Naked Science Forum
General Science => General Science => Topic started by: roisinfahy on 31/12/2021 17:16:16
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This is a question I've always wondered. I have autism and suffer quite a number of sensory issues. I live in Ireland where it can get quite cold in the winter.
Growing up, I always disliked the heat that came out of radiators and felt that it was "uncomfortably warm". I recently purchased a Hot & Cool fan which I find is very comfortable. It might seem like a preference but the heats is very different. Radiators often feel like being in a furnace while the air conditioner simply feels like a breeze on a summer day.
I know that radiators use warm water to spread heat via radiation while the air con blows warm air.
Product Placement removed - moderator
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I know that radiators use warm water to spread heat via radiation while the air con blows warm air.
Despite the name, "radiators" disperse heat principally by convection. They are attractive because they are very low-maintenance once installed, generally do not occupy "living space" in the middle of a room, and are silent and do not create a draft. Also very useful for drying clothes and towels, and the primary heat source can be anything combustible.
True "reversible aircon" systems transfer more heat per unit input power but are noisy and drafty. Definitely the best option in a well-insulated house with electricity but no mains gas supply. Air- or ground-source heat pumps do the same thing but also provide hot water: very efficient but depressingly complex and I have yet to find a contractor who can actually maintain one!
"Assisted convection" fan heaters can cost anything from £10 to £600 for a domestic gadget,depending on whether you want it to humidify and filter the air or just circulate a bit of heat. Since you can't get much more than 2.5 kW out of a domestic socket, and direct conversion of electrical energy to heat is pretty well 100% efficient, they all do exactly the same job of heating or circulating the air, with more or less noise depending on the model.
The British Isles are blessed with a comfortable outdoor temperature range and one live sheep for every 3 people. My solution is an open window and a woolly sweater - Irish traditional designs are particularly attractive and the close-knit Guernsey is ideal for outdoor work - it's the basis of the military "woolly pully". No noise or fuel bills.
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Radiators are the best in terms of getting a good real heat. But you need a big solid one, small radiators are not good, they lose heat quickly. Most of companies sell small radiators, I never seen anyone sell big one. So, on today market radiators has poor quality and do not hold the heat for a long period of time.
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Differences between heating from air conditioners and radiators. One is that air conditioners tend to be more efficient, meaning they use less energy to produce the same amount of heat. Additionally, air conditioners repair circulate for air condenser.
Follow these instructions: Spam removed
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Differences between heating from air conditioners and radiators. One is that air conditioners tend to be more efficient, meaning they use less energy to produce the same amount of heat. Additionally, air conditioners repair circulate for air condenser.
Follow these instructions: Spam removed
Sorry mate, you are beginning to feel the heat from spamming.
Better cool off for a while, bye
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yes
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There are some major differences between blown things like fan heaters and air conditioners versus radiators.
Radiators are usually set to 60C or so which is really quite hot, whereas with fan heaters and air conditioners the hot air coming out of them can be closer to body/room temperature.
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With the increasing cost disparity between electricity and primary fuels, I'm beginning to wonder whether blown aircon is worthwhile in these islands. Makes sense where you might need cooling too, so I use it in rooms full of computers and stuff, but the overall utility of a hot water system, whether heat pump or boiler, now seems advantageous. You can maximise floor space and eliminate hotspots with underfloor or skirting board radiators running at lower temperatures than the old iron steam rads.
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Hey, you are talking about It might seem like a preference but the heats is very different. Radiators often feel like being in a furnace while the air conditioner simply feels like a breeze on a summer day. for this you have to search on Google.
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With the increasing cost disparity between electricity and primary fuels, I'm beginning to wonder whether blown aircon is worthwhile in these islands.
The trick is to insulate well and use night rate electricity to preheat (or cool) the space. With achievable COPs it's much cheaper to do that than natural gas.
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How does the air know it is meant to feel different?
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fan heaters can cost anything from £10
I caught a cheap fan heater blowing sheets of flame.
direct conversion of electrical energy to heat is pretty well 100% efficient, they all do exactly the same job of heating or circulating the air
The HSE will have it that radiant heat is more efficient that convection because it heats the body directly without the need to heat air and building. Personally, I'm a bit puzzled why the air and building won't heat up eventually anyway, but I suppose there's some benefit in the interim.
How does the air know it is meant to feel different?
Wind speed.
Two fan heaters at the same power can feel very different: the lower the air volume the higher its temperature will be for any given power, and the smaller the aperture the higher the velocity for any given volume. My experience is that small aperture fan heaters feel warm, and large aperture ones feel like a chilly draught. I think that low velocity air flows have time to cool down before they've travelled from heater to body.
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Personally, I'm a bit puzzled why the air and building won't heat up eventually anyway,
Did anyone say they wouldn't ?
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Radiators often feel like being in a furnace
How would you know?
How much time have you spent in a furnace?
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With the increasing cost disparity between electricity and primary fuels, I'm beginning to wonder whether blown aircon is worthwhile in these islands. Makes sense where you might need cooling too, so I use it in rooms full of computers and stuff, but the overall utility of a hot water system, whether heat pump or boiler, now seems advantageous. You can maximise floor space and eliminate hotspots with underfloor or skirting board radiators running at lower temperatures than the old iron steam rads.
Beginning? Unless you have hydroelectric electricity gas is always far cheaper. Blown air electric is known to be inefficient along with radiant heat, blown air from gas has also been long since dropped. Unsure as to why blown air from gas is rubbish, but it is.
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definitely radiators are dangerous compare to air conditioners
Nonsense
Lots of people survived radiators with no harm.
The idea that they are dangerous is just silly, isn't it?
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Unless you have hydroelectric electricity gas is always far cheaper.
Actually, no.
Right now gas is about 8-10p/kWh, whereas night rate electricity is 8-19 p/kWh depending on the tariff.
When used in conjunction with heat pumps, the electricity delivers far more heat.
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Unless you have hydroelectric electricity gas is always far cheaper.
Actually, no.
Right now gas is about 8-10p/kWh, whereas night rate electricity is 8-19 p/kWh depending on the tariff.
When used in conjunction with heat pumps, the electricity delivers far more heat.
Moron. You are going on the naughty list.
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Moron. You are going on the naughty list.
Before calling someone a moron, you should check that they aren't correct. (for example because the CoP of a good ground-source heat pump can be 400% and the efficiency of a bad gas boiler might be as little as 60% ).
And then, whether you are correct or not, you still shouldn't call someone a moron.
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Yup, that... and he's not correct.
The reason I know this fact is because I was pricing up house batteries and solar panels, turns out that even the average cost of solar power over the life of the system is about 8p, and the lowest tariff I could find on grid electricity to charge a battery was BELOW that of the gas. If you're on that tariff, running space heaters or immersion heaters at night is actually cheaper than using gas right now. Maybe in the long run, natural gas will come down again, but so may grid electricity, and my point about heat pumps remains.
And I haven't even touched on the environmental credentials.
The model I have of the battery/solar panel system is giving double digit ROI, and seems to be a goer.
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Yup, that... and he's not correct.
The reason I know this fact is because I was pricing up house batteries and solar panels, turns out that even the average cost of solar power over the life of the system is about 8p, and the lowest tariff I could find on grid electricity to charge a battery was BELOW that of the gas. If you're on that tariff, running space heaters or immersion heaters at night is actually cheaper than using gas right now. Maybe in the long run, natural gas will come down again, but so may grid electricity, and my point about heat pumps remains.
And I haven't even touched on the environmental credentials.
The model I have of the battery/solar panel system is giving double digit ROI, and seems to be a goer.
Oh no the electricity company says that electricity is cheaper at night.
Except no, that's bullshit, because electric is cheaper in Norway with hydro electric than Qatar with gas.
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Except no, that's bullshit, because electric is cheaper in Norway with hydro electric than Qatar with gas.
Do you think I can use a very long extension lead, or do you realise that what you said is irrelevant?
Here in the UK a heat pump may can easily be cheaper (it largely depends on installation costs. If I could tap into the underground river culverted under the street where I live, I'd be on a winner).
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Oh no the electricity company says that electricity is cheaper at night.
That's because... it is cheaper at night.
Did you not realise that?
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Except no, that's bullshit, because electric is cheaper in Norway with hydro electric than Qatar with gas.
Do you think I can use a very long extension lead, or do you realise that what you said is irrelevant?
There already is a long extension lead, and it's 450 miles long (!):
https://en.wikipedia.org/wiki/North_Sea_Link
But yeah, the price of electricity varies depending on usage and availability, either average or instantaneous and a whole bunch of other factors.
In general, the idea that electricity MUST be more expensive than natural gas per kWh is flawed, although it's historically true, the price of natural gas is determined by the world market and isn't necessarily causally related to the price of electricity, because some of the ways of producing electricity, including hydroelectricity, wind and solar, don't necessarily require much natural gas or other fossil fuels to produce them.
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Except no, that's bullshit, because electric is cheaper in Norway with hydro electric than Qatar with gas.
Do you think I can use a very long extension lead, or do you realise that what you said is irrelevant?
There already is a long extension lead, and it's 450 miles long (!):
https://en.wikipedia.org/wiki/North_Sea_Link
But yeah, the price of electricity varies depending on usage and availability, either average or instantaneous and a whole bunch of other factors.
In general, the idea that electricity MUST be more expensive than natural gas per kWh is flawed, although it's historically true, the price of natural gas is determined by the world market and isn't necessarily causally related to the price of electricity, because some of the ways of producing electricity, including hydroelectricity, wind and solar, don't necessarily require much natural gas or other fossil fuels to produce them.
You're just lying. You could steal the electric making it free.
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It all comes down to quantity. As I write, 60% of UK electricity is derived from gas and 12% from nuclear. The retail price from all suppliers is linked to the current price of gas, and all the undersea cables can only contribute about 5%, plus or minus (we supply them from time to time).
As demand for electricity increases with the adoption of electric cars, short-term economics will favor building more gas-powered generators because they offer a quicker return on capital than any other and the retail price is of no concern to the suppliers as long as it is profitable, which is inevitable because they are under no obligation to supply at a loss. Longer term economics favors offshore wind, at around 3 times the capital cost per unit installed capacity and no obligation to supply at all.
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Nah. The grid is scaled for peakload, but the typical load is much less, and baseload less still. There's plenty of capacity, nobody is likely to build a lot more natural gas plants. Electric cars charge when electricity is cheap, which right now, is around the daily baseload. In future with more solar they will charge more around midday, depending on the tariffs available.
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Current UK grid demand as I write is 40 GW. Maximum capacity is 55GW, it isn't particularly cold right now, and there are very few electric cars (less than 1 in 20) and almost no electric trucks and buses. Pity the sun has gone down and there is no wind.
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Current UK grid demand as I write is 40 GW. Maximum capacity is 55GW, it isn't particularly cold right now, and there are very few electric cars (less than 1 in 20) and almost no electric trucks and buses. Pity the sun has gone down and there is no wind.
I see you have, once again, forgotten about this sort of thing.
https://en.wikipedia.org/wiki/Rechargeable_battery
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Here's the output of the model I made with three times the wind capacity and extra solar and 2 TWh of hydrogen salt cavern storage:
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Here is the info straght from the horses mouth
Based on your £20/day figure that equates to roughly 50kWh, which at this time of year is not an unreasonable amount
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/massive-electricity-cost
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/our-ashp-is-costing-24-a-day-to-run
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/whats-your-current-daily-damage
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The incompetence in those threads is high. One general idea is to use off-peak electricity to mostly warm up your house. The overnight cost of electricity is a third, so heat the main living areas well above the normal living temperature, and only run the heat pump during the day to stop it falling too much- using the house as a thermal battery. They're doing more like the opposite, heating the house to a lower temperature overnight and then trying to warm it up higher during the day on the expensive electricity! Madness!
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The incompetence in those threads is high. One general idea is to use off-peak electricity to mostly warm up your house. The overnight cost of electricity is a third, so heat the main living areas well above the normal living temperature, and only run the heat pump during the day to stop it falling too much- using the house as a thermal battery. They're doing more like the opposite, heating the house to a lower temperature overnight and then trying to warm it up higher during the day on the expensive electricity! Madness!
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you're flat out lying
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The point is, they should be running the night rate flat out, even if it means going well above 18C. The heat will leak away slightly faster at a higher temperature, but the cost of heating is a third of the day rate. Depending on the insulation they should set the night rate thermostat to 25C or higher, and even run fan heaters on the cheap rate to get the temperature up. Any electricity used on the day rate means they messed up.
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I'm missing something? Well, the original claim
Unless you have hydroelectric electricity gas is always far cheaper.
Actually, no.
Right now gas is about 8-10p/kWh, whereas night rate electricity is 8-19 p/kWh depending on the tariff.
When used in conjunction with heat pumps, the electricity delivers far more heat.
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The point is, they should be running the night rate flat out, even if it means going well above 18C. The heat will leak away slightly faster at a higher temperature, but the cost of heating is a third of the day rate. Depending on the insulation they should set the night rate thermostat to 25C or higher, and even run fan heaters on the cheap rate to get the temperature up. Any electricity used on the day rate means they messed up.
WTF