I am using OpenStudio / EnergyPlus to model a residential building that utilize water source heat pumps with cooling tower and boiler, after running the simulation I received warnings related to range temperature and approach temperature being out of the model boundaries and suggesting that it will not impact the cooling tower performance. Since I am not an expert in EnergyPlus I wanted to check the effect of this warning so I plotted the inlet and outlet temperature for the supply side of the loop, I noticed that the inlet and outlet temperatures increase and fluctuate when the outside air wet bulb temperature reaches 66 F as you can see in the first and second screen shot. I am guessing this will impact the energy consumption because the WSHP performance decreases when the loop temperature increases, any Idea how to solve this?

I am using OpenStudio / EnergyPlus to model a residential building that utilize water source heat pumps with cooling tower and boiler, after running the simulation I received warnings related to range temperature and approach temperature being out of the model boundaries and suggesting that it will not impact the cooling tower performance. Since I am not an expert in EnergyPlus I wanted to check the effect of this warning so I plotted the inlet and outlet temperature for the supply side of the loop, I noticed that the inlet and outlet temperatures increase and fluctuate when the outside air wet bulb temperature reaches 66 F as you can see in the first and second screen shot. I am guessing this will impact the energy consumption because the WSHP performance decreases when the loop temperature increases, any Idea how to solve this?