The full method, published. Nothing here is proprietary — it is thermodynamics and arithmetic, and you should be able to check any vendor’s recommendation with it, including ours.
Everything downstream is decided here, which is why a vendor who starts at model numbers has skipped the only step that mattered.
Characterize. Starting moisture, target finished moisture, physical structure, fat and sugar content, and how the product loads onto a tray. Fat loads the condenser differently. Sugar affects collapse temperature. Structure decides whether shelf contact can serve the product at all.
Batch weight. How many wet pounds enter per cycle. This is the number most buyers arrive with, and on its own it is not enough to size anything.
This is the step that converts a product into a machine requirement.
Dry solids = batch weight × (1 − starting moisture).
Finished weight = dry solids ÷ (1 − final moisture).
Water removed = batch weight − finished weight.
| Batch | Start | Final | Solids | Finished | Water removed |
|---|---|---|---|---|---|
| 1,000 lb | 90% | 2% | 100.0 lb | 102.0 lb | 898.0 lb |
| 1,000 lb | 80% | 2% | 200.0 lb | 204.1 lb | 795.9 lb |
| 1,000 lb | 60% | 2% | 400.0 lb | 408.2 lb | 591.8 lb |
Identical pallets. A 52% spread in the work required. This is why batch weight alone sizes nothing.
Water removed divided by target cycle hours. The word that carries the weight is sustained.
795.9 lb over 24 hours is 33.2 lb of water per hour — every hour, including hour fourteen when the condenser is already carrying most of a batch. A system that hits that rate in hour one and not in hour fourteen does not make the cycle.
This is the single number that should appear in any vendor’s written commitment about your product.
Condenser, refrigeration and vacuum sized together against the rate.
Condenser ice capacity must trap the vapour as fast as it sublimes, or chamber pressure rises and drying stalls. Refrigeration must hold the condenser cold under sustained load at your ambient, not at a favourable test condition. Vacuum must hold working pressure with a wet chamber, sized for the real vapour load.
Shelf area is the output of this step. It answers how much product fits, which is a different question from how fast the water leaves — and confusing the two is the most expensive mistake in this industry.
Start from the pounds of water a batch must remove, not the machine’s advertised capacity. Batch weight minus finished dry weight is the water load; divide by target cycle hours to get the sustained removal rate. That rate selects the machine.
Shelf area decides how much product fits. It does not decide how fast water leaves — condenser capacity, refrigeration under load and vacuum performance do. Two systems with identical shelf area can behave completely differently.
The pounds of water per hour a system can keep removing for the whole cycle, not a peak figure. It is the number that should appear in a vendor’s written commitment about your specific product.