Back up generator for glycol chiller ?

[RyanR]

Does anyone use a back up generator for there glycol chiller? how big? Natural gas? The company I talked to said I would need one in the 24 kwh size range.

Thanks
Ryan

[gitchegumee]

Nearly every brewery I install overseas has a backup generator. Not only for chiller, but for everything. Why stop at the chiller? What happens when power goes out during malt milling, or mash or boil or transfer or filter? Besides, you'll need at least power for your control/solenoids to effect chilling. As for size, they are measured in kW or KVA (power), not kWh (energy), and the size will obviously depend on your chiller size. Fuel depends on your specific pricing and availability. If you have unreliable power, then you should consider a generator. Do a cost analysis to make your decision a sound one. Cheers & good luck!

[Scott M]

I agree completely with Phillip.

Your standby generator will be sized to handle the starting current of the compressor and the rest of the load of the brewery if you choose to go that route. If running the chiller is your only concern, and I think Phillip explained quite well why it shouldn't be; the capacity of the generator set would only have to satisfy the starting current and load of the chiller system and controls.

It will mean that the electrical wiring for the chiller, valves and control system will be dedicated to the generator transfer switch, may require some re-wiring and another distribution box, the generator set should have an automatic start and transfer feature, and if you are not a 24 hour facility be sure to tie in an auto dialer to call you when your system or brewery is on standby power.

[gitchegumee]

Your chiller is likely to be the largest load in the brewery. And quite possibly the most expensive motor you have. You should have a timer on the restart of the chiller compressor so that when the generator kicks on, you give it a chance to stabilize the load. After a few minutes, the chiller starts. Saves the compressor motor from trying to start against the entire brewery load. Brown power will kill a large motor quickly as the lower voltage will generate high amperage and fry your windings which are not sized for it. I've done it a couple of times before I wised up.

[RyanR]

Thanks guys, I was trying to get a little more insight as to what would be involved in doing this. It looks like backing up all of the brewery makes more sense. We are located in Houston so losing power from tropical storms or hurricanes is not beoynd reason. However we are a small start up and its looking like the cost to do this is much greater than the cost of product in all three fermenters. So I'm thinking this makes more sense down the road.

Thanks,
Ryan Robertson
Buffalo Bayou Brewing

[gitchegumee]

"...all three fermenters..."
Yeah, I guess with three small fermenters in Houston you probably won't need a generator. Hard to justify it on a very small scale. And if fermenters are your main concern (as opposed to a large brewpub with serving tanks in a walk-in where cooling is crucial), you wouldn't even necessarily harm your beer much with unregulated jackets. Most brewers have had issues with a fermenter not keeping temperature correctly, and the beer is usually not ruined by it. Maybe not absolutely perfect, but acceptable.

[Scott M]

What is the size of your chiller and what do you estimate the load would be for the entire facility? Is your chiller a single phase or three phase 240VAC unit?

Here is a good guide for selecting the size of a generator http://www.dieselserviceandsupply.co...Generator.aspx

There are standby generator sets here:

http://www.generac.com/
http://www.wincogenerator.com/catalo...tural_Gas.html
http://www.kohlerpower.com/industria...61&filter_1=60 Hz
http://www.apelectric.com/Kohler-Gen...FUwZQgodPjsNfg
http://www.everygenerator.com/filter...229~17963.html

I would rather have a diesel or natural gas genset over propane because the tank or fuel source is underground away from the potential for wind damage. If your natural gas service is an iron ball, go with that. It is clean burning and will result in increased longevity of the engine driving your generator. You can browse on natural gas standby generators to find what you are interested in and prices.

Hope this helps...