Flue gas water
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The reason why we have a cooker hood is to remove the water and other combustion products from the kitchen, there is no need with an electric hob.
Burning most hydro-carbons produces water, every gallon of petrol burnt produces gallon and a half of water, and if you look as a pre-cat car you will see the water running out of exhaust pipe before it gets warm, modern cars the pipe gets hot before the water reaches end, so don't see it so much now.
My house today at 47% humidity in bedroom where I am sitting, hall at 43% according to Nest, but my father-in-law cooking with gas, his house rarely below 70% seen it into 80's, simply due to cooking on gas without a cooker hood to remove combustion products.
I am sure if some one invented the gas cooker today, it would be banned, some places they are after Ronan Point they waste a load of energy as so little gets into the pan, my daughter would boil the water in an electric kettle then pour it into the pan, I asked why, so she demonstrated, filled kettle to mark, poured into pan, then filled again to mark, started both to boil at same time, cooker rated 5.5 kW kettle 2.8 kW and the kettle won by a huge margin, did same at home with my induction hob, 3 kW with kettle 2.8 kW boiled at near enough same time.
If the heat does not go into the pan, it clearly goes into the room, making the kitchen into a sweat box in the summer, not helped when people install infrared heaters in the ceiling (down lights) and also do washing in kitchen. It is harder to remove heat, than not put the heat in the room to start with.
As to safety when you have a naked flame, induction hob has sensors, at 60°C it lights up warning hot, at 200°C it starts the safety reduction and at 300°C it has turned completely off, it turns off when pan is removed, and after about 3 minutes will not turn back on again until turned off with knob, and it also has a maximum on time, which is longer as the setting are set lower, so if you forget to turn it off, there is a maximum time it can run for. And in the main an isolator is installed some where near the cooker, so if you should get a chip pan fire, although unlikely with no naked flame you can turn whole cooker off without touching the cooker within the kitchen. Not seen any of these safety features with gas.
I would love gas, it is great for central heating, but for cooking, only when using a wok has gas any advantage.
Old gas and oil central heating did not gain the latent heat, modern gas central heating does, so the flue is far cooler, we want the change of state to happen inside the boiler, so it pre-heats the water, if we are seeing plumes of water vapour from flue, it is clearly running too hot. But it hardly matters for a short time, so until the boiler starts to modulate, it may eject water vapour, but as the TRV's start to control the room temperatures, the boiler will turn down (modulate) and the water vapour ejection from the flue will in the main stop, unless some one uses an on/off thermostat which defeats the whole idea of a modulating boiler.
Burning most hydro-carbons produces water, every gallon of petrol burnt produces gallon and a half of water, and if you look as a pre-cat car you will see the water running out of exhaust pipe before it gets warm, modern cars the pipe gets hot before the water reaches end, so don't see it so much now.
My house today at 47% humidity in bedroom where I am sitting, hall at 43% according to Nest, but my father-in-law cooking with gas, his house rarely below 70% seen it into 80's, simply due to cooking on gas without a cooker hood to remove combustion products.
I am sure if some one invented the gas cooker today, it would be banned, some places they are after Ronan Point they waste a load of energy as so little gets into the pan, my daughter would boil the water in an electric kettle then pour it into the pan, I asked why, so she demonstrated, filled kettle to mark, poured into pan, then filled again to mark, started both to boil at same time, cooker rated 5.5 kW kettle 2.8 kW and the kettle won by a huge margin, did same at home with my induction hob, 3 kW with kettle 2.8 kW boiled at near enough same time.
If the heat does not go into the pan, it clearly goes into the room, making the kitchen into a sweat box in the summer, not helped when people install infrared heaters in the ceiling (down lights) and also do washing in kitchen. It is harder to remove heat, than not put the heat in the room to start with.
As to safety when you have a naked flame, induction hob has sensors, at 60°C it lights up warning hot, at 200°C it starts the safety reduction and at 300°C it has turned completely off, it turns off when pan is removed, and after about 3 minutes will not turn back on again until turned off with knob, and it also has a maximum on time, which is longer as the setting are set lower, so if you forget to turn it off, there is a maximum time it can run for. And in the main an isolator is installed some where near the cooker, so if you should get a chip pan fire, although unlikely with no naked flame you can turn whole cooker off without touching the cooker within the kitchen. Not seen any of these safety features with gas.
I would love gas, it is great for central heating, but for cooking, only when using a wok has gas any advantage.
Old gas and oil central heating did not gain the latent heat, modern gas central heating does, so the flue is far cooler, we want the change of state to happen inside the boiler, so it pre-heats the water, if we are seeing plumes of water vapour from flue, it is clearly running too hot. But it hardly matters for a short time, so until the boiler starts to modulate, it may eject water vapour, but as the TRV's start to control the room temperatures, the boiler will turn down (modulate) and the water vapour ejection from the flue will in the main stop, unless some one uses an on/off thermostat which defeats the whole idea of a modulating boiler.
Surely if you are cooking on an electric hob you are producing steam as well as cooking smells? They need to be removed from the room.
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The induction hob I use has a boil/simmer selection, so very little steam produced, it auto drops to simmer, and I don't cook anything which does not smell nice, I actually now do have a cooker hood, but only the lights are ever used.
I used gas in the caravan, no real option to use anything else, the problem was I am use to using electric, so the extra safety steps needed with gas did not come naturally to me, or my wife, having to remind her to turn off gas when not in use etc.
But old house the cooker location was dictated by where the cooker connection unit both gas and electric was placed by the builders when the house was built, which did not have any option to install ducting required for a cooker hood, using a carbon filter you can remove smells to some extent without ducting the air outside, but that does not remove combustion products.
I used gas in the caravan, no real option to use anything else, the problem was I am use to using electric, so the extra safety steps needed with gas did not come naturally to me, or my wife, having to remind her to turn off gas when not in use etc.
But old house the cooker location was dictated by where the cooker connection unit both gas and electric was placed by the builders when the house was built, which did not have any option to install ducting required for a cooker hood, using a carbon filter you can remove smells to some extent without ducting the air outside, but that does not remove combustion products.
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Surely all forms of cooking release water vapour?
I have induction hob, which I use regularly if you have a pan cooking away, and place your hand over it, you can feel it's slightly sweaty, is this not water vapour? I agree that it's a lot less than gas cooking, and not as hot above the pan.
I recently been using an air fryer. If the air fryer is too close to the tiled wall, after 20 mins of cooking there is condensation on the wall.
I have induction hob, which I use regularly if you have a pan cooking away, and place your hand over it, you can feel it's slightly sweaty, is this not water vapour? I agree that it's a lot less than gas cooking, and not as hot above the pan.
I recently been using an air fryer. If the air fryer is too close to the tiled wall, after 20 mins of cooking there is condensation on the wall.
Thanks for all the inputs, however I am still stumped by where this condensation is coming from. From what I understand, the combustion chamber heats the heat exchanger, water passes through the exchanger and is heated to the desired temp, and then either exits a tap or is pumped around the rads.
The gas flame is heating a metal block, so no water produced there. It must then be produced by the evaoporation of the water in the heat exchanger, in which case, how does that work ? If CH water is evaoporating and used as latent heat, isn't the CH pressure going to drop ? Either that steam exits the flue or condensates in the trap and exits the boiler.
I must be missing something here.
The gas flame is heating a metal block, so no water produced there. It must then be produced by the evaoporation of the water in the heat exchanger, in which case, how does that work ? If CH water is evaoporating and used as latent heat, isn't the CH pressure going to drop ? Either that steam exits the flue or condensates in the trap and exits the boiler.
I must be missing something here.
The water is "in" the gas and released when burned (I believe about 1.5 litre per m³ - a boiler running for an hour or so, but obviously not all will condense) - nothing to do with the water in or passing through the boiler.
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By product of burning gas, nothing to do with the water in the heating system.
It is produced during combustion. In the case of natural gas, methane reacts with oxygen, to produce carbon dioxide and water.
CH4 + 2O2 → CO2 + 2H2O
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What are you expecting to see?
Some vapour/steam.
That's a good question. I think the reason we don't see it, is because when steam is very hot, like it will be as it leaves the flame ((hundred of degrees), it is purely in the form of water vapour, which is an invisible gas. When we see steam coming out of a kettle, I don't think that is pure water vapour. Instead, it is mixture of water vapour and water droplets, and we are seeing the water droplets.
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Put a pan of icy cold water onto the gas flame - you're likely to see condensation on the outside of the pan until it warms up.
As said, it comes from the gas combustion.
As said, it comes from the gas combustion.
Likewise - most cooking doesn't need to actually boil, a gentle simmer with a lid fitted, has hot and efficient in both respects. The difference, I cook on gas.
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