Having a chiller does not mean you have glycol and vice-a-versa. Glycol is simply an additive you can add to the chiller fluid (which could be anything, but city water is great). With glycol you can run your chiller much colder than you can with water alone. We run only water, simply because the cleanup of glycol is messy if there is a leak and it operates steady at 48-52 degress F in Texas heat. As we expand and need to run more equipment off of it, we can add glycol to improve the cooling efficiency and lower the system temp. A chiller is simply an advanced version of what you are talking about, a reservoir, fans and the addition of a condenser. Our chiller has a 100 gal reservoir, twin small condensers and a small pump. We run a 1300 gal mash tun/still and a 130 gal still. While overkill, we can add a mash tun and 8 fermenters without having to change the chiller. While utilizing warm or hot water for other processes is definitely a positive, it only works if you are setup for near continuous operations. FYI, don't use distilled or R/O water in a closed loop, the lack of minerals increases the corrosivity.
