I quite agree with Jeremy. Heat pumps are fine for new-build properties where the heating system can be designed around the lower temperatures of the medium. Even in some older properties with existing systems there may be improvements to insulation possible (if not already carried out) which would allow the reduced output from existing radiators to suffice. of course there are HP units available which will produce output temperatures comparable to a boiler, however the higher output temperatures inevitably come at the cost of reduced efficiency.
The BIG problem with HPs, which is a favourite bete noir of mine, is the extra demand they place upon the electricity grid, not only from the loading (bearing in mind recent stories in the media about the dwindling spare generating capacity in the UK) but also the effects upon local distribution networks which -in many rural areas- if not quite the proverbial 'piece of wet string' would then would require much upgrading to cope with the additional demand, with a resulting increase in either installation costs for new supplies or higher bills for consumers to fund the work.
Am I the only one who is a little concerned about the push to install more heat pumps? While the intentions are honourable in reducing emissions/ increasing efficiency etc. has anybody done any serious investigation into how these things will be powered?
We have already had warnings that the UK is heading for power shortages within a couple of years unless more power stations are built, and such things do not happen overnight. So, when the masses decide to opt for heat pumps to replace expensive to run oil boilers or tick the required boxes for building efficiency, will they suddenly discover that this is the straw which breaks the camel's back?
It appears to me that -on the one hand- the government is pushing such technologies as a cure for our energy woes while on the other they are being remarkably tardy in ensuring the necessary infrastructure is in place to support it.
So, what will you do when the lights go out?
Comment on: Radiators out in the cold under the Green Deal
I may be a little thick here, but how does a radiator improve the eco standards of a property?
The only method I can see is to install massively oversized radiators and run the heating system at a lower temperature enabling boilers to run in condensing mode more often. Bearing in mind that most properties of my acquaintance tend to be lacking in places to site such large objects I would suspect that such a proposal would fall at the first hurdle.
I agree that changing the method of control with intelligent TRVs, zoning etc. can bring massive benefits, but the actual radiator itself is a passive object, you only get out what you put in (or through as it happens).
Having checked the voltages present at a couple of sites in different parts of the country it is normally within a hair of 250V. Considering the 'old' standard was 240V +/-6% (ie 225-254V) the new standard of 230 +10%/-6% (216-253V) is not a lot different and in fact was chosen to allow the UK to continue with its existing voltages while the rest of europe harmonised on 230V nominal.
As for the supply being 20% higher than appliance ratings, I suggest a new set of batteries for your calculator as according to mine a 230V appliance subject to 250V is receiving 8% more.
Finally, I recollect something from one of my electrical courses some years ago that motors or other inductive loads are much less efficient when run below their designed voltage, so just reducing the voltage to the stated 230V would cause more problems than it would solve (bearing in mind that the vast majority of inductive loads in this are probably designed for the original 240V).