[h.mortezaee]

hi everyone i am simulating a borehole thermal storage , 4 u pipe that are connecting to each other in series form , each of them are 42 m deep in ground (ground is cylinder in 50 m diameter and 60 meter depth ) and water flows in them , i am trying to calculate how much heat is dumped and extracted from ground in a whole year , the inlet temperature is calculated by udf from the calculated outlet temp and the building load and heat pump cop , now my question is this : since the flow in pipes are converged within 5 times steps and i want to simulate a large domain of ground in a whole year is it okay to make the time step as big as 3600 secs ?
note that my building load is hourly .