Site Survey & Infrastructure Readiness: The Pre-Shipment Checklist for Overseas Vacuum Cooling Projects
floor loading, electrical, water supply, ceiling clearance, and ambient conditions for vacuum cooler installation.
You have selected the right vegetable vacuum cooler or food vacuum cooler. The compressor spec matches. The vacuum pump model is correct. The voltage is confirmed.
Now comes the part that kills projects: the site itself.
We have seen installations delayed or compromised because the customer's facility was not ready. A 3-tonne compressor cannot sit on a suspended floor. A 50 m³/h cooling tower needs water that meets pH 7.0–8.5. A 380V panel with a 32A MCB will trip before the vacuum pump reaches 1,000 Pa.
This article is the field-tested infrastructure readiness checklist we send to every overseas customer before the container leaves Dongguan. It covers what we check, why it matters, and the real consequences of skipping each item.
1. Floor Loading — The Silent Showstopper
The problem: A CVF-3000-6P vegetable vacuum cooler weighs approximately 4,800 kg. The compressor skid alone (Bitzer CSH6553 + receiver + oil separator) is ~1,200 kg on a 1.2 m × 1.2 m footprint — that is 833 kg/m² point load. Standard warehouse slab design (5–7.5 kN/m² = 500–750 kg/m²) is borderline.
What we check:
| Parameter | Check | Red Flag | Fix |
|---|---|---|---|
| Floor slab thickness | ≥150 mm reinforced concrete | <120 mm | Reinforce or redistribute load with steel spreader plate |
| Point load capacity | ≥1,000 kg/m² at equipment footprint | <750 kg/m² | Use 10 mm steel baseplate (1.5 m × 1.5 m minimum) |
| Floor levelness | ±5 mm over 3 m | >10 mm deviation | Self-levelling compound before installation |
| Proximity to expansion joint | Compressor ≥500 mm from joint | Compressor straddles joint | Relocate or bridge joint with steel channel |
| Basement/crawl space below | Confirm load path to foundation | Equipment over void | Structural steel spanning beams |
Real example: The CVF-4500-6P (4,500 kg capacity, ~6,800 kg total weight) was installed on a warehouse slab built for dry storage. At 950 kg/m² point load, the slab was right at the limit. We added a 12 mm steel spreader plate (2 m × 1.8 m) under the compressor skid and installed vibration pads. Eight years of operation — no cracks, no settlement.
Real example: The CVF-400 food vacuum cooler (1,600 kg) was to be installed on a first-floor mezzanine. The mezzanine was rated for 400 kg/m² — insufficient for the compressor's 900 kg/m² point load. Solution: relocate to ground floor adjacent to the production line.
2. Electrical Supply — The Most Common Failure Point
The problem: A vacuum cooler's peak draw is during pump-down (first 3–5 minutes). The vacuum pump + compressor + control panel can draw 2.5× the running current. If the site MCB or undersized cable trips during pump-down, the cooling cycle fails and the batch is lost.
What we check:
| Parameter | Check | Red Flag |
|---|---|---|
| Voltage at site (measured under load) | Within ±5% of rated | >±10% deviation |
| Available current (main breaker) | ≥3× running current for inrush | ≤2× running current |
| Cable cross-section | ≥16 mm² for 30 m run at 32 A | <10 mm² at 30 m |
| Frequency | 50 Hz or 60 Hz confirmed | Mixed-frequency supply |
| Earth resistance | ≤4 Ω | >10 Ω |
| UPS/backup generator | Stable voltage, automatic transfer | Manual switch only |
| Separate MCB for compressor | Dedicated ≥40 A Type C | Shared circuit |
Real example: Customer's CVF-100 food cooler site had only 220V single-phase available. The unit draws 11 kW running, 22 kW peak. A single-phase 220V supply at 22 kW requires 100 A — requiring a 125 A cable. The site's existing wiring was 6 mm² (max 32 A). We shipped a phase converter (220V 1-phase → 380V 3-phase, 15 kVA) and required the customer to install a 100 A dedicated breaker and 25 mm² cable from the mains panel.
3. Water Supply & Drainage — The Overlooked Utility
For water-cooled and evaporative condenser systems, water quality and flow rate determine whether the system runs efficiently or fails from scaling within 6 months.
| Parameter | Check | Red Flag |
|---|---|---|
| Water flow rate | ≥1.5× condenser-rated flow | <1.0× rated flow |
| Water pressure at inlet | 2–4 bar | <1.5 bar (need booster pump) |
| pH | 7.0–8.5 | <6.5 or >9.0 (risk of corrosion or scaling) |
| Total hardness | ≤100 ppm CaCO₃ | >200 ppm (requires water softener) |
| TDS | ≤500 ppm | >1,000 ppm (scale risk) |
| Drain location | Floor drain within 3 m of unit | No drain within 5 m |
| Drain pipe diameter | ≥50 mm | <40 mm |
| Cooling tower make-up water | Automatic float valve with backflow preventer | Manual refill |
Real example: The evaporative condenser on CVF-3000-6P required 8 m³/h make-up water at 3 bar. The customer's site had well water at 2.1 bar and 380 ppm TDS — borderline. We installed a 2-stage filtration system (100 µm + 5 µm) and a pressure booster pump. Without these, the condenser nozzles would have clogged within 3 months, reducing heat rejection by 40% and forcing the Bitzer compressor into high-pressure cut-out.
4. Ceiling Clearance & Access
Vacuum coolers are tall. The chamber door swings outward. The vacuum pump and compressor need service clearance. These dimensions are not negotiable.
| Model | Height (m) | Door Swing (m) | Service Clearance (m) |
|---|---|---|---|
| CVF-1000-2P | 2.2 | 1.0 (door arc) | 1.0 rear, 0.8 sides |
| CVF-3000-6P | 2.6 | 1.5 (door arc) | 1.2 rear, 1.0 sides |
| CVF-4500-6P | 2.8 | 1.8 | 1.5 rear, 1.2 sides |
| CVF-8500-12P | 3.1 | 2.5 | 2.0 rear, 1.5 sides |
What we check:
- Ceiling height: minimum unit height + 0.5 m for rigging/hoist
- Door opening width: chamber door + 0.3 m for forklift/pallet jack access
- Access path: confirm that the unit can be moved from container drop-off point to final position — door widths, corridor turns, ramp slopes
- Overhead obstructions: pipes, cable trays, sprinkler heads above the installation area
Real example — Netherlands 2023: The CVF-3000 flower cooler (2.6 m tall) was to be installed in a 2.8 m ceiling space. We had to remove the removable top panel during installation, slide the chamber in on steel rollers, then reinstall the top panel. Door clearance required removing a sprinkler head and rerouting the pipe. The whole manoeuvre took 4 hours instead of the usual 30 minutes.
5. Ambient Conditions Survey
Vacuum coolers are industrial refrigeration equipment. They perform differently in a 45°C tropical factory vs a 10°C climate-controlled facility.
| Parameter | Check | Impact |
|---|---|---|
| Ambient temp range (summer peak) | Recorded hourly over 1 week | Condenser selection, compressor derating |
| Ambient temp range (winter low) | Recorded over 1 week | Compressor oil viscosity, crankcase heater sizing |
| Humidity (RH max) | Recorded | Evaporative condenser effectiveness, electrical panel protection |
| Dust/particulate level | Visual inspection | Air-cooled condenser fin spacing, filter frequency |
| Altitude | GPS or barometric | Compressor capacity derating (3% per 300 m above 1,000 m) |
| Ventilation | Air changes per hour in compressor room | Condenser placement (condenser cannot discharge into enclosed space) |
Real example: The CVF-400-1P mushroom cooler operates in a desert climate with summer ambient reaching 48°C. Standard air-cooled condenser would result in 58°C condensing — beyond the Bitzer compressor's safe operating envelope. We switched to an evaporative condenser sized 1.3× and added a pre-cooling pad. Without the site ambient survey, the unit would have failed its first summer.
6. The Complete Pre-Shipment Checklist
This is the checklist we email to every overseas customer 4 weeks before the container ships. It is not optional — the installation team will verify every item before commissioning begins.
Structural
- Floor slab: ≥150 mm reinforced concrete
- Point load capacity confirmed ≥1,000 kg/m²
- Floor level within ±5 mm over 3 m
- No expansion joint under compressor skid
- Foundation load path verified (no void/crawl space unaccounted for)
Electrical
- Voltage measured under load: __ V (±5% of rated)
- Frequency confirmed: 50 Hz / 60 Hz
- Main breaker capacity: ≥3× running current
- Dedicated MCB for compressor: ≥40 A Type C
- Cable cross-section confirmed for run distance
- Earth resistance: ≤4 Ω
- Generator/UPS: automatic transfer, stable voltage
Water (for water-cooled or evaporative systems)
- Flow rate at inlet: ≥1.5× condenser rated
- Pressure: 2–4 bar
- pH: 7.0–8.5
- Hardness: ≤100 ppm CaCO₃
- TDS: ≤500 ppm
- Floor drain: within 3 m, ≥50 mm diameter
- Cooling tower make-up: automatic float valve, backflow preventer
Access & Clearance
- Ceiling height confirmed: __ m (min unit height + 0.5 m)
- Door opening: chamber door + 0.3 m
- Access path clear: container drop-off → final position
- No overhead obstructions in installation area
- Service clearance: 1.0 m rear, 0.8 m sides minimum
Ambient
- Summer peak ambient: __ °C (1-week logged data)
- Winter low ambient: __ °C
- Humidity (RH max): __ %
- Dust level assessed: low / medium / high
- Altitude: __ m above sea level
- Compressor room ventilation: adequate for condenser rejection
Summary
Exporting vacuum cooling equipment is not just matching voltage and climate. The site itself must be ready. After 12 years across 11 countries, roughly one in four overseas installations requires last-minute site modification because the infrastructure checklist was not completed before shipping.
The cost of a missed item:
- Floor loading inadequate → 2–4 weeks delay + structural steel cost
- Undersized electrical cable → repeated MCB tripping, production loss
- Water quality poor → condenser scaling within 6 months, compressor failure
- Ceiling too low → unit cannot be installed without modification
- Ambient not surveyed → wrong condenser type, system stuck in high-pressure cut-out on first hot day
For engineering teams planning their first vacuum cooling installation, request the full site survey template at www.vacuum-fresh.com. Use it 4 weeks before the container arrives. It saves more time than it costs.
