Mitsubishi Electric PAC-IF012B, Техническое руководство

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Pressure loss (kPa)
0
5
10
15
20
25
30
35
40
45
50
5 10 15 20 25 30
Flow rate (L/min)
What is ATW heat pump? 1
1-1. Compare with conventional fossil fuel boiler
• Heat pumps produce water at 30°C – 60°C
• Ideal for under
fl oor heating
• Average under fl oor heating circuit 35°C
• Fossil fuel boilers heat water to 80°C
• Flow temp in rads design temp. approx. 70°C
• Heat pumps can still be used with radiators
• Larger surface area to emit heat from lower temp water
1-2. Points to notice
1-2-1. Design (Radiator sizing)
• Careful consideration must be given to appropriate application of this technology to maximise its bene fi ts – it will not suit all
properties, especially many retro fi ts
• Heat emitters may need to be larger
• Lower
fl ow temperatures maximise COP
• Various regulations apply to the design and installation of such systems
• Because the
fl ow temp. of heat pump is low compare to fossil fuel boiler, the temperature difference between the primary ( fl ow
water) and secondary (room air) becomes little, it makes the heat emission little.
To emit the same amount of heat energy, it is needed to select the radiator that has a larger surface area.
Be especially careful of the surface area when you design the radiator.
1-2-2. Defrost
Note: Occasionally, vapor that is made by the defrost operation may seem as if smoke come up from the outdoor unit.
1-2-3. Water Pressure loss (for packaged type outdoor unit)
• Water pressure lose of the heat exchangers are as follows.
Be aware of the in fl uence when you design total piping system.
Hex for PUHZ-W50VHA (ACH30-30Plates)
Secondary (Water - side)
Flow rate (L/min) 5 10 15 20 25 30
Pressure Loss (kPa) 1.7 6.0 12.4 20.9 31.4 43.8