How Much Electricity Does a RATIONAL Oven Use?

How much electricity does a RATIONAL oven use? It depends on the model, the load and how you cook, because a combi oven’s rated power is a ceiling and not what it draws all day. This guide explains how combi oven energy use works, how gas compares with electric, and how to estimate your own running costs without relying on invented numbers. Where we give example figures, they are clearly labeled as typical or illustrative.

Babak Food Equipment sells RATIONAL iCombi Pro ovens, and we are also an authorized UNOX dealer, so we can talk through both options with you. Start with our combi ovens category if you want to browse first.

How much electricity does an oven use?

Electricity is measured in kilowatt-hours (kWh). One kWh is a 1 kW load running for one hour. Every electric oven has a connected load in kilowatts, listed on its data plate or spec sheet. A few things decide how many kWh it actually uses:

• Connected load (kW). This is the maximum draw when every heating element is on. Small countertop combis are often in the single-digit kW range, while large floor models can be well above 20 kW (typical range; check the data sheet for your model).
• Duty cycle. Elements switch on and off to hold temperature. After preheating, the average draw is usually well below the maximum.
• Cooking mode and temperature. Steam, combination and dry convection modes use energy differently, and higher temperatures draw more.
• Load. A full oven makes better use of each hour than a half-empty one.
• Hours of use and idling. An oven left hot between services uses energy while producing nothing.

For comparison, a typical household electric oven has an element load of a few kilowatts and might average around 1 to 2 kWh per hour when running at normal cooking temperatures (typical figure, varies by model). A commercial combi is bigger, but it also cooks far more food in that hour.

Combi oven energy use: what RATIONAL says and what is general

A combi oven cooks with hot air, steam or both. Steam moves heat into food much faster than dry air, which often shortens cook times. Less time at temperature means less energy per portion. That is the general principle behind the efficiency claims of combi ovens.

RATIONAL builds its iCombi Pro range around intelligent cooking control. The manufacturer describes features such as sensors that monitor the cooking chamber, automatic adjustment of cooking time and temperature, and an automated care system for cleaning and descaling. RATIONAL publishes the connected load and, for many models, energy and water consumption figures in its technical data. We recommend asking for the official data sheet for the exact model you are considering, rather than relying on a general average.

Features that tend to affect energy use in any good combi oven include:

• Good insulation and a tight door seal, so heat stays in the chamber.
• Fast, accurate temperature recovery after loading.
• Sensors that stop cooking at the right point rather than on a fixed timer.
• Automatic cleaning and descaling, since scale on a steam generator wastes energy.
• Efficient use of steam, because water use is part of the operating cost too.

RATIONAL oven gas vs electric

RATIONAL makes both electric and gas versions of its combi ovens. Neither is better in every kitchen. The right choice depends on your building, local utility rates and installation costs.

• Electric combi ovens convert almost all the electricity they draw into heat inside the oven. They need a suitable electrical supply, which for larger models is three-phase power. They generally do not need a flue, though they do need ventilation for steam as the manufacturer specifies. Browse electric combi ovens, such as the RATIONAL iCombi Pro XS electric combi oven.
• Gas combi ovens burn natural gas or propane to make heat. They often have lower running costs where gas is cheaper than electricity per unit of energy, but they still need an electrical connection for the fan and controls, and they need a flue and adequate ventilation. See gas combi ovens or the RATIONAL iCombi Pro full-size natural gas combi oven.

To compare apples to apples, convert both to the same unit. One kWh equals about 3,412 BTU, so an oven rated in BTU per hour can be compared with an electric one rated in kW. Then multiply by your local gas and electricity rates (in BC these come from your utility, for example BC Hydro for electricity or FortisBC for natural gas, depending on your location). The cheaper fuel per unit of heat often wins on running cost, but compare the full picture including installation.

Gas installation in BC

In British Columbia, gas appliances must carry a certification mark or be field approved, and regulated gas work must be done by a gas fitter licensed through Technical Safety BC, working under a permit. Commercial gas appliances need a commissioning approval request before use. Your licensed gas contractor will handle the permit and the request. Ask them early, because gas hookups can take time to schedule.

Electrical installation

Larger electric combis can need a dedicated three-phase supply and a significant breaker size. Have a licensed electrician check your panel capacity, voltage and phase before you order. Electrical equipment in BC must carry a certification mark from a certification agency accredited by the Standards Council of Canada.

Estimating your own running cost

You do not need exact lab figures to get a decent estimate. Use this method:

1. Find the connected load in kW on the data sheet.
2. Estimate the hours of use per day, including preheat.
3. Apply an average load factor (the fraction of time the elements are actually on). A value between 30 and 60 percent is a common starting assumption, but real values vary with cooking mode and load.
4. Multiply: kW x hours x load factor = kWh per day.
5. Multiply by your electricity rate per kWh from your bill.

Illustration only, not a measurement of any model: a 10 kW oven running 6 hours a day at a 40 percent average load factor would use about 24 kWh per day (10 x 6 x 0.4). Multiply by your rate per kWh to get a daily cost, then by the number of operating days.

The best figure is a measured one. A licensed electrician can fit a sub-meter, or your RATIONAL oven’s own software can report energy use for a given cooking program. Track it for a typical week.

How to cut combi oven energy use

• Right-size the oven. A large oven used half-empty wastes energy. Pick the number of pans for your real peak volume.
• Load it fully, and plan batches. Group items that share a cooking temperature.
• Preheat only when needed. Avoid leaving the oven hot between services.
• Keep the door closed. Every opening dumps heat and steam.
• Use the right mode. Combination or steam modes can shorten cooking for many foods, so use programmed recipes.
• Descale and clean on schedule. Use the manufacturer’s care system and approved cleaners.
• Check the door gasket. A worn seal leaks heat.
• Ventilate correctly. A proper exhaust hood or ventless solution, as your authority and the manufacturer require, protects the oven and your kitchen.

Rough RATIONAL and combi oven prices in CAD

People who ask about energy savings usually ask about cost too. These are rough estimates for new equipment in Canada and vary by brand, size and spec. They are not Babak prices or a quote.

• Compact and countertop combi ovens: roughly $8,000 to $20,000 CAD.
• Mid-size floor-standing combi ovens: roughly $20,000 to $40,000 CAD.
• Large capacity combi ovens: $40,000 CAD and up.

Request a quote for current pricing on the specific models you are considering. A more efficient oven can pay back over time through lower energy, water and labour costs, but the payback depends on how heavily you use it.

UNOX combi oven: an alternative to consider

If you are comparing combi ovens, look at UNOX as well. Babak is an authorized UNOX dealer, and UNOX combi ovens come in countertop sizes with electric and gas options. One example is the UNOX CHEFTOP MIND.Maps PLUS 7 x GN 1/1 electric countertop combi oven. Compare pan capacity, power supply, controls and the manufacturer’s published energy data before you decide. Our team can help you compare RATIONAL and UNOX models for your menu.

Combi oven energy comparison table

Frequently Asked Questions

Want help comparing combi ovens? Browse our combi ovens and commercial ovens, visit the showroom at 7190 Randolph Ave, Burnaby, call (604) 566-9747, or request a quote. Pricing, availability, delivery and installation are confirmed at the time of purchase.