Our omakotitalo has direct electric heating via radiators, and we recently installed air source heat pumps for both floors. They are supposed to be enough for our heating needs in mild to cold weathers, but supplementing them with direct electric heating is recommended for harsher weather.
Our radiators are old and I have been told by a couple of people that replacing them might be a good idea to improve efficiency, especially given the rise in electricity prices. But ever since I watched [this video by Technology Connections](https://www.youtube.com/watch?v=V-jmSjy2ArM), I was under the impression that there isn’t a lot of efficiency to be gained from switching to newer electric radiators. Is that wrong?
Recently a local electricity company sent an installer to come and take a look, but he didn’t know much about the savings that I stood to gain from making the switch. He focused on the precise heating needs per sqm and how the installation would go. He gave us a quote of 3000 euros to replace the heaters of the entire house (125 sqm) and I’m trying to figure out if it’s worth it.
For reference, here’s one model he recommended for our living room (biggest room in the house):
https://www.onninen.fi/nobo-lammitin-nobo-front-nfk4n-12-1-25kw-ip24-40x93cm/p/CFN477
This (above) 1250W model will replace this old 1200W model:
This is just one of nine radiators that would be replaced in this plan. Installing the heat pumps was an easy decision due to how efficient modern ones are, but I’m having a hard time convincing myself that this would be worth the investment. I’m mainly approaching the issue from the perspective of savings, but would love to hear other considerations that you think may be important. Thank you.
13 comments
You would get better efficiency by installing a heat-source pump. An electric radiator is such a simple concept that I’m doubtful that modern radiator would be noticeably more efficient.
Any electric radiator basically radiates all the electricity they consume as heat. You might want to replace them for safety purposes, but they won’t be any more effective.
Unfortunately not really, at least directly. The load is resistive so there’s no way to increase efficiency by switching to a similar sized but new radiator. They are in essence just big resistors in a housing. New ones might have better air flow which would warm the surrounding air faster, but I feel that the effect on your electricity bill would be negligible. I would suggest relying on the air pumps as much as possible, it’s what I’m also doing atm.
Source: I’m an electrical engineer.
Old electric radiators are just as efficient as new ones because they basically convert everything to heat. The new one in the example you showed will consume more because it has a higher wattage.
Yeah, there’s no difference on efficiency. The only saving would come from if your current radiators have bad thermostats.
My advice would be … not worth it, if they work properly
You actually can save if you buy different kind of radiators. There are ones that store heat (massavaraaja). You can keep them on during night and they release heat during the day
1200 W is 1200 W, doesn’t make a difference whether they are new or old. I considered this change some 15 years ago, an electrician came over, looked at them and said there’s nothing wrong with them. To my knowledge they still work.
In case of a fault, the radiator either goes dead, drops less current, or creates thermal losses, which in direct heating is a wash.
No 1000w in 1980 is still same as now only what changed is some has fan which helps distribute heat faster
As people have said, turning electricity into heat is basically 100% efficient, so the new ones won’t be any better at doing that.
Instead, you could look into heat pumps. They are often **more** than 100% effective, as they can move more heat inside the house from outside than you could produce with the same electricity. This is possible, because we can move heat more effectively than straight up convert electricity into heat.
There is no need to change them if they are not broken. Just keep them clean from dust. Dust reduce efficiency and might cause fire hazard.
The new one has better airflow and probably better control electronics, but otherwise both are 100% efficient in converting electricity to heat. And maybe look better.
Use the heat pump, they are much more efficient in heating.
Forget updating radiators if they are not broken. No benefits there. Except maybe those that have a blower spread out heat faster, but no efficiency boost just comfort (or not if the house is good, then the blower is useless).
Go for the heat pumps. My parents installed 2 to their 115 sqm house and use fire place to support those on very cold weather. Saves a lot.
Keep the radiators, just tune thermostats to 18-19C or so. Heat pumps to 20-22C. If your heatpumps cant keep up, radiators will help. If heat pumps fail, radiators will save your water piping from freezing if you are away.
Just remember to do yearly maintenance to those. Basically
– Remove filter, clean all the dust away.
– Blow compressed air (bottle or compressor) trough the heat exchanger element inside the house to get all dust away there.
– Check that there is no crap in the condense piping, you dont want it to get blocked.
– Outdoor unit: clean out all leaves etc crap. To maintain top efficiency blow compressed air trough the heat exchanger element. Check condense piping.
And this way you save 200-400€/unit for yearly maintenance.
They should last 15-20 years. My summer cottage has fine running 25y old unit, but I dont trust it anymore.
No. The only caveats being that it needs to have minimal obstructions, specially the backside flow can slow down but even then.. it’ll even out over a day. You may lose some thru the wall but it is minimal compared to ideal flow. Resistive heating is 100% efficient, and water heaters are similarly giving out all of the heat they have. If the return water is hot, then the heater unit does not need to work as hard.
With electric heating there are some possibilities for savings. Heat storing is a thing, oil filled electric radiators are quite awesome since they can store heat when electricity prices are low and use that stored heat to release when prices are highest. There are also other storage solutions, world is your oyster when it comes to making your house more energy and cost efficient… strangely, we are somehow focusing a lot of attention to those things.. weird, isn’t it that demand is growing and supply is answering… One of the few areas of life where that concept works very, very well is to fill out sudden demand spikes in completely new areas. Once we standardize and regulate and then mandate, things are looking good in this area.
There are loads of solutions available, some are cheap, some are reliable when it comes making your heating smart. Easiest way to do is to get programmable wifi receptacles: Basically a plug and socket, with a control board between that can shut off the power when told to. The automation goes so far that it can check the current market price and turn things on and off based on that.. And the good and bad news is that DIY is quite cheap, with not a lot of smartness requires from the user but familiarity with some type of automation, home network and “how to upload firmware to a Raspberry pi” is the level of expertise needed. The bad news is that commercial side is expensive and vendor locks are all over the place.. but here i have to admit that i don’t actually know, i just assume based on 30 years of working with stuff that is easy to vendor lock and this sounds exactly like that.. I know that DIY is surprisingly simple, but then again the complexity of logic needed could be done with ~~commodore 64~~ VIC 20 and MS BASIC, if it had external processing for wifi and internet..
Insulation and clever ventilation are very important. Heat exchangers are very handy for keeping your indoor air fresh without losing energy. The simplest DIY i know has 6m of outer and 12m inner tube and that can get you +18C incoming air when outside temperature is -22C and indoor air +22C… That is 40C of warming with 40W duct fan. I consider that free. And of course, heat pumps are the final answer, they are too clever and reach over 100% efficiency as they use the heat of two difference spaces, pumping it from out to in. If you want to go over what is sane, you start to look at hotspots in your roof, utilizing hot pockets that can be well over 20C higher than the outdoors temps (read: my dad retired, now he is making a heat exchanger that collects sun light as heat…Which is not as stupid as it sounds, falls and springs are longer now. And they turn of heating in April and turn it on at September, have cool house during summers.. Whatever the old man is doing, it fucking works so if he is doing that, it will then make sense… Thousands saved each year, and a lot of that is coming from that one over sized heat exchanger that has been there since 1984).