# How to calculate the heat input of SPRING panels?

Edited

The caloric contribution of the DualSun SPRING panels** on a solar tank or swimming pool is calculated using the formula for the amount of heat**.

The input data are:

The temperature difference between the inlet and the outlet of the panels

The volume of fluid transported through the panels

The heat capacity of this same fluid (i.e. the amount of thermal energy it can transport)

The formula for the amount of heat is as follows Q=mCpT

Q in J

m mass of the fluid in kg (i.e.m=Dhuse),

Cpmass heat capacity of the fluid in J.kg-1.K-1

T = T°panel output-T°panel entry

Cp 40% glycol water = 3.5 J.kg-1.K-1

Cp salt or chlorinated water = 4 J.kg-1.K-1

To learn more about the actual performance of our panels, you can consult our blog.