Domestic Hot Water & Dishwasher Types Explained

Domestic Hot Water & Dishwasher Types Explained

Undercounter Dishwashers
A compact, bench-height machine you slide a rack into from the top. Typically under a 34″ countertop, used in bars, small cafés, and satellite kitchens. Processes 20–30 racks/hr with 2–3 minute cycles and uses 0.6–2.0 gallons per cycle.

Door-Type Dishwashers
A tall, freestanding unit with a hood/door you pull down over each rack. Common in full-service kitchens. Handles 50–60 racks/hr with ~1 minute cycles, using 1.0–1.8 gallons per rack.

Rack Conveyor Dishwashers
A belt-driven tunnel: racks move through wash and rinse zones on a conveyor. Found in hotels, cafeterias, banquet halls. Continuous flow at 100–200 racks/hr, each rack spends ~1–2 minutes inside, using 0.6–1.0 gallons per rack.

Flight (Belt-Washer) Dishwashers
A stripping belt carries dishes (no racks) through wash, rinse (and sometimes dry) zones. Used in universities, hospitals, large institutions. Processes 10,000+ dishes/hr with fresh water usage of 50–70 GPH.

ASHRAE Rinse-Flow Data (Table 15, 2023 Handbook)
Type
Low-Temp
GPM
Low-Temp
GPH
High-Temp
GPM
High-Temp
GPH
Undercounter
2.1-4.4
22-65
3.2-6.6
19-51
Door-Type
1.9-5.1
33-68
2.7-7.1
28-92
Rack Conveyer
1.3-4.8
78-290
0.7-4.8
44-290
Flight Conveyer
-
-
1.0-6.0
57-360

Usage & Throughput Table
Type
GPC (gal)
Cycle Time
Cycles/hr
Avg. GPH
Ang. GPM
Undercounter
0.6-2.0
2-3 min
20-30
20-40
0.5-0.7
Door-Type
1.0-1.8
~1 min
50-60
70-110
1.2-1.8
Rack Conveyer
0.6-1.0/rack
continuous
100-200
100-200
2-3
Flight Conveyer
N/A
continuous
10,000+ dishes/hr
50-70
1-2