A practical starting range for small laundries, hostels, guest houses, restaurants, institutional messes and businesses that do not need a full industrial plant.
A simple small laundry can begin with a heavy-duty washer, separate hydro extractor and ironing/finishing station. A tumble dryer can be added where rapid turnaround is required or outdoor drying is impractical.

A 7 kg machine is useful where batches are small and varied. 15–20 kg models reduce the number of cycles when daily loads are higher. The correct capacity depends on actual dry-weight load per batch, not simply the number of garments. Bulky towels and bedding consume drum volume differently from lighter uniforms or clothing.
A separate hydro extractor removes a significant portion of retained water after washing, which can shorten subsequent drying time and help reduce dependence on long line-drying periods. The extractor should be selected so that workflow capacity does not become a bottleneck between washing and drying.