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Ultra Efficient Chiller Technology - How It Works

chiller heat pump outdoor unit
CX34 ODU (Outdoor Unit)
Self-contained 2 Tons Cooling / 3 Tons Heating

IPLV Cooling EER 21 Heating COP 3.92

diagram of chiller air conditioning system

Up to 8 indoor units (IDUs) can be used.
One Chiltrix ODU can connect to an amount
of IDUs rated for up to 115% of the ODU
ODU can also be used with ducted air handler
floor heating, or integrated with existing
boiler or solar hydronic heating.

Test Conditions
CX34Cooling at A95°/W54º30,537~9~30
CX34Cooling at A95°/W44º24,002~6~21
CX34Heating W95º/A47ºdb/43ºwb34,1204.31NA
IPLV / NPLV values per AHRI 550/590

Ultra Efficient Chiller Technology

The CX34 air cooled chiller works by cooling or heating a water or water/glycol fluid distribution loop with a high efficiency DC-Inverter compressor and pumping the fluid through ductless fan coils, hydronic air handler, and/or floor heating system. Any or all of these types of indoor equipment can be used, and can be used in combination with each other if desired. The fluid is returned to the chiller ODU to heat or cool it back to its operating temperature. The fluid contains water with 0-50% glycol, depending on the location and expected winter conditions. The CX34 uses a variable speed compressor and variable speed water/fluid flow, along with a variable speed condenser fan. This is not an "evaporative" chiller, it consumes no water and works fine regardless of humidity, performing strong dehumidification as needed. The water/glycol is used to only to distribute heating and cooling between the outdoor unit and indoor units, no water is consumed.

The Chiltrix system uses a DC-inverter compressor and a DC-inverter water pump (both are variable speed) controlled together to achieve the best possible balance of water flow rate and compressor speed. A microcontroller constantly watches the T between the leaving and returning water and adjusts the pump and compressor speeds independently of each other to maintain the needed capacity with the lowest possible total power draw. MODBUS Compatible.

heat pump chiller controller main screen- psychrologix

Psychrologix™ Controller - the DHC (Dynamic Humidity Control) function is designed to dynamically control humidity in real time and operate the chiller above its already high efficiency rating. DHC prevents over-dehumidification and wasted energy. The CX34 with DHC dynamically manages compressor speed, pump speed, fan speed, and adjusts its loop temperature as needed to tightly manage humidity and increase efficiency. DHC control allows the chiller to operate well above the IPLV rating at times when humidity is under control, resulting in EER far in excess of the official ratings.

What's Inside The Box

The CX34 ODU, a higher efficiency and larger version of the CX30, is a complete chiller - with our technology there is no additional pump or indoor storage tank, etc. needed. It's air cooled, so no water source or cooling tower is needed. You can use the CX34 with any brand of industry standard fan coils, we also provide fan coils including our ultra-thin DC-Inverter FCUs. We have incorporated the evaporator, condenser, all controls, valves, etc., into a sealed self-contained outdoor unit.

Chiller ODU with cover removed
No refrigeration gauges, vacuum pumps, extra Freon, or special skills, are needed to install the system. The installer will only need to connect power, and connect the fan coils and water lines.

chart comparing dc inverter motor to standard ac motor

Above left, standard AC unit running at full speed, either on or off. Above right, variable capacity DC inverter unit running to match the load and avoid the on/off cycle. In addition to using less watts per BTU at a given speed, the ability to vary the speed to match conditions saves even more.

Simplified Explanation of Controls

The CX34 uses a patent-pending controls methodology that, among other things, accurately matches compressor speed and water flow rate (BTU capacity) directly to the cooling/heating load using real-time dynamic control. Following is an example of a possible controls calculation at steady state operation, operating at 12,000 BTU, and assuming a baseline IPLV condition where the chiller leaving water temperature (LWT) is 44F and return temperature (entering, or EWT) is 54F. The formula is BTU=500 x T x GPM (assumes 100% water, adjusted for other fluids)

12,000=500 x 10 x 2.4, where:
BTU capacity =12,000
10 is the T between leaving (LWT) and return (EWT) (F)
2.4 is GPM flow rate
One BTU is the energy needed to raise or lower one pound of water by 1 ºF.
500 is the normalizing factor (8.33 lbs./gallon x 60 minutes per hour x specific heat, in this case, water, 1.0)

In the example below, the cooling load increases. The chiller would immediately see this when the EWT rises. For example if return (EWT) increased by 3F to 57F the new conditions would be:
15,600=500 x 13 x 2.4

In this case, the CX34 would compensate with an increased compressor speed to match the new load of 15,600 BTU and adjust the pump speed as follows, returning the T back to 10F:

15,600=500 x 10 x 3.12

In this way, the chiller capacity, compressor speed, flow rate are all dynamically adjusted to match the cooling load.

Note - the LWT set point itself may also change in response to indoor humidity requirements


Per AHRI 550/590 @ LWT 54F
Factory Tested Performance
Evap Condenser % Load / 100% = 30,537 BTU
Power, kW5436446512752566
Efficiency, COP (W/W)14.5610.865.733.49
Efficiency, EER (BTU/W)49.6737.0519.5511.91
COP R,CD13.54270010.70159
EER (at 54F LWT)30.30655
IPLV Per AHRI 550/590 @ LWT 44F
Factory Tested PerformanceEvap Condenser % Load / 100% = 24,002 BTU
Power, kW4440752313482715
Efficiency, COP (W/W)10.697.744.472.83
Efficiency, EER (BTU/W)36.4726.4115.259.65
COP R,CD10.023497.79001
IPLV (at 44F LWT) EER:21.74343

Dynamic & continuously variable control of the CX34 allows normal operation between LWT 44F and LWT 62F,
with an average of ~EER 27. Operation as low as LWT 40F for extreme dehumidification, when needed.


Heating is another area where the CX34 has great performance.

cx34chiller heat pump performance chart

Heat capacity curve

*RED=W@122F, BLUE@113F, BLACK@95F

Efficiency curve

*RED=W@122F, BLUE@113F, BLACK@95F

ENERGY Star & Geothermal Comparison

Get geothermal efficiency at an air-cooled price.

There is no current ENERGY STAR program for air-cooled chillers. But it is interesting to note the CX34 air-cooled chiller exceeds the
Energy Star efficiency requirements for variable speed water-cooled chillers (geothermal chillers) which are usually considered to be the most efficient type available. S


Chillers do not use SEER ratings, they are rated based on EER, COP, and IPLV per AHRI 550/590(I-P)

. IPLV is provided by AHRI for air cooled chillers. Below, we have applied the AHRI IPLV and NPLV formula to our residential air cooled chiller CX34.

EER = Cooling capacity (kW) / Consumed energy (e.g. electricity) (kW)
COP = Heating capacity (kW) / Consumed energy (e.g. electricity) (kW)
IPLV = The Integrated Part Load Value

IPLV = 0.01A+0.42B+0.45C+0.12D
A = COP or EER @ 100% Load
B = COP or EER @ 75% Load
C = COP or EER @ 50% Load
D = COP or EER @ 25% Load

The IPLV EER cooling rating for the CX34 is rated as follows:

IPLV EER = ~21

CX34 NPLV= EER ~30, NPLV STC is W54F/A95. For an easy to understand explanation of IPLV see the FPL Chiller Efficiency Document

Multiple Fan Coil Units - Up to 8 FCUs Per CX34 Outdoor Unit.

All CXI-series indoor unit are built for universal mounting: Wall, floor, or ceiling

Above: Wall mounted fan coil unit.

IDUs connect using flexible PEX water lines. The system is designed to use up to 50% glycol, depending on climate/location. Below is a ceiling mounted CXI fan coil unit.

celing mount fan coil unit for chiller

All of the thin-line (5.1" thin) wall, floor and ceiling fan coil units use DC-Inverter fan motors and run on 120v 60Hz power. Shown below is floor mounted fan coil unit.

low wall or floor mount chiller fan coil unit

high wall chiller fan coil for ductless minisplit chiller

The high-wall fan coil unit shown above uses a standard FCU fan, operates on 208-240V 50/60Hz power.

Shown below - hydronic AHU air handler for ducted central system. CX series air source chillers are compatible with most brands of AHU and hydronic fan coil units, contact us for compatibility and sizing assistance. Ducted hydronic air handlers are available through Chiltrix.

Hydronic Air Handler Units (AHU)
For Ducted Chiller systems
firstco vmb hydronic air handler
Above: FirstCo 12VMB

Ducted water coil chiller air handler units come in 4 different sizes and use DC Inverter motors for high efficiency.