 40%). During the subcooling mode the discharge gas solenoid valve is de – energized and closed.

Sub-Cooling Mode Operation

The third mode of the Humidi-MiZer unit is when there is only a demand for dehumidification, the system will operate in Hot Gas Reheat mode. The reheat control board will energize the compressor and supply fan motor. The liquid solenoid valve will be energized closed and the discharge gas solenoid will be energized open. This hot gas will mix with liquid refrigerant leaving the condenser coil and flow to the Humidi-MiZer coil. The conditioned air coming off the evaporator coil will be cooled and dehumidified. The heat from the bypassed discharge gas offsets the sensible cooling effect from the evaporator coil during hot gas reheat mode. This will warm the evaporator leaving air to a neutral condition between 72 and 75 degrees.

HGRH Mode Operation

The Humidi-MiZer Adaptive Dehumidification System can be used in many applications, such as in Schools, Restaurants, Health Clubs, etc. The adaptive dehumidification system allows for dual humidity control mode in the unit, because of the subcooling/reheat dehumidification coil located downstream of evaporator coil. This innovative design provides the capability for the unit to operate in both a subcooling mode and a hot gas reheat mode for maximum system flexibility.

The Humidi-MiZer® is available as a factory option on the Carrier® Packaged Rooftop Units shown above.

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Alabama Locations

Anniston(256) 241-3026105 E D St, Anniston, AL 36201
Auburn(334) 734-80112295 1st Ave, Opelika, AL 36801
Birmingham(205) 250-7714516 31st St N, Birmingham, AL 35203
Dothan(334) 836-1035205 Wedgewood Dr, Dothan, AL 36303
Gulf Shores(251) 968-2660820 Commerce Dr, Gulf Shores, AL 36542
Huntsville(256) 859-2691391 Nick Fitcheard Rd NW, Huntsville, AL 35806
Loxley(251) 964-270730020 Co Rd 49, Loxley, AL 36551
Mobile(251) 476-2220703 Western Dr, Mobile, AL 36607
Montgomery(334) 262-4855861 Plantation Way, Montgomery, AL 36117
Muscle Shoals(256) 383-6904107 Commerce St, Muscle Shoals, AL 35661

Georgia Locations

Albany(229) 432-5254205 Baldwin Dr, Albany, GA 31707
Athens(706) 548-2563105 Whitetail Way, Bogart, GA 30622
Atlanta(404) 875-77551290 Tacoma Dr NW, Atlanta, GA 30318
Augusta(706) 651-19503618 Wrightsboro Rd, Augusta, GA 30909
Brunswick(912) 265-5193275 Rose Dr, Brunswick, GA 31520
Columbus(706) 322-38706201 W Hamilton Park Rd, Columbus, GA 31909
Conyers(770) 918-9132335 Gees Mill Business Pkwy NE, Conyers, GA 30013
Forest Park(404) 361-24745158-C Kennedy Rd, Forest Park, GA 30297
Gainesville(770) 297-93352472 Hilton Dr, Gainesville, GA 30501
Lawrenceville(678) 442-10602111 Cedars Rd SE, Lawrenceville, GA 30043
Lithia Springs(770) 948-3451320 Thornton Rd #106, Lithia Springs, GA 30122
Macon(478) 474-85445527 Thomaston Rd, Macon, GA 31220
Marietta(770) 426-05511060 Triad Ct, Marietta, GA 30062
Newnan(770) 239-210570 Enterprise Ct, Newnan, GA 30265
Norcross(770) 239-21006675 Jones Mill Ct, Norcross, GA 30092
Savannah(912) 232-1228103 Central Jct Blvd, Savannah, GA 31405
Statesboro(912) 764-8841126 W Parrish St, Statesboro, GA 30458
Valdosta(229) 245-8200363 Connell Rd, Valdosta, GA 31602
Warner Robins(478) 953-3727110 Byrd Way, Warner Robins, GA 31088

South Carolina Locations

Hilton Head(843) 689-34043715, 21 Hunter Rd, Hilton Head Island, SC 29926

Florida Locations

Fort Walton Beach(850) 244-201776 Beal Pkwy SW, Fort Walton Beach, FL 32548
Panama City(850) 913-05853012 Lisenby Ave, Panama City, FL 32405
Pensacola(850) 438-10054405 N. Palafox Street, Pensacola FL 32505

Mississippi Locations

Hattiesburg(601) 579-96701851 Lincoln Rd, Hattiesburg, MS 39402
Ocean Springs(228) 497-5090Sunplex Industrial Park, 5717 Suntec Drive, Ocean Springs, MS 39564

Commercial Sales

Norcross – North Georgia Hub
(800) 282-4911

Birmingham – North Alabama Hub
(205) 250-7714

Macon – Southwest Hub
(800) 342-9250

Loxley – Gulf Coast Hub
(800) 239-7419

Savannah – Southeast Hub
(800) 822-7617

Commercial Parts

(844) 99-CHILL

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