Gas or electric?

[IT Minion]

Why buy one that cant

If it were an air to water heat pump (sucks heat out of the air and makes hot water for radiators) then it'd probably be very ineffective at extracting heat from your rooms in the summer. The radiators would have to be nearly freezing to have any heat transfer. Similar for Ground source heat pumps I think.

For air to air, I don't see why you wouldn't buy one that goes both ways.

 

[Captain Nemesis]

The radiators would have to be nearly freezing to have any heat transfer.

But think of all the distilled water you could harvest.

 

[StephenOak]

It is exactly hours, but I'll admit days probably doesn't apply to gas, and I must have been thinking of coal or even more old school systems.

Well 'hours or days' sounded like a lot more than two hours to me!.

And that is the outside time for a simple CCGT, b/c of the need to cope with RE unreliability a lot of work has been done on making them start faster.

https://www.power-eng.com/emissions/fast-start-combined-cycles-how-fast-is-fast/
Shows a conventional start taking 90 minutes and a fast start only 30. Also "During cold start conditions (typically greater than 72 hours following plant shutdown)", which is likely that a fully cold start is rare.

Emitting greenhouse gases.

The most potent of which is of course - H2O.

Friend of mine lives near a farm growing bamboo for Drax.

But that is a minor source. "At Drax we use sustainably-sourced wood pellets from working forests, primarily in the US South but also in Europe, Canada and South America", from https://www.drax.com/sustainability/responsible-sourcing/#chapter-1

 

[mikeey84]

The radiators would have to be nearly freezing to have any heat transfe

I imagine if you have radiator fans, it would work much more effectively

 

[Captain Nemesis]

The most potent of which is of course - H2O.

Doesnt matter, the point remains the same, less efficient = more fuel burned for the same amount of power generated = more emissions = more polluting. Not an odd definition.

 

[endecotp]

(greenhouse gases)
The most potent of which is of course - H2O.

WHAT?

 

[IT Minion]

WHAT?

Probably a reference to clouds. They trap heat and prevent it radiating into space. You'll have noticed it yourself when you have a clear, utterly freezing, night sky. It's both true and almost completely irrelevant.

You don't see many references to it these days as few people claim that we're making a direct change to the cloud cover. Indirectly cloud cover is a feedback mechanism that might make a big difference to global warming due to CO2 and other more potent pollutants.

 

[Harry Bloomfield]

Normal electric heaters generate heat by making a bit of metal very hot. It converts electricity into energy and it's 100% efficient, 1W of electrical power gives 1Ws worth of heat..

Heat pumps are different, instead of heating an element up they collect heat from the surrounding area. It turns out that they can collect more heat than they would generate by just heating up some metal. So instead of using 1W of power to make the equivalent heat, it uses 1 W of power to collect 4Ws of heat.

Except the 4w of heat is poor quality heat, not very hot heat - which means massive radiators needed to be installed, because they run so much cooler. The heat pumps are also quite noisy, so may annoy you and/or neighbours.

 

[StephenOak]

Probably a reference to clouds.

Of course not. There aren't 'clouds' of CO2, just CO2 in the air, similarly there is masses of H2O in the air and it is by far the most important GHG.

All the predictions (e.g. from the IPCC) are that increased CO2 will raise temperatures in the coming decades by something like 0.5C (or a bit more). The models say this will increase the amount of H2O in the atmosphere and that this will raise temperatures by something like 1.0C.

CO2 absorbs radiation in a very narrow band of frequencies and so is quite limited in its ability to delay heat loss. H2O covers a much wider band and so is much more effective. This is fairly basic radiation physics.

more emissions = more polluting

So more water vapour = more pollution. And you think that is not an odd definition.

 

[IT Minion]

Of course not. There aren't 'clouds' of CO2, just CO2 in the air, similarly there is masses of H2O in the air and it is by far the most important GHG.

You mean the extra water vapour that the atmosphere will be holding due to the increased temperature caused by the increased temperature caused by, wait for it, CO2 and other GHGs?

If so well done, your point is both technically valid and utterly useless. The presence of an amplifying effect means it's even more important not to pump CO2 into the air.

Or is your point that sprinklers are evil? It's hard to be sure.

 

[jeds]

However, a plumber i use has made me aware that electric heater technology has advanced a lot and that modern electric heaters could be the way to go instead of gas system.

Quite an interesting comment. Does your plumber not know that all electric heaters are 100% efficient. 1kW of incoming electrickery is converted to 1kW of heat output. One with a thermostat might be said to be 'more efficient' than one without but otherwise all electric heaters are the same. A twelve hundred quid unit filled with magic oil or some sort of mysterious ceramic stuff inside is no more efficient than a twenty five quid fan heater.

 

[Captain Nemesis]

So more water vapour = more pollution. And you think that is not an odd definition.

Rewind.

https://www.diynot.com/diy/threads/gas-or-electric.560961/page-5#post-4847848

Unless you want to claim either of the following:

Gas powered generating emits zero CO2
CO2 is not a pollutant

Then gas powered stations do pollute, and therefore less efficient ones are more polluting.