Chilled, frozen or dual: quick decision
You know you need a cold room. The next question is immediate: positive or negative? Or both? This decision drives 30 to 40% of the investment cost and 90% of the day-to-day use. Here is the clear decision grid.
Chiller vs freezer: definitions
Positive cold room (chiller): a temperature range of +2 to +10 °C (typically +2 to +4 °C for meat, +4 to +6 °C for cheese, +6 to +8 °C for mixed catering). Keeps products fresh without freezing them. Accounts for 80% of food-sector needs.Negative cold room (freezer): a range of -18 to -25 °C (down to -30 °C as an option). Freezes for the long term. Accounts for 20% of needs, for long-term storage or products already frozen at purchase.
The choice depends on what you store and how long you keep it.
Table by product
| Product | Recommended temp. | Type | Duration |
|---|---|---|---|
| Fresh beef | +2 °C | Positive | 3-7 days |
| Dry-aged meat | +2 °C / 75% RH | Positive | 14-42 days |
| Charcuterie / cured meats | +4 °C | Positive | 7-14 days |
| Soft cheese | +6 °C / 85% RH | Positive | 10-21 days |
| Hard cheese | +8 °C / 75% RH | Positive | 30-90 days |
| Hard fruit (apples) | 0 °C / 90% RH | Positive | 6-9 months |
| Leafy vegetables | +1 °C / 95% RH | Positive | 5-14 days |
| Cut flowers | +4 °C / 90% RH | Positive | 5-10 days |
| Human vaccines | +2/+8 °C strict | Positive | Per marketing authorisation |
| Frozen meat | -18 °C | Negative | 6-12 months |
| Frozen ready meals | -18 °C | Negative | 6-18 months |
| Commercial ice cream | -22 °C | Negative | 6-12 months |
| Dressed game carcasses | -20 °C | Negative | 3-6 months |
| Frozen vegetables | -22 °C | Negative | 12-24 months |
If your products are all in the positive zone: a single positive room is enough. If you handle frozen goods only: a freezer. If you have both: dual-zone or two separate rooms.
Dual-zone or two separate rooms?
Advantages of dual-zone (combined):- Reduced footprint (-25 to -30%)
- Reduced investment (-15 to -20%)
- One delivery, one slab, one installation
- Removable partition: flexible split between zones
Advantages of separate rooms:
- Total isolation between zones (useful under strict food-safety constraints)
- Modular expansion (you can add a room without touching the other)
- Independent maintenance (one unit failing without risk to the other - although the dual-zone is also designed with two independent units)
Rule of thumb: below 30 m³ total, with a stable split (you know it will be 60% chiller + 40% freezer over the next 10 years), dual-zone is almost always the best choice. Above 30 m³, or if you anticipate having to expand one zone and not the other, separate rooms are more flexible.
Worked cases by trade
Craft butcher: 70% chiller (ageing, fresh products), 30% freezer (frozen storage for large orders, surplus stock). -> Dual-zone 20 m³ (14+6).Game-management / shooting syndicate: 50% chiller (hanging and ageing), 50% freezer (storage after dressing, off-season). -> Balanced dual-zone 20-30 m³.
80-cover restaurant: 80% chiller (daily fresh), 20% freezer (buffer frozen goods, ice cream). -> Dual-zone 15 m³ (12+3) or positive 15 m³ + small chest freezer.
Diversified market gardener: 100% chiller with 2 set-point zones (leafy vegetables at +1 °C, long-storage fruit at 0 °C). -> Dual-zone positive 20 m³.
Independent florist: 100% positive at +4-6 °C / 90% RH. -> Single positive 10 m³.
Event caterer: 60% chiller, 40% freezer. Seasonal. -> Dual-zone 25-30 m³, mobile trailer format to follow the contracts.
Catering kitchen, 500+ meals: 70% chiller, 30% freezer. -> Two separate rooms 20+10 m³ or dual-zone 30 m³.
Our bespoke quote sizes precisely to your case - and that is the difference between a room that fits and a room that is saturated every Thursday evening.
Frequently asked questions
Can a positive room be switched to negative?
Technically, the refrigeration unit on a positive room is sized for +2/+10 °C and will not hold stably below 0 °C. You cannot convert a chiller into a freezer simply by changing the set point.
Does a freezer room need defrosting?
Yes, automatically. Frost builds up on the evaporator and reduces heat-exchange efficiency. Our Dixell controller schedules an electric defrost every 6-12 hours depending on humidity, with no manual intervention. Allow 20-30 minutes per cycle, with no significant temperature loss in the product zone.