Safety and steady heat are the hallmarks of these electric heaters
Oil filled space heaters are a good choice for heating individual rooms of your home if you don’t have central heating, or if you want to save money on heating by turning the central heating down and heating selected rooms.
But there are a couple of myths we should clear up first. I did a quick survey of other websites that cover these heaters, and found the same two kinds of misleading information on many of them. Let’s cover each of these myths in detail.
1. Efficiency of electric heat in general
People trying to sell you an oil filled space heater will try to convince you that oil radiator heaters are more efficient than other types of heaters. There are a couple of problems with the efficiency argument. In the first place, electric heat is one of the least efficient forms of heat in terms of its ability to convert a fuel source into heat. There are two conversions you need to think about. The first conversion is that you have to convert the energy source to electricity. If the energy source is a fuel such as coal, natural gas, oil, or nuclear, then it is used to create steam which in turn drives a turbine to produce electricity. This conversion process is typically 30-40% energy efficient, because 60-70% of the energy from the fuel (or nuclear fission) is waste heat at the power plant. So from the outset, electric heaters are a maximum of 40% efficient when the electricity is generated from a thermal source – compared to natural gas furnaces which can reach efficiencies of up to 96%.
The second conversion occurs in the electric heater itself. Your electric heater converts electricity to heat at 100% efficiency – because of the second law of thermodynamics, there is really nothing else for the electricity to turn into other than heat. Even electric heaters with a fan, in which some of the energy goes to driving the fan, are still 100% efficient, because eventually the kinetic energy used to drive the fan produces friction in the moving air molecules, and in the moving parts of the fan, and that kinetic energy turns to heat because of the law of entropy. So when you see marketeers trying to convince you that their electric heater is 100% energy efficient, you will know that they are trying to dupe you into thinking their heaters are more efficient than someone else’s. And when they tell you their heaters are almost 100% efficient, they’re trying to dupe you with modesty. The fact is:
All electric heaters are 100% efficient at converting electricity to heat, but electricity is still the least efficient way to produce heat from a fuel source.
2. Efficiency of oil filled radiators vs. other electric heat sources
The other myth you’ll see repeated endlessly is that oil filled space heaters are more efficient than other forms of electric space heaters. As the above explanation makes clear, there is simply no way for this to be true. What is true is that oil filled space heaters are more effective in certain situations, namely where you want a very steady flow of heat. Why is that? Because oil filled space heaters have thermal mass: instead of heating an air space directly as a convection heater does, or heating solid objects from a distance as a radiant heater does, an oil filled space heater heats the oil inside the heater, and that oil in turn heats your living space. The oil acts as a buffer, slowly letting out heat, so that you won’t burn yourself or set fire to your house with a red hot heating element exposed to the air. So to clear up myth #2, the fact is:
Oil filled electric heaters are no more efficient than any other form of electric heat. They are just more effective in situations where you want diffuse, evenly distrubuted heat over a large air space.
Efficiency of the heater vs. efficiency of the heating regimen
Many people claim to save energy by heating with electric heaters such as electric oil rad heaters. The truth is that the savings come not from the type of heater, but from the flexibility that electric heaters offer. When you have central heating, it can be pretty hard to set different temperatures in different rooms at different times of day. And your whole house may wind up being either too warm or too cold. But you can place electric heaters strategically around your house – or even wheel them room to room if the rooms are on the same floor – and only heat the rooms you need to use at the moment. This is the main place that cost savings come into play with electric heaters of any type: the fact that they allow you to heat a smaller space than a central heatng system typically does.
Oil filled vs water filled
There are a couple of water filled space heaters on the market, such as the Westpointe water filled convection heater. What are the differences between water filled and oil filled space heaters?
One of the main advantages of oil-filled space heaters is that diathermic oil has a much higher boiling point than water, which means there’s very little vapor pressure build-up as the oil gets heated. With water filled space heaters the radiator material needs to be made stronger to withstand the added pressure as the water heats towards the boiling point. While water has a higher thermal capacity than mineral oil (roughly 2.5 times as much heat can be stored in a liter of water as in mineral oil) the added weight of the material required to contain the water means that water-filled space heaters wind up being heavier and therefore harder to move around. (Water is also denser than mineral oil, although not by that much.)
Oil also has a lower thermal conductivity and therefore higher thermal inertia than water, which means it can act as a buffer in averaging out the amount of heat radiated by the heater as the element switches on and off.
If you need heat quickly – for example, you come home late at night to a freezing cold bedroom and want to warm the room up quickly – an oil filled space heater is probably the least effective way to warm the room up: because of the high thermal inertia of oil, by the time the oil in the heater has warmed enough to provide substantial heat to the room, you’ll either have fallen asleep under a mountain of blankets, or have died of hypothermia. A water filled space heater will warm more quickly, and therefore warm the room more quickly, but for this type of quick heat the best solution is a convection space heater, which will warm the air directly without an intervening liquid.
In case you are interested in the specifics: water has a thermal conductivity of 0.6 watts per meter kelvin, while mineral oil has a thermal conductivity of about 0.14 W/(mK). So it will take roughly four times longer for oil filled space heaters to warm up as water filled space heaters.
This brings up another myth of oil filled space heaters: Some manufacturers claim their heaters are filled with a ‘special heat conserving oil’. But the thermal conductivity of oils ranges from 0.1 to 0.21, which relative to water would mean that any oil is a special heat conserving oil. It’s just marketing.
Drawbacks of oil filled space heaters
There are three main drawbacks worth considering when you are thinking of buying an oil filled space heater:
- Oily or chemical smell on first use
- Bulkiness and difficulty of moving around
- Risk of oil leaks
Oily or chemical smell on first use: Oil filled radiator heaters are sealed units, and if properly manufactured there should be no oil appearing on the surface. However many consumers report unpleasant odors from these heaters, especially the first few times they are used. There are two reasons for this: the first is that tiny amounts of the oil used to fill the space heater may be present on the surface. The second is that the paint coating on the space heater may give off a chemical smell. However, in most cases the smell goes away within a few days. Many manufacturers recommend turning on their oil filled space heaters in a well ventilated place for a few hours before they are first used in a more confined space.
Bulkiness and difficulty of moving around: Naturally an oil filled space heater is heavier than a ceramic space heater or a radiant heater (although as previously noted, it should be ligher than a water filled space heater). Most of these units come with casters so you can roll them from room to room. But there are a couple of problems – often the casters don’t roll well on carpets, so if you have a lot of carpets or rugs, be prepared for the occasional snag. And some models are poorly designed in terms of their mobility, in that they don’t provide proper handles to hold while moving. While oil filled space heaters don’t generally get hot enough to cause burns, you’ll be hard pressed to hold onto the radiator itself for more than a few seconds without feeling discomfort, which makes it hard to move a heater that doesn’t have proper handles.
Risk of oil leaks: This is the biggest drawback of oil filled radiator heaters. If they are poorly made, you could be in for an unpleasant surprise down the road. A slow leak may manifest itself simply as an unpleasant smell like that of heated motor oil – just enough oil is seeping out to get onto the surface of the heater, and the heating cycle causes volatile organic compounds to evaporate from the surface, creating the odor. If your heater starts producing this smell after burn-in, check it carefully for any sign of leaks. And if it produces the smell for more than the first day or two of use – that is, if burn-in doesn’t address the initial smell problem – send it back to the seller.
But even worse than a slow oil leak with its accompanying unpleasant odors is the sudden leak of large quantities of oil. While this is a rare occurrence, it can be a costly one. A carpet soaked in mineral oil is not going to be easy to clean, and the smell will be with you long after you have tossed the heater in the trash bin.
Best uses for an oil filled space heater
The main reason I would recommend oil filled space heaters is for people who pay different electricity rates for different times of the day. Because oil has good thermal inertia, you can arrange for your heater to fire up when electricity is cheap, and still get some benefit from the heat when electricity is more expensive and the radiator is switched off. For example you can put an oil filled space heater on a heavy duty electric timer (be careful to buy one that supports the high amperage of space heaters – not just any timer will do), and have the timer switch on an hour before you wake up, since electricity in winter tends to be cheaper before 7am, before people are out and about and manufacturers and offices start using large amounts of electricty. Most people can get buy with temperatures in the high 50’s and low 60’s in their bedroom if they are in pajamas and buried under blankets, but it’s hard to get dressed in a room that cold, so setting an oil filled space heater to heat up an hour before you wake up is a pleasant and efficient way to wake up and dress in comfort.
On the other hand, a water filled space heater can hold roughly 2.5 times as much heat as an oil filled space heater. While it will radiate heat more quickly because of its higher thermal conductivity, it will also hold a lot more heat so you’ll be able to capture more during the low rate period.
Another good reason to buy oil filled space heaters instead of convection fan heaters is that oil filled space heaters are virtually silent. If you have trouble sleeping to the sound of white noise, the fan of a convection fan heater will keep you up. The only noise you will hear from an oil filled space heater is the occasional creaking caused by thermal expansion or contraction of the radiator metal, as the unit warms or cools, but this is infrequent and almost inaudible because these heaters tend to keep a fairly steady temperature. Even baseboard heaters – or convection heaters without fans – tend to be noisier, as their thermostats cause the heat to turn on and off, which makes the metal in those heaters expand and contract more noisily.
On the other hand, if white noise helps you fall asleep or stay asleep, maybe a convection fan heater is the way to go.
Safety is another consideration: it is much harder to burn yourself (or for a small child to burn themselves) with an oil filled radiator heater than with a convection or radiant heater, because the heating element heats the air only indirectly through the oil, not directly. And it is much harder to tip over an oil filled radiator because of its bulk and weight.
Finally, other than the caster wheels that some oil filled space heaters provide so you can easily move the units around, these electric heaters have no moving parts to wear out, unlike convection fan heaters which have a continually moving fan.
Best brand of oil filled space heater
I would recommend the Delonghi brand of oil filled space heater over most others. For one thing, they have been building these units for many years. They have a solid reputation for dependency. For another, many Delonghi heaters are made in Italy where standards of manufacturing quality are reasonably high. Delonghi does seem to have moved some of its manufacturing to China, which may explain why some of the more recent models get the occasional bad review, but on average 8 out of 10 Delonghi customers seem to be at least satisfied with their purchase (with nearly half being extremely satisfied) and Delonghi offers a better selection than just about anyone else.
A digital model is a worthwhile additional investment. While digital models are more expensive, they offer finer-grained control over temperature: you can actually set your heater to a particular temperature and have that temperature maintained. Most oil filled space heaters simply have a number dial, and you choose a setting between 0 and 9 or 1 and 10 without really knowing at what temperature the thermostat will shut the heater off. With a digital thermostat model, the heater will shut off when the desired temperature is reached, so if you know that 70F is your comfort temperature, you can set the heater to that temperature.
Honeywell makes one digital oil filled space heater that comes highly recommended: the HZ-709. This heater is a little more pricy than some but is very solidly built, includes a 12 hour timer so you can set it to switch off, for example 9 hours after you start it, if you want to be sure it doesn’t keep running after you’ve risen and gone off to work. Its quality is backed up by a 3 year warranty, and consumers report it is very quiet and odor-free. You can set it as high as 85F and you can also choose a heating speed, from low through medium to high, so whether you want a slow build-up of heat or rapid heating you’ll have your pick.
One final thing to bear in mind about oil filled space heaters: if you have any sensitivity to dust, you’ll find these heaters preferable over fan-based convection heaters – or even forced air furnaces – because there is no steady blow of air sending dust swirling about the room. For anyone with allergies an oil filled space heater can provide plenty of comfort in an enclosed space, at a fraction of the cost of keeping an entire home warm.
We have my gran’s old cottage in wales and want to leave some heating on over the winter whilst nobody is living there so that it doesn’t get damp – it is heated by a Rayburn which we can’t leave on…so I was thinking of getting some oil filled electric heaters – just 2 maybe – and leaving them on low. Is this safe though?
If you want to keep your gran’s cottage from getting damp in the winter, rather than a heater I suggest a low temperature dehumidifier as described in the “Extra Cold Basement?” section of my article Energy Efficient Dehumidifiers. A low temperature dehumidifier will take moisture out of the air, will produce heat, and can operate at temperatures as low as 5C. For example, the Frigidaire 50 pint dehumidifier is a low temperature dehumidifier. It can be hooked up, with a drainage hose, to a nearby drain, so that it can draw moisture out continuously.
I don’t know how cold it gets in the part of Wales where your cottage is. If it does get below 5C, then you could combine an electric heater and a dehumidifier. Put the heater on a plug in thermostat and set the thermostat to only turn on below 7 degrees. That way the heater will only heat the cottage when it is cold enough that the dehumidifier will shut off. The end result of this combination will be to minimize moisture and minimize heating costs. The alternative is to use just an electric heater and a plug in thermostat that shuts the heater off above a certain temperature (electric heaters have thermostats too but most of them cannot be set to a low temperature) but I am pretty sure you will use more electricity with just a heater, or get less moisture out of the air, than with a dehumidifier or a dehumidifier and heater combination.
As to whether oil filled heaters are safe, yes, they are. But they do not give any advantage for your situation over any other type of electric heater. The advantage of an oil filled heater is that whether they are drawing current or not, they provide roughly the same amount of heat over long periods because of their heat reservoir (the heated oil). This advantage is useful if you are sleeping close by the heater, but there’s no real advantage in an empty cottage and you might as well go with a cheaper convection heater. Just don’t get a radiant electric heater.
I live in under-insulated house and this oil filled heater The DeLonghi EW77 has no problems maintaing the temperature.
The nice thing about these types of heaters is that once it gets hot, it stays that way for quite a while.
Should I buy a 9 fin or a 15 fin? I know a lot of people say that it’s all about the wattage but I think that the 15 fin would be efficient since it would cool the room faster because of the larger surface mass and since it has more oil inside then the thermometer rest intervals would be longer – though this is just a personal opinion and I need second opinions. Any answer would be appreciated.
You are right that a larger surface area will distribute the heat to the room more quickly, and a larger thermal mass would likely mean the rest intervals are longer. However neither of these has any effect on overall electricity consumption. In terms of the total heat produced, total watt hours consumed is the only factor that counts. If anything, a larger thermal mass would mean (A) slower heating time when you turn the heater on, and (B) more heat wasted on an empty room, if you turn it off and leave the room for an extended period. If you are keeping the room at the same temperature all the time, then neither of those issues applies.
Great article. Thanks. I have heard that you should place an oil filled radiator in the coldest part of the room. Any views on room placement?
The best place for an oil filled space heater is in the center of the room, so that the heat radiates from there to all parts of the room. The closer to an outside wall the heater is, the warmer that part of the room will get and therefore the more heat will escape through the wall. The closer to an inside door the heater is, the more heat will flow through the door itself, or through the doorway when the door is open, into other parts of the living quarters, and the less heat will remain in the room. If it’s a bedroom and your goal is to stay warm at night, having the heater near the bed makes sense.
I haven’t heard that you should place it in the coldest part of the room. I would be interested to know the rationale, but it seems to me that is probably the worst place to put it from an energy efficiency standpoint. (It may be the best from an overall comfort standpoint though, come to think of it – since the thermostat will keep it running longer if it is the coldest spot, which will make that spot – and the rest of the room – warmer.)
I just got an oil filled radiator and the directions said to place the heater on the floor (on the floor? No duh … really?!) beneath the coldest window in the room, or any other location. Or any other location? Then why say beneath the coldest window. Just put the damn thing anywhere you want but make sure it’s on the floor! 😉
i just got one of these and it said to do this in the manual as well . i think they said its because of drafts ? like , if cold air is flowing into the room from the window , it warms that air as it flows over the heater . i was skeptical too as i thought heat would escape through the window
Just took my oil heater out of storage…plugged in and it started to make a crackling sound and smell funny…Is that normal?
The crackling sound is normal, that’s just the oil being warmed up. That is, if the crackling sound is a slow one as of oil in a frying pan gently sizzling, or metal expanding.
If the sound is sharper and faster, it could be a wiring issue. Try turning the heater on high, then unplugging. If the crackling sound stops immediately on unplugging, and the burning smell is coming from close to where the wire enters the heater or where the thermostat is, it may be a wiring issue. If the crackling sound continues for a few seconds after unplugging, it’s still just the oil.
If the smell is oily, there may be a small leak in the heater. Run your hands around the heater to check for any leaks or oily spots. Another possibility is something got onto the outside of your heater while it was in storage, and the heating is cooking that something and drawing out its smell.
I found a couple of oil spots under my heater. When I checked I found it was leaking from the heater. Should I get rid of the heater or is it easy to repair?
If the heater is still under warranty I would suggest contacting the seller or manufacturer for a warranty replacement.
I don’t think you’ll find anyone willing to repair a leaking oil heater, the cost of the repair will probably exceed the cost of a new heater.
This is not likely something you could fix yourself. You might be able to solder over the leak but I wouldn’t trust it, and it would be a shame to assume the leak was fixed only to turn the heater on, leave it running, and come back to find oil all over the floor.
I have a small 5 foot by 6 foot cloak room that is well insulated with no heat. Can I put an oil heater in it for the winter time in northern Wisconsin?
The room you describe seems ideal for a personal space heater. You’ll probably only want something with 750-1000 watts capacity for a space that size, otherwise it will cycle on and off frequently. I’m not sure why an oil filled space heater would be a better choice than a plain old electric heater. Certainly a small ceramic heater would be much more compact, and they are quite cheap.
My heater doesnt distribute as much heat as it used too. What could the problem be? It makes no difference in my room anymore. Its as if its not even on.
It sounds like it is distributing at least some heat, but not as much. The most likely problem is the heating coil is burned out. Probably time to get a new one, these units generally aren’t worth servicing. If it’s still under warranty make a warranty claim, if not get a new one.
I have solar and would like to heat a room during the day when it’s free electricity and then hope to need less heating during the night. I thought a large mass would be best… any suggestions? I like the idea of an oil heater holding heat for longer… thanks
If you have a way of pumping excess electricity from your solar panels to the oil filled heater, beyond what you need to save to batteries for later use, this makes sense, but what you may want instead is a storage heater. These are specifically designed to produce heat from electricity during low-rate hours, and release it at a later time. The trouble with stock oil filled space heaters is that they aren’t designed specifically for this, so you wind up heating not only the heater, but the room it’s in, when you’re generating power yourself, and not that much of the heat it produces will still be in the heater and available at night. An oil filled space heater is better than other types of space heaters for what you’re after, but far from perfect.
Can I leave my oil heater in below freezing temperature for,the winter?
The main concern people have about leaving an oil heater in below freezing temperatures is that they’ve experienced that unpleasant problem of water in a glass jar or bottle expanding when frozen and cracking the jar or bottle. There’s a fear that the freezing of oil in an oil filled radiator will somehow expand the oil and crack the radiator.
Fortunately water is one of very few substances that expands when going from a liquid to a solid state. If you had a water-filled radiator it would indeed crack when the water froze. However with an oil filled radiator you don’t need to worry about this. It is fine to leave your oil heater in a below freezing room for the winter. Cottagers in Canada do it all the time – if they have an oil filled heater for the shoulder season in a three-season cottage, they leave it at the cottage all year and it has no effect on subsequent performance.
I am away from parts of the winter in Canada, I have an oil furnace on 5 celsius on nothing freezes. I was looking for a temporary backup in case something ever happened to the forced air oil furnace while I’m away. I’m installing a wifi thermostat. Would an oil filled heater be ok for temporary fix?
An oil filed heater, or any heater, would be a suitable backup for a room, but not for an entire house. Since your main goal is probably to prevent freezing water pipes you would need an electric heater on in each room that has water pipes in its ceiling (e.g. the basement), walls, or floor. You would need that WiFi thermostat to work with all the heaters in question (or have one for each). The other challenge you may have is that if you set the thermostat to 5C on both the electric heaters and the oil furnace, you can’t prevent the electric heaters from turning on some of the time or contributing some of the heat, which will cost you a lot more than heating with oil. You’d be better to set the oil furnace to 7C so it keeps the house warmer than 5C, that way the electric heaters will only ever kick on when the oil runs out or the furnace fails. Also note that this won’t help if the power to the house fails – a forced air furnace needs electricity to run its fan, but then so do the electric heaters.
I have a 10×10 vegetation room. I put a space oil filled heater in there. It’s going to run nonstop all winter. I also put a Oscillating fan on low speed behind it. I find it the best heat source for the plants. Do you believe this to be a good way to go with a oil heater.
Yes, one advantage of an oil filled space heater is that if there’s a power loss there’s a fair amount of thermal inertia in the heater so it will provide heat a little longer.
The oscillating fan will help a little. It’s probably not necessary. If plants are near windows or cold walls, the fan may help circulate air to them. If not, you’re better off without the fan as you’re circulating warmer air to the colder parts of the room, increasing heat loss through those windows and walls.
My father is suffering from pneumonia. Is an oil heater ok for my father at winter or it is harmful for him?
The oil heater provides warmth, which I’m sure your father would benefit from. The oil is enclosed in the heater and will have no effect. It is safe.
Does an oil filled radiator increase humidity in the air? I’ve ran mine for a few days and now everything in my apartment is damp and gross!
The oil filled radiator should not have any impact on humidity levels, except that as air warms, the relative humidity increases (ie. for a given amount of moisture in the air, it feels more humid as it gets hotter).
The humidity issue is related to condensation on cold surfaces. You have to maintain a constant temperature above that of condensation compared to humidity. If the oil heater is the only heating source, you must keep it on all the time, and not set it to minimum. If it is supplemental heat, you need to increase the temperature of the primary heat. Forced air tends to dry out the air, which is why we often use humidifiers with that type. But with radiant heat your nearly 100% humid exhaled breath just slowly increases humidity. When the humidity reaches a certain point, it will condense on surfaces that are cold enough to increase the humidity at that area to 100%. I tried using only electric radiant heat once winter to test cost, and though it was slightly less expensive, i had space heaters in every room and mold behind the sofa in the living room where the outside air had caused the wall to cool and the sofa insulated it from convection.
Our electricity bill went up drastically this winter and we think it is because we have been using our portable air conditioner as a heater. Does this make sense?
Also which is the most energy efficient: oil radiator, small blow heater, or heat mode on portable air conditioner?
If you’re venting to the outside and using your portable air conditioner in reverse as a heat pump, it’s quite possible that would drive up your electricity bill. The efficiency of your portable AC at pumping heat from the outside air into your living space may not be that good, and the colder the outdoor air the less efficient it is.
Most heat pumps draw heat from the outside through an evaporative refrigeration loop in which there is no air exchange between indoors and outdoors. A portable AC typically has a hose to exchange indoor and outdoor air. So in cold weather you may be pumping cold air in to heat it, or pumping warm air out.
There is no difference in efficiency between electric heaters (other than electric heat pumps such as your portable AC used in reverse). See my Energy efficient electric heaters article for an explanation of that.
I have a DeLonghi that’s about 20 years old. Questions: 1) Is it still safe to use? 2) are newer models preferred over older ones in terms of energy efficiency ?
If there are no signs of leakage on it, or rust, it should be safe to use. I suggest you turn it off when you’re not nearby, for the first 12-24 hours of use, so that if any leaks develop you’ll be there to spot them. In terms of energy efficiency, all electric heaters are 100% energy efficient at converting electricity to heat, so there’s no difference in efficiency between your old one and newer ones.
I am renting a 1/2 double home in PA. My cement block basement is about 20×20. It is being heated by an 8 foot electric baseboard heater. The thermostat is set at 50 degrees. The entire home is electric. With the cold we have been experiencing, it seems to be on all the time. Would an oil-filled heater be a better choice? I’m afraid to see this month’s electric bill!
An oil filled heater and a baseboard heater use the same amount of electricity. You won’t save any money by switching. 100% of the electricity going to an electric heater becomes heat. And yes, I’d be afraid to see the electric bill this month based on the cold weather, if I had electric heat.
My oil heater, like most, has two controls. Wattage output and Thermostat. What is the most efficient setting? To me, it seems like leaving the wattage at the max would heat the oil up to temp faster and then kick off. Wouldnt that be more efficient than a lower wattage setting taking longer to heat up the oil?
As I explain in Energy efficient electric heaters, all electric heaters are 100% efficient at converting electricity into heat, due to the law of entropy. That is, to produce a given amount of heat takes the same amount of electricity for any heater. The lower wattage setting will be more efficient in cases where the temperature in the room naturally fluctuates (e.g. because of changing outdoor temperatures), but only because at a lower wattage the heater will take longer to heat the room. The longer it takes to heat, the less heat is being lost through walls, so the less energy is being used. But this is not really efficiency.
So for the cheapest energy bill, should I leave it on 1500w?
Is it safe to leave an oil based space heater running in our home when no one is home? Are there any other risks except for an oil leak? There are no pets etc. in the home to tips it over.
It should be safe if the heater is new. They are designed to operate unattended.
I live in central Finland and in an old (100 years) wooden house in an apartment on the bottom floor. It is two main rooms plus off shoot bathroom and storage. At the moment the house is heated with electric panel heaters (no fan) under external windows. The two rooms are roughly 13×13 ft with 8 ft high ceilings. Houses in Finland are well insulated as you would guess, all triple glazing etc but the floor is not particularly well insulated from the cellar below me. The apartment has always maintained a 22’C during winter with 2 x 800w in the front room/ bedroom and 1 x 800w in the kitchen. At least two of the heaters are generally always on when I look at them during winter, they do have thermostats. The temperature here is generally 0’C down to -20’C fluctuating over 4 months. In this case, to receive a constant heat throughout, staying at 22’C, should I think about wall mounted oil heaters to save money? I do have different tariffs for day and night electricity.
I’m not familiar with wall mounted oil heaters. If you mean storage heaters (which heat up a thermal mass during times of low electricity rates, and then blow air on the thermal mass later to provide heat) then this would help. But if they are just oil heaters as opposed to normal baseboard heaters, they are not designed for storing heat, only for providing a more even flow of heat, so it’s unlikely to make too much difference to your heating bill. Oil filled heaters have the same energy efficiency as all other electrical heaters.
I would like to point out that oil-filled heaters have the huge advantage of being safest around pets and small children (not to mention safest to leave unattended overall, due to their low surface temp). Bad behavior cats who often or occasionally spray to mark territory indoors have, for whatever bizarre reason, a real affinity for electricity in all forms, especially wall outlets and space heaters (ask any fireman). Cats causing shorts by spraying wall outlets have been known to cause house fires, and I don’t even want to imagine the result of a cat directly spraying the exposed glowing elements of certain types of heaters. I have cats and would never, ever trust them around any other type of heaters. Oh, and they also have zero sense about cozying up to hot objects in winter.
All my cats will happily wrap themselves in direct contact around oil-filled heaters, which I would think are way too hot for comfort but, again, go figure.
I was just given a new DRAGON4 PROGRAMMABLE PORTABLE RADIATOR HEATER and like an idiot tipped it over and didn’t know there was liquid in it. I thought it was water so like a dope was rocking the heater back and forth to try and hear what it was. My question is, did I just ruin the oil area? The DeLonghi website says the oil never has to be replaced but as I was tipping it and sloshing it around like a dope, it didn’t sound like there was much fluid in it.
Did I ruin the heater do you think? Is the oil encased in a spill-proof container so it won’t spill when the heater tips over, etc.??
Thanks so much,
If no oil leaked out you should be okay. Plug it in and see if the entire radiator portion gets warm. If it does you should be fine.
Perfect! everything seems to be working great. I will say that at 52 yrs old this is the first forum I have entered and I am really impressed. Robin – you are great!!! Thanks so much..
Another question if I may… How do I know I got a reply from someone? shouldn’t it alert to my email or do I just bookmark this page and keep checking here?
Thanks again! I really appreciate your help.
Thanks for explaining how an oil heating system will provide a steadier and more consistent flow of heat to your home. My wife suffers from arthritis, and the cold really aggravates her symptoms. It certainly looks like switching to an oil heating system will help her get around the house easier.
This article is about oil filled space heaters, not an oil heating system. In any given room, an oil filled electric space heater will give more even heat than a radiant or convection heater. “Oil heating system” is typically a term to describe a central heating system with an oil-fired boiler with radiators, or an oil-fired furnace with forced air venting of heat.
My oil filled heater 1500 watt, 3 years old, keeps giving off a “burning smell” with no oil leak, but i had it in same outlet as a box fan with both set to max settings. And my house is very old, old outlets in usa. Do you think it was the outlet burning ? There are no indicators of burning on outlet or the heater’s plug-in. Pelonis radiator oil filled heater. Now when i turn it on i have to jiggle the circular switch thing so i stored it away and plan to buy a ceramic heater.
Anyway the heater was in the kitchen when it stunk, but i ate the food laying out anyway. Should i have thrown the food away? It only stunk 1 hour and then i opened windows and moved fan away from heater to vent out the window. Can fumes “settle” in 1 hour on say a cooked chicken or chopped bananas that sat out? Can the oil vaporize? I thought the oil used was not able to vapour and it doesn’t leak anyway. I overloaded circuit? No smoke, but the smell. Should i throw the food out? So worried !
I don’t see how having your oil filled space heater in the same socket as a box fan would account for the oil smell. Try plugging the heater into a different outlet, you’ll probably detect the same smell. Are there any signs of leaks out the bottom, or any oily residue on it? If there are signs or smells of oil it’s time to recycle it. You can contact your local recycling facility / waste depot or a local scrap metal recycler and find out if they accept oil filled space heaters with the oil still in them. If they don’t you may be able to take the heater to an oil change shop although someone will need to drill a hole in the heater to drain it.
As for fumes settling on your food I don’t think you need to worry about that, the amount of oil that actually vaporized is likely extremely small, so the food should be safe. Unless you have clouds of smoke in the room before it settles on food it’s not going to be enough to cause adverse health effects. Of course if the food tastes of oil, don’t eat it – who wants to eat oil? Note that most oil filled heaters contain either mineral oil or silicone oil, both of which have relatively low toxicity, so it’s a flavor issue not a safety issue.
Well I cannot describe the smell except a slight burning of something either outlet or electrical or oil I dunno what exactly it was. No smokes just a hint of a “funny smell” No oil leaking on floor or when I wipe the bottom anywhere.
The box fan has 90 Watts on max and the radiator is 1500 watts on max.
I want to keep using it since I’m on a budget but the 1st knob with 3 settings I have to jiggle to get it to turn on. The switch malfunction is normal in this Pelonis brand radiator. I used the it again in kitchen and this time no smell. So maybe I ran it on too high last time though?
My aunt gave me a radiator to borrow but it is Optimus brand and websites say this radiator can expose me to lead! Should I use my aunts? I’m scared to touch her heater even haha.
Thanks for the thorough article.
I’m looking to heat a small micro sized studio apartment with a space heater. I prefer oil radiator heaters, but I’m worried about the release of oil fumes and odors. I’ve read reviews that say the smell lingers. I have a chemical sensitivity as well as asthma, so I feel like breathing in fumes is not wise. What are your thoughts and possible alternatives? I need something that does not have a fan because of allergies. Are ceramic, radiant, or infrared heaters possible solutions? What would you recommend? I’ve read that infrared can be bad for you as well!
Thanks in advance!
You shouldn’t smell oil from an oil filled space heater. If you do it’s defective – the oil is supposed to be completely contained within it. Remember that the people who complain about the smell are more likely to post comments to a page like this or to a review of a heater, than those whose heaters are working happily.
The smell people experience when a heater is new is likely just the paints on the heater, and you’ll experience this with any kind of heater. Over time the smell should reduce.
Radiant and infrared heaters are the same thing. They are great if you want to point the heater at you, and heat only what the heater points at, not the whole room. Ceramic heaters are a good choice too. See my article Energy efficient electric heaters for a more detailed description of each heater type and its advantages/disadvantages.
I have a 2000 sq ft home in CT that has electric baseboard heat in every room. We only beat the rooms we live in. The baseboards are the regular electric units and i have been considering replacing them with hydronic units, again all hardwired to individual thermostats. My thinking is that if the heat ks stored the thermostats should not need to go o as often therefore saving on my electric bill. Do you agree?
The fact that the thermostats don’t turn heat on as often doesn’t save you any energy. The main benefit of hydronic heaters is that you can store the heat in the unit, and therefore take advantage of tiered electricity pricing, ie. heat the units up during an off-peak period, when electricity costs less, and then enjoy the heat during a peak period without having to pay peak rates for the electricity that gave you that heat.
Hello! I have an oil filled electric heater. It smells like burning oil every once in a while but not consistently. Mostly when I turn it on for the first time for winter or turn to high. I leave it on continuously, even overnight as we do not have other forms of heating our bedroom. I have noticed a stain on the unit (the unit is white). It’s where the openings are to let heat out. It’s like a reddish brown color. I haven’t noticed any leaking though. Is that stain normal? It’s about 6 years old. It’s a cheaper brand. Thank you!
I’m in the recycling biz, and a resident is having trouble disposing of an old oil filled heater. It has no plug, and won’t be accepted for scrap metal with the oil in it. Is it safe to drill a hole in it to drain and recycle the oil and scrap the metal? I wish these (and so many other) things were built with disposal in mind.
It should be safe to recycle the oil, normally these heaters just have mineral oil in them. Alternately if your municipality has a toxic waste drop-off or pick up service you could store the oil in pop bottles, label it as oil from an oil space heater, and the service should know what to do with it. Once the heater is drained it should be fine for scrap.
I agree that we need better laws around full product lifecycle, as they have in the EU for instance where manufacturers have to take back their products at the end of the product’s life. If I know I have to take back all products I manufacture, I have a much stronger incentive to apply a set of standard approaches to manufacturing, to make recycling easier.
Good article, just a couple of things——
—(But oil has greater thermal inertia than water, so while oil filled space heaters take longer to warm up). Water actually has a higher capacity to hold heat than oil .. water…. 4179 J/kg K, mineral oil….1670 J/kg K
(except that as air warms, the relative humidity increases)…………..It decreases.
Thx for the article……….Darrell