Project Overview
- Project Name: Villa
- Total construction area: 320 m2
- Heating area: 280 m2
- Room type: residential building
- Wall: the outer wall is 37 CM, and the outer wall is insulated
- Functional requirements: heating in winter and cooling in summer
- Heat source equipment: ultra-low temperature air source heat pump
- Terminal system equipment: floor heating coil and fan coil unit
Design Ideas
The residence is located in the outer suburbs, there is no municipal heating, gas pipeline, coal-fired heating will pollute the surrounding environment, and affect the beauty of the house, easy to have dust, and inconvenient to use. The customer belongs to a high-income private business owner. The temperature requirement is above 25℃, and summer is 24℃. The residential area includes master room, two guest rooms, elderly room, two children’s rooms, two study rooms, two living rooms and one dining room.
According to the needs of each room in the villa, the heat source of this scheme adopts an air source heat pump, and the matching heating terminal has floor heating and fan coils. There are elderly people at home, and floor heating is the best choice. Because the heat of floor heating starts from the bottom up, it first heats the feet of the person, which is most in line with the theory of keeping feet warm and keeping cool in Chinese medicine. In addition, the air source heat pump floor heating and fan coil units can be controlled by households and rooms. There are many rooms in the villa, and independent thermostats can be set in each room. For rooms that you often live in, you can set the most comfortable temperature. For idle rooms , You can lower the temperature and reduce unnecessary waste.
Calculation Parameters
1. Calculation parameters of outdoor design in winter
| Seasonal parameters | Average minimum temperature | Extremely cold minimum temperature | Relative humidity% | Outdoor average wind speed (m/s) | Atmospheric pressure KPa |
| winter | -7 | -15 | 55 | 1.5 | 102 |
2. Calculation parameters of outdoor design in summer
| Seasonal parameters | Average minimum temperature | maximum temperature | Relative humidity% | Outdoor average wind speed (m/s) | Atmospheric pressure KPa |
| summer | 27 | 34 | 55 | 1.5 | 102 |
3. Indoor calculation parameters
| parameter | Indoor temperature | Relative humidity % | air velocity（m/s) |
| winter | 25±2 | 45 | ≤0.3 |
| summer | 22±2 | 45 | ≤0.3 |
Heat load calculation of heating
According to the Design Manual of Heating, Ventilation and Air Conditioning, the household heating heat load consists of the basic heat consumption of the outer envelope and the inner envelope, its additional heat consumption and cold air infiltration heat consumption. According to the outdoor temperature parameters in winter, the unit heat load index is designed to be 100W/㎡.
Heat load determination:
Q1=280×100=28kw
Combined with the characteristics of buildings and climatic conditions, the output heat of the ultra-low temperature air source heat pump should be ≥38kw under the working condition of -7℃.
System principle
Air source heat pump absorbs a large amount of low-temperature heat energy in the air through very little electric energy, which is compressed by a compressor and changed into high-temperature heat energy, which is transferred into water to heat the water, and the hot water is used for heating through a floor heating pipe.
The air source heat pump compresses the recovered low-pressure refrigerant into high-temperature and high-pressure gas through the heat pump unit, and then the cooled refrigerant becomes liquid under the continuous action of pressure, and then enters the evaporator after passing through the expansion valve. Because the pressure of the evaporator drops suddenly, the liquid refrigerant evaporates rapidly and becomes gaseous here, and absorbs a lot of heat. Under the action of the fan, a large amount of air flows through the outer surface of the evaporator, the energy in the air is absorbed by the evaporator, the air temperature drops rapidly, and it turns into cold air and is discharged into the fan coil to provide refrigeration service.
Cold and warm power is free air heat energy, which only needs to consume a little power when absorbing air heat energy, and the thermal efficiency is as high as 270%-430%. Compared with traditional energy sources, it not only has high thermal efficiency, but also avoids the pollutant emission caused by the use of chemical energy, thus achieving the dual effects of energy conservation and environmental protection.
By adopting the physical working method, no toxic gas will be produced in the whole heating process, and in this process, the water-electricity separation will not produce leakage accidents and will not be affected by the environment. Whether it is rainy days or cold winter, the air-source heat pump unit is fully intelligently controlled and automatically operated unattended, and the maximum water temperature can reach 60℃.
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