Is gel heater really cheaper to run than a normal electric heater?

[daxu]

Hi,
I got a normal electric heater (not storage heater) and my place doesn't have gas pipe.

Yesterday I got a builder to fix something and we chatted how expensive my heater's running cost is. He think I should replace it with a new gel heater, as:
1. new heater's thermostat are much more accurate than my old one.
2. A gel heater (1.5kw one for example) costs the same to a 1.5kw electric heater to run in the first hour. But the second hour the running cost will be half. I wasn't too sure why it is. Maybe the gel is slower to cool down or something?
3. You can set a minimal tempeture (e.g. 8 degree) on new heater, so it guarantees that your room won't be frozen.

He think that a gel heater is cheaper to run than storage heater (at least for my case, as no one is in during the day when storage heater releases the heat)

I start to do some research on gel heater, just wondering is it really the case?

many thanks

Jerry

 

[JohnD]

No.

An electric heater, or any heater with a thermostat, uses less energy once the room has become warm, than when it is trying to increase the temperature of a cold room.

 

[stem]

For the same heat output the costs will be the same.

Electric resistance heating is virtually 100% efficient, so any heater rated at 1.5kW will produce 1.5kW of heat.

Heaters with a thermostat will turn off the heating element when the set temperature is reached, so may use less energy once the room is warm, but that applies to all of them. If the current heating doesn't have a thermostat and the room is too warm for you, then a thermostat will stop this happening and save some energy, if not it won't

Gel and oil filled heaters are slower to cool which is correct, but they are also slower to heat up, so what you gain at the end is what you missed at the start.

 

[endecotp]

2. A gel heater (1.5kw one for example) costs the same to a 1.5kw electric heater to run in the first hour. But the second hour the running cost will be half.

Nonsense, he’s an idiot.

 

[oldbutnotdead]

Untrue. Its all physics- to warm the room you need energy, which inyour case comes through the electricity meter. Different types of electric heat may give different perceptions of warmth but thats about it. I find fan heaters more effective than radiant heaters but they are noisy

 

[ericmark]

As @stem says "Electric resistance heating is virtually 100% efficient." however you can also look at efficiency being how much heat is used vs how much heat is required. So if a room is used for 1 hour and to pre-heat the room prior to use the heater needs to be on an hour before that then it uses more energy to a heater that needs to be on ½ before use so if the heater never turns off then we could say the 1 hour pre-heat is 50% efficient and the ½ hour pre-heat 66% efficient and I have seen it expressed like that, however the heater will not be on all the time, it will start to cycle, and as the fabric of the room heats up the on part of the cycle will reduce, so yes time to heat up the room can affect how efficient, but not to that extent.

So an inferred heated is more efficient for short term use of a room because it heats up so fast, but it is also hard to control, a heat pump is more efficient but it costs more and has higher maintenance costs, so we want a heater which heats up reasonably fast and is easy to control in a way to stop hysteresis of the temperature, fan heater is great for a kitchen, but too much noise for bedroom where a oil filled radiator would be better, the problem with any panel heater is the thermostat built in relies on thermals being set up to bring the air to the thermostat to be measured, so bottom of stairs does not work very well as takes ages to start the circulation.

So there is best for that location, but not a simple best. As yet I have not seen occupancy detect and geofencing used with electric, there is it seems no reason why the energenie socket should not be set up same as energenie TRV, I read they can, but think they use IFTTT (stands for if this then that) protocol, it was free, however there was talk of charging for it, don't know if that happened, and although read it can be set up, never bothered as my wall thermostat turns off the boiler, using occupancy detect and geofencing and if boiler not running then neither are radiators, so only time set on radiators.

What we want is dedicated sockets on a contactor (electric operated switch) which will connect to some thing like Nest so it can like with wet central heating control when it all turns on/off. But as published if we are all going to be forced to use electric and we are going to build a fleet of nuclear power stations and an infrastructure of car charging points, and finally finish electrification of the railways after being doing it for some 50 years, longest and biggest construction job in the country, then I am sure all the control stuff we need will arrive on the market soon.

In 1990's I wanted to protect my children from electric shock and I had to use two fuse boxes converted with trips, and a box feeding them with two RCD, last year wanted to do this house and could buy off the shelf a special box with it all built in called a consumer unit, the technology was there in the 90's but not the market forces.

So if you spend a fortune now on electric heating systems, you will likely find in a few years time there will be far better systems due to market forces, we have the technology now, but not the will to use it. Where I work we still heat the mass transit transport using steam, it is heated with the steam when the engine has excess, and turned off when the engine is pulling the train up a steep hill, but the modern diesel and electric trains don't use the waste heat not used by the engine but independent diesel and electric heaters because of the work involved in connecting steam pipes up when adding or removing carriages. Some times it seems we are going backwards?

 

[daxu]

Nonsense, he’s an idiot.

Interestingly, I talked with my neighbour, who had the same wall heater (as it comes with the flat) and then replaced with an oil based heater. He said his electricity bill is indeed better now and said I should throw my heater away.

 

[stem]

There are external forces that come into play here. Maybe the new heater is more accurately controlled than the old one, the weather has been warmer, perhaps his home isn't as warm as it was before, maybe he's changed electricity supplier for a cheaper deal, replaced incandescent lightbulbs with LED's, fitted new windows, stopped growing Cannabis. etc, etc. At the end of the day with restive electric heating each kW of electricity will provide one kW of heat regardless of the device it comes from.

 

[endecotp]

Interestingly, I talked with my neighbour, who had the same wall heater (as it comes with the flat) and then replaced with an oil based heater. He said his electricity bill is indeed better now and said I should throw my heater away.

EDIT, silly me, I see you wrote very clearly “Not storage heater”. So the following is all irrelevant, sorry.




Storage heater, right?

These are certainly going to be less useful for people who are out during the day than for people who occupy the house continuously. If you don’t need the heat till the evening, you need the heater to be very good at retaining the energy during the day. I think there are some that can open their outlet vents on a timer; if yours don’t do that then you need to manually do it when you get home in the evening.

According to https://www.moneysavingexpert.com/utilities/economy-7/ Economy 7 night rate is about 9p versus 14p for non-economy7. So if 5/14ths (i.e. about a third) of your storage heater energy is wasted during the day when you’re not there, it works out no better than using e.g. an oil filled radiator on the standard rate.

There is a difference between living rooms, where you need the heat in the early evening, and bedrooms where you don’t need it until later. If you currently have storage heaters everywhere, consider replacing the bedroom ones first and seeing what happens. (Except of course that means paying the economy 7 higher rate, hmm.)

(You are on an economy 7 tariff, right?)

Regarding “external factors”, in my experience in a flat one of the most important ones is how hot the flat downstairs is.

 

[endecotp]

Interestingly, I talked with my neighbour, who had the same wall heater (as it comes with the flat) and then replaced with an oil based heater. He said his electricity bill is indeed better now and said I should throw my heater away.

Proper answer this time, not off on a tangent about storage heaters....

It is certainly true that a thermostat and a timer can reduce the cost of electric heating. The most important thing, IMO, is that they are easy to use so that you actually bother to set them and don’t waste energy heating the place when you’re not there or hotter than you need. (I’ve seen some student places with a button that you press for 30 mins of heat - that’s the ultimate economical heating system.). There are also subtle issues of human perception of temperature - for example, we feel warmer when the temperature is rising than when it is falling, so a room that slowly warms from e.g. 16 to 18 degrees over the course of an evening might be perceived as warmer than one that falls from 19 to 17.

There is, however, a surprising amount a snake-oil mumbo jumbo about the efficiency of heating systems. Remember that, apart from heat pumps, all electric heaters convert 100% of the electrical input energy into heat. That’s a very fundamental bit of physics and anyone who tells you otherwise should be ignored.

 

[JohnW2]

There is, however, a surprising amount a snake-oil mumbo jumbo about the efficiency of heating systems. Remember that, apart from heat pumps, all electric heaters convert 100% of the electrical input energy into heat. That’s a very fundamental bit of physics and anyone who tells you otherwise should be ignored.

Indeed - but, although it is an inescapable fact that a certain amount of electricity will always produce the same certain amount of heat, that doesn't mean that one should not consider the relative merits of different types of electrical heating - since, as you and others have said, both the patterns of actual heat production/distribution and individual's perception of heat vary appreciably.

Some (like fan heaters) rapidly heat a room when they are switched on but stop heating it immediately they are switched off. Others (e.g. oil- or gel-filled) will heat the room much more slowly at switch-on, but will carry on heating for a significant time after switch-off. Some (those employing radiant heat) will primarily heat just objects (like people) without having much effect on air temperature, whereas most heat the air in the room. And, as you've just said, things like rate of change of temp can have an effect on perceived levels of 'warmth'.

Hence, whilst it's crazy to try to defy the Laws of Physics, it does make sense to consider what type/pattern of heat production and distribution best suits one's personal needs and preferences. There's probably a lot to be said for fan heaters, since they are probably the method which most readily allows one to 'have heat' (and spend money on it) only when one actually needs/wants it.

Kind Regards, John

 

[ericmark]

I am personally undecided about fan heaters, as @JohnW2 says fast heating and fast cooling, but stirring up air can mean blowing warm air past cold walls or windows. My first house had hot air central heating and it cost a fortune to run, likely as at that time no double glazing and unlike radiators air was being circulated.

@endecotp also has a good point, this house the radiator is a long way from wall thermostat, so in the morning it steps up 0.5°C per hour, and even when showing 18°C I don't feel cold, but in the evening when it turns down from 20.5°C to 17°C over night, I quickly feel cold even when it is still at 20°C.

There is a balancing act, electric contacts switching 2 kW ever 5 minutes will not last long, so filling the heater with oil or gel so they switch every 20 minutes means they last longer, but it takes longer before you feel the heat, and also longer to cool down when finished with and that heat is lost.

However at 20p per kWh the difference is likely less than 20p per day, you are unlikely to be able to measure the difference, I bought an energy meter, and had to play of course, and yes heat loss is logarithmic not linear to temperature, so yes any heater which over shoots wastes heat, but that is down to control not type, so when @stem said

At the end of the day with restive electric heating each kW of electricity will provide one kW of heat regardless of the device it comes from.

he was spot on.

 

[JohnW2]

I am personally undecided about fan heaters, as @JohnW2 says fast heating and fast cooling, but stirring up air can mean blowing warm air past cold walls or windows.

Very true, but equally true of what happens above the radiators of a conventional wet CH system, or any sort of electric heater ('convector', oil-filled or whatever) positioned (as they commonly are) near to a wall.

Kind Regards, John

 

[ericmark]

I have questioned the placing of a radiator under a window many times, the problem is the thermostat traditionally is on the opposite wall, so in most cases either the radiator is on outside wall which means hotter air against outside wall, or thermostat on outside wall which means it reads lower than actual as cooled by outside wall.

However place thermostats around the room and it becomes apparent air does not move that fast, at moment thermometer on living room window sill is showing 31.7°C but radiator just below the window is showing 20°C and one diagonally to it shows 22°C. Clearly the thermals are not evening out the room temperature.

In mothers house I experimented with thermostat position, and found setting on the low side and close to radiator actually worked better than opposite wall sitting on the gas fire so not in contact with the wall but thermals are slow moving the air around, so you get a large hysteresis if the thermostat is too far from heat source.

So at the side of the heat source low down around an inch from it is not so bad as it seems, and my TRV with duel sensors that compensates for water temperature is to be far rather good at controlling the room temperature.

The chimney effect is well known, so two panels with a gap between them works far better than a larger area but no chimney effect, which is why the double panel radiators works better than old school type cast iron type.

This all means what works A1 in one house can be rubbish in another, which is why the rules of thumb often don't work, like not putting a TRV in same room as a wall thermostat, it will work where the room is normally cool, has no outside doors, and no alternative heating and is on entrance floor, but on the entrance floor every one of my rooms has an outside door, except for toilet/shower room and with an extractor fan and radiator set reasonable high as one gets undressed in that room, that is not suitable either.

So one needs to think, and weigh up how house is likely to heat, and how best to control in your house, not walk around blinkered. Life style also matters, retired it is rare the house in winter does not have one of us in the house, so some room is always being heated. But when younger it was common for house to be empty 7 am to 6 pm, so heating could be off while not at home, the return time was variable and I looked at geofenceing and occupancy detection, however the TRV I have does not have a learning ability (think the Hive one has?) so the anti-hysteresis software means the temperature raise tappers off sharply as the target is approached, so heat from 10°C to 18°C reasonable quickly, but 18°C to 20°C quite slow, and in the main house does not cool to 10°C it only cools to 17°C so the geofenceing and occupancy detection means coming home to a house nearly as cold as it would be if you manually turned on the heat when you came through the door, again time taken from work place to home will change that, but for many people simple timed works better.

Some "Smart" thermostats do work out the time taken to heat the home, Nest wall thermostat and as said the Hive TRV I think does that, so it can heat flat out until the crucial point and then start reducing the output, without over shooting, and for geofencing that is important, however the Hive TRV costs around £50 and a simple programmable TRV costs £10 so it seems we are looking at £40 per unit to get reasonable control required for geofenceing and occupancy detection.

So I googled "electric heater with geofenceing and occupancy detection" and got this result the price tag of £432 is rather off putting. When I can get a heater from Argos at £37 how long would it take to save £395?

It seems we have all the controls for wet central heating, but with non centralised heating there are not enough made, so we look at silly prices. So maybe we need a return to the old Economy 7 wiring even if not the tariff, so all heaters can be switched on as we start on our way home? Well not me I am retired, but those who will likely be forced into electric heating.

Look back just 30 years ago, and although we had RCD's to buy a box with a RCD for every circuit would cost an arm and a leg, today they are stocked in every electrical whole sale outlet. So in even 15 years time likely electric heater with geofenceing and occupancy detection will be common place and cheap, do you remember the prices for the early LED watches, my friend in around 1975 paid around £200 for one, a year latter LCD came out and it was worthless.

So at moment I would keep it simple, and wait and see what market forces cause to be made. I was telling everyone how bad Hive was compared with Nest, then Hive released their TRV head and Nest withdrew support for the one that worked with their wall thermostat, so they have switched position. Now wish I had Hive not Nest. But in 6 months time would not be surprised to see a Nest TRV so maybe they will swap again.

So some one in 6 months time will find these posts as say what a load of nonsense because some thing new has been released.

 

[daxu]

Very true, but equally true of what happens above the radiators of a conventional wet CH system, or any sort of electric heater ('convector', oil-filled or whatever) positioned (as they commonly are) near to a wall.

Kind Regards, John

Hi,

Can you recommend a wall mounted electric heater? Base on what you guys saying, seems anything with an accurate Thermostat, 7 Day Timer and Anti Frost Function should do the trick.

I checked on amazon, seems any wall mounted heater with oil or gel are costing more than 200£. Then a normal heater with LCD Thermostat is around 70 or 80£.

Thanks