Sizing method
- Daily demandLitres per day at 60°C from rooms, beds, kitchens, laundry and other users.
- Peak demandThe busiest 1–2 hours, often 30–40% of the daily total in hotels.
- Temperature classCold water about 27°C to 60°C = 33°C rise, so Class II heat pump (COP 3.3–5.0).
- Heat pump capacitykW = daily litres × 33 ÷ 860 ÷ operating hours (typically 12–16 h).
- Calorifier volumeEnough storage to cover the peak hour after allowing for heat pump recovery.
Worked example: 150-room hotel
- 150 rooms × 1.8 guests × 60 L = 16,200 L/day at 60°C.
- Heat required: 16,200 × 33 ÷ 860 ≈ 622 kWh per day.
- Over 14 operating hours: 622 ÷ 14 ≈ 44 kW, so one PHM 15 (about 45 kW at Class II) or two PHM 7.5 units for redundancy (about 45 kW together).
- Peak hour about 35% of daily use = 5,700 L. With recovery during the peak, a PACHM1000 (4,540 L) to PACHM1200 (5,448 L) calorifier is a sensible starting point.
- Electricity: about 622 ÷ 4 ≈ 155 kWh/day instead of 622 kWh/day with electric heating.
This example is a guide only. Actual design depends on occupancy, kitchens, laundry, pipe losses and local codes. Pecol provides a full design calculation free with each proposal.
Model and calorifier tables
| Model | Compressor | Class I output (BTU/h, COP 5) | Class II (COP 4) | Class III (COP 3) | Dimensions L×W×H (mm) | Weight |
|---|---|---|---|---|---|---|
| PHM 3 | 2.25 kW / 3 HP | 38,385 | 30,708 | 23,031 | 1067 × 890 × 483 | 160 kg |
| PHM 5 | 3.75 kW / 5 HP | 63,975 | 51,180 | 38,385 | 1220 × 1169 × 724 | 210 kg |
| PHM 7.5 | 5.62 kW / 7.5 HP | 95,878 | 76,702 | 57,526 | 1220 × 1169 × 724 | 260 kg |
| PHM 10 | 7.50 kW / 10 HP | 127,950 | 102,360 | 76,770 | 1372 × 1169 × 800 | 300 kg |
| PHM 15 | 11.25 kW / 15 HP | 191,925 | 153,540 | 115,155 | 1372 × 1169 × 800 | 330 kg |
| PHM 20 | 15.0 kW / 20 HP | 255,900 | 204,720 | 153,540 | 1372 × 1169 × 800 | 400 kg |
Special capacities can be made to order; the range extends to PHM 40 (30 kW compressor). 1 kW = 3,412 BTU/h, so a PHM 15 delivers about 45 kW of heat at Class II.
| Calorifier | Capacity L (gal) | Outer dimension (mm) | Weight empty / full (kg) |
|---|---|---|---|
| PACHM100 | 454 (100) | Ø700 × 1700 | 142 / 597 |
| PACHM200 | 908 (200) | Ø1000 × 1800 | 256 / 1,165 |
| PACHM300 | 1,362 (300) | Ø1000 × 2500 | 331 / 1,695 |
| PACHM400 | 1,816 (400) | Ø1400 × 1900 | 408 / 2,226 |
| PACHM500 | 2,270 (500) | Ø1400 × 2300 | 464 / 2,736 |
| PACHM600 | 2,724 (600) | Ø1400 × 2700 | 531 / 3,258 |
| PACHM800 | 3,632 (800) | Ø1700 × 2400 | 649 / 4,285 |
| PACHM1000 | 4,540 (1,000) | Ø1700 × 2800 | 753 / 5,298 |
| PACHM1500 | 6,810 (1,500) | Ø2000 × 3000 | 1,270 / 8,086 |
| PACHM2000 | 9,080 (2,000) | Ø2000 × 3800 | 1,951 / 11,042 |
Intermediate sizes (700, 900, 1,200 gal) and custom dimensions available.
Cooling towers and heat recovery
Buildings with water-cooled chillers reject heat through cooling towers. A heat pump or heat recovery system can capture part of that heat for hot water, reducing both water heating and cooling tower load. Pecol also supports water-to-water heat pump systems using chiller condenser water as the heat source.
Frequently asked questions
How do I size a heat pump for a hospital?
Use beds, staff, kitchen and laundry demand to find daily litres at 60°C, then apply the same method with extra redundancy. Pecol will calculate it with your consultant.
Is it better to have one big heat pump or several smaller ones?
Several units give redundancy and better part-load efficiency, which is preferred for hotels and hospitals.