In the air heating pump system, how to select the buffer tank?

## Selection of buffer tank size

### 1. buffer water tank capacity = water required for system stabilization-actual system water.

First calculate the amount of water required for system stabilization, and set it to M1, then M1 = QT / (C △ T), where Q is the unit’s heating capacity unit is KW; T ​​is the defrost time, the unit is second, and C is the specific heat capacity of water , Take 4.187, △ T is the maximum allowable drop in water temperature, take 3 ℃.

The actual water volume of the system = the water capacity per meter of the floor heating pipe × the total length of the system pipe. If the end is a radiator, the water capacity of the radiator is also included.

For example, a brand of Beijing machine, 150 square meters, equipped with 7P low-temperature heat pump heater, heating capacity of 20KW, the system requires 20 × 4 × 60 ÷ (4.187 × 3) = 382 (L).

The actual water capacity of the system: Take the 20 pipes commonly used in the north, the water capacity of 20 pipes is about 0.314L per meter, and the actual water capacity of the system is about 235L according to about 5 meters of one square.

Therefore, the buffer tank capacity is required to be: 382L-235L = 147 (L), and 150L can be used in actual installation.

### Method 2: Mostly use 100L or 150L

If it is a new type of household heating and you do n’t know how to calculate it, you can use 100L or 150L, ​​that is, regardless of the size of the buffer tank, you can use 100L or 150L. Usually, these two models are always available, which is sufficient for most projects. Need it.