“Four trays” is a geometry statement, not a throughput figure. Two ovens that both take four trays can differ by a factor of two in what they deliver across a shift, because throughput depends on tray size, chamber volume, recovery time and how disciplined the loading is.
The geometry behind the number
In our four-tray convection models each aluminium tray measures 580 x 400 mm, and the 6 kW chamber measures 620 x 420 x 450 mm. Those dimensions are what decide how much product fits on a tray and how much air can move around it.
Forced air circulation is the working principle: the fan drives heated air across the chamber so that every shelf sees roughly the same temperature. That only holds if the trays are not packed edge to edge and the airflow path is not blocked. A tray loaded to its physical limit bakes unevenly regardless of how good the oven is.
A simple batch model
Write the shift down as a sequence, not as a daily total:
- Bake time for the product, for example 25 minutes
- Load and unload, realistically 4 to 6 minutes including closing and reopening the door
- Recovery back to set temperature, which is where element rating shows up
A conservative planning figure is one full four-tray batch every 30 to 35 minutes, which is roughly 1.7 to 2 batches per hour. At four trays per batch that is under 8 tray-loads per hour, and the honest output is what those trays actually hold for your product.
| Batch cycle | Batches per hour | Tray-loads per hour |
|---|---|---|
| 30 minutes | 2.0 | 8 |
| 35 minutes | approx. 1.7 | approx. 7 |
| 40 minutes | 1.5 | 6 |
Change the bake time and the whole table moves. This is why a capacity question cannot be answered from the tray count alone.
The bottleneck is usually outside the oven
In most bakeries we hear from, the oven is not the constraint. It is one of these:
- Proofing that cannot keep pace with the bake, so trays queue and the oven idles
- Loading discipline: one person loading a hot chamber with a door held open loses most of the recovery gain
- Cooling space, which decides how fast a tray can be cleared for the next batch
- One tray size for everything, when the product mix would be better served by two
Adding a deck does not fix any of those. Fixing them is usually cheaper than adding capacity.
Size for the peak hour, then check the week
Average daily output is a comfortable number that hides the problem. The oven has to clear your busiest hour, because that is the hour you lose orders in. Take the single busiest hour of the week, multiply by the batch model above, and see whether four trays clear it with a margin. If they do, the constraint is elsewhere. If they do not, that is when a second chamber earns its place, as described in our deck selection guide.
Practical tray notes
- Aluminium trays conduct well and recover quickly; they also distort if handled roughly when hot, so plan a landing area beside the oven
- Keep a consistent tray-to-product loading pattern so bake results stay repeatable between operators
- Trays are consumables over years of service: confirm the spare tray specification at order time rather than trying to match them later
The four-tray models in this range are the 4.5 kW 220-240 V oven and the 6 kW oven. If you send your busiest hour and your product mix through the quotation form, we will run the batch model against both.
