AboutJim Wixson, CFSP Expertise I can answer any questions about food production process, alternate food process methods, new technologies, layout and design, energy choice issues, ventilation, health codes, productivity, profitability, and labor staffing issues.
Experience 32 years in the food equipment business. Familiar with all phases of the commercial restaurant business, specializing in appropriate equipment selection. Cutting edge in production techniques.
Question QUESTION: I want to start a pizzeria. If I use a deck oven, will it be cost efficient to use LP Gas or electricity. I live in the Philippines. The electricity rates we have are the second highest in Asia. Furthermore, our LP gas component is different from Western countries like the USA.
Can you help me out in computing the cost of LPG & electrical cost. We purchase our LP Gas for restaurant use in 40 kgs. tank. The deck oven I was considering using has for its LP gas its maximum BTU is 30,000 input wheres its electrical unit electrical input is 8.5 kw, 220V & single phase.
Your kind assistance shall be highly appreciated. Thanks.
ANSWER: Zenon -
Given your electric rates in the Philippines with the surcharges, it may well be that LP is the better fuel if you are simply looking for cheaper. The electric operates at much cooler temperature to the space, so that the employees are not exposed to high kitchen heat. Electric is extremely efficient and is worth the reduction in air-conditioning costs. Also, electric cooking equipment lasts longer and cost less to service than gas does.
With that said, the way to determine the cost of operation is to multiply the average pesos per kWh for electric. The 8.5kW oven will only use approximately 3.5 kilowatts per hour. The 8.5kW is the potential if run wide open for a solid hour, but since the oven has a thermostat the elements cycle on and off after the 7 or 8 minute pre-heat. Therefore, 3.5 x pesos per kWh = Cost per hour. Check with your electric supplier to ask what an average kilowatt hour costs a business such as yours. The electric demand cost is imbedded in the average. We always compare comparable businesses by taking their total invoiced bill and dividing it by the kWh used.
For the gas unit, the 30,000 btu unit consumes about 18,000 btu per hour. At 100,000 btu per therm, this is .18 therm (18,000/100,000. The next step is to take the cost of 2.28kg of propane which equals 1 therm, and multiply that times .15 = pesos per hour to operate the gas oven for 1 hour. We always figure gas the same way as electric, we take the total monthly invoiced amount and divide it by the total therms consumed.
Hope this helps.
---------- FOLLOW-UP ----------
QUESTION: Thanks for the advise. Please explain how you arrived at 3.5 kw/hr. as the actual usage consumption from the given 8.5kW utility sonsumption of the oven. Please also explain how you arrived at 18,000 btu/hr. Why multiply it at .15?Are we talking about natural gas or lp gas with regards to 100,000 btu per therm? Is it not 250,000 Btu's?
Our cost here is P54.50/kg. So we multiply this to 2.28kg arriving at P124.26 x .15 =P18.64 LP Gas cost for 1 hr. Is this correct?
Answer Zenon - You are correct, P54.50 x 2.28 = P124.26 x .15 = P18.64 per heavy hour. The 30,000 btu on the nameplate of the oven is the amount of btu consumed by the ovens burners if running wide open for an hour. Because the oven has a thermostat, the oven reaches temperature and the burners shut off. Typically, a conveyor oven consumes a little more than 50% of the name plate rating of gas and about 22% of the name plate rating of electric. This is how we figure that an electric conveyor oven with a nameplate of 8.5 will use no more than 3.5 kilowatt hours in a heavy hour.
I used 3.5 as a conservative number. It will be more like 2.9 and 3.1. If you multiply 3.5 x P per kilowatt hour, then you should be able to compare gas to electric.
A therm of gas energy = 100,000 btu = 2.28kg of propane. If the gas conveyor oven uses 18,000 btu per hour, then 18,000 divided by 100,000 = .15 therm.
