Under normal circumstances, if the air source heat pump is working outdoors in an ambient temperature of less than -5℃, if the power outage lasts for more than 4 hours, the heat exchanger may freeze and crack, causing losses. Therefore, compared with the above two methods of thawing the air source heat pump water system after freezing, the best method is to take anti-freeze measures.
1. Do a good job of pipe insulation.
The pipe insulation of the air source heat pump is 30mm thick in B1 grade outdoors, and 20mm thick in US B1 grade indoors. The outer layer of outdoor insulation is aluminum foil, and the outer layer of indoor insulation is tied with white cable ties. Pipe valves and bends must be well insulated, and no exposed points on the pipe should appear.
When connecting the pipe sleeves of the air source heat pump, insulation glue must be applied to the seams of the pipe sleeves. The longitudinal seams of the pipe sleeves are required to be staggered, and the longitudinal seams are usually not allowed to go vertically downward. The joints between the pipe sleeves are sealed with glue. When the pipe sleeve is connected to the heat pump and the wall, thermal insulation glue must be applied to the end face of the pipe sleeve and the end face of the main unit and the wall.
2. Keep the system powered on
Even if there is no heating demand during the day or in a short period of time, the air source heat pump cannot be shut down. The air source heat pump uses water as the intermediate medium to transfer heat. Therefore, after the system is powered off, the water temperature will drop rapidly, which is very easy to cause ice and freeze the shell and tube. When the customer does not need heating indoors in a short period of time, it is recommended to lower the set temperature or perform interlock control protection of the circulating water pump to ensure that the water system will not freeze and add antifreeze. In areas with low ambient temperatures in winter, it is recommended to add antifreeze at -15℃ and -25℃ in the pipeline to prevent freezing caused by low ambient temperatures and temporary power outages. In the selection of antifreeze, ethanol alcohol is not recommended because ethanol is highly volatile. When the exhaust valve is installed in a relatively closed space, it is very easy to cause the ethanol content in the space to exceed the standard. If there is an open flame, it may cause a fire. It is forbidden to use antifreeze mixed with methanol, which is corrosive to pipelines and will cause great damage to valves, pipe fittings, water pumps, and air source heat exchangers.
3. Drain all water when shutting down for a long time
If the customer is away for a long time, the air source heat pump will incur considerable costs even if it is running at a low temperature. In this case, all the water in the water system can be drained to prevent the air source heat pump from freezing and the power supply can be cut off. When the customer returns to the room and needs to restart the heat pump heating, the air source heat pump system should be fully inspected to ensure that there is no fault.
Under normal circumstances, if the air source heat pump is working outdoors in an ambient temperature of less than -5℃, if the power outage lasts for more than 4 hours, the heat exchanger may freeze and crack, causing losses. Therefore, compared with the above two methods of thawing the air source heat pump water system after freezing, the best method is to take anti-freeze measures.
1. Do a good job of pipe insulation.
The pipe insulation of the air source heat pump is 30mm thick in B1 grade outdoors, and 20mm thick in US B1 grade indoors. The outer layer of outdoor insulation is aluminum foil, and the outer layer of indoor insulation is tied with white cable ties. Pipe valves and bends must be well insulated, and no exposed points on the pipe should appear.
When connecting the pipe sleeves of the air source heat pump, insulation glue must be applied to the seams of the pipe sleeves. The longitudinal seams of the pipe sleeves are required to be staggered, and the longitudinal seams are usually not allowed to go vertically downward. The joints between the pipe sleeves are sealed with glue. When the pipe sleeve is connected to the heat pump and the wall, thermal insulation glue must be applied to the end face of the pipe sleeve and the end face of the main unit and the wall.
2. Keep the system powered on
Even if there is no heating demand during the day or in a short period of time, the air source heat pump cannot be shut down. The air source heat pump uses water as the intermediate medium to transfer heat. Therefore, after the system is powered off, the water temperature will drop rapidly, which is very easy to cause ice and freeze the shell and tube. When the customer does not need heating indoors in a short period of time, it is recommended to lower the set temperature or perform interlock control protection of the circulating water pump to ensure that the water system will not freeze and add antifreeze. In areas with low ambient temperatures in winter, it is recommended to add antifreeze at -15℃ and -25℃ in the pipeline to prevent freezing caused by low ambient temperatures and temporary power outages. In the selection of antifreeze, ethanol alcohol is not recommended because ethanol is highly volatile. When the exhaust valve is installed in a relatively closed space, it is very easy to cause the ethanol content in the space to exceed the standard. If there is an open flame, it may cause a fire. It is forbidden to use antifreeze mixed with methanol, which is corrosive to pipelines and will cause great damage to valves, pipe fittings, water pumps, and air source heat exchangers.
3. Drain all water when shutting down for a long time
If the customer is away for a long time, the air source heat pump will incur considerable costs even if it is running at a low temperature. In this case, all the water in the water system can be drained to prevent the air source heat pump from freezing and the power supply can be cut off. When the customer returns to the room and needs to restart the heat pump heating, the air source heat pump system should be fully inspected to ensure that there is no fault.
