Water on demand

[mreilly9090]

any experience with a rinnai water on demand system that would replace a hot liquor tank for a 7 bbl direct fire brew house. Space is a factor and premier mentioned this option. Obviously its more wasteful and we don't like that option very much but water is going to be a flat fee. We're not charged by the gallon? They would also double as the kitchen's hot water as we will be running a 110 seat brew pub. Thanks in advance.

[Starcat]

Kitchen

There are a lot of people using these types of units and they may have some merit for smaller systems.
I would not advise sharing this type of machine with the Kitchen as that demand for hot water can be quite high. This will increase the operating cycles on the machine significantly, which on a gas fired configuration is risky. All gas fired ignition systems have multiple failure points and they will fail. Its just a question of when, and whats required to get it back up. As thus, redundancy of systems or spare parts must be considered.
If you go with that type of unit I'd suggest having yours as dedicated if you want hot water when you need it.

[TGTimm]

Be sure to look at your water analysis (you do have one, right?). If you have high hardness, particularly carbonate hardness (temporary hardness), you'll be acid-washing your heater very frequently, depending on use. Home on-demand heaters in my area start to loose efficiency after a few weeks, and need acid-washing every few months to work at all.

[NigeltheBold]

I agree that it's not a great idea to share the heater with the kitchen. If someone in the kitchen needs hot water at the same time that you need it to clean or fill a tank or mash in, the pressure could be pretty low. Our building has pretty low pressure to begin with. If someone turns on the hot water behind the bar and I need it in the brewery, I basically have to wait until they are finished using it. We have a Rinnai tankless heater AND a hot liquor tank. The idea was that we could fill the HLT with hot water to reduce heating time for strike and sparge water. It works well for that. The absolute highest we can set the water heater is 140 degrees F, and that's with the extra "switch" turned on inside the unit that allows you to do so. I'm not sure how hot other models go...

My opinion? Get a tankless water heater (maybe even one for the brewery and one for the kitchen) AND an HLT. Depending on your building's water pressure, you may not want to run a hot water line to your HLT, but it's nice to have hot water in the brewery for cleaning, etc. (obviously).