Air conditioning Automation

Hello:
Hello, does anyone knows air conditioning units that can be monitored and controlled by a PLC or SCADA, on a Modbus network or another?
A client has requested be placed in some of their rooms, air conditioning equipment in order to maintain a pre-set temperature so as to control humidity .

For this reason I need to know about brands and models of air conditioners that support control from a PLC or Scada.

Thanks for your help.

Alex

Check this link
http://www.arktika.ru/catalog/intesis_modbus.pdf

Depending on what all the parameters are (product moisture load, infiltration, %RH setpoint, temperature setpoint, door openings, etc) the choice of an air conditioning unit may not be the right selection.

Also note that there are some companies that make specialized air handling units that will have a condensing coil following the expansion coil (the actual cooling coil) to help make the process cost effective to reheat the air when there is no cooling load, but a moisture load may exist. Companies like this should have no problem supplying you a unit that has a Modbus interface. Trane has a commercial division that has solutions for this type market, as does Carrier and York. You can also look at Munters Cargocaire, which bought Deschamps several years ago and they have a unit called a Wringer that will do what you want.

To cool with an A/C unit you will need to cool below the dewpoint to extract the moisture and then possibly reheat the air to not over cool the room.

If the required %RH setpoint is too low you will need to go with another technology like a desiccant dehumidifier.

look at carrier, or mitsubishi, most standard packer do have communication.
if the units are already in place automation could be simple, just give us a drawingset and anybody can make a program, as you could use on/off control.