{"id":5910,"date":"2026-08-16T17:06:42","date_gmt":"2026-08-16T09:06:42","guid":{"rendered":"https:\/\/domirefrigeration.com\/?p=5910"},"modified":"2026-08-16T17:06:42","modified_gmt":"2026-08-16T09:06:42","slug":"oem-condenser-coil-specification-checklist","status":"publish","type":"post","link":"https:\/\/domirefrigeration.com\/fr\/oem-condenser-coil-specification-checklist\/","title":{"rendered":"OEM Condenser Coil Specification Checklist: Design, RFQ and Quality Fields"},"content":{"rendered":"

An OEM condenser coil specification should connect the system duty to a buildable coil drawing. State total heat rejection, refrigerant and design pressure, entering air condition, target subcooling, airflow, pressure drop, tube and fin materials, circuiting, connections, casing, corrosion exposure, inspection, and test evidence. A request that says only \u201ccondenser coil, copper tube and aluminum fin\u201d leaves too many decisions open for a comparable quotation. This checklist gives equipment manufacturers and procurement teams the fields to define before requesting a custom condenser coil.<\/p>\n

\"Industrial <\/figure>\n

What the specification must accomplish<\/h2>\n

The specification has three jobs. It tells the engineer what performance the coil must deliver. It tells the manufacturer what geometry and materials to build. It gives quality and purchasing teams a way to compare offers without treating a lower price as an equivalent design.<\/p>\n

The coil is also part of a larger high-side assembly. Compressor discharge piping, fan selection, receiver location, liquid-line routing, controls, ambient conditions, and service access can change the correct coil. The ASHRAE condenser chapter<\/a> describes air-cooled condensers as heat exchangers that reject evaporator load plus compressor input. That is why an OEM specification should begin with system duty rather than a preferred tube diameter.<\/p>\n

Define the application and equipment boundary<\/h2>\n

Identify the condenser type<\/h3>\n

Write whether the requirement is for an air-cooled, water-cooled, evaporative, remote, integrated, microchannel, plate-and-fin, or another construction. State whether Domi or the supplier is quoting the coil core only, a coil-and-frame assembly, a complete condenser, or a condensing unit with fans and controls.<\/p>\n

The boundary changes the evidence required. A coil-only quote may need connection locations and pressure testing. A complete condenser quote also needs fan curves, motor data, guards, controls, sound, mounting, and wiring. Do not compare a coil-only price with a finished assembly price.<\/p>\n

Identify the equipment and installation position<\/h3>\n

Record the equipment model family, indoor or outdoor location, service side, airflow orientation, footprint, maximum height, mounting points, and clearance restrictions. If the condenser is remote, state line length, elevation difference, receiver arrangement, and expected liquid-line pressure drop.<\/p>\n

\"Technician <\/figure>\n

Heat rejection duty and rating conditions<\/h2>\n

Specify total heat rejection, not only refrigeration capacity<\/h3>\n

The condenser must reject the evaporator load plus compressor heat and other defined inputs. Use total heat rejection when comparing condenser ratings. If the equipment team starts with net refrigeration effect, record the compressor model, operating point, motor input assumption, and conversion method used to reach total heat rejection.<\/p>\n

State the rating point and allowable envelope<\/h3>\n

Include refrigerant, evaporating condition, saturated condensing temperature or condensing pressure, entering air dry-bulb temperature, airflow, target liquid temperature, and any required subcooling. Include minimum and maximum operating points if the equipment will run across seasons or with capacity control.<\/p>\n

\n\n\n\n\n\n\n\n\n
Rating field<\/th>\nWhat to state<\/th>\nWhy it affects the quote<\/th>\n<\/tr>\n<\/thead>\n
Heat rejection<\/td>\nTotal condenser duty at the named operating point<\/td>\nPrevents a refrigeration-capacity figure from being mistaken for condenser duty<\/td>\n<\/tr>\n
Air condition<\/td>\nEntering dry-bulb, humidity when relevant, and ambient range<\/td>\nChanges the air-to-refrigerant temperature difference and condensation behavior<\/td>\n<\/tr>\n
Refrigerant condition<\/td>\nRefrigerant, saturated condensing condition, inlet superheat, and liquid outlet target<\/td>\nDefines the refrigerant-side load and any desuperheating or subcooling zones<\/td>\n<\/tr>\n
Airflow<\/td>\nVolume flow, fan speed or fan curve, and allowable air-side pressure drop<\/td>\nConnects coil performance to the actual fan and cabinet<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Use units, tolerances, and measurement locations in the rating schedule. A supplier should identify every assumption that is not supplied by the OEM.<\/p>\n

ASHRAE guidance<\/a> explains that air-cooled condenser selection is commonly based on the temperature difference between entering cooling medium and saturated condensing temperature. The same coil can show very different capacity, pressure drop, and fan power at different TD values. A quotation without a rating condition is not comparable.<\/p>\n

Separate the design point from the control limit<\/h3>\n

The design point is used to size the coil. The control limit is the condition at which the system must still protect the compressor, maintain liquid feed, or manage low ambient. Put both in the specification. For example, a summer design point may define heat rejection while a winter condition defines fan cycling, head-pressure control, or minimum condensing pressure.<\/p>\n

\"Color-coded <\/figure>\n

Refrigerant, pressure and subcooling fields<\/h2>\n

Refrigerant and oil compatibility<\/h3>\n

State the refrigerant designation, blend glide if relevant, oil family, and any restrictions on internal cleanliness. If the system may change refrigerant, treat that as a design review. A new refrigerant can change mass flow, pressure, discharge temperature, circuiting, and material requirements.<\/p>\n

Design pressure and test pressure<\/h3>\n

Specify design pressure for the high side, allowable working pressure, test pressure, test medium, hold time, and acceptance criteria. Distinguish a factory strength or leak test from a field pressure test. The supplier should identify whether the test covers the entire circuit, each circuit separately, headers, brazed joints, and any factory-installed valves.<\/p>\n

ASHRAE\u2019s halocarbon system guidance<\/a> notes that condenser refrigerant pressure drop must be obtained from the supplier for the particular unit and specified load. Put that result into the required submittal instead of accepting a generic pressure-drop statement.<\/p>\n

Subcooling requirement<\/h3>\n

State required liquid temperature or subcooling at the condenser outlet, where it is measured, and whether the receiver is included. A circuit that provides extra subcooling can change refrigerant charge and liquid-line behavior. Make sure the rating sheet identifies the outlet condition and the measurement location.<\/p>\n

\"Industrial <\/figure>\n

Air-side duty, fans and clearances<\/h2>\n

Airflow and face velocity<\/h3>\n

Record design airflow, allowable air-side pressure drop, fan operating range, air inlet temperature, altitude, and whether air recirculation is expected. For an outdoor condenser, include solar load, prevailing wind, nearby walls, screens, and seasonal ambient. For an indoor unit, specify duct resistance and discharge path.<\/p>\n

Fan arrangement<\/h3>\n

State draw-through or blow-through, fan diameter, number of fans, speed control, motor voltage, frequency, direction, guard, and service access. Ask for the fan curve at the coil pressure drop. A fan that delivers the required volume in free air may not do so through a dirty coil, guard, grille, or discharge duct.<\/p>\n

\"Large <\/figure>\n

Clearance and recirculation<\/h3>\n

Provide the minimum free area around the coil and fan. Recirculated hot air can raise entering air temperature and discharge pressure even when the nominal outdoor temperature looks acceptable. Ask the supplier to identify the assumed inlet and outlet clearances on the layout drawing.<\/p>\n

Tube, fin, header and casing materials<\/h2>\n

Tube and fin construction<\/h3>\n

State tube material, tube outside diameter, wall thickness or applicable standard, fin material, fin thickness, fin type, fin pitch, and tube-to-fin bond. Copper tube with aluminum fins is common, but aluminum tube, copper fin, coated fin, stainless components, and microchannel construction may be suitable in other applications.<\/p>\n

\"Close-up <\/figure>\n

Header and return-bend materials<\/h3>\n

Include header material, return-bend geometry, connection material, braze alloy requirements, and any heat-treatment or cleaning requirement. If the supplier is expected to use an equivalent material, define the acceptance basis. \u201cEquivalent\u201d should mean equivalent pressure, corrosion, joining, thermal, and service performance, not only a similar appearance.<\/p>\n

Frame, casing and coating<\/h3>\n

State frame and casing material, finish, drain or rain management, lifting points, fasteners, vibration isolators, and service panels. For outdoor or coastal service, describe salt, dust, grease, chemical vapor, humidity, and washdown exposure. Coating selection should name the surface, preparation, coating type, thickness or process control, curing, and inspection method.<\/p>\n

The separate commercial refrigeration coil coating guide<\/a> can support the corrosion portion of the review. Keep coating requirements in the specification instead of adding \u201canti-corrosion\u201d as an undefined commercial phrase.<\/p>\n

\"Comparison <\/figure>\n

Circuiting, connections and pressure drop<\/h2>\n

Circuiting must match the refrigerant flow<\/h3>\n

The number of circuits, circuit length, parallel paths, header size, and outlet arrangement affect refrigerant velocity, pressure drop, oil return, distribution, and subcooling. Require a circuiting sketch or drawing. A coil with the same face dimensions can behave differently when the circuit arrangement changes.<\/p>\n

\"Close-up <\/figure>\n

State all connection geometry<\/h3>\n

Include inlet and outlet tube outside diameters, connection orientation, center-to-center dimensions, projection from the frame, brazing or flare requirement, service valve interface, and tolerance. For replacement or constrained OEM assemblies, show datum references and mounting holes on the same drawing as connections.<\/p>\n

Ask for both refrigerant-side and air-side pressure drop<\/h3>\n

Refrigerant-side pressure drop affects condensing temperature, liquid delivery, and compressor work. Air-side pressure drop affects fan power and airflow. Require the test or calculation condition for each value. ASHRAE Chapter 39<\/a> identifies pressure-drop calculation as part of condenser design, not a post-purchase detail.<\/p>\n

\"Industrial <\/figure>\n

Microchannel versus fin-tube construction<\/h2>\n

Microchannel and fin-tube coils can both be valid choices. The comparison should include thermal duty, pressure drop, refrigerant charge, joining, repair method, corrosion exposure, cleaning, weight, and supply risk.<\/p>\n

\n\n\n\n\n\n\n\n\n\n
Specification area<\/th>\nCopper-tube aluminum-fin<\/th>\nMicrochannel<\/th>\nBuyer decision<\/th>\n<\/tr>\n<\/thead>\n
Tube geometry<\/td>\nRound tubes with return bends and headers<\/td>\nMultiport flat tubes with manifolds<\/td>\nWhich geometry fits the available envelope and circuit layout?<\/td>\n<\/tr>\n
Joining and repair<\/td>\nBrazed joints and replaceable connections may be familiar to service teams<\/td>\nManifold and tube joints need process-specific repair controls<\/td>\nWhat repair method is acceptable in the installed market?<\/td>\n<\/tr>\n
Air-side surface<\/td>\nFin pitch, rows, tube pattern, and bond define surface<\/td>\nFlat multiport tubes and fins create a compact core<\/td>\nIs compactness worth the change in service and inspection method?<\/td>\n<\/tr>\n
Corrosion review<\/td>\nDissimilar-metal interfaces and coating may need attention<\/td>\nAluminum surface and galvanic interfaces need their own review<\/td>\nWhat exposure and cleaning chemistry will the coil see?<\/td>\n<\/tr>\n
Evidence<\/td>\nCircuit drawing, braze inspection, leak test, rating<\/td>\nManifold design, leak test, rating, and handling controls<\/td>\nWhich evidence must be included in first-article approval?<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Do not select one construction only because a catalog lists a higher nominal capacity. Use the same rating point, airflow, pressure-drop limit, and service assumptions for both options.<\/p>\n

\"Two <\/figure>\n

Drawing and dimensional specification fields<\/h2>\n

The drawing should allow a manufacturer and an incoming inspector to identify the same part. Include:<\/p>\n