Step 1: Confirm it's a genuine freeze dryer.
A true freeze dryer must include a low-temperature cold trap, vacuum pump, and sealed chamber. The cold trap temperature should ideally be ≤-45°C, and vacuum level preferably ≤10 Pa. Devices without a vacuum pump that rely solely on air circulation and heat drying are not real freeze dryers.
Step 2: Select capacity based on household usage.
For 1–2 people using occasionally, choose models with a batch capacity of up to 1 kg. For 3–4 people or making pet treats, opt for 1.5–2.5 kg per batch. Consider larger models only if you plan to produce in bulk.
Step 3: Evaluate materials, pump type, and after-sales service.
Prioritize food-grade 304 stainless steel for inner tanks and trays, and use food-safe silicone gaskets. Oil-lubricated pumps offer greater stability; oil-free pumps are suitable only for light use. Also, check consumable costs and after-sales support.
Pitfall warnings:
Avoid "air freezing" or "hot-air dehydration" devices—these are fake freeze dryers.
Don't blindly go for high-capacity models; running at full load may result in incomplete freezing and reduced efficiency.
Beware of exaggerated specifications, low-quality pumps, easily aged seals, and poor after-sales service.