DOES the rate of water condensation increase by decreasing temperature way further than dew point or the rate will be the same to that at the temperature slightly less than dewpoint for example is the rate of water condensation the same at 7 c and 24 c considerning dew point at 26 c? Is there any calculation for it a formula or so on?
As soon as condensation starts, some heat is released raising the temperature around. So, if the temperature is just below the due point, it may take some time for the air to cool down again and support further condensation, which will translate to a relatively low condensation rate. At lower temperatures, the heat exchange should be more robust and, therefore, the rate of condensation should increase.
The above process will depend a lot on the exact setup, but, everything else the same, with due point at $26C$, the condensation rate at $7C$ should be faster than at $24C$.
Calculating the exact condensation rate may be difficult, considering that it will depend on the air/vapor diffusion to and from the condensation area, possible heat exchange with liquids or solids around, etc., so, if there are some formulas, they are likely to be applicable to very specific setups.