Views: 0 Author: Site Editor Publish Time: 2026-11-04 Origin: Site
At CSTHEATEXCHANGER, we engineer and manufacture heavy-duty Through-Wall Straddle Type Monoblock Condensing Units specifically designed for commercial and industrial walk-in freezers, meat blast holding rooms, seafood cold storage, butcher processing facilities, and seafood distribution centers (low-temperature freezing capacities engineered from 1.2 kW to over 28 kW, operating at evaporating temperatures of −20∘C to −32∘C and maintaining room temperatures down to −18∘C to −25∘C with R404A, R448A, R449A, or eco-friendly R290). Featuring an engineered straddle "saddle" chassis that mounts directly over the vertical insulated wall panel, our units completely eliminate on-site copper brazing, vacuum pulling, and field refrigerant charging. Built with low-temperature hermetic/semi-hermetic scroll and reciprocating compressors, heavy-gauge inner-groove copper tube coils with hydrophilic anti-corrosion blue fins (or marine AlMg3 fins), and dual-circuit pan-first rapid hot gas defrost (<15–20 minutes<15–20 minutes), CST straddle monoblocks provide reliable, deep-freeze preservation that prevents freeze burn, locks in protein freshness, and resists coastal marine salt corrosion.
The straddle-type monoblock features an inverted U-profile saddle frame engineered to straddle the top edge of a vertical polyurethane (PU) cold room wall panel before the roof panel is placed (or installed through a simple vertical wall slot):
STRADDLE TYPE MONOBLOCK OVER-THE-WALL REFRIGERATION SCHEMATIC
======================= OUTSIDE COLD STORAGE ROOM (CONDENSING SECTION) =======================
┌──────────────────────────────────────────────────────────────────────────────────────────┐
│ • Low-Temperature Scroll / Reciprocating Compressor (Emerson / Bitzer / Secop) │
│ • High-Static Air-Cooled Condenser Coil (Inner-Groove Copper Tube + Hydrophilic Blue Fins│
│ • Low-Noise Axial Condenser Fan with Protective Weatherproof Cowling │
│ • Heavy Galvanized Steel Casing with Zinc-Phosphate C4 Anti-Corrosion Coating │
└────────────────────────────────────────┬─────────────────────────────────────────────────┘
│ [PRE-INSULATED STRADDLE SADDLE BRIDGE]
│ Straddles 100 mm / 150 mm PU Wall Panel
▼
======================= INSIDE MEAT & SEAFOOD FREEZER (EVAPORATOR SECTION) ===================
┌──────────────────────────────────────────────────────────────────────────────────────────┐
│ • Deep-Freeze Evaporator Core with Progressive Fin Pitch (12 mm -> 8 mm -> 6 mm) │
│ • Dual-Circuit Hot Gas Defrost Headers (Pan-First Heating prevents ice damming) │
│ • High-Throw Cold Air Circulation Fans with Streamlined Air Deflectors │
│ • Double-Wall Insulated Stainless Steel 3° Sloped Drain Pan (Zero Water Carryover) │
└──────────────────────────────────────────────────────────────────────────────────────────┘================================================================================
CST STRADDLE MONOBLOCK VS. STANDARD THROUGH-WALL CUTOUT VS. SPLIT SYSTEMS
================================================================================
Evaluation Metric CST Straddle Monoblock Unit Standard Wall Cutout Monoblock Traditional Split System
--------------------------------------------------------------------------------
Wall Panel Structural Impact Straddles top edge (Zero cut) Requires large wall hole (Weak) Requires drilled pipe holes
Refrigerant Integrity 100% Hermetically Sealed Loop 100% Hermetically Sealed Loop Site-brazed joints (Leak risk)
Installation Speed Plug-and-Play (< 2 Hours) Requires heavy lifting frame Complex piping (2 to 3 Days)
Roof / Ceiling Load Capacity Zero load on ceiling panel Zero load on ceiling panel Indoor evaporator hung on roof
Internal Cold Room Usability Flush vertical wall profile Protrudes deeply into room Hangs down from ceiling
Service & Maintenance Access Ground / Ladder accessible Accessible from outside Requires scaffolding / roof walk
Coastal Seafood Salt Defense C4 Powder Coating + AlMg3 Fins Standard sheet metal Unprotected outdoor condenser
Defrost Water Management Integrated hot gas evaporator Standard drain pipe Requires external PVC + trace wire
================================================================================Standard through-wall units require cutting large rectangular openings through the middle of structural PU panels, which weakens wall rigidity and creates potential air leak paths over time. The CST straddle design drops directly over the top edge of the wall panel, maintaining 100%100% wall structural integrity while providing thermal isolation via dense injected polyurethane insulation.
Meat (beef, pork, poultry carcass quarters) and seafood (shrimp, whole tuna, salmon fillets) require continuous deep sub-zero temperatures to prevent cellular moisture migration and microbial spoilage. Our units maintain evaporating temperatures down to −32∘C with tight digital PID temperature control (±0.5∘C), preserving product weight and meat bloom color.
Meat butchery and seafood processing rooms expose equipment to high humidity, fatty acids, washdown chemicals, and marine salt air:
CST STRADDLE FREEZER MONOBLOCK SUBASSEMBLY INTEGRATION
======================= WEATHERPROOF C4 POWDER-COATED FRAME =======================
[ Zinc-Coated Heavy Gauge Steel Housing with Sound-Attenuated Compressor Bay ]
│
▼
┌────────────────────────────────────────────────────────────────────────────┐
│ CORE SUBASSEMBLY INTEGRATION │
│ ┌────────────────────────┐ ┌────────────────────────┐ ┌──────────────────┐ │
│ │ LOW-TEMP COMPRESSOR │ │ CORROSION-PROOF COILS │ │ SMART CONTROLLER │ │
│ │ R404A / R448A / R290 │ │ Inner-groove Cu tubes │ │ Carel / Dixell │ │
│ │ Heavy vibration mounts │ │ Hydrophilic/AlMg3 fins │ │ Modbus & HACCP │ │
│ └────────────────────────┘ └────────────────────────┘ └──────────────────┘ │
└────────────────────────────────────────────────────────────────────────────┘ CST MEAT & SEAFOOD STRADDLE FREEZER REFRIGERATION CYCLE
FROM MEAT / SEAFOOD FREEZER ENCLOSURE (-18°C TO -25°C RETURN AIR)
┌─────────────────────────────────────────────────────────────────────────┐
│ [ EVAPORATOR: STAGED FIN SPACING CORE WITH EEV EXPANSION ] │
│ High-velocity air circulation eliminates warm pockets; locks humidity │
├─────────────────────────────────────────────────────────────────────────┤
│ [ COMPRESSOR: HIGH-DISPLACEMENT LOW-TEMP SCROLL / RECIPROCATING ] │
│ Maintains high volumetric efficiency even at high compression ratios │
├─────────────────────────────────────────────────────────────────────────┤
│ [ CONDENSER: HIGH-STATIC AIR COOLED CORE WITH EC SMART FANS ] │
│ Seamless heat rejection up to +45°C ambient summer temperatures │
└─────────────────────────────────────────────────────────────────────────┘
MAINTAINS ROCK-SOLID SUB-ZERO FREEZING TO WITHIN ±0.5°CFreezing fresh, unpackaged meat and seafood releases substantial surface water vapor. Standard close fin spacing clogs with ice within hours. CST equips its straddle evaporators with staged fin spacing (12 mm inlet →8 mm intermediate →6 mm discharge), allowing frost to distribute evenly across the coil depth and extending continuous freezing runs to 16–24+ hours.
Electric defrost takes up to 60 minutes60 minutes and raises the freezer temperature, risking partial surface thawing of seafood and meat. Our pan-first hot gas defrost system routes compressor discharge gas through stainless steel coils inside the insulated drain pan first, preheating the pan surface to +25∘C to instantly melt falling ice slabs before clearing the coil block in under 15 to 20 minutes with minimal room temperature rise (<+3∘C).
CSTHEATEXCHANGER STRADDLE MONOBLOCK TOPOLOGIES
[1. STANDARD WALL-STRADDLE MONOBLOCKS (INDOOR CORRIDOR)]
• Condensing section discharges warm air into an indoor ambient warehouse or plant corridor.
• Ideal for food processing halls, wholesale butcheries, and cold storage distribution centers.
─────────────────────────────────────────────────────────────────────────────
[2. WEATHERPROOF OUTDOOR WALL-STRADDLE PACKAGES]
• Equipped with an insulated, IP55 rainproof outer enclosure and crankcase heaters for outdoor walls.
• Condensing section faces outdoor ambient air (-20°C winter to +45°C summer ready).
─────────────────────────────────────────────────────────────────────────────
[3. HEAVY-DUTY SEAFOOD BLAST STORAGE STRADDLE UNITS]
• High-airflow evaporator blowers designed for fast freezing of fresh seafood catch and bulk cartons.(Note: The following engineering parameters represent standard manufacturing design envelopes. Compressor displacement, wall straddle slot widths, refrigerant types, and casing formats are customized to specific walk-in freezer box drawings.)
================================================================================
CSTHEATEXCHANGER STRADDLE MONOBLOCK FREEZER UNIT (CST-STRAD-FRZ SERIES)
================================================================================
Engineering Parameter Standard Manufacturing & Design Range
--------------------------------------------------------------------------------
Low-Temp Freezing Capacity 1.2 kW to 28+ kW (4,100 to 95,000+ BTU/h / 1.5 to 25 HP)
Walk-in Freezer Room Temp. Range-18°C to -25°C (-0.4°F to -13°F) Deep Storage
Evaporating Temperature Floor -25°C to -32°C (-13°F to -25.6°F) Deep Freezing
Ambient Operating Temperature -15°C to +45°C (+5°F to +113°F) High Ambient Ready
Straddle Wall Thickness Range 100 mm, 120 mm, 150 mm, or 200 mm PU Panel Insulation
Mounting Configuration Formats Over-the-Wall Straddle Saddle, Slotted Wall Insertion
Compressor Technologies Hermetic Scroll (Copeland/Danfoss) or Semi-Hermetic (Bitzer)
Compatible Refrigerants R404A, R448A, R449A, R452A, Eco-Friendly R290 (Propane)
Refrigerant Charge State 100% Factory Pre-Charged & Hermetically Sealed
Expansion Device Options Electronic Expansion Valve (EEV) or Precision Low-Temp TXV
Evaporator Fin Spacing Staging Progressive: 12 mm (Inlet) -> 8 mm (Middle) -> 6 mm (Outlet)
Tube Metallurgy & Geometry 3/8" (9.52 mm) or 1/2" (12.7 mm) Deoxidized Inner-Groove Copper
Fin Material Options Hydrophilic Blue Aluminum, Marine AlMg3, Epoxy Coated
Casing Construction & Finish Zinc-Phosphate Galvanized Steel with C4 Powder Coating (RAL 7035)
Drain Pan Configuration Double-Wall Insulated Stainless Steel Pan with 3° Slope
Defrosting Systems Dual-Circuit Hot Gas (Pan-First Loop) or Incoloy Electric Heaters
Fan Motor Specifications IP55/IP66 Washdown Low-Noise Axial Fans, Optional EC Motors
Digital Controller & IoT Carel / Dixell Microprocessor with HACCP Data Logging & Modbus
Supply Electrical Standards 1-Phase 220V/50-60Hz or 3-Phase 380V-460V/50-60Hz
Safety & Quality Standards CE / PED 2014/68/EU, ISO 9001:2015, HACCP Compliance Ready
Testing Quality Gate 100% Helium Mass Spectrometer Leak Tested & 4-Hour Factory Run Test
================================================================================Standard through-wall units require cutting large, heavy structural openings in the middle of cold room panels, which weakens the box structure and can cause thermal bridge leaks. The CST straddle monoblock drops directly over the top of the wall panel, preserving the structural panel integrity, simplifying installation, and keeping the indoor evaporator high and out of the way of pallet forklifts.
Electric defrost takes up to an hour and heats the entire room, causing surface thawing that ruins seafood glaze and discolors fresh meat. CST's pan-first hot gas defrost utilizes compressor discharge heat (+35∘C to +40∘C) to clear the coil in under 15–20 minutes, limiting room temperature fluctuations to less than +3∘C to preserve meat bloom, moisture content, and protective seafood glazes.
Yes. We manufacture straddle units with custom insulated bridge dimensions matching 100 mm, 120 mm, 150 mm, or 200 mm polyurethane (PU) wall panels, ensuring an airtight, thermally unbroken seal for any walk-in freezer enclosure.
Achieve deep sub-zero freezing, eliminate field piping leaks, and streamline your cold storage installation with CSTHEATEXCHANGER:
Custom Through-Wall Straddle Monoblock Freezing Units (1.2 kW to 28 kW+)
Over-the-Wall Saddle Architecture for 100 mm to 200 mm PU Wall Panels
100% Factory Pre-Charged with R404A, R448A, R449A, or Natural R290 Propane
Rapid 15–20 Minute Dual-Circuit Pan-First Hot Gas Defrost Systems
Hermetic Scroll/Reciprocating Compressors with Inner-Groove Copper & Hydrophilic Fins
Full CE / PED Compliance, 100% Helium Leak Tested & Factory-Direct Global Delivery
Contact our industrial cold chain refrigeration engineering team today with your walk-in freezer dimensions, target room temperature (−18∘C−18∘C to −25∘C−25∘C), product load (meat/seafood kg/day), and wall thickness for custom CAD drawings and factory-direct quotations.
Website: https://www.cstheatexchanger.com/
Technical Inquiries: info@cstheatexchanger.com
