In a split solar water heater or a large and medium-sized heating system, people will be confused about what kind of solar water tank to use. It is unclear what is the difference between a pressurized water tank and a non-pressure water tank, and which one is more suitable for oneself. For example, figure out how to choose the solar water tank that suits you.
1. Pressure solar water tank
Pressurized solar water tank is for hot water storage of solar heating systems, electric power or gas heating systems. Its capacity is from 150L to 2000L with working pressure 0.6Mpa, and the test pressure 0.9Mpa.
As per different situations,different numbers of heat exchangers (copper coils) can be add inside tank. Some examples are below.
(1) In places having good water quality, you can use tank without copper coils;
(2) For majority of solar water heating systems, it is better to use tank with 1 coil;
(3) The two coil water tanks are mainly used for floor heating system or system with auxiliary heating power like gas heater, boiler etc.
2. Unpressure solar water tank
Unpressurized tank is for hot water storage of large and medium-sized solar central heating system, solar floor heating, electric or gas heating system, with capacity from 1000L to 15000L.
Depending on its application, different numbers of heat exchangers (coils) can be set inside the tank
(1) Tank without coils is just for hot water storage or system with SFE non pressure vacuum tube solar collector;
(2) Tank with 1 coil is for system with SFB heat pipe solar collector;
(3) In a medium-sized (1000L-3000L) solar heating project, 1 more coil can be set to provide pressurized hot water;
(4) Tank with 2 or 3 coils is for solar floor heating system or systems having gas heater as backup power;
(5) If there is no heat exchanger (coil) inside the tank, flat plate heat exchangers can also be used for solar heating systems.
3. Generally speaking, in a small split solar water heater system, a pressurized solar water tank is recommended.
Large and medium-sized solar heating systems, such as engineering projects, hotels, schools, factories and other systems that require a lot of hot water, it is recommended to use non-pressure solar water tanks.
In the case of a Madagascar customer, her hotel needs a 3000L solar heating system to supply hot water to customers. She hopes to use two water tanks. We offer the following solutions:
(1) Two 1500L pressurized water tanks are adopted, and the cost of the pressurized water tank is high. The advantage is that the hot water supply pressure is not considered. The pressurized water tank can achieve a maximum of 2000L, and the cost of using two water tanks is much higher than that of using one water tank. We don't recommend this option very much, it doesn't apply to large systems, and the cost is much higher.
(2) Using two 1500L non-pressure water tanks, the solar collector first heats tank1 and then heats tank2. Tank1 is used as a hot water supply tank. Its advantage is that tank1 can supply hot water at any time to meet customer's requirements.
If you can provide customers with high-pressure hot water, customers will be satisfied with the hotel service and facilities because they enjoy a good experience of comfortable hot water.
It will cost less than a pressurized water tank.
(3) With 3000L double coil non-pressure water tank, this design can bring the same pressure of hot water to the pressure tank. But the total cost is much lower than the pressure tank. If you use a pump to supply hot water, the hot water pressure will be higher than the pressure tank, which will give the customer a better experience. Has a good effect. This is also the solution we recommend and the one with the lowest cost. Most customers use this solution.
In general, when the tank volume is greater than 1000L, we recommend using a non-pressured tank. When the volume of the tank is less than 1000L, you can choose a pressurized water tank. This is mainly due to the pressure and cost of hot water supply. Mainly depends on your needs to choose.