How do you select solar heater?

  Currently there are a variety of solar collectors on sale. These solar heaters can be classified vacuum type and panel type in term of type, combined or split in terms of construction structure or loaded type and non-loaded type in terms of manufacture workmanship. Most solar heater available on market is non-loaded type vacuum solar heater for domestic use. Pay attention to the following when you select solar heater:
   1. Among the thermal performance index, the higher the average daily efficiency is, the better; the lower the average thermal loss coefficient is, the better.
   2. The key part of domestic use heater is glass vacuum tube. Quality of vacuum tube will directly affect the performance of entire heater. Carefully examine the coated layer on tube at the time of purchase. The layer is termed solar power selective absorbing coat. The coat color may vary depending on different workmanship of manufacturers, but usually it is black, deep blue or deep gray. The coat should be color uniform, without film scratch, free from expansion scab or loose part, free from stain or burl. The bracket part to support glass tube inside should be installed right and tight.
   3. At the time of purchase, pay attention to tube spacing which is usually 70mm center to center of tube.
   4. The bracket incorporated into solar heater should be strong and rigid enough to ensure the efficient bearing capacity. At the areas with strong wind such as coastal areas, take care and examine whether the heater is designed to withstand heavy wind.
  5. At present, there are many types of the reflective plate used for solar collector: plain plate, curved plate and knurling aluminum plate. Pay attention and examine whether the reflective plate is designed to fully utilize heat absorptive surface of vacuum tube, whether it is exposed to sunlight to the maximum extent.
  6. Care should also be taken to consider number of permanent residents in a family so as to ascertain the water tank capacity. In general case, 40 liters of water a day is suitable for one person for all living purpose. In addition, please note that the tank capacity is calculated by summing up the capacity of each tube and inner container of tank. But in practice, the water below the tank outlet level cannot be released for daily use. The water customers can use is only the water contained above outlet and below overflow port. So, at the time of purchase, you are advised to consult the sales person whether the nominal capacity is total capacity or usable capacity and make clear the difference.
  7. Take care that the auxiliary heating device, if any, should be the product with electrical safety design.
  8. If optional part or fitting is required such as automatic water feeding device, temperature and water level gauge or electromagnetism valve, be precautious that it is reliable and may cause trouble due to complexity of parts although it appears attractive. And make sure of the lifespan and warranty terms.
  9. After you have purchased a heater, during its installation, take care that bracket is installed tightly with all bolts, nuts and fittings are securely tightened. Make sure that incoming water pipe and outgoing pipe are fixed at proper location and whether the heater itself is fixed securely. Check that the non-turn device is provided with incoming water pipe to avoid hot water backflow and flow into cool water pipe.
  10. After sale service is also important. You are advised to buy known brand product and good after sale service provider since solar heater is durable product and usually installed on rooftop. In case of fault, customers themselves cannot fix it. Therefore make sure the after sale service is ensured. Currently, warranty for an entire heater varies from 3 years to 5 years.
  11. Since solar heater is installed outdoor, vacuum tube is covered with dust after long time use, resulting in decline of heat absorbing efficiency. It is recommended that you get the vacuum tube cleaned regularly. It is necessary in snowy area especially after snowfall. In case that you cannot clean yourself due to building design, you are advised to consult the sales office whether regular cleaning is included in after sale service.
  Click to view technical feature and advantage of Zhongli Solar Heater.