Boiler Size

[ParishBrewingCo]

I know this has been talked about before and I have searched previous threads without finding the info I'm looking for. I'm really interested in real-world experience more than anything.

I am familiar with the 1 BHP per BBL batch size rule. I have also heard from several equipment manufacturers that this size is too small for practical use, heating a HLT and boiling the kettle simultaneously. I would tend to agree that 1 BHP / BBL is undersized, but have no experience. We have purchased a 30bbl kettle. I would like to be able to heat hot water for subsequent batches while boiling in the kettle. I am between a 39 HP boiler up to a 47 HP. I would like to be able to get away with the smaller if I can due to price difference. If money were no object I would get the biggest boiler I could fit spacially, but we all know money drives a lot of these decisions.

Does anyone have actual, real-world experience with boiler size that allows them to boil and heat the HLT in the 15 bbl to 40 bbl range? What size boiler / kettle works in your experience?

Many thanks in advance and cheers!

Andrew

[BrewinLou]

We use a 28 bhp that provides 1.2 mbtu/hr on a 30 bbl system.

As with everything the answer you seek is dependent on other variables. Like how efficiently does your HLT, mash tun, and kettle heat up. Our kettle (bottom and side jackets) which is an older Specific Mech heats up faster than our HLT so we heat up water in it while we are mashing in, then transfer it to the HLT. The HLT has an internal calandria that just does not get the job done fast. But you get the point. I think you would be fine with a 39 bhp. I am in the market for a new boiler and the sales folks keep telling me a 50 would be best, but is a lot more expensive. We have managed with the 28 for well over a decade. Newer equipment will be a L of a lot more efficient then the old stuff as well. Good luck.

[lhall]

In my experience you need more than 1 hp per bbl. Our 40 bbl system called for a 60-75 hp system. We found a used 100 hp system and went with that. There shouldn't be a huge price difference between a 39 and 47 hp boiler, is there? The associated piping, condensate return, valves, blowdown seperators, etc, will be more than the boiler.

[ParishBrewingCo]

Linus - Price difference b/w the 39 and 47 is nearly 10k. That's not a show stopper, but enough to make me question what I really need. Would like that 10k for other things like towards another FV or just more safety cash.

Joel - are you brewing back-to-back like that or just one batch per day? I think your experience being able to boil effectively with a 28 hp is a good benchmark. Any boiler output not used for the kettle boil would go to the HLT to heat. Do you use all of that 28 hp to boil or are you throttling steam to the kettle at all?

BTW, one great way to heat water in a HLT is to use a seperate heat exchanger, brazed plate or something like that, to heat water that is filling the HLT directly with steam. Could even recirc the HLT water to the HX and back.

Thanks guys. This is very helpful info.