I've made a REALLY expensive mistake, help!

supertuber

Wow, an incredible amount of inaccurate nonsense written here.

Night storage heating is good in principle, but due to the heat loss during charging and the home-owners absence the amount of useful heat is small. Add to that, modern NSH bricks are less dense that the traditional ones, which although improves appearance, holds less usable heat. If you try to gauge heat need and turn them on/off according to weather/season, you will likely get it wrong more often than not. Forget NSH's with todays lifestyles.

There is no such thing as a magic radiator that will offer LOW running costs, only an improvement at best. New dynamic convector heaters, whether they contain thermal fluid or fire-clay bricks are a big improvement on heaters with a simple element. They DO retain heat and offer a reduced running cost compared to basic elements in a tin box convector heaters, BUT and its a big but, no heating system on the planet can offer low energy usage unless your insulation levels are good and I mean GOOD ... AND your thermostat is quality and correctly placed away from influences. Unit thermostats at floor level are pointless unless you have air tightness from draughts and are wall mounted and correctly located away from cold/hot spots and passive solar influences.

If your current insulation is poor/average and running costs are of main concern to you, an insurance upgrade is required, but be careful what you install. Over insulation and air tightness will likely lead to appalling surface condensation or interstitial condensation within the building fabric unless your ventilation is correct and the correct vapour barriers are in place.

As you live in a flat, space is likely a problem when insulating external walls so rather than 75-100mm of EPS foam, I would go for aerogel blanket bonded to either plasterboard/magnesiaboard with vapour barrier between. It only has a 19mm thickness and can be fixed directly to your solid wall. Its not cheap (£50m2), but aerogel has the lowest thermal conductivity of any known solid, has a lifespan of 50yrs and is hydrophobic so any moisture doesn't affect its performance unlike any other insulation.

If you are between floors and you insulate the walls, weak thermal bridges and have quality windows with trickle vents, your new heating system will operate brilliantly. I know of a room 5m x 4m that has been insulated with aerogel blanket (walls and ceiling) where it has to be very cold before back up heating (500W) is put on. No insulation will heat a home, but 4 people in a room emitting 350W can heat a room to a comfortable temperature if the ambient temperature is above 12C.

With the heating you have, I suggest timing it correctly to suit your lifestyle and during the coldest spells to leave it on v low when not at home if your flat has solid walls. High density walls take a long time to heat from scratch, so don't let your place cool too far.

The answer is always insulation and the better the material (aerogel), the lower your heating needs and energy consumption will be. To superinsulate a 5m x 2.3 external wall inc reveals and bridges is not hard to do and can be done for around a £1200 which may sound a lot, but to reduce your heating costs by up to 70%, its not much.

Good luck

rogerblack

supertuber wrote: »

New dynamic convector heaters, whether they contain thermal fluid or fire-clay bricks are a big improvement on heaters with a simple element.

Improvement in what sense?

supertuber

They hold heat longer than other materials. When a bare element is turned off there is no residual heat remaining in the unit so you are relying purely on thermal insulation to retain the rooms heat, whereas with a thermal fluid or fire clay core the unit will stay warm and release heat even though the unit is not drawing any power.

Under central heating a thermostat recognises the room is at the desired temperature and the boiler stops burning. The hot water in the radiator will continue heating the room until it cools far enough for the thermostat to activate boiler again. An oil filled radiator will stay warmer for longer than water will, a gel or thermal fluid radiator will perform better again and a fire clay one better again so naturally there will be less energy consumption during the heating period.

That all sounds great, but heaters of all kinds have to get the room to temperature before the thermostat will activate and the cores can start doing their job so during the initial period of heating the room it will cost the same regardless of the core (although some radiator designs are quicker than others at balancing room temperature). Once the room is at temperature, a dynamic heater will give reduced running costs than a standard basic heater due to its core, but once again it all comes down to the rooms thermal heat loss. If a room loses 2000w an hour and you only provide 2000w, it doesn't matter what the heater is, it will consume energy for 100% or the time.

A dynamic radiator that can 'store' heat in its core while it is providing heat and continue to offer heat during the period when no power is being drawn naturally costs less to run. Fire clay cores are best for this purpose, but natural soapstone beats anything.

Dynamic electric heaters are a sensible heating choice and can be very cheap to run, but ONLY if your insulation is up to the job. If it isn't, you can only expect improved energy consumption or no difference at all. Any insulation is better than none, but for really low running costs aerogel is the best answer especially when retrofitting.

penrhyn

A dynamic radiator that can 'store' heat in its core while it is providing heat and continue to offer heat during the period when no power is being drawn naturally costs less to run. Fire clay cores are best for this purpose, but natural soapstone beats anything.

It uses energy to put the heat into the core in the first place, so would cost exactly the same to run as any other heater of the same rating.

laptop80

If the big problem is the storage heater being too ugly, why not just fit a cover? Something like this http://i285.photobucket.com/albums/ll64/CamHog123/Radiatorcovers002.jpg perhaps?

Richie-from-the-Boro

Wow, an incredible amount of pork product written here

Join Date: 18-01-2011 - This whole thread from #42 leads to nothing more than an improvement in aerospam sales

#42

Para01 & 03 are ok because it leads to more aerospam in Para04
Para05 & 06 are also ok because it leads to more areospam in Para07

#44

All 4 paragraphs are ok because they lead to more areospam in Para05

This whole thread leads to nothing more than an improvement in areospam sales / advertising by spamming Martin's forum. Now Areospam may or may not have good R-values but its supposed to be the other side of drywall so no use in these applications. At 3 / 5 and 10mm, prices about £12, £16 and £19.50 per square metre in uber insulated homes it may have a place, but boy what a price. Solid walls would need about 30mm of areospam to give any real U~value improvement and at about £60 a meter trade that's an expensive product.

David_Partington

The origininator of this post seemed very easily offended, I think the people who they thought were ridiculing them were just trying to make a friendly joke about the appearance of the feet etc.
Another option would be conventional radiators and an electric boiler (in effect a big kettle), they are available but I don't know how the running costs would compare with what you have.

supertuber

Heat is a balance of power and thermal energy. Thermal energy is an internal molecular property of a material. The same mass of different materials can 'hold' different quantities of heat. Heavyweight masonry materials, such as fire clay have high densities. This means small volumes of these materials have a large mass and therefore provide a high heat capacity within a small volume.

A high capacity radiator will take just as long and perhaps longer to heat a room as a low capacity radiator because the unit material must also be heated, so you're right that it will use the same amount of power (+) to bring the room to temperature. Once the room is at temperature, thermal energy within the core takes over and provides 'heat'. Why do you think kiln ovens, pizza ovens, modern wood burners are lined with fire clay? That's right, to reduce fuel costs.

Fire clay radiators have the properties needed to provide 'thermal heat' for longer, but as I have already stated, they are pointless if your home has high thermal heat loss. I should also state that some of the claims made by radiator sales companies (30%in the hour) are misleading to say the least. Their 'potential' to lower running costs is correct, but they are miss-sold as magic radiators by ex-double glazing salesmen.

Moving on to aerogel. Am I happy to sing its praises and hope sales quantities rise? Of course I do, it will become cheaper. It's the world's BEST insulator whatever its application and solves many tight space insulation problems (my camper being one) and the need to move domestic services which adds cost and time to a job.

Yes, its dear, but not that horrific when you do the sums and the extra cost often well worth it. I don't need to write an essay on Aergel blanket benefits because its quite simple:

Aerogel thermal conductivity - 0.014
EPS thermal conductivity - 0.040
Do the math

I have nothing to do with aerogel sales by the way, I'm just stating the facts. Something that is missed on many MSE forums.

Richie-from-the-Boro

Ok, I'll do the math on Aerospam.

Average lounge, north facing, cold room, fully glazed etc. 3.5 x 5.5 x 3.1m, that's a smidge under 30m2 of internal insulation to the two external walls. Even at the cheaper price of aerospam @ £25/m2 retail and discounted that works out at £750 for the two walls, and then people need to pay for re-boarding.

NOTE : For your comments on """30%in the hour""", put the word > snake < in the 'search this forum' button on the TRHS of the page.

supertuber

Hmmm, you may live in a Georgian mansion, but average ceiling height is 2.4. Therefore your calcs should be 13.2m2 + 8.4m2 - 3m2 (windows) = 18.6m2

18.6 x £25 = £465. Add a further 4m2 for reveals and partition walls returns to reduce thermal bridging makes it £565

Typical u-value 1.7 w/m2k for 350mm stone/brick wall. To bring it down to 0.50 wil require 19mm of aerogel (thermal conductivity 0.014)

Not cheap I grant you, but look at the alternative.

EPS would require 75mm and would need to be battened for fixing which creates unwanted thermal bridges unless you use aerogel strips to combat it. This is used by any timber frame building company that wants to he job properly. Plus on a retro fit, reveals and thermal bridging from partition walls would suffer so the overall u-value naturally rises, although not by much.

Same m2 area for EPS = £154 saving £411, but losing extra 0.5m2 (2.5%) of room size PLUS likely cost of extending electrical points.

If you wanted to to the job right, the partition walls would need insulating 500mm from external wall, but with EPS this would leave a return on the wall of about 90mm. This is ugly so for a clean wall, you'd probably take it all the way back meaning a further cost of £180 and any electrical work so total insulation cost would be around £334. Saves £231, but means losing (3.5-5%) overall floorspace depending on partition wall insulation depth.

Aerogel isn't the cure all, single option and it is about 40% more expensive, but it saves space and potential extra hassles. Do I care if you buy it? Couldn't give a monkeys, it's your money. But I do care that it's benefits are misrepresented by people who clearly know very little about it.