How to Turn a Cold Room Enquiry into a Sales-Ready Proposal
Most cold room enquiries only include length, width, height, and storage product. This guide helps your team collect the missing information, sketch a reliable layout, calculate heat load with confidence, and move into equipment selection without rework.
Some enquiries may require on-site consultation for dimensioning and space utilization. That is a separate topic, and it deserves its own guide.
For this guide, we assume the customer already has a target room size and product type in mind. Most customers are not concerned with minute technical details such as wall thickness, exact door dimensions, or compressor model. They simply want a reliable cold room that supports business operations, and your job is to turn that simple brief into a sales-ready proposal with solid engineering behind it.
Step 1 - Retrieve information
The goal here is to retrieve information as complete as possible from the client. Every piece of information gathered will collectively determine the cold room heat load, and that heat load will then determine the sizing of evaporator, compressor, and condenser.
It is a chained reaction: heat load sits at the top, and everything else follows from it.
Some manufacturers or supply houses provide quick sizing tables based only on room dimensions or volume. We should avoid using these tables for proposal engineering. They may make life easier, but they do not help you win the job with confidence.
We need the right heat load to increase our chance to close the deal, not an undersized or oversized design.
Ok, let's dive in.
1) Product daily load
We need to know the total product weight loaded into the cold room on a daily basis. This is the most important input because it affects most parts of the heat load calculation.
Some clients cannot give exact daily load in kg. In this case, ask the right operational questions and estimate from truck movement instead of guessing.
Questions to ask when daily load is unknown
- How many cold trucks are unloaded into this room per day?
- What truck type/tonnage is used for each delivery?
- Is the truck typically full, half full, or mixed with other products?
- Is this inbound only, outbound only, or both in the same day?
Use truck tonnage and typical utilization to estimate daily product load:
| Tonnage | Typical length | Typical capacity | Best use case |
|---|---|---|---|
| 1 Ton | 10 ft (about 3.0 m) | ~1,000 kg | Small business and home deliveries (for example cakes or small quantities of meat). |
| 3 Ton | 14 ft (about 4.3 m) | ~3,000 kg | Restaurant and retailer supply, plus frozen food distribution. |
| 5 Ton | 16 to 17 ft (about 4.9 to 5.2 m) | ~5,000 kg | Wholesale supply, large supermarkets, and medium-distance logistics. |
| 10 Ton | 25 ft (about 7.6 m) | ~10,000 kg | Large-scale deliveries, long-haul movement, and port transfer work. |
| 20+ Ton | 32 to 40 ft (about 9.8 to 12.2 m) | 15,000 to 30,000 kg | Heavy industrial consignments and bulk international freight. |
If the client refers to containerized supply, use standard reefer container data instead of truck class assumptions.
| Reefer type | Internal size (L x W x H) | Typical payload | Typical volume | Common use |
|---|---|---|---|---|
| 20 ft reefer | ~5.4 m x 2.3 m x 2.2 m | 21,000 to 27,000 kg | 28 to 30 m3 | Denser cargo and shorter-haul international cold-chain movements. |
| 40 ft high-cube reefer | ~11.6 m x 2.3 m x 2.5 m | 26,000 to 29,000 kg | 65 to 68 m3 | High-volume international shipments with better cube utilization. |
Note: exact dimensions and payload limits vary by manufacturer, refrigeration unit, route regulation, and product density. Confirm with client logistics records whenever possible.
2) Product entry temperature
Product entry temperature is the product temperature before it goes into the room. Most clients can provide this if we ask the right question: how long do products stay in ambient conditions before loading?
For a frozen room with storage temperature at -18°C, products may leave the truck at around -18°C, but their temperature can rise while waiting to be loaded. We need to estimate that raise and define the real entry temperature (N C).
Here is a practical estimation guide:
| Handling condition | Frozen room (-18°C storage) | Chilled room (2°C storage) | Fresh room (-2°C storage) |
|---|---|---|---|
| Loaded immediately | -15°C | 2°C to 4°C | -2°C to 2°C |
| Short waiting time | -10°C | 10°C | 15°C |
| Long waiting time | -5°C | 15°C | 20°C |
3) Determine cold room operation type
Classify the room as Long Storage, Medium Usage, or High Usage. This affects door opening assumptions, traffic behavior, and load profile.
Long Storage (Low Traffic)
Products stay for long periods and access is infrequent.
- Cold storage warehouse
- Backup inventory storage
- Seasonal storage
- Meat or seafood stored for weeks
- Door opens only a few times per day
Medium Usage (Normal Cold Room)
Daily product movement with regular but controlled access.
- Restaurant cold room
- Supermarket backroom storage
- Small food factory storage
- Fruit and vegetable storage
- Workers enter several times per hour
High Usage (Heavy Traffic)
Continuous movement with frequent door openings.
- Dispatch rooms
- Production staging rooms
- Distribution centers
- Forklift loading cold rooms
- Door may stay open during loading
4) Pick the right door size
Door sizing is fairly straightforward when you collect the right inputs. First, identify the maximum product size that needs to pass through the door. Then confirm how goods are transferred: by hand, pallet jack, reach truck, or forklift.
Practical door sizing rule
In many projects, a 2400 mm wide drive-in door may look narrow on paper, but field experience often shows it is adequate and helps reduce infiltration load compared with wider openings.
| Room category | Typical handling method | Recommended door size | Notes |
|---|---|---|---|
| Walk-in room | Manual loading by labor | 900 mm W x 2100 mm H | Good baseline for smaller rooms around 3 m height; choose swing or sliding based on circulation space. |
| Walk-in room | Pallet jack transfer (pallet around 1200 x 1100 mm) | 1200 to 1300 mm W x 2100 mm H | Gives practical side clearance while controlling door opening area. |
| Drive-in room | Reach truck or forklift traffic | 2400 mm W x 3000 to 3900 mm H | Door height should follow vehicle mast height + 600 mm free clearance. |
This is not only about accessibility. Door size also affects air change load. A larger opening can increase infiltration, so the target is practical clearance, not oversizing by default.
Step 3: Visualize the system configuration
Before selecting specific equipment, think at a high level: how does the refrigeration cycle look? What are the evaporating and condensing temperatures? What refrigerant are you using? This step helps you establish the thermodynamic envelope—suction pressure, discharge pressure, and capacity—before diving into evaporator and compressor catalogs.
Use the interactive diagram below to explore how refrigerant, room temperature, ambient, and evaporating TD affect the cycle. Once you have a clear picture of the system configuration, you can confidently move to evaporator selection in the next step.
Scenario: walkthrough of each input
- Refrigerant: R-507a (common for low-temp/freezer; near-azeotropic, minimal glide)
- Ambient: 35 °C (design ambient for condenser heat rejection)
- Condensing kTD: 10 K (range 7–15 K)
- Lower kTD → lower condensing temp → larger condenser, smaller compressor, better efficiency
- Higher kTD → higher condensing temp → smaller condenser, larger compressor
- Trade-off: efficiency vs equipment cost and space
- Room temp: -18 °C (set by product storage; e.g. frozen food)
- Evaporating kTD: 7 K (typical freezer; range 5–12 K). TD = room temp − evap temp
- Higher kTD → lower evap temp → smaller evaporator (larger ΔT for same capacity)
- Lower kTD → higher evap temp → larger evaporator, better efficiency (higher suction)
- Trade-off: efficiency vs evaporator size; lower TD also improves humidity control
- Liquid subcooling: 1 K
- From condenser subcooling zone, or heat loss in liquid line/receiver
- Prevents flash gas ahead of expansion valve; increases useful capacity
- Useful superheat: 6 K · Non-useful: 4 K · Total 10 K
- Useful: at evaporator outlet; ensures dry vapor, prevents liquid slugging
- Non-useful: heat gained in suction line; adds no cooling, raises compressor inlet temp
- Cold rooms: lower non-useful SH (insulated suction); showcases: higher (uninsulated runs)
- Pressure drop (Max ΔT Sat): 1 K (ASHRAE: design for ≤1–2 K equivalent)
- Pressure loss in suction line (pipes, fittings, filters)
- Expressed in K: lowers saturation temp at compressor inlet
- Compressor evap temp = evap temp − pressure drop
- Higher drop → lower suction pressure, lower density → less mass flow → reduced capacity (excessive drop can cause significant loss; size pipes per ASHRAE tables)
Design insight: Lower evaporating TD and lower condensing TD both improve efficiency but require larger heat exchangers. The scenario values above balance efficiency, equipment cost, and typical practice for -18 °C freezer applications.
Step 7: Design summary
This summary brings together the cold room sketch, heat load, and equipment selections from the previous steps. Use it to verify the design before moving to implementation.
Cold room sketch
- Project
- Demo Project
- Sketch
- Step 2 Scenario
- Dimensions
- 9 × 18 × 6 m
- Volume
- 972 m³
- Wall thickness
- 100 mm
- Ambient
- 35 °C
Room & load
- Room temp
- -18 °C
- Heat load
- —
- Evap. KTD
- 7 K
- Cond. KTD
- 10 K
Selected evaporator
No evaporator selected. Complete Step 4 to select one.
Selected compressor
No compressor selected. Complete Step 5 to select one.
Selected condenser
No condenser selected. Complete Step 6 to select one.
Cost list
| Item | Model | Cost |
|---|
Complete Steps 4–6 to select equipment and view costs.
Process recap:
- Sketch the room (Step 2)
- Calculate heat load (Step 2)
- Configure cycle (Step 3)
- Select evaporator (Step 4)
- Select compressor (Step 5)
- Select condenser (Step 6)
- Each step builds on the previous; revisit any step to adjust the design
Ready to Sketch Cold Room Layouts?
Put this guide into practice. Try SupaCAD for simple, fast cold room layouts.
Get started with simple cold room layouts, doors and evaporators, and professional PDF exports
No Credit Card Required • No Setup • No Learning Curve • Ready to Use