Beer Forum

Built my Minibrew based HLT with a 240V 4500W element. Timed to temperature rise from 48F to 165F. Accomplished that in 42 minutes. Ran the calcs based on a formula found at a water heater manufacturer's website (Volume x temp diff)/(372 x Heat up time)*1000 = element wattage required.

Based on 42 minutes or 0.7 hours, the formula suggested a 4493W element. Not bad.

Based on your numbers, your volume is about 11 gallons?

Good Stuff code.

Yes, left out some things. Ambient was 47F, 10 gallons of water total, full circluation pump flow as well. Thanks for the reply!

You had 10* 8.34 = 83.4 pounds of water. You heated it (165 - 48) = 117 °F which required 117*83.4 = 9757.8 BTU which at 1055.05 joule/BTU equals 10295024 joule. As these were delivered over 42*60 = 2520 seconds the rate of delivery of heat to the water was 4085 joule/sec = 4085 watt. If the heater produces 4500 watts at exactly 240 V and the line voltage was exactly 240 V then the remaining 4500 - 4085 = 415 watts went into the room as heat lost through the walls of the container, the pump and the tubing, heat of vaporization and i^2R losses in the wiring and you would have 4085/4500 = 90.8% efficiency. OTOH if the line voltage drooped as little as 10 V a 4500 W heater would only produce 4123 W heating and the efficiency would be higher.

AJ, measured voltage as well, and it was 238V at element terminals. FYI.

Mash Tun is a Minibrew 15 Gallon system, 0.375" wall, assuming Polypropelene.

Thanks guys!

and how much did the elec. cost for this? ~$0.36?

My electricity is $0.06x / kwh, so that would come just under 20 cents. Nice to put that into perspective compared to propane.

nice!