Chiller question for calgarian

[TVR]

Hi All:
I am newbie at this. I've set up 260 Custom Reef (170G + 90G Sump&Refug)
After everything got done, I just found out that I missed count one important tjhing: Chiller.
My question here is to those in calgary, do we really need a chiller to help our reef system in summer?
Some advice on this would be great.

Thanks in advance.

TVR