Intergrating cooling tower loop into a hot water supply sytem.
I’ve been looking for a good way to reclaim the heat produced by my refrigeration equipment and use it in my domestic hot water production.
Currently I have a tank less heater (Navien) that provides heat to my restaurant through a radiant floor and hot water to two bathrooms, a few bar/kitchen prep sinks and a dishwasher. I also have air cooled refrigeration equipment that has been retrofitted with water jackets which reject their heat to a cooling tower. I put the system together hoping to at some point add piping that could reclaim heat from the cooling tower loop. Unfortunately, the demands of the kitchen activity and the lack of a storage tank, have led to a host of other problems. I’ve had a boiler failure and inconsistent hot water supply to the dishwasher. The dishwasher is about 30 linear piping feet away from the boiler.
My first thought was to add a recirculating system and a storage tank and that the storage tank would have a heat exchanger in the lower half of the tank. Here are my concerns:
1. Is the return temperature of the cooling tower loop (I have no real data on this but think return temperature is around 100 deg F) high enough to transfer heat in the storage tank. What if the storage tank temperature at the bottom of the tank is greater than the return temperature of the cooling tower loop.
2. What size tank do I need and where should it be placed. My thinking is that it should be near the dishwasher. The dishwasher is a low-temp unit (140 deg F) that uses less than two gallons per cycle. Cycles are about 90 seconds. I doubt we use the dishwasher more than 5 cycles in a row. Usually, it runs every five minutes at its peak. Is a 20 gallon tank enough to keep the boiler from short cycling?
3. I need a recirculating loop to provide instantaneous hot water at all the bar and kitchen equipment.
Anybody have a diagram of a system like this? Tank you
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