Key Aspects About Gas Consumption

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Simplified approach

Gas consuming devices are easy to assess since they have limited but important functions. The most frequently considered one is for cooking equipment while the second most common covers hot water heaters for consumption or space heating purposes, when part of a central heating system.

The first class of devices, cooking equipment, is used with little seasonal variation while hot water heaters have higher consumption between autumn and spring and central heating systems are used only during this time.

Consumers have requirements that rarely fit exactly to predictions and even to previous patterns, as there is always some variability due to activity, external or internal factors. This is why gas consumption control is, most of the time, a best-effort attempt. No two business or home consumers are alike but there are some good practices that can be followed to determine what could be done to control consumption.

While in the case of electricity devices suggestions centered around finding more efficient equipment, for gas appliances the discussion is centered around switching to electrical ones due to better optimization prospects, lower maintenance, automation and better control, as explained below.

Activity specificity

It is essential to know and monitor how frequently large appliances are being used. Cooking machines have medium while and boilers for hot water or central heating have the highest energy consumption. They may be required to work at different temperatures and for different amounts of time. Keep in mind that a higher desired temperature and a long operation means a high consumption.

An important distinction from similar electricity powered devices is that, particularly in the case of cooking machines, they are turned on for extended periods of time, mostly for convenience and operation predictability when in the hot state. This leads to increased gas consumption.

For a business centered on selling food, the whole production chain may have to be studied to determine what could be done quicker or with less heating. Sometimes, there may not be easy solutions that would not compromise quality, variation or appeal.

When gas appliances operation is considered, there are other aspects that affect a building. Since cooking devices are frequently open-flame designs or ones that have little insulation, they are generally contributing significantly to space heating on the area around them. This is an unavoidable aspect even when special fume extractors are being used as most heat simply radiates around the appliance.

Just as importantly, humidity is also massively increased in cooking areas, mainly due to cooking but also as a byproduct of gas burning that is frequently not taken into account. This means that using gas appliances generally influence much more the living or working environment than it may seem at first sight. Of course, since we have been operating such devices for decades, we are aware and understanding of them.

While it is true that there are some closed-flame appliances such as water heaters and central heating systems based on water heating devices, they are never a true closed-flame system. They require outside combustion air and have reduced efficiency due to its changing demands. These appliances still draw a very small amount of air from around them, since they do not have airtight combustion chambers.

In the end, the best approach is to limit consumption, on the one hand, and to slowly migrate to electricity powered devices on the other hand. These have much better prospects for improved efficiency in the near future as well as avoiding the need for additional air circulation and mitigations for release of carbon dioxide and water vapours.

Most common gas consuming devices

Gas cooking machines, stoves

Gas cooking machines are highly popular. They traditionally had many advantages compared to any electrical appliance equivalent such as great temperature control and high heating capability. A variety of gas burner sizes, types and valves meant that hobby or professional cooking ended with very good results. Mastering a gas cooking machine's operation was a neccessity.

Device Typical power rating Sample rating Daily use Monthly consumption
Home gas cooker and oven 7-10 kW 3 kW (one burner) 2 hours 180 kW/h
Professional gas cooker 28-36 kW 12 kW (2 burners) 8 hours 2,880 kW/h

In the context of increased natural gas prices, cooking with gas becomes less attractive. Gas cooking devices are much more dangerous to use than electrical ones due to risks of flame cutoff, explosion in case of leaks. They also require massive amounts of air circulation to avoid affecting people standing near them due to gas burning byproducts.

One important disadvantage of gas cooking appliances compared with modern similar electrical equipment is the amount of optimization, programming and automation. Electrical devices can have any convenience feature that controls temperature easily and precisely while gas ones are difficult to be made to same specifications.

This means that I advise against purchasing new gas appliances even if they may be cheaper than equivalent electrical ones. Even if gas appliances are typically more powerful, the range of features, lack of gas burning constraints and future prospects of fuel price make electrical appliances a much better choice.


While ovens can be considered along with cooking machines, the best approach seems to be to treat them distinctly. They are a class of devices that can range from compact to medium but they all share some important traits and limitations.

An gas powered oven is, in most cases, the device that compromises the most on efficiency. The requirement of ensuring combustion air and burned gas byproducts exhaust wastes a lot of energy. Cold air has to constantly enter the oven and be heated to a certain temperature. All the effort of heating air is wasted when exhaust leaves the oven.

Device Typical power rating Sample rating Daily use Monthly consumption
Old professional gas oven 6-10 kW 6 kW 8 hours 1,440 kW/h

An airtight or controlled airflow system would be limited in an electrical appliance and inside air circulation could be more easily ensured to reach an optimal uniformity.

All the above limitations of gas appliances and the advantage of airflow optimization in electrical appliances means that a electrical ones have the double advantage of using much less energy and being more productive. This means that the traditional higher cost of electricity and the purchasing one of the appliance itself are more than covered by the efficiency improvement

For a business or home user there is also the additional advantage of having much reduced training and monitoring requirements when operating the appliance, which brings multiple benefits.

Gas stoves and grills

Gas stoves have been popular for many decades, particularly in space constrained premises. The ability to have a high powered food preparation solution was appreciated. However, recent advances in technology, such as the induction plate, gave electrical appliances a major boost in efficiency and convenience. Since induction plates can vary well the power delivered to the pot, the end result is the same as on a gas stove.

It is true that there are still some cooking situations that may not be fully covered by induction plates, such as the ones requiring a particular vegetable frying technique that uses the wok pan. The shape of the wok pan is not flat, as the induction plate requires. To achieve similar results with a flat pan, the cooking technique would have to be changed.

Device Typical power rating Sample rating Daily use Monthly consumption
Common "kebab" professional grill 9-12 kW 6 kW (2 burners) 8 hours 1,440 kW/h
Common chicken roasting grill 5 kW 2.5 kW 8 hours 600 kW/h

Electrical grills are more compact and easier to use than gas grills. Although they may not be as powerful and taste or end result of food preparation may not be at the same level as on a gas grill, the convenience of easy operation and predictable results may be worth to consider.

Large grills and particularly the ones created for outdoor operation are a special case. For the moment, there are no electrical appliance equivalents, as far as I can tell. The situation may change in the future.

Boilers and Water heaters

There are two distinct classes of heaters, instant and accumulation types. Accumulation types are bulky and easily noticeable due to their large hot water tank. The instant ones are much more compact. The preference for one type or the other was based upon water flow requirements.

Instant water heaters can be very powerful and capable of covering various water flows. In many countries they were a traditional favourite amenity. In the last decades, these devices became relatively rare as combined central heating systems combined hot water and space heating requirements.

Device Typical power rating Sample rating Daily use Monthly consumption
Standard Instant Gas Boiler 12-25 kW 20 kW 1.6 hours 1,188 kW/h

Generally, instant gas water heaters or boilers cannot be easily replaced with electrical equivalents as they require large currents that may not be possible to supply easily without an upgrade of the electrical system. Sometimes, even with an upgrade of the electrical system the electrical appliance may still not work since the branch current carrying capability from the utility provider may not be enough.

If space can be accommodated to house an electrical accumulation boiler, the most widely used product, it would offer additional improvements in tighter temperature control, noise-free operation and very little maintenance over many years.

Central heating appliances

Central heating is the most complex system you may encounter. While more modern gas appliances still have higher power ratings than equivalent electrical ones, and are particularly more affordable than them, it is certain that future heating systems would have to transition from gas to electrical ones.

While gas appliances have traditionally been much cheaper to operate than similar powered electrical ones, this has slowly changed. 30 years ago, gas may have been 10 times as cheap as electricity, and almost a decade ago it was around 4 times as cheap. In the last few years gas prices increased and an equivalent gas energy consumption is now around 2-3 times as cheap as electricity.

Device Typical power rating Sample rating Daily use Monthly consumption
Standard Central Heating Gas Unit 20-30 kW 25 kW 6 hours (during winter) 4,500 kW/h

It is important to note, in this case as well, that no gas heater is 100% efficient, its efficiency varies on flame temperature, combustion air, airflow, maintenance state. In practice, the efficiency reaches around 80% of the rating. Since electrical appliances can easily reach 90% and require less maintenance, it is obvious that gas ones are at an additional disadvantage.

A central heating system has much lower energy efficiency than it may be assumed just from the gas boiler itself since all the pipework, radiant heater positioning near walls and the overall system state and balance of flows come into play as losses. Note that air heaters also have their losses, first due to conversion efficiency, but mainly due to distance to actual delivery points and other aspects.