In hotels and hospitals, the boiler is often determined by the peak of domestic hot water and heating in the morning. The wizard finds the hot water load from the number of rooms or beds and the hotel class, and deducts the usable volume of the boiler tank from the draw of peak hours. This is the most critical decision: if the boiler is not taken into account, the boiler will be 2-4 times larger. In a 5-star hotel with 300 rooms, the hot water load is 648 kW with a 22,000 L boiler and 1,507 kW without a boiler.
Which consumer wants how much heat?
| Consumer | Typical capacity | Heat or steam (engine) | Fluid |
|---|---|---|---|
| Hotel domestic hot water | 300 rooms, 5 stars, 600 guests, 22,000 L boiler | 648 kW (557,300 kcal/h); average day 136 kW | primer 80/60 °C · 3 bar g steam ≈ 1.09 t/h |
| Hospital domestic hot water | 300 beds, 150 L/bed·day | 312 kW (268,300 kcal/h) | 80/60 °C |
| Dormitory hot water | 1,000 students, 90 L/person·day | 578 kW (496,700 kcal/h) | 80/60 °C |
| Building heating (detailed) | Heating section of a 5-star hotel, Antalya | 355 kW (305,700 kcal/h) | 80/60 °C |
| Air handling unit fresh air coil | 60,000 m³/h, Ankara, without recycling | 643 kW (553,100 kcal/h); 257 kW with 60% recovery | 80/60 °C · steam 1–3 bar g |
| Indoor swimming pool | 25 × 12.5 m, 1.8 m, 28 °C | continuous 58.7 kW; first fill 145 kW in 72 hours | 80/60 °C, pool heat exchanger |
| Outdoor swimming pool | 312.5 m², night 15 °C, wind 2 m/s | uncovered 259 kW (830 W/m²); covered 70 kW | 80/60 °C |
| Laundry and kitchen | ≈ 500 kg/day laundry, 2 cooking boilers | Simultaneous ≈ 400 kg/h steam | steam 8–10 bar g |
Hot water with and without boiler: why does the boiler change 2 times?
In the boilerless (instant, plate heat exchanger) system, the heater has to meet the entire draw of the peak hour at that moment. The boiler, on the other hand, gives the water it accumulates in the morning and evening peaks; the boiler spends the day with a flatter load.
| Facility | Hot water daily (60 °C) | Load with boiler | Load without boiler | Difference |
|---|---|---|---|---|
| Hotel, 100 rooms, 3 stars | 22.400 L | 132 kW (4,490 L boiler) | 502 kW | 3.8 times |
| Hotel, 300 rooms, 5 stars | 110,000 L | 648 kW (22,000 L) | 1,507 kW | 2.3 times |
| Hospital, 300 beds | 45,000 L | 312 kW (7,590 L) | 471 kW | 1.5 ply |
| Dormitory, 1,000 students | 90,000 L | 578 kW (18,000 L) | 1,057 kW | 1.8 times |
| Collective shower, 20 heads | 3,150 L/session | 88 kW (4,200 L) | 352 kW | 4 floors |
The boiler recommendation also varies accordingly: 700,000 kcal/h with a magician boiler and 1,500,000 kcal/h without a boiler for only hot water in a 300-room hotel; For a dormitory for 1,000 people, it recommends 1,100,000 kcal/h against 600,000.
Example: 5-star holiday hotel with 300 rooms, Antalya
Hot water and heating are fed from the hot water boiler, laundry and kitchen are fed from the steam boiler.
| Equipment | Quantity | Capacity |
|---|---|---|
| Domestic hot water | 1 | 300 rooms × 2 guests, 250 staff, 1,500 meals/day, 22,000 L boiler |
| Building heating (detailed) | 1 | wall 8.000 m², window 3.000 m², roof and flooring 3.000 m² each, TS 825 zone I, 30.000 m³/h fresh air (60% recovery), 22 °C, Antalya +3 °C |
| Washing-wringing machine | 2 | 30 kg |
| Steam drying drum | 2 | 37 kg |
| Ironing roller | 1 | Ø500 mm, 2,5 m |
| Steam cooking boiler | 2 | 150 L |
| Dishwasher (steam) | 1 | Industrial |
- Hot water side: domestic hot water 648 + heating 355 = 1,004 kW; 1,159 kW = 996,800 kcal/h with 5% line loss and 10% growth share
- Hot water boiler recommendation: 1,000,000 kcal/h, flow 80 °C, ≈ 51 m³/h circulation, ≈ 131 Sm³/h natural gas at full load
- If the same hotel were without a boiler: 1,900,000 kcal/h (≈ 1.9 times)
- Steam side: simultaneous 399 kg/h, 461 kg/h with shares → 0.5 t/h steam boiler, ≥ 9.5 bar g (10 bar class); ironing roller 8 bar g
Hotel and hospital boiler: type, temperature and pressure
The domestic hot water, heating, fresh air coil and basin are supplied from a single hot water boiler circuit (80/60 °C); domestic water is prepared by boiler or plate heat exchanger and the tank for legionella is kept at least 60 °C. Laundry, steam kitchen and sterilization require steam: Package type or hybrid type steam boiler with a requirement of 0.5–1.5 t/h, 8–10 bar g. Heating and hot water can also be supplied from the same steam boiler as the steam-water exchanger: 1 kW ≈ 1.69 kg/h steam at 3 bar g. In the all-inclusive resort with 1,000 rooms (indoor pool, ≈ 2 t/h laundry), the magician recommends a 2,500,000 kcal/h hot water boiler and a 1.5 t/h steam boiler. For laundry details, see the laundry steam requirement page.
How to do the calculation?
On the design day, 155 L is charged per guest in a 5-star hotel and 63 L in a 1-star hotel (2.25 × Spanish CTE averages). Peak hour in the hotel lasts 1/7 of daily consumption and 4 hours, boiler is 1/5 of daily consumption and 75% usable (ASHRAE/ASPE); peak rate in hospital is 30/160 and 2 hours, in dormitory 0.19 and 2 hours. Measurements show that the actual average consumption is half of the design value (164 L/room vs. 75 in ≈ 800-room hotel in London; CIBSE Journal), but the boiler is selected according to the peak of the design day, not the average. It is assumed that the morning hot water peak coincides with the heating peak; the first filling of the pool is the campaign load, not added to the winter peak.
Use the wizard at the top of the page to calculate with your own plant; Boiler Capacity Calculator for all sectors.
The results of the wizard are predictions to give a preliminary idea; boiler selection should be finalized by on-site exploration and engineering calculation. Contact us for free pre-engineering support.