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How to heat a small room efficiently

(34 posts) (15 voices)

Started 8 years ago by mfread
Latest reply from johnmath

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mfread
Member

Hi all.

I'm trying to determine the best way to heat my bedroom (office).

Home sits in concrete slab. 2 stories (so office ceiling is insulated). Timber/veneer construction. Room is at corner of house so 2 of the walls face the outside. These 2 walls are insulated (I think). Both outside walls are under a verandah. Room faces south. 2 windows single glaze aluminiue. No drafts. Rooms is approx 16m2 (4x4).

Currently using a 2400 watt oil column heater (cheapie from Target). Keeps chill out of room all day as I work., but running the equiv of 24 x 100w lightbulbs is costing me a lot of money (I suspect).

I was thinking of buying a 12v (or 24 or 48v) ceramic heater (but have done no research yet so no idea if these animals still exist), run from car/deep cell batteries, and top up batteries via a solar panel. I'm a complete novice so have no idea if this is the best method to heat small space (from say 8am to 8pm).

I'm hoping the photovoltaic input will supply the juice read to keep the batteries at full capacity while they are supplying the necessary amps to drive the heater.

I don't need the room hot, just warm enough to keep the chill off while I work.

Oil heater heats room to approx 24 degrees when it's 10 degrees outside air temp thru the day. Some times this is too warm for me so I'll shut it off for a couple of hours.

I'm open to any reasonable suggestions. Trying to keep costs to a minimum (isn't everyone?).

If I can find a satisfactory solution then I'll also implement for 2 other bedrooms same size (so my 2 boys can ditch their 2400w column oil heaters too when they do homework etc at night or play all day on their pc over the weekends).

Cheers,
Mark

Posted Tuesday 2 Jul 2013 @ 9:26:14 am from IP #
TonyT
Member

You could consider

1 x 1 Kw copper convection heater with a circulation pump added to an existing hot water system.
$550.

This is listed near the bottom at:

http://www.runonsun.com.au/runonsun/Solar_central_heating_%26_convection_heaters.html

Posted Tuesday 2 Jul 2013 @ 9:32:37 am from IP #
Majik
Member

Mark, I am not an expert, but do find the topic vitally interesting.
The room faces South, but I would be looking to gain the benefit of heat from the sun. Because we do not understand the exterior situation, I would nonetheless take some time contemplating how you can bring sunlight into the room. The big free heater, free and constant.
The other focus should be to consider where heat is being lost, which is a key factor.
At our home we have moved from column heaters to reverse cycle air-conditioning. We will be looking at the winter quarter electricity bill to assess the change in daily usage rates.
Intuitively, my expectation is that air-conditioning will be more efficient than column heaters. Certainly, it is more efficient with a room warming up in a few minutes.

Wonder what scientific analysis has been done to compare air-conditioning with column heaters? Surely it has been determined. I would like to include factual data on my website: http://www.solar-cell-panels.com if someone can point us to the analysis.
I do hope you get good support with such a reasonable real world problem for solution, and I will be watching with interest.

Posted Tuesday 2 Jul 2013 @ 11:42:43 am from IP #
mfread
Member

@TonyT - Thanks for the suggestion, but this suggestion will not work for me as my hot water is an on-demand Rheem Affinity natural gas system (turn on a hot water tap, a pilot light comes on in the Affinity box mounted on a wall outside my house, which heats the cold water in the copper tube flowing over the pilot light). Takes around 30 seconds for me to get hot water flowing out the tap (what a waste of water incidentally ... yes, yes, I can just hear people in the background saying things like 'water recycling' and 'grey water' etc ... yep, I'll get all that done when I can, one project at a time ).

Posted Tuesday 2 Jul 2013 @ 11:43:21 am from IP #
mfread
Member

@Majik - I do use reverse cycle split system upstairs to heat a much larger room (one or more column heaters or 240v convection heaters would be impractical upstairs).

I do have a natural gas convection heater in my family room. But it illegal to put one in a bedroom (even if I am using it as an office), and I don't like the idea of breathing in all that gas all day long either (even if I could get a bayonet point into my office room).

I too have heard that R/C A/C is more efficient than oil column heaters. However, installing a ducted R/C A/C into my house is impractical (2 storey home if you recall), not to mention the cost ($15k plus).

And putting a split R/C A/C into the 3 bedrooms I mentioned is costly too.

Now, my bedroom (being used as an office) is pretty air tight as I mentioned. So loss of heat is minimal (I presume most would be through the single glaze glass windows). I do believe there is a magnetic seal of some sort that acts as a second glaze (on the inside of course). Not sure how much this costs.

And it is impractical for me to 'redirect' the sunlight (what little there is in winter) into my room.

No, what I am looking for is a cheap way to power a cheap heater (something cheaper than what the grid electricity costs).

And sorry, no, I don't want to go to the expense of installing a dozen solar panels on my roof and feed the electricity back into the grid to 'wind back the meter' as I'm selling my home.

Hence why I thought what I suggested was the most practical/portable solution for my needs.

Surely there has to be something out there that is cheaper than grid electricity?

And no, I don't believe a big noisy diesel generator running on vege oil isn't the answer either

My goodness, we can send man to the moon (supposedly), but we can't create a cheap efficient way to produce the electricity (onsite) needed to run a home?

The world if full of greedy stupid selfish people running governments and power utility companies etc. It truly is disgusting. What kind of world will my 3 sons be living in? And my grandchildren?

The eCat and other tech can't come soon enough. But that's a long way off (if they ever see the real light-of-day for normal civillians).

Sorry for the outburst people, but it really does get my goat

Anyway, on to more positive thoughts ... :)

Posted Tuesday 2 Jul 2013 @ 12:04:25 pm from IP #
darrynm
Member

How about a solar air heater / collector? Cheap to make if you can DIY and with a large enough collector for a small room it should be quite sufficient. And keep the oil heater for cloudy days

Example link: http://www.builditsolar.com/Experimental/AirColTesting/ScreenCollector/Building.htm

The trick will be to use a fan & ducting to get the warm air into the south facing room and this might be impractical. Depends on your roof & ceiling access etc.

Otherwise, discounting gas options or diesel(!), a small reverse cycle air con unit with give you the lowest running cost per KW as you should be able to get one with a COP of at least 4 so peak rate power ~ 28 cents / 4 = 7 cents per KW. The unit plus install might be only $1200-1800.

Oil heaters = fan heaters = ceramic heaters = 1KW power = 1KW heating (give or take) = efficiency 100%
Reverse cycle air con = COP 4 = 1KW power = 4KW heating = efficiency 400%

Anyway, another thing to consider is that your 2400W oil heater wont be running at 2400W all day. Do you have a power meter to check the actual power consumption? It might be using less / costing less than you think.

Posted Tuesday 2 Jul 2013 @ 12:21:04 pm from IP #
darrynm
Member

Majik said:

Intuitively, my expectation is that air-conditioning will be more efficient than column heaters. Certainly, it is more efficient with a room warming up in a few minutes.

Wonder what scientific analysis has been done to compare air-conditioning with column heaters? Surely it has been determined.

As above all standard electrical heaters convert 1KW power into 1KW heat, more or less.

Reverse cycle heating converts 1KW into 4KW (assuming a decent quality unit & above zero outside air temp).

But the up front install cost is substantially more expensive so you need to consider how much power you intend to use as more consumption will mean using reverse cycle can save you more per year which in turn will justify the install cost.

Posted Tuesday 2 Jul 2013 @ 12:25:03 pm from IP #
rockabye
Member

mfread said:

No, what I am looking for is a cheap way to power a cheap heater (something cheaper than what the grid electricity costs).

And sorry, no, I don't want to go to the expense of installing a dozen solar panels on my roof and feed the electricity back into the grid to 'wind back the meter' as I'm selling my home.

Hence why I thought what I suggested was the most practical/portable solution for my needs.

Surely there has to be something out there that is cheaper than grid electricity?

And no, I don't believe a big noisy diesel generator running on vege oil isn't the answer either

My goodness, we can send man to the moon (supposedly), but we can't create a cheap efficient way to produce the electricity (onsite) needed to run a home?

Anyway, on to more positive thoughts ... :)

Your request and comments are an indication of how difficult it is to meet everyones expectations of a 'cheap and plentiful' supply of electricity while at the same time we try to deal with the results of a growing human impact on the planet. I am pleased you took the time to make them.

The words 'cheap and efficient' are generally incompatible however people in cold climates like the UK often build a sun room to take advantage of the free solar energy that is available even on cloudy days.

Our real enemy is the word 'cheap'. At its source solar energy is the 'cheapest' and most efficient. Soon it will be 'cheaper' than coal fired power which is destroying our environment your children will have to live in.

The problem stems from the fact that most houses are poorly designed and insulated because its 'cheaper' to build them that way. Of course the end user then has to pay a high price for the energy to keep it within a comfortable temperature range.

So as you are selling your home you have been presented with an opportunity. By choosing a better designed property you may be able to resolve some of these issues. The other real problem is behaviour. This 10 minute video might be worth watching.

http://www.ted.com/talks/alex_laskey_how_behavioral_science_can_lower_your_energy_bill.html

Ending on a positive note we need to be grateful we live in the first world. At least we have a choice.

Posted Tuesday 2 Jul 2013 @ 10:06:07 pm from IP #
mfread
Member

@Rockabye - I do appreciate your comments. But I am not interested in why those who live in a first world country are better off than those living in a 3rd world country. This is something I cannot change. I'm not even in a position to go solar/feed the grid, nor am I in a position to redirect sunlight into my south-facing room, or insulate the walls, or install a one-off split system aircon, etc etc etc.

What I am trying to do is improve a particular circumstance with the application of a simple, cheap and effective system via the use of technology. I'm sure there must be thousands of others who are just interested in doing the same and not discussing the merit of living in a first world country etc (no offence but this isn't what my thread is about).

My initial thought was if it was practical to power a DC fan with a solar panel (and use a battery in the middle as a voltage regulator). A self-sufficient system running totally off-the-grid.

The quick answer is of course yes, if you have a large enough battery bank to power the size of DC heater required to heat my room size (air volume) to a certain temperature, and a large enough solar panel array to provide the constant energy required to run the whole process.

Now, I cannot imagine a single 12v car battery is going to power a 12v DC heater (ceramic or otherwise) for very long, yet alone heat my room to the desired temperature.

Hence why I'm trying to discover if people have used a similar setup effectively (what heater for greatest effeciency? how many batteries and of what type and why? did they use a solar panel to keep the battery bank topped up? or did they use a 240v battery charger - which kinda defeats the entire exercise?).

Anyway, I'm still looking for creative, inventive, practical answers to the original question posed. I guess I'll need to get into far more depth re: amps, watts, volts, heating air, etc etc etc - something I was trying to avoid by deferring to those more knowledgeable than myself.

Meanwhile I'm researching far and wide for creative ideas.

What about supercapacitors?

I do like darrynm's take on this - a system with a COP > 1 would be most desirable for obvious reasons.

Cheers all.
Mark

Posted Wednesday 3 Jul 2013 @ 1:41:57 am from IP #
scott drew
Member

Mark,

Couple of portable suggestions for heating in the office.

Can you draw some of the upstairs aircon heated air downstairs? Best case in my mind would be that you could put a vent from your office ceiling to upstairs and draw some warm upstairs air down to your office. Maybe with a computer fan or something. Not something that will provide a wind chill, but will draw the warm air from the room above your office. Worst case is that above your office is nowhere near the upstairs air con and that wipes that idea!

Can you forget heating the whole room of the office and heat yourself instead? I purchased my wife some usb slippers. They are simply slippers that have a heat pad in them and it plugs into the computer via a usb. While she sits at her computer she slips them on to heat her feet. She thinks they are great. Is that a possibility? If no computer they can be plugged into any usb socket/adaptor for a powerpoint I think. Its a special usb outlet/adaptor for powerpoints, not a mobile phone charger. Don't think mobile chargers will power the heating pads.

Not having direct access to the sun for that room is a bummer.

You will get heat loss out your single glazed window. Do you require it to be unshaded? Perhaps draw the curtains/blind and try seal that off to prevent heat loss. Means you will have to turn on the light probably, but a darn sight cheaper than the magnetic second glazing type thing. I understand they are quite expensive, and they wont be portable to anywhere new, they'll have to stay at that window probably.

Does your column heater have a thermostat in-built? Perhaps turn that down initially. 24 is pretty warm. That will instantly reduce electricity consumption. Maybe you could get a thermostat that cuts off the powerpoint if there is not one in-built on the heater.

There's a few suggestions.

Posted Wednesday 3 Jul 2013 @ 1:47:32 am from IP #
Benny
Member

Whats your most recent electricity bill like Mark ? How many units/kWh per day ? If you haven't had a bill in winter I'd strongly recommend you get/borrow an energy meter and plug it in to the heater to see how many units its using per day. Alternatively read your electricity meter for a few days and track usage there - you could be in for a nasty surprise when the bill comes.
I'm afraid there is no "simple, cheap" way to provide heat in this situation - otherwise we'd all be doing it (-;
I don't think your idea of solar PV + "a few car batteries" will give you a solution either. You'd be lucky to get 20% efficiency from the PV so about 200W/sqm of panels (under ideal situation) - and 200W wouldn't provide much heat to the room. Then there's the cost of batteries + charge controller. A 12V/40Ahr car battery contains 480Wh or about half a unit of energy - thats enough to run your 2400W heater (on full) for about 12 minutes.
As others have said the heater is probably not running flat out all day - I presume it has a thermostat ? If the rooms getting up to 24C sometimes then I;d suggest turning it down to 20C - every 1C reduction in the setting will save you 10% of running costs.
A better solution might be a radiator style heater - keep this near you and let it heat you rather than the whole room. There are also very low power electric blankets you can put on your chair to keep you warm.
In my office I built a solar air heater which took over from the fan heater by about 9am each winter morning.

Posted Wednesday 3 Jul 2013 @ 1:58:16 am from IP #
darrynm
Member

I'll do a forum post soon on my solar collector - I just finished it today and testing it right now: midday sun and I'm getting 50 degree heat through a 5 metre section of ducting and the fan is moving 125-150 m3 per hour and using 21 watts per hour. It's a very clear & sunny day with the outside temp around 20.

In more familiar terms, I'd say the heat and air movement is like one of those little electric fan heaters going on full at 1.5-2 KW = approx the same as your column heater. Cost me around $500 in materials to build and next time that would be cheaper given the things I've learnt

+1 for radiant heat = much more comfortable. Even a fan heater is nicer than an oil heater if you dont mind the fan noise.

Posted Wednesday 3 Jul 2013 @ 2:30:20 am from IP #
mfread
Member

I like the open discussion and thoughts/ideas from everyone

Ok, a little bit more information for everyone:

1) I am not trying to have a lavously heated room. I am simply wondering if I could heat it "for free forever" (after a modest investment) via a smart (creative/intelligent) self-sustaining mechanism comprising of a solar panel with one or more car/deep cell/lithium ion batteries and a noiseless heater like a ceramic heater). The concept is more about coming up with a technological solution and less about how to conserve energy. It's where 'need' drives 'invention'.

2) My room is sealed quite well. This is why I can, for the better part of the day, sit here without a heater and be fairly warm (albeit cold hands). I'm warm because I have 3 layers of clothes on. I wear fingerless gloves (uncomfortable). I program (write code) all day long. This is despite it being 0 to 5 degrees over night, and 5-10 degrees through the day (I live in the mountains). I was using a fan driven convection heater from time to time but the noise just drove me nuts (and yes, I did wear earphones, but they and the music just give me a headache after a while - sometimes I just want piece and quiet so I can concentrate).

3) I also wanted to find a solution that I could replicate into 2 other bedrooms of same size for my sons. They are not about to dress like me and put up with the cold, nor should they have to (we don't live in the dark ages). The use column oil heaters. If there is something as quiet that pumps out about the same amount of heat while using less power then I'd like to know what my alternatives are.

4) I've taken quite a few other steps to reduce our electricity bill. Mainly behavorial patterns etc. This thread I've started isn't about what can be done to reduce my energy footprint; it is a singular premise designed to test what *heating* alternatives that might exist that I am not aware of. Yes, they will be more effective if I ensure I have no drafts, have double-glazed windows yada yada yada - but let me find a self-sufficient heating system *first*, then determine after implementation how to make it more efficient. Get me?

@Scott - I like the USB sock warmer type idea. I will investigate. The split air con upstairs isn't on that often, and I have no easy way of diverting/pumping some of that warm air down my way.

@Benny - I have yet to buy a gizmo that will allow me to measure the energy consumption of each heating device I have (oil column heater, noisey electric convection fan heater). Simply watching/recording what my power meter does won't do it - think about the fridge cutting in and out etc. Yes, oil column heater does have a thermostat. I used 24 degrees as an example as I don't have any thermostat/temp gauge to tell me what the room temp actually is. When I feel too cold (despite my clothing etc), I'll turn it on until the room gets warm enough, then I'll turn it off. I do like the low power electric chair blanket idea too - I'll Google for products.

@darrynm - I'm interested in what you've achieved. While it's not suitable for my setup right now, it might be a very useful system for me in the future.

Cheers all.
Mark

Posted Wednesday 3 Jul 2013 @ 4:05:44 am from IP #
darrynm
Member

For low / zero noise the best option is hydronic heating = radiators. But it's a lot of installation with the pipework etc so more a long term solution for the whole house vs 1-2 rooms.

Otherwise a low speed air heater either in the room = small reverse cycle unit, or ducted from another room or larger reverse cycle unit (which could heat several rooms).

Energy meters: http://www.originecostore.com.au/store/c/1362-Energy-Usage-Monitoring.html

I've got an Arlec one and works fine to do a simple check of power use.

Posted Wednesday 3 Jul 2013 @ 4:13:55 am from IP #
Greg C
Member

For right now I would invest in a good thermostat that plugs into the power point and then controls the heater, or find a heater that has a decent thermostat. This is easier said than done though. My great Aunt had an oil column heater in the 1970s that had a good thermostat but I have never seen another. Likewise for fan heaters we had one with a good thermostat but after it died it took a while to find another with a good one. It now does duty on the odd night we need to boost the solar gain. After you have sorted a thermostat set it to 20 degrees for winter. The reason I like fan heaters over column type is they heat the room faster so you don't need to run the heater for long before you notice a difference, and because they move air through themselves you have a better chance of getting one with a good thermostat. Make sure you position a fan heater so it does not blow air on you though. Replicate for the sons rooms and glue the thermostat to 20, if it is too cold put on a jumper....

That should save a bit of energy while you research the more effective alternatives.

Posted Wednesday 3 Jul 2013 @ 10:53:31 am from IP #
mfread
Member

@Darrynm - Thanks for the power meter link.

@Greg - Much appreciated. I actually went out today and purchased power consumption meter from JayCar. Once I set it up I'll be testing the draw on a number of heating appliances I have, just so I know which device draws more and which draws less etc. Then I'll need to buy a good thermometer so I can measure the rate at which the air in my room is being heated over the same period of time for each appliance (being careful to do so at the same time of day for each test; ie. start temp, temp every 15 minutes for 1 hr, end tempt).

Posted Wednesday 3 Jul 2013 @ 11:03:14 am from IP #
dmaunder
Member

As others have said, it is not just the draw that matters, but the usage per hour or day since different heaters will cycle on and off differently. The Jaycar meter does that as well, you just need to reset it after each appliance.

Posted Wednesday 3 Jul 2013 @ 11:32:33 am from IP #
mfread
Member

@dmaunder - Thanks for your input. I'm not going to get too technical with the testing - just a basic idea of how different heating appliances I have at my disposal perform given all things being close to equal as possible.

Posted Wednesday 3 Jul 2013 @ 11:36:41 am from IP #
Johnnojack
Member

You said " The(y) use column oil heaters. If there is something as quiet that pumps out about the same amount of heat while using less power then I'd like to know what my alternatives are."
They (the column heaters) are already 100% efficient as most resistance heaters are, so it is not possible to get a heater which will do what you ask here. The only exception is a heat pump which you have ruled out. Maybe your only option is to temporarily improve the insulation of the room. Consider fixing double sided foam filled foil insulation to the inside of the outside wall. Even cover the window. Cheap and you can remove it when you leave. Should cut the power needed to heat the room by quite a bit.

Posted Wednesday 3 Jul 2013 @ 1:02:53 pm from IP #
Buzzman
Member

Mark
The cheapest and most eco-friendly way to "heat your office" is *not* to do so!

Seems obvious, doesn't it, but I ma not intending to be fatuous - I'm serious.

Last winter I attempted to solve the same problem as you, and realised that no matter what I tried, all the solutions used power and therefore, by definition, were not as cheap as not heating the room in the first place.

I solved my problem by purchasing a set of thermals, which I wear under my normal everyday clothes, and a jacket and beanie over the top. Much of the heat loss is via your head, so a beanie is essential.

Then I bought an accurate thermometer, and hung it on the wall near the desk. I worked out the level I could "cope" with and vowed never to turn on the heater until the air temp went below that.

I found that with tracky dacks over my jeans and thermals, I was warm and comfortable down to an air temp of 12 degC. If it goes below that, I use a small 1.8kW ceramic blower heater on it's low setting (ie: 900watts).

This is located under the desk so my legs rapidly get warm, and after 15 mins or so I can turn it off again for another hour or so.

In other words, insulate your own body and most of the time you will not need any form of external mechanical heating. Which is VERY cheap.

Oh, and for the record, I have not used the heater once this winter...but my office is on the north side of the house, has windows all the way done two walls, and is usually about 3-4degC warmer than the rest of the house. That's why the office is in that room!

Warm socks, warm boots and a beanie prevent the most heat loss from the body, as these areas are where the blood suply is closest to the surface.

The first rule *ought* to be - ALWAYS - <<warm the body FIRST, not the air around it>>.

Posted Tuesday 16 Jul 2013 @ 7:40:54 am from IP #
johnmath
Member

Buzzman said:
If it goes below that, I use a small 1.8kW ceramic blower heater on it's low setting (ie: 900watts).

This is located under the desk so my legs rapidly get warm, and after 15 mins or so I can turn it off again for another hour or so.

In the olden days people often installed a heat lamp under desks for personal heating. My father-in-law in Japan has a desk sized heated floor pad, which works really well as a low running cost personal heater.

To the OP: Mark, you are working in a coldroom as per your description:

Timber/veneer construction. Room is at corner of house so 2 of the walls face the outside. These 2 walls are insulated (I think). Both outside walls are under a verandah. Room faces south. 2 windows single glaze aluminiue.

The walls and windows may as well not be there except for stopping the wind!

There are two ways you can heat the room: 1. Heat the air which indirectly heats the objects in the room (furniture, humans, etc), or 2. heat the objects (including humans) in the room directly.

1. All electrical convection heaters whether oil column or fan heater are equally efficient at turning electricity into heat. They turn 1 watt of electricity into 1 watt of heat. However a fan heater under the desk pointing at you will save you from having to heat the whole room and thus be more effective for the same amount of electricity.

A heat pump has a "magnification" (COP) factor because it is stealing heat from somewhere else and making that area colder (outside) and pumping the heat inside. This means that 1 watt of electrical input can give you 3 - 4 watts of heat in the room and will be a better choice if you need to heat the whole room.

2. Radiant heat passes through the air and make objects warm without dissipating energy raising the temperature of the air. The warmer objects in the room do heat the air indirectly to some degree. But it is possible to be comfortable in a room with quite a low air temperature if the radiant heat level is high. I suspect this approach uses even less electricity than a heat pump with its magical COP.

Radiant floor pads and ceilings are very popular in the coldest regions of Europe and Japan and are considered electrically very efficient. They also embrue a comfortable, noiseless, draft-less, odour free environment. The only caveat is that you can't have drafts through cracks or non-sealing windows and doors, because moving air has a cooling effect (which is another reason why heat pumps don't work as well in reality as they do on paper).

Posted Tuesday 16 Jul 2013 @ 8:20:08 am from IP #
Catopsilia
Member

Mark, I do not think there is a cheaper alternative to mains power for heating your study.
If it is a case of keeping comfortable while you work, I agree with Buzzman that suitable warm clothing can be very effective. A web page that has been mentioned before in the forum says that modern thermal underwear is not only practical but also sexy!
http://www.lowtechmagazine.com/2011/02/body-insulation-thermal-underwear.html
That page has a lot of other practical information about room heating and "clo" units etc. That whole web-site, "Low Tech Magazine" is an absolute goldmine of useful, almost forgotten facts.
I have two suggestions. The first is very simple and cheap: lay a rug under your feet. The second may not be practical for you: divide the room in half with a full length curtain hung from the ceiling. That will halve the volume of air you have to heat. My kitchen/dining room has such a curtain. In the recent cold overcast weather I have been retreating into the curtained kitchen, heated by the stove, to eat dinner there.

Posted Tuesday 16 Jul 2013 @ 11:32:55 am from IP #
mfread
Member

I want to thank everyone for their insightful contributions.

My primary aim was to discover if I could power a DC ceramic (or such) heater with the use of an inexpensive solar panel and battery (a fairly portable solution).

The purpose behind my aim was to (a) determine if it could be done with today's tech, and (b) to keep my office - and myself - warm.

Keeping my office warm also meant that the walls would be dry, keeping mould etc at bay during the winter months.

Many came up with innovative ideas and practical solutions to either heat my office or to keep myself warm (via clothing, various personal USB heating devices etc), but none met my primary goal.

I have spent the last week or so looking at various devices that could power a 400W load but nothing inexpensive exists (it would take several years at grid prices to acquire my return on investment).

So while a solution meeting my requirements hasn't been found, I am keeping warm via extra clothing and a burst of heat from a fan heater once in a while. Meanwhile my children's rooms are being heated the same way as before - oil heater plugged into the wall socket (ie. grid powered).

Cheers all.

Mark

Posted Wednesday 24 Jul 2013 @ 12:42:08 pm from IP #
rockabye
Member

"My primary aim was to discover if I could power a DC ceramic (or such) heater with the use of an inexpensive solar panel and battery (a fairly portable solution)."

"So while a solution meeting my requirements hasn't been found...."

If it was possible to do this you would not have needed to have asked the question. Everyone would be doing it already and your local supermarket would be selling them for $100.

The good news is you have discovered that by altering your behaviour, ie wearing warm clothes and using a short burst of expensive energy, you have been able to keep warm.

Posted Thursday 25 Jul 2013 @ 8:56:14 pm from IP #
mfread
Member

@rockabye - I disagree with your assumptions.

a) If it were possible and everyone was 'doing it', then isn't this the perfect forum to ask the question and discover if 'everyone was doing it' and how ??

b) I highly doubt supermarkets would be selling a portable solar + battery + heater "solution" !!

c) This forum is called "Alternative Technology" for a reason.

Regards,
Mark

Posted Friday 26 Jul 2013 @ 12:05:12 am from IP #
mfread
Member

Further to my post above to rockabye (as I can't seem to edit the post), yes, I can keep warm by adding clothing, wearing gloves, using low powered (USB) personal/body 'warmers' or 'heaters' etc, but that doesn't address my primary goal.

Yes, I could ask my children to do the same (add clothing etc) and unplug their 1000W oil column heaters, and go to the expense of replacing their cedar sash windows with aluminium double-glaze, etc, etc, etc, but I don't live in a 3rd world country. I want to discover if technology can address a basic small room heating issue. Smarter technology. The creative use of technology. For little cost.

I realise it may not exist (yet), but that's why I'm in this forum, to discover if anyone else has creative suggestions. Some did, but they weren't practical for my situation (but many others visiting this thread in the future might have a 'ah-ha' moment though for their particular need).

Posted Friday 26 Jul 2013 @ 12:16:37 am from IP #
rockabye
Member

As I said much earlier on it is good to ask the question. I'm sure there are people out there trying hard to achieve what you seek.

The solutions to date all involve better dwelling construction aka 8 star houses. Trying to heat, or cool, poorly designed dwellings involves expensive solutions, often heavily polluting like fossil fuels. To date there is no 'cheap' alternative.

But price is a relative thing. Our power use here in Qld is quite low because even though the house is uninsulated we still spend less than $1000pa including infrequent use of reverse cycle aircons. In fact most of the energy is used, or wasted, on discretionary devices like computers and TV's, where as the essential stuff like fridges and hot water use less than $500 pa.

This is why I mentioned behaviour early on as being so important to how we achieve outcomes. You have demonstrated how well it works.

Posted Friday 26 Jul 2013 @ 1:29:07 am from IP #
fireflies
Member

I'm sure Tony T would have added some value to this thread. Unfortunately he has gone missing for a week or more now . What Tony would have been able to provide mfread that I am unable to, is work out energy/hour required to warm your room from cold to comfortable. Then work out energy available from external source KJ/m2 - i.e. solar collectors - PV or heat. Work out the efficiency of those different heat sources. Losses involved in converting or storing that energy. From there you could work out how much area is required for solar collectors and from there, the cost. Unfortunately, the person required to work that out isnt me.

Posted Friday 26 Jul 2013 @ 1:39:27 am from IP #
johnmath
Member

mfread said:
I want to discover if technology can address a basic room heating issue. Smarter technology. The creative use of technology. For little cost.

I realise it may not exist (yet), but that's why I'm in this forum, to discover if anyone else has creative suggestions.

With respect, you seem to be seeking a solution that breaks the law of Conservation of Energy. http://en.wikipedia.org/wiki/Conservation_of_energy There is unlikely to be a solution like you seek anytime in this universe. You need to ask that one in the Alternative Reality Association forum, not the Alternative Technology one.

Posted Friday 26 Jul 2013 @ 1:43:38 am from IP #
dbindoff
Member

Mark I am struggling with the same issues as you (for some time now). Lance posted (a few months ago) a link to a cheap car seat heater, 12v, which he said is working ok as a 'personal heater' on his office chair. I think he is using mains power and a 12v transformer to run it.

I also have a coldish office, towards south of house and no direct sun in winter.

I decided some time ago to emulate Lance's solution but to experiment further using a small battery mounted on the chair and manually charge with a solar panel. Other issues intervened but finally a few days ago I received an 80w solar panel ($79.00 delivered), already had received the car seat heater and 2 small 7AH AGM batteries. (I ordered silicone batteries in May but they have not arrived yet)
I've mounted the batteries on the chair with Velcro self adhesive spots and so far that seems to be enough to hold them ok. The solar panel is charging the battery in fairly short time and once connected the heat is quite adequate (on low - high will drain the batteries too fast). (It's getting a little warmer now so I've missed the worst of winter.) When the solar panel is not charging the battery, I connect it directly to an old 50w halogen light bulb to add heat to my old DIY solar air heater and that appears to be working ok.

It has all been experimental and temporary so far. I need to decide on the exact location for the panel, connectors and cabling and I can't find my very old soldering iron so I've ordered a new one but so far it looks like it should 'work' once it's all set up.
So that's my labour intensive and experimental (for me ) approach. Battery size is probably a little low ($22.00ea for 7AH) and they are very light so I could up the size to get another hour or so out of each cycle I think.

Posted Friday 26 Jul 2013 @ 4:59:33 am from IP #

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