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Saturday, December 18, 2010

Hot Water

In my last post, I said I knew right away that I'd need a good source of hot water on demand.  If I had to rely on a single direct fire 55g HLT to heat strike and sparge water for 4 different 1bbl batches, as well as all the water needed for cleaning, ... well, let's just say it's not a good idea. It would take way too long. I'm not sure of the exact time involved, and of course alot depends on the btus of your burner, but I seem to recall reading some brewers complaining about the time involved to heat water via direct fire for even a single 1bbl batch.

Thankfully, there's a great solution involving tankless water heaters. More and more small breweries are using them as their hot water source. With a commercial grade tankless water heater, you can add water to your HLT at 160 to 185F and tweak the temperature more precisely from there.


Assuming approximately 60F ground water, the Rinnai R94 has a flow rate of 5.6gpm at 120F, 3.5gpm at 160F, 2.7gpm at 185F.  To get above 140F, you'd also need to purchase the remote control, which has two setpoints (160F and 185F), with an accuracy of +/-2F of setpoint.  It is possible to use 2 or more units in a chain, and you need a water source with at least 30psi.

More expensive, the Noritz NC380's output at 160F is 6.2gpm (flow rate chart here).

So, depending on the temperature of your ground water and the model of tankless water heater chosen, you could fill up a 55g HLT with 160F water in ten to fifteen minutes, using the burner under the HLT to tweak the temperature more precisely, and recirculating the water in the HLT to help prevent temperature stratification.  Well, that's the idea anyway!  :-)

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