Timelord, one of our top member is working on a great project: a complete apartment air conditioning based on airflow. You can check out his idea here After a little chat using our private messaging system he “disclosed” some details about the project. HVAC (heating, ventilation, and air conditioning) is the technology of indoor and automotive environmental comfort.

Below is a fragment from our conversation

Outdoors is big combi freezer on the balcony with a few extra compressors on top.
Indoors just a few holes in the walls and the evaporator and fans/ducts are all hidden in a lowered ceiling.

This is about what I’m working on.

HVAC for 300m3 = 10594ft3

On highly economical basis for ±35% of standard cost
Based on flow ( as in hospital burnvictims units)

(extra bonus ±25 gallons of potable water daily at 70% humidity)

Phase ONE

Digital Outputs freezing

Compr I 220v 400 watt deepfreezer 30 mins max run / 15 mins off
Compr II 220v 200 watt freezer 20 mins max run / 15 off
Compr III 220v 200 watt freezer 20 mins max run / 15 off
Compr IV 220v 200 watt freezer 20 mins max run / 15 off

Pump I 220v 10 watt circulation deepfreezer (permanent on)
Pump II 220v 10 watt circulation freezer
Pump III 220v 10 watt circulation ventilation
Internal deepfreeze circulation pump 5 watt

Valve I 220v 500 milliwatt circulation deepfreezer
Valve II 220v 500 milliwatt circulation return lines
Compr. Fan 220v 20 watt compr. air circulation

Digital Inputs Freezing

Power OK (also circulation pump)
Min temp hardware -14 trough -20 Celsius
Temp Protection Hardware protection compressors -25 C.

Analog Inputs Freezing

Temp I (temp liquid) @ maximal -14 C rising/ramping gives
max amount of compressors

Digital Outputs Ventilation

Main Fan Motor 220v. 2.5 watt 50 Hz. ± 300 mtr³ / hr. (need 600 mtr³)
Main Fan Motor 220v. 2.5 watt variable frequency 50 ~ 200 Hz.

Intake fan motor I 220v. 5 watt ± 200 mtr³ night time only
Exhaust fan Motor II 220v. 5 watt ± 100 mtr³

Digital Inputs Ventilation

Thermostat standard room temperature heating / cooling

Analog Inputs Ventilation

Temp II ( liquid @ -11 Celcius)
Temp. III ( air intake main fan )
Temp IV ( air exhaust main fan)

Analog Output (PWM)

Increase or decease main fan motor ~ (See LED/LDR 0-5 volt)

Phase II

Desert Cooler implementation.
Excess water at 33.5 degrees F.
Return into circulation air.

Digital out

Fan motor inclusive drumrotation filter

Analog / Digital IN

humidity sensor ( set to always complete dry out)

Excess water output to indoor pond.
2nd excess to outdoor pond.
6 # I/O

Phase III Heating

Solar I/O
Boiler I/O
Blocking cooling I/O
heat exchanger.

Phase IV

Digtal 14 Outputs
Digital Inputs 8

Analog Input 4
Analog OUT 1 (PWM)


65-SP12AS PSU 12v / 3amp & UPS
65-18DC-DA-TN 8 digi/ana+4 digi 6 transistor(PNP)
E-16DC-DA-TN 8 digi/2 ana 8 transistors(NPN)
65-Ethernet-DC 9
65-ELC-BC1 C-Bus cable x3


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  • Timelord

    Finally running the system on 100%

    A load of problems … all solved.
    Next year the refrigeration unit is moved outdoors again to avoid extra heat accumulation in the living quarters.

    The system has stabilized at -16.7°C ( see picture )
    The indoor temperature is 24°C in a modified environment.
    Wow, more then 5°C to optimize the complete system
    (-11°C is the optimal temperature to exchange between evaporator and air.)
    Now the variable speed drive can be installed and the airflow can get some 100% – 200% higher.
    Instead of running at 50Hz.(100- 150 Hz.) with this adapted inverter.

    There is still a load of (nice) work…
    Conclusion : Phase ONE is operational 😉

    T L.

  • Timelord

    Finally got the system working…
    Temperature deviation is 5 degrees Celcius lower at 300 Qubic Meters an hour.( far to high)
    It’s difficult to explain , it’s flow , not blow.. no forcing and it is as if the incoming air feels different like ionized or electrically neutralized or something.

    Interfacing the EATON OPC server with the SCADA system from Winlog.
    It’s Winlog Lite , works as a charm…..
    Maybe it even works with Arduino via a serial connection
    (I have to check that)

    Starting trending (Winlog) for the amount of cold liquid versus the variable speed..
    Must work with One single PID in PLC II .. there is only on analog output (0-10 volt) at the moment.
    Maybe something inverted.
    We’ll see
    TTYL T L.

  • Timelord

    Thx Marian for placing the pictures.

    The PLC’s are connected with a modbus cable as a sort of DMC’s, Distributed Micro Controllers, and each puts all I/O on the Bus towards the other PLC’s or to the SCADA system.

    PLC I is in a IP65 box ,
    it has to come outside for the Compressors, Pumps and valves.
    There are 4 switches for manual and pump control.

    PLC II is for the main motor and temperature control,
    added to this comes the 220v frequency controller (under construction)

    PLC III is not fully completed ,
    the relays for the Desert Cooler need to be placed IN the desert cooler on a 5 mtr. distance with a multicore.
    The contactors for the Solar system come on a distance of about 15 mtr. on a separate circuit with the LDR’s

    Each PLC has an extra circuit board for the various voltages of the analog and digital inputs.

    Just found out that I need to start the Desert Cooler automatically, so another input.
    Adapting this circuit
    Changing IC1 (S201S02) to a Celduc D91A3108.
    I need a 24v isolated input on PLC III.

    When finished I upload the diagrams.

  • Timelord

    Concluded the different PLC brands and purchased the best one for my purposes.
    It’s is the Eaton Easy… as a matter of fact I bought 3 plc’s.
    The main reasons are:
    1) The total price of the equipment.
    2) I have separated locations for my project.
    Outdoor, Compressors, Hall Mainmotor, Fans, Heating,,
    Roof Pumps & Solar system.
    A modbus connection is preferable then multicore cables
    with extra connectors and additional relays.
    One single ethernet cable interlinking all programs and I/O.
    3) Highly expandable , can connect another 6 PLC’s
    for the rest of the automation.(appliances and outlets)
    4) Versions of Windows W2K upto W8 are supported.

    The SCADA system is still in the works… Got at present one single supplier that actually connects in REAL-TIME via an OPC-Server (EATON).

    If Marian allowes me I would like to thank here Mr.A.M from Xlogic-Soft for his Free support and to make it possible for a little invention within any PLC software.
    I could not purchase their hardware only due to fact # 2)

    This little invention is this :
    4 (fridge) compressors , running in sequential rotation.
    20 mins. run, 10 minutes OFF., next compressor 20 minutes
    -18°C –> 1 compressor.
    -16°C –> 2 compressors.
    -14°C –> 3 compressors.
    -12°C –> 4 compressors.
    Due to the fact that the compressors are different size and brand the 20 minute runtime is a variable.

    The amount of compressors remains running until the minimum value -19°C is reached. (THX Andy ;))

    It has become a heck of project.

  • Timelord

    With the last Pictures I entered the SCADA systems.

    I found this:
    Got to Winlog Lite. (there is another brand around)
    And must say it all looks great and promising.

    My reasons to integrate a SCADA system are , easy of adjustment , trending , alarms and testing of the prototype and expandability.

    I’ve come up now with a total of 86 I/O
    Analog and digital I/O ( relay and transistor)
    These are on various locations balcony, roof, indoors.
    All linked via the Ethernet and OPC server.
    Expansion with further home_automation (lights, coffee, security etc) is simple.

    So a ‘simple’ PLC with integration of SCADA on multiple PC’s is out of the question.
    I have 3 linked PLC’s now, with SCADA on 1 PC and direct programming on 1 PC and a laptop.

    Compliance to ‘The IEC 61131-3 Standard’ is mandatory.
    For security .NO. Internet/WiFi connections.
    I don’t like waking up ICY 😉

    Lately I’ve been testing some 15 different PLC brands in simulation and got most of the in and outs of various brands.
    Busy as a bee.

  • Timelord

    THX Marian for updating the software picture.

    It has become quite some project and the amount of I/O is still increasing.( >770 KB program)
    An extra I/O module isn’t that pricy.

    Working on the intermediate cabling indoor / outdoor.
    A new variable frequency converter (220v. 50 to 400~) is also under construction.
    Hooked on the PLC PWM output. see picture software.

    I still have to deal with the amount of water which the system is generating.
    So I decided to build something like a hydroponics bay in the hall with lighting and pumps.
    With a pond and plants for extra water treatment.
    From there pumping to the existing outdoor pond.

    I’ll make some more pictures these days.

    TTYL T L.

  • Timelord

    Added a fast RPM counter for the main fan motor with audible alarm.
    An extra Input in the hardware is available anyway.

  • Radio Fanatic

    Is this project only for cooling a room or it can warm up too? I think it’s kind of huge, can not be made smaller?

    • Timelord

      For heating I got Phase III.

      Discussed heating this morning with a neighbor,
      he wants solar panels integrated. (we’ll see)

      It isn’t that big , the total apartment flooring is
      ± 30 by 30 feet.
      It can be made smaller , yes , also even bigger.
      Planning is for even (bigger) existing offices.
      When the unit goes in production it will be integrated in a fridge.

      It’s a Prototype, I’m looking for maximum values for the lowest price (< 1 KwH )
      So I need to be able to adjust it all the time.

      Besides that, I live in this apartment 😉

      I'm working on software now and will ask P.Marian to put a pic of that also with the rest.

      T L.

  • Timelord

    It’s over the years designed in hardware only.
    For 2013 a new outdoor cabinet and a 4th. Compressor.
    Now I’m implementing a PLC.
    Working on the software and simulation
    Then decide which PLC I’ll purchase.($$$)

    A lot of work 😉

    T L.