(一) The performance of the air source heat pump unit should comply with the relevant national standards*, such as: This section is taken from the "warm regulations" (GB50736-2012), "2009 technical measures, HVAC" (including energy-saving articles)
1. With advanced and reliable defrost control, the total defrost time should not exceed 20% of the operating cycle time;
2. The unit performance coefficient (COP) in winter design conditions, the hot and cold air blower is not less than 18, and the hot and cold water unit should not be less than 2.0;
3. The following items should be noted when using air source heat pump units in cold areas:
1) For outdoor calculations where the dry bulb temperature is below -10 °C, a low temperature air source heat pump unit should be used;
2) When the outdoor temperature is lower than the air source heat pump equilibrium point temperature (ie, the air source heat pump heat supply is equal to the building heat consumption), an auxiliary heat source should be set.
(二) The setting of the air source heat pump unit or the outdoor unit of the air-cooled refrigeration unit shall comply with the following provisions:
1. The airflow speed at the air inlet of the unit should be controlled at 1.5m/s~-2.0m/s, and the exhaust speed of the air outlet should not be less than 7m/s; the distance between the air inlet and outlet should be as large as possible;
2. Units with low noise and low vibration should be preferred; care should be taken to prevent the impact of noise on the environment, and noise reduction measures should be taken when necessary;
3. In order to prevent backflow and poor unit operation, the clearance between units and between the unit and the wall should meet the requirements of equipment manufacturers. If there is no data, please refer to the following requirements: the distance between the air inlet side of the unit and the side wall of the building is ≥15m, the distance between the unit control cabinet surface and the building side wall surface is ≥1.2m, the head clearance of the unit is ≥15m, and the two units are ≥2m. ≥3m between the inlet side of the two units; only one wall height is allowed to be higher than the unit height around the unit;
4. The bracket for installing the unit should be stable and there is no safety hazard; the setting of the unit should meet the requirements for easy cleaning of the heat exchanger of the outdoor unit;
5. The height of the heat pump foundation should generally be greater than 300m. When it is placed in places where there may be snow, the foundation height needs to be increased;
(三) When calculating the heat load of the household supply system, it is advisable to add factors such as living habits, architectural features, intermittent operation and other factors.
(四) The household air source heat pump heating system shall be provided with an independent power supply circuit, and the defrosting water shall be discharged in a concentrated manner.
(五) The supply and return water temperature of the household heating system and the circulating water pump shall be matched with the end heat dissipating equipment.
(六)The household heating system shall have anti-freeze protection, room temperature control function, and exhaust and drain devices shall be provided.