Most efficient space heater?
 

Long story short: Raw sewage sprayed into the basement and one area it hit had ALL of the space heaters for my place. I find them sometimes at my job when people move out of their homes, so I had a nice collection. :(

Anyways, I had the oil-filled radiator type, ceramic disk with blower, a safety one for the kid's room (thin element, large shell with a blower), etc.

Now I have to replace them for at least 2 rooms this winter, which type is the most effecient at heating a room?

Heat Lamp would be the way to go because it's not heating the air it's heating whatever it's pointed at, otherwise anything that radiates is going to be more efficient then heating the air.
Otherwise the watts to BTU output is going to be about the same on all of them.

It was explained to me that a watt is a watt is a watt.

I like to use those yellow halogen work lights with the glass removed as space heaters- I get the light as a byproduct thus the regular room lighting can stay off. Obviously such a set-up needs to be treated with respect.

This one looks better than many, because it has a 750 watt setting in addition to the common 1500 watt setting. And it has a digital timer for auto shut off, which must be safer too (overnight): TVH500

[EDIT: and this one uses less power, is far cheaper, tho without as many cool features and probably with half the heating area abilities: http://www.vornadocentral.com/produc...o-vh101-heater

we only use oil filled radiator type, i usually have it on the low 600w setting. anything with a fan will be "wasting" energy to move air.

EER ratings = BTU Output / electrical Watt Input
The higher the EER the more BTUs per Watt of input = more efficient

Coefficient of Performance ( COP ) is a unitless measure of the efficiency = Watt of heat output / watt of electricity input

COP * 3.412 = EER

SEER uses an adjustment to the EER to try to account for operating differences throughout the year and different conditions... Common rule of thumb about SEER * 0.875 = EER... but the specifics of conditions and design can and do deviate from this.

A COP of 1 = 1 Watt of heat per 1 watt of applied electrical energy ... This would also be an EER of 3.412 ... generally about a SEER of ~3.9 ... this would be any resistive heating element based unit that converts 100% of the applied electrical energy input into heat energy output ... in practice it's never 100% ... but that is the best any resistive heating unit can do.

On the other hand ... many heat pumps are able to move heat from one place to another far more efficiently ... Getting a heat pump with a SEER above 4.0 is not very hard to do at all ... 12 and above is also not particularly difficult.

A Heat pump that is operating with a SEER of about 12 will move 4x as much heat energy from point A to point B than that resistive heating element based space heater can.

So ... if you are looking for a more energy efficient form of space heating ... and you don't mind a bit of a project ... you could try to convert a window type AC unit which is a heat pump often with SEERs of 10 , 12 or better ... and just switch it around ... heat pumped into the room ... instead of pumped out of the room ... the crucial part of that would be the sealing up of the interface so you don't have cold air leaking back in ... and of course be mindful that the hot side will get hot ... etc.

Also keep in mind ... it most likely is not the design intended purpose of the units ... so performance will likely not = the advertised summer SEER ... and you may have to include a few design adjustments of your own.

I suspect that a heat pump is out of the question as a space heater, but if it's not then it is by far your best option.
Like Frank I use work lights to heat from time to time as well because the heat from them is radiant heat, it's not heating the air, heating air to heat objects is dumb!
With the smoking ban in bars here there are a number of bars that have out side areas with a few infrared shop heaters on timers, you give the timer a twist and it lights up orange, warming the people up who are next to them, they are still breathing in cold air, but it feels like you are standing in front of a fire, your face and hand get toasty, objects get warm but the air hardly heats up, to do the same thing heating air you would need a pretty good sized furnace.

Wow, great ideas! The mini-split ductless heat pump deals would be awesome, but way out of my price range for a rental :) I thought the fan on some of them would be a relative waste of energy. I will probably search for one that actually maintains a certain temperature and controls itself. We dealt with run-away heat with the room heaters before, especially after the furnace kicks on in the morning.

Never even considered that an airconditioner is an efficient heat pump... wow. Will have to think about that one, I have a few extra window units sitting in my basement (the part that didn't get sprayed with poo water)

On a side note: I am going to be attacking my place aggresively this year for energy management. Any chance someone is going to set up an overall list of things to start checking/changing for efficiency? Kind of like the eco-driving tips. I have been searching around and have happened across different areas to look at, sealing up ducts, attic work, insulating fridge, etc. But it would be nice to have them all in one place, then it's just a matter of searching for the topics that look doable.

The sister site to ecomodder.com is Ecofriendly DIY Home Projects It will help you.

I've crudely used a window unit with a 12.0 SEER to pump heat into or out of a room ... and a continuation of that project to make it better and to properly quantify the results is one of many things on my project list ... eventually I'll get to it.

But I will give a few considerations to keep in mind if you also plan to tinker a bit with the idea yourself.

#1> Mass produced window units don't seal well in the window ... You don't want to reduce the insulation of a room , from the outside cold by a larger joule amount than any heat pump gains... there are a variety of options ... either to better seal the units ... or to put the units hot and cold sides in a box that vents the heat from point A to point B ... which ever direction you want.

#2> The hot side of the heat pump for even a small ~5,000 BTU window unit ... can get pretty hot ... so before you leave it to run unattended you should test it hard to make sure ... like any hot surface inside ... you don't want a fire hazard.

#3> Sense most are OEM designed for the controls to be on the cold side ... in your tinkering you either want to relocate the temperature sensors and controls ... or some other mechanism to allow the same effect ... ie ... when used to pump heat into a space ... you are not trying to regulate the air temperature of the cold side.

#4> Be aware that although any performance better than a SEER of 4.0 is more energy efficient than a resistance based space heater ... and many window AC units have SEER ratings many times better than this ... just remember that the Labeled SEER rating is not likely under the conditions you will be using it ... and it will perform differently under those different conditions ... so if say you have a unit with a SEER of 12 label ... don't be surprised if your effect SEER drops significantly ... but even a SEER of 8 ... is still twice as much heat joules of energy for the same amount of electrical joules as the best 100% efficient resistance based space heater.


Best of luck ... no matter what method of increased efficiency you explore.
:thumbup:

I will probably pick up at least one radiator type heater to have something and then focus on sealing up leaky drafts in the ceiling/attic and foundation/frame interfaces, along with aluminum tape on the highly accessible ductwork in my basement.

The A/C heatpump tinkering can then be looked into. :)

Another idea in my head is humidifying the house so it will feel warmer at lower temperatures.

This idea of a reversed air-conditioner has me excited, I have a 500 watt window air conditioner.
If it does provide 4 x the heat per watt then a space heater it will turn my 500 w air conditioner into a 2000 w forced air heater. I likey that idea:), It would heat my house on all but the most demanding cold days of the winter.
If i mounted it in my basement where i would not be disturbed by its noise i could leave it running on a thermostat all winter :thumbup:

Would ice build up be a problem ?

"Would ice build up be a problem ?"

could be .. there are full up heat pumps[cool & heat] available as window units .

as you may know the efficiency of a heat pump in heat mode falls off as the outside temps drop so use on *the coldest days * might not yield full efficiency .when its real cold here[not so very cold] the heat pump wants to switch on its axillary resistance , i have that disabled. in cold damp air they will build up ice on the coils outside
the heat pump senses that someway and heats the outside coil from time to time by reversing its function, quite a sight, at first glance one thinks the unit is on fire so much steam is emitted

What brand and model pump are you using... and do you know the COP, SEER, or EER ratings? I ask because I am still shopping for one to heat and cool my whole house (not a space heater). I'm having trouble identifying and documenting the most efficient models.

More on topic: I just bought a Vornado VH101 space heater. It is cheap! And it will serve the small room, take the edge off the cold mornings for my wife, purpose. It has no thermostat, which I like, because I will put it on one of the timers I have and therefore have it turn on 20 or 30 mins before she wakes up. Some think it too small for a room, but I think they are looking for more than I need or else are in older climates than I am in Southern Cali.

Although drying isn't what you want but the cheapest most efficient space heater is a dehumidifier (heat pump), if you can locate it in your swamped basement and dry it out while also heating the whole house maybe it would be worthwhile?

I use a 22,000 BTU Monitor thermostatic controlled, closed heating chamber with circulation fan, vented kerosene unit which is considered a space heater, but I heat all of our 1400 sf house with it. I use to live in the Charlotte, NC area and now live in southwestern KY, in 17 years use I have never used more than 150 gallons of kerosene per heating season with the heater's thermostat set at 70*. The heater is set up to come on when the room temperature reaches the set temperature and stays on until the room reaches 4* above the set temperature. I have it located in the living room/kitchen (open area) so it keeps both the living room and kitchen at or near the temperature the heater thermostat is set at. The bedrooms are a few degrees cooler, but for my family that's an advantage since we like our sleeping area a little bit cooler. These heaters usually cost in the $1250-$1500 range when new, but often they can be found on ebay for much less. My son bought a used Monitor 22,000 BTU unit on ebay last winter for his 1000 sf home for $500 + $50 shipping. Monitor also makes a 40,000 BTU unit for larger homes. Installation consists of cutting one hole in the wall for the vent pipe, if I recall correctly the hole is either 2 1/4" or 2 1/2" diameter. The 22,000 BTU unit can be hooked up to a outdoor tank or the optional 1.33 gallon capsule tank that fits directly into the heater. The 40,000 BTU unit has to be hooked up to an outdoor tank. My Monitor will be 17 years old in January 2013 and the only work I've ever done to it was last winter when I replaced the burn mat and burn ring which amounted to less than $100. We had a mild winter here in KY last winter. I heated all winter on less than 85 gallons of kerosene while neighbors were paying $200-$300/month for electric heat. Monitor quit making kerosene units a couple years ago, but there are still a few new units available from suppliers. Toyotomi and Rinnia also still make similar units.

COP[ coefficient of performance], SEER,[seasonal energy efficiency rating] or EER[energy efficiency rating] ratings?
a Trane whole house heat pump Xl 16i . the energy star tag on it says the SEER is 17.0 , HSPF[heating seasonal performance factor] 8.5, other information i got [required to file for the gov. rebate]

indicates SEER 16.5, EER 12.5 ,COP 3.7 , HSPF 9

i would have to study a whole lot for any of that to have meaning to me .
something i understand better is that this unit has a scroll compressor that is set up to work as a 2 stage unit, when the demand is low it functions l as if it were 2/3 the size it is, releasing the compressed working fluid part way up the compression. thus using less energy .. i have a 4 ton unit , so on low demand it works like it was a 2.6 ton unit , then when demand is higher it ramps up. ..
likewise the air handler is a multi speed unit , some times the outside unit is operating at 2/3 and the air is just slightly sighing out of the vents, then as demand increases so does the outside unit and the CFM on the air handler increases , when its ramped up all the way the air fairly whistles out the vents. i have the info on the CFM somewhere in the document pack.
i think all the major manf. have similar units for efficiency.
costs more than a single stage . the one i wanted was a xl20i . it has 2 discrete compressors , a big one and a little one , when demand is low the little one runs , when high the big one , shucks maybe even both idk. however it cost even more . what i really wanted was a geothermal but the costs on those are outofsight. .
i replaced a 20 year old single stage 3.5 ton that failed to keep up with demand , it cooled the air pretty good[ showed 68F air out of the vents but did not move enough air. on the hottest days it would not keep up.
i have seen a considerable decrease in the power bill and stay cool , not to mention state and federal gov. gave me a substantial taX Credit , too bad it was just a 2 year program , this year i would have installed light pipes to illuminate the dark rooms with daylight vice running electric lights .

hope this helps
mrb

All 4 units are just slightly different ways to measure the operating efficiency of the heat pump unit ... how many joules are moved per joule consumed.
That unit is listing numbers that indicate it is ~2.6x and ~4.0x better at moving joules of heat from Point A to Point B than a 100% Efficient Space Heater that just converts joules of electricity to heat... the lowest ~2.6x ( from the HSPF of 9 ) number is what it references for heating season expectations.

COP:
Is a direct real time Watt Output / Watt Input term
A COP greater than 1.0 is better than any resistance based space heat ... for those conditions.
COP is often used in engineering and scientific testing contexts.

EER:
Is a real time measure in BTU Output / Watt Input.
Because it mixes unit type of BTU and Watt ... it is basically just an adjusted COP ... COP * 3.14 = EER
EER is often used for labeling Air Conditioning Devices for Consumers.
Any EER greater than 3.14 is better than any resistance based space heater... for those conditions.

SEER:
Is also in BTU Output / Watt Input ... but is adjusted to be more of an average , to account for changes to performance under the different conditions during the tested seasonal conditions ... an effort to give a more accurate expectation of average operation under the tested seasonal conditions ... not yearly conditions.
SEER is often used for labeling Air Conditioning Devices for Consumers.

HSPF:
Is another performance ratio ... this one tries to give a single cumulative estimate for the whole operating season ... instead of just an average like the SEER or a snap shot like the EER and COP.
HSPF is often used for heating applications.
It's in BTU / Wh as units.
It can be converted to a entire season average COP.
HSPF * 0.293 = Entire Season Average COP
Any HSPF greater than 3.42 is better than any resistance based space heater , for those conditions.

ty
Seasonal energy efficiency ratio - Wikipedia, the free encyclopedia says :
when a heat pump operates near its most inefficient outside temperature, typically 0 °F (−18 °C), the heat pump will perform close to the same as a resistance heater.

Lower temperatures may even make a heat pump operate below this threshold, which is why conventional heat pumps include heater coils or auxiliary heating

i suppose if we ever see single digits here again i would be advised to enable the auxiliary heat.
the way i under stand the machine works is that when sensed temp falls a small # of degrees [3 ?] below the set or demand temp auxiliary heat is engaged.
i have the aux. heat disabled with software/hardware because the resistance heat elements are quite large , 3 banks .
i choose to let the heat pump struggle to maintain demand in winter w/o aux resistance heat . i now learn that this is not an economic decision when the temp falls below a critical temp. .

to return to the OP question . if the space heater is to be used on *the coldest days* and those cold days are below 0F resistance heat would seem to be the choice.
in my cold basement i have a quartz type radiant in the laundry area. it is nice since when turned on and one is in font of it it is as warm as a roaring fire. the downside is that these types of units are less safe than others and if not monitored a roaring fire might ensue.
..a good safety unit such as the oilfilled radiators would be more appropriate if continuous unmonitored usage is desired

after reading this i just ordered an inexpensive electric oil filled convection radiator type , space/ auxiliary heater , intended for bathroom use. 50 $ delivered from uncle wally . 3 power settings 600/900/1500. . other units i have are 2 each 300W radiant parabolic. 750/1500 quartz type radiant [ the radiant heats objects better than it heats the air. ] these radiant types are more hazardous, news in winter will always report people burned from them and house fires that result from incautious usage.

then the old wood burning fireplaces have gas [propane] logs . these are quite inefficient and are truly emergency heat .we are always in danger of catastrophic ice storms that takes the power out for .. weeks

then i suppose one could consider the 400 Watt mercury vapor , 'Grow Light ' a heater also . it is optimized for visible light but gets plenty hot, runs 6 hours a day winter evenings to night .


efficiency is always related to application . the 300 watts don't throw a lot of heat [ they are considerably more efficient than a 300 watt light bulb, the light bulb element is optimized for visible light with infrared[heat] as a waste byproduct, the heater s element optimized for infrared with light as a byproduct[waste]]
300W is excellent to keep ones feet warm in a cold space.
the 750/1500 radiant will keep one toasty 6 feet back from it in a 40F room , as long as you are in front of it , likewise it will ignite curtains at 3 feet in short order .
i expect the oil filled at 1500W to heat the bathing spaces air in short order from a cold start . and to maintain warmth adequately at the 600W setting
the 600W setting at current rates would cost me 5.4 cents an hour to run. the 1500 W setting 13.5 cents an hour
while the main heat plant is much more efficient[3.7 times as efficient ?]
less efficient space heating of *selected* spaces allows a lower setting
on the main plant and disabling of the aux electric heat, im not sure what the rating is on those resistance heaters organic to the main plant but they are big , on the order of 5-10KW possibly as much as 15-20KW. at 10KW cost per hour would be 90 cents an hour .
in the cold of winter the room temp often falls more than 3 degrees below the set /demand temp at that time the resistance heat would function[were it enabled] i chose to disable the organic aux resistance heat and let the room temp fall as far as it will to the equilibrium temperature. using space heat in *selected*spaces .
it would be an easy matter to enable the first bank of resistance heat with simple reprogram of the thermostat, then there are 2 more banks of resistance heat on a hard switch..
id druther wear a sweater and use the 300 watt to keep my feet warm than spend a dollar an hour or more to heat the whole shebang..,.