older/newer GCH radiator efficiency?

Years ago I got I think 2C room temp increase from a 4" pc fan. I suspect fanned rads will make a comeback some day once people realise they can have a much smaller rad without all the fan noise of the old ones.

NT

NT: > useful energy out over energy in is the definition.

With a wet radiator there are only 2 places energy can go: into the room or out the outlet pipe. In neither case does the rad lose any energy, hence efficiency is 100%.

NT

Not so either. A standard convector heater element produces light, although likely outside the visible spectrum.

Nothing to do with me but the builder/carpenter who renovated the place in the 80's. Knowledge of plumbing and heating systems minimal. The thermostat was in the utilty room, without a radiator.

Single pipe might be easier to adjust. B-)

s/fanned/finned/ ?

Energy efficiency is always going to be 100% for a radiator.

Efficiency has several meanings. This might assist:

It doesn't just have to be time, money or energy. It could be weight or area in respect of a radiator. A radiator may be more efficient radiating heat if the water is at a higher temperature.

Some further examples

There may be occasions where you might swap the word for effectiveness, in many instances they are synonyms.

Perhaps English has moved on since you were at school?

connected

Perzackerly.

isn't!)

Maybe not but it enables you to setup an even starting point relatively quickly and painlessly.

No the rads with a lower flow resistance get more flow, they may or may not be further away.

The inclusion of "useful" was good. But you then :

a. ignore the fact that not all the energy leaving through the output pipe is "useful" if the rest of the system has losses (i.e. heat lost where it's not wanted); and

b. assume that all energy released into the room is equally useful when in many cases it's not because the idea is to make people in the room /feel/ comfortable.

Measuring (b) is complicated and I don't pretend to understand all the components. But a simple example is that a pure convector in a room with a high, cold ceiling is not the best source. And I don't need to as clever people have written BS 7726 (Ergonomics of the thermal environment ? Instruments for measuring physical quantities) which defines an "operative temperature". So my definitions of the efficiency of a radiator would focus on how much it increases the operative temperature for (a) a given (net) energy released by the radiator and (b) the corresponding (gross) energy the system has to provide.

I stumbled across this subject some years ago when looking for evidence about the claims for tall radiators - which do seem to have benefits for a given area.

Don't think I've ever seen an oil filled radiator style heater that emits light. As for bare element ones, some do some don't.

NT

Not sure what that means, but they do tend to go together. A fan with a flat panel works for a diy job but is not optimal design costwise for a new product.

All you need for a fanned rad to work, take up way less space and be much preferred is silence, and that's not a challenge.

NT

only one of which applies here, and that is: Energy efficiency (physics), the ratio of power consumed to useful power output

a usage of the word that applies primarily to a person's actions. 'with no waste of energy' certainly applies to radiators. Good & careful certainly have nothing to do with radiator efficiency.

sorry but no. The definition of efficiency in physics & engineering is useful energy output divided by input. That's just what efficiency is.

Radiation from a radiator versus convection is irrelevant to its efficiency. That is more relevant to filament lamps.

those are of course the efficiency that we are discussing, useful energy output over input.

Generally waffly bs uses of the word

again useful output over input, though used with rather less precision

not even true. Old bodies do become less efficient at doing work this calories, but not less efficient at burning them.

It's moved on since all of us were at school, but like most words, efficient still has the same meaning. And like so many words it also gets used inaccurately, imprecisely and for the purposes of promotional bs.

NT

It's not being ignored, we know there are losses in the boiler & in a minority of cases the pipework running where heat is not wanted. Those inefficiencies occur in those devices, not in the radiator.

It's also not news that often one component's operation affects efficiency elsewhere in a system.

It's sometimes relevant, in a huge domed hall, heat in the dome could be regarded as waste. But in your average domestic semi it's not normally an issue and does not affect system efficiency. It never affects radiator efficiency.

NT

Which has now become common usage. I suspect you still think kinky means fashionable and gay means happy.

Old bodies also become more senile and resistant to change too. They use the English language less efficiently and still think they are kinky and gay.

No, many words like 'efficient' have changed. Do you really still think kinky means fashionable and gay means happy.

You're very much on your own when it comes to your definition of radiator efficiency. This should help give you an indication of your losing argument:

If it isn't visible light, you won't see it.

But it's the case that simply nothing is 100% efficient. May come very close, though.

Looked at just in those terms, that could simply be a function of the flow rate... What is perhaps a more useful metric is the product of the flow rate and the temperature drop - It would at least give a correlation to power (i.e. rate of heat transfer into the room).

Isn't conversion of energy to heat free of that theoretical restriction on efficiency?

Adjective: doing something in a good, careful and complete way with no

I don't buy that in this circumstance, since we have already highlighted that in those terms its always 100% and also meaningless.

Hence one has to use the common English definition, which alludes to the thing we do want to know, how *fast* the radiator can dissipate heat. In other words what we are interested in is the output power, not the proportion of energy out vs in.

Except we ain't...

Good, lets all stop talking about radiator efficiency.

You can talk about overall system efficiency, or radiator power...

I can see how you get quiet for a reasonable amount

For you, maybe :-)