Which type of portable electric heater do you think is more energy efficent?

[Michael Yadfar]

Portable electric oil heater, or portable electric ceramic tower heater? Right now I heat my small shop with an electric oil heater, which just radiates heat. It has a 600W mode, 900W mode, and a 1500W mode. To keep the shop at 55 degrees, I usually have the thermostat half way to thee quarters on 600W mode, and when I'm in there and I want it at 70, I usually start at 1500W mode with the thermostat all the way up, then switch it over to 600W mode. I don't know the exact cost, but I believe this is costing somewhere around $40 a month to run. Part of the problem is that the thermostat isn't based on air temperature, so if it's on 3/4, it would keep it around 55 on a 25 degree day, but if it's 35 degrees outside, the shed will be like 70. So I often use too much heat.

I was considering buying a ceramic tower heater, which includes a programable thermostat based on air temperature, has a fan blowing the air, and oscalates. These are usually 1500W. I don't know the actual efficiency of these things, because it's probably running 24/7, but then again it may distribute air better.

[Jim Becker]

Sadly, none of them are very efficient...it's the nature of resistance heating, regardless if it's direct or radiant. I'm considering getting something like a ceiling/wall mounted 240v Farenheat type unit with an intelligent blower for my shop to replace the electric radiant units I currently use, but I'd still never leave it on unless it was a day I was planning on working in the shop. The power usage is just too great for that. If I could find a small heat pump...a scavenged one preferably...I'd opt for that as it would be relatively efficient in my geography's climate. But that's certainly not a "portable" solution!

[Michael Yadfar]

I looked into permanent/fixed systems a few times, but the reason why I'm going with portable is because I technically don't own my shop, and I plan for it to be short term 2-3 more years. I don't feel like putting big money into climate control. I put a lot of money into insualting, but even what I did was a bit light

[Ed Aumiller]

Buy a wall thermostat for baseboard heat at any BORG... mount it in a small outlet box with a 115v plug to go into the wall and a receptacle coming out of the box... I simply wired it in the middle of a 15' extension cord... Plug it into any outlet then plug the heater into the receptacle... You now have a thermostat the will keep the room at whatever temp you set it at.... put the heater on 1500w as it will cycle on / off as needed... turn it down when not in shop and turn it up when needed...
Total cost is less that $25 and it is very convenient ....

Had this set up in my shop for years... and they are portable...
When I need heat in my RV in the cold weather, simply take a heater & thermostat and put in RV... keeps it at constant temp with no waste...

Recommend hanging the thermostat about chest height for best results...

As far as efficiency is concerned, you get the same amount of heat on 1500w from an oil filled heater as from a ceramic heater... I used the oil filled for fire prevention reasons... although the ceramic would heat up & cool off faster....

[Art Mann]

The information I am about to provide is not necessarily intuitive but it is coming from someone who has been an electrical engineer and studied such things for over 30 years. There is absolutely no difference in the type of heater you use as far as efficiency goes. Most of the resistance heaters designed for residential use are 1500 watts and they will heat a particular area to the same degree. Buy a 1500 watt heater and choose whatever safety or comfort features features that you like. They will all generate the same amount of heat for the same wattage.

The cost is calculated as follows. A 1500 watt heater consumes 1.5 killowatt-hours of energy every hour it is run. In my area, 1 KW-H costs about 10 cents. So, it costs me about 15 cents per hour to operate the heater wide open. Of course, if a thermostat cycles the element on and off periodically, the cost will be reduced accordingly.

Jim's comment about efficiency is only applicable if you are comparing the costs of different heaters. Resistance heating is not very cost effective compared to heat pumps and fossil fuels in most areas. Resistance heaters are almost 100% efficient from an energy standpoint. All that 1500 watts will turn into heat energy with the exception of a tiny amount that is radiated as light.

[Bryan Rocker]

You need to couple it with the location of the heater, heaters up on the wall or at the ceiling are much worse and ineffective than a same size heater setting on the floor. Heat rises so heating warm air doesn't help as much......

[Tom Stenzel]

Just a point of reference, a 1500 watt resistance heater on full will give off 5118 BTUs/ hour (the Internet sez so).

If you can arrange a heater to warm you and your work without having to heat the entire area -using less power in the process- you can possibly reduce your electricity costs.

Electricity sets me back about 14 cents per kilowatt-hour here. My small work area in the basement is usually in the mid 50s. I use an old 400 watt heater, enough to take the chill out.

-Tom

[Brian Elfert]

Resistance heating is basically 100% efficient. 100% of the electricity used gets converted into heat. It is not cost effective as it is one of the most expensive sources of heat.

[Mike Cutler]

Resistance heating is basically 100% efficient. 100% of the electricity used gets converted into heat. It is not cost effective as it is one of the most expensive sources of heat.

Exactly.
Electric heaters are the most efficient method of providing heat. They generally have an efficiency rating of .98 to 1.00. The drawback is the cost per btu is high.
Programmable wall thermostat reduce the cost only because they limit the temperature swings around a given set point, and can be programmed for runback. Personally I like the oil filled models because if you accidentally bump into them they aren't really super hot to the touch.

Michael
If you can defeat the installed temperature switch in the heater, and wire it into a line voltage controller, the best one I know of is the AUBE 120, or 240, series 7 day programmable line voltage controllers. These are self tuning, pulse width modulating, PID controllers. In other words they "teach" themselves the heating characteristics of the room they are heating, and control the temp very closely. They're usually about $55-$70 bucks.
Many of the ones at the 'borg are not much more than a simple bi-metallic strip in a plastic box, with a triac control output circuit. (One step above a button style brood heater.).

[Larry Frank]

I use a oil filled electric heater and a heavy duty electric timer. I also have a second fan electric heater to use for short times to quickly get the temp up.

I used a "Kill A Watt" meter which helped me understand the costs and came up with this plan. You plug the meter in the wall and then plug anything into it and it keeps track of the watts used and can calculate cost by day, week, or month. Using it around the house on various things was interesting.

[Rod Sheridan]

All electric heaters are 100% efficient as all losses are heat.

Any electric heater with a thermostat that measures the air temperature will do what you want.

There isn't any difference in ceramic, oil filled or just plain nichrome wire heaters go as far as efficiency, they all convert 100% of the electricity into heat.............Regards, Rod.

[Art Mann]

If you can arrange a heater to warm you and your work without having to heat the entire area -using less power in the process- you can possibly reduce your electricity costs.

-Tom

That is a very good point. If someone is going to be standing or sitting in one location for a long time, he can feel warmer with a quartz style heater that focuses heat energy on whatever is in front of it while the overall room temperature remains lower.

[Jason Beam]

I would drop any and all thought of leaving a "portable" heater unattended ever. Ask a fire marshal. That's just not safe (regardless of how long you've managed to escape peril).

It's good that you're doing the "maintain" strategy, though - It's usually cheaper to maintain a temperature than it is to try to catch back up periodically. But, since you're maintaining, I think you should be using a heater that is 1) not plugged into an outlet and 2) designed for unattended use. I have a Dayton 5000w hardwired heater with built-in fan for circulating the warm air.

It's a great little unit. Properly installed, it's awesome for leaving unattended for short periods. I would never use a space heater to maintain a temperature when I'm not in the space it's warming.

That's just my opinion ... you should be looking at permanent heaters.

[Larry Edgerton]

Resistance heating is basically 100% efficient. 100% of the electricity used gets converted into heat. It is not cost effective as it is one of the most expensive sources of heat.

This always comes to mind when I see the adds for the Amish heaters and their efficient design. Amish are known for their cutting edge electronics.;)

Art, thanks for the heads up on operating costs. I'm heating my temp shop this winter and only get a bill once a year, now I know what to put away.

I stick one electric register inside my planer, keeps it nice and toasty.

Larry

[Pat Barry]

Portable electric oil heater, or portable electric ceramic tower heater? Right now I heat my small shop with an electric oil heater, which just radiates heat. It has a 600W mode, 900W mode, and a 1500W mode. To keep the shop at 55 degrees, I usually have the thermostat half way to thee quarters on 600W mode, and when I'm in there and I want it at 70, I usually start at 1500W mode with the thermostat all the way up, then switch it over to 600W mode. I don't know the exact cost, but I believe this is costing somewhere around $40 a month to run. Part of the problem is that the thermostat isn't based on air temperature, so if it's on 3/4, it would keep it around 55 on a 25 degree day, but if it's 35 degrees outside, the shed will be like 70. So I often use too much heat.

I was considering buying a ceramic tower heater, which includes a programable thermostat based on air temperature, has a fan blowing the air, and oscalates. These are usually 1500W. I don't know the actual efficiency of these things, because it's probably running 24/7, but then again it may distribute air better.
I don't think the problem you have is efficiency. The problem you have is a control problem. You need a remote thermostat such as described by Ed previously b because the internal thermostat in the heater can't regulate your shop properly. You could do as he suggests, just plugging in your existing heater and maintain the temperature you want in your shop. I checked and HD sells the thermostat you need for less than $15. You need place it in a place that represents the area you are concerned with keeping warm, wire it up and plug in your heater.