EQUIPMENT / EQUIPMENT FAMILY

Cling CEZDD R744 bus heat pumps

Select the R744 pressure and relief package, cold-climate map and vehicle service arrangement as one specific configuration.

From Zhengzhou Cling · Vehicle HVAC and thermal management

Individual product research · HVACDeck Editorial · Sources checked 2026-10-11

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Manufacturer catalogue image · CEZDD

01 / UNDERSTAND THE EQUIPMENT

Approve CEZDD CO₂ pressure controls and climate duty

Cling’s CEZDD bus heat-pump family uses R744 (CO₂), with a dedicated variable-speed compressor, high-pressure heat exchangers and described pressure/relief controls. The official page lists CEZDD-04 and CEZDD-06 together; it does not provide a design-pressure schedule, refrigerant charge, electrical platform or relief-discharge installation detail. Selecting this family therefore requires its own pressure, service and vehicle-interface file rather than reusing R407C or R410A documentation.

CEZDD-04 is listed at 30 kW cooling and 34 kW heating, with 6,000 m³/h evaporator airflow and a 3,250 × 2,000 × 345 mm body reference. The source gives a shared indoor-40°C/outdoor-35°C-style footnote with an unclear separator and advertises operation from −30°C to 45°C. It does not prove those nominal duties at the extremes or define the baseline for its promoted low-temperature COP improvement.

02 / READ THE CONDITIONS

Published parameters and their scope

This is an equipment family; its range does not identify one orderable configuration.

Family designation: CEZDD

Swipe the table, or focus it and use arrow keys, to read the conditions and sources.

Manufacturer-published values · conditions are part of the specification
Parameter	Published value	Conditions and evidence
Actual refrigerant	R744 (CO₂)	Original table; no charge or complete pressure envelope provided. Source
CEZDD-04 reference	30 kW cooling; 34 kW heating; evaporator 6,000 m³/h; compressor displacement 7.3 m³/h	Source table; displacement is not electrical power or full performance map. Source
CEZDD-06 reference	33 kW cooling; 37 kW heating; compressor displacement 10.9 m³/h	Same family, separate selected size; no extra nominal-model URL. Source
Climate claim	−30°C to 45°C ambient operation	No conditioned duty/input/defrost map at those extremes reviewed. Source
Mechanical reference	CEZDD-04: 3,250 × 2,000 × 345 mm; CEZDD-06 length 3,500 mm	No weight/support/service envelope in inspected table. Source
Pressure and efficiency claims	Relief valve plus pressure control; about 30% heating-COP improvement at −10°C	No pressure settings, comparison baseline or complete test file supplied. Source

Selection and application review

Obtain a current R744 pressure and relief specification

Request design/working pressures, component ratings, pressure-control settings and relief arrangements for the exact ordered assembly. The page’s high-pressure components and multilevel protection wording does not supply the values or prove the installed function. Identify the legal conformity and service documentation applicable to the vehicle/destination.

Approve the relief route, installation orientation and access with the vehicle builder and supplier instructions. The source describes CO₂ in broad reassuring terms, but does not document the concentration/exposure, ventilation or service controls for a particular installation. Use an issued R744-specific package rather than transferring another refrigerant family’s procedures.

Select cold-weather heating and defrost at actual conditions

Provide winter ambient/humidity, cabin heat load and operation at idle/driving. Require capacity, input and defrost/backup behaviour at the chosen points. The stated −30°C operating boundary does not establish 34 kW heating at −30°C for CEZDD-04.

The advertised improvement at −10°C omits a clear baseline and equal-duty comparison. Obtain the comparison system, heating conditions and complete power boundary before using any COP percentage. No independently checked route-energy or vehicle-range result was reviewed.

Define cooling duty and electrical integration separately

The cooling table and shared test footnote do not state humidity, supply voltage, input/current or a complete load map. Request those and resolve the unclear separator in the temperature footnote. Do not borrow the 400–750 V/24 V entries from the ordinary EZDD/EZDS table.

Specify vehicle-control signals, startup/shutdown, alarm priorities and power/communication-loss response. The description names defrost management and remote monitoring but provides no wiring/register file. The selected compressor displacement is a volume-flow-style entry, not a direct electrical-demand rating.

Coordinate the taller roof assembly and R744 service access

The CEZDD drawing reference is 345 mm high, with different lengths for the two models. Obtain roof supports, mass, mounting points, air openings and vehicle-clearance drawings. The table’s bus-length suggestions do not establish structural fit or delivered passenger comfort.

Approve refrigerant service access, pressure-test/leak-check provisions and trained service responsibilities for the ordered R744 configuration. Confirm condensate, airflow and vibration/acoustic requirements. No exact sound, mass or installed relief/service detail was supplied in the reviewed page.

Accept the selected CO₂ heat-pump configuration

Issue thermal/climate loads, vehicle drawings, power/control architecture and destination requirements. Obtain a current conditioned schedule, component pressure file, protective sequence and installation/service instructions. Treat the source’s standard-configuration/update warning as a reason to freeze a signed revision.

Agree thermal tests at representative climate points, defrost operation, relevant pressure/protective functions and vehicle integration checks. Current price, stock, firm delivery, certified whole-vehicle efficiency and independent low-temperature comparisons remain unknown.

Approve the R744 package
Close pressure limits, relief route and conformity/service scope.
Select climate performance
Require duty/input/defrost maps and any comparison baseline.
Validate on the vehicle
Check power, roof interfaces and protective/control functions.

Sources and review scope

Compiled by HVACDeck Editorial. Source review identifies what the publication states; it is not an independent performance test or certification.

Official CEZDD R744 pageChecked 2026-10-11 · Complete two-model table, climate/COP/protection statements and update warning read; unknown definitions not filled from other families.
Original CEZDD family imageChecked 2026-10-11 · Original roof-family image visually inspected; pressure/electrical/service package not documented by the photograph.

Editorial method and corrections · Report a detail with this page URL