Please can anyone advise me as to a suitable portable heater for my caravan. I have a small fan heater but was wondering if a convetor would be more suitable?
Heater
- Thread starter Freedomfairy
- Start date
I use one of these............they have a thermostat......a timer with multiple off/ons
......and 3 heat settings...750 watts...1250watts and 2000 watts.
My caravan has a blown air heating system which can be set to 800watts so the two systems can be run together if the supply from the EHU is sufficient.
......and 3 heat settings...750 watts...1250watts and 2000 watts.
My caravan has a blown air heating system which can be set to 800watts so the two systems can be run together if the supply from the EHU is sufficient.
I have one of these . The lowest heat setting is 75W (3A)
Argos Value Range 2kW Convector Heater.
Cat No.415/2181 £19.99
Product description / spec
To keep you warm throughout the winter months, this Argos Value Range white and black convection heater is thermostatically controlled with three heat settings and a safety cut out feature.
•Heat output 2kW.
•3 heat settings.
•Safety cut out switch.
•Thermostatically controlled.
•Wall mountable.
•Wall fixings included.
•Size H39, W52, D11cm.
•EAN: 4152181.
Argos Value Range 2kW Convector Heater.
Cat No.415/2181 £19.99
Product description / spec
To keep you warm throughout the winter months, this Argos Value Range white and black convection heater is thermostatically controlled with three heat settings and a safety cut out feature.
•Heat output 2kW.
•3 heat settings.
•Safety cut out switch.
•Thermostatically controlled.
•Wall mountable.
•Wall fixings included.
•Size H39, W52, D11cm.
•EAN: 4152181.
I bought a small fan heater in France many years ago which is switchable between 750 and 1200 W. Both elements can be switched off so it just circulates the air. Because it is so old, it's nothing more than a black box about 8" square, but it warms the caravan very quickly - much quicker than the fitted Truma Ultraheat.
Hello Jaydug,
Its quite likely a portable fan heater will seem to warm the caravan more quickly than the installed heating. One of the really nice things about electric heating is that its 100% efficient, all the electrical energy fed to the appliance is liberated as heat, and that also applies to the electric elements of the Truma Ultraheat heater. The difference is, the Truma distributes the heat further around the caravan, and under the seats where the ducts run, so it is actually heating more of the structure of the caravan, where as the fan heater only blows air into the living space, and because the living space is smaller and has less exposed structure, for the same electrical rating it will warm up more quickly.
The advantage of heating up the under seat lockers is that it will reduce condensation in them, and thus help to keep your belongings a bit drier.
The fan heater will rapidly warm the air in the caravan In doing so it will allow the air to absorb more moisture. But because there is a greater temperature differential between the living space and the lockers, when the air finds its way into the lockers, it cools and has to get rid of some of its moisture as condensation.
So for short term quick warm up, the fan heater is an excellent choice, but for extended periods its better to switch to the blown hot air system whether is gas or electric.
Its quite likely a portable fan heater will seem to warm the caravan more quickly than the installed heating. One of the really nice things about electric heating is that its 100% efficient, all the electrical energy fed to the appliance is liberated as heat, and that also applies to the electric elements of the Truma Ultraheat heater. The difference is, the Truma distributes the heat further around the caravan, and under the seats where the ducts run, so it is actually heating more of the structure of the caravan, where as the fan heater only blows air into the living space, and because the living space is smaller and has less exposed structure, for the same electrical rating it will warm up more quickly.
The advantage of heating up the under seat lockers is that it will reduce condensation in them, and thus help to keep your belongings a bit drier.
The fan heater will rapidly warm the air in the caravan In doing so it will allow the air to absorb more moisture. But because there is a greater temperature differential between the living space and the lockers, when the air finds its way into the lockers, it cools and has to get rid of some of its moisture as condensation.
So for short term quick warm up, the fan heater is an excellent choice, but for extended periods its better to switch to the blown hot air system whether is gas or electric.
Hello Freedomfairy
You've had an excellent and full answer from ProfJohnL.
He makes the crucial point about warm air giving up moisture as it cools, leaving condensation on cold surfaces.
If this is problem for you, you may want to think about radiant heating.
Radiant heating doesn't directly warm the air but, instead, warms the surfaces in the caravan.
How warm you feel is all to do with the rate of heat loss from your body and this is best controlled by eliminating cold surfaces. Tests have shown that a floor temperature of around 27degC means a lightly clothed person will feel neither too hot, nor too cold.
Most underfloor heating installations in buildings will operate at this sort of temperature.
After a while, the air becomes warm from being in contact with the warm surfaces but you won't have the same condensation problem you get with fan or convector heaters.
Hope this is helpful!
You've had an excellent and full answer from ProfJohnL.
He makes the crucial point about warm air giving up moisture as it cools, leaving condensation on cold surfaces.
If this is problem for you, you may want to think about radiant heating.
Radiant heating doesn't directly warm the air but, instead, warms the surfaces in the caravan.
How warm you feel is all to do with the rate of heat loss from your body and this is best controlled by eliminating cold surfaces. Tests have shown that a floor temperature of around 27degC means a lightly clothed person will feel neither too hot, nor too cold.
Most underfloor heating installations in buildings will operate at this sort of temperature.
After a while, the air becomes warm from being in contact with the warm surfaces but you won't have the same condensation problem you get with fan or convector heaters.
Hope this is helpful!
Hello William,
Thankyou for your kind comment. However, I can't agree with some of the points you make.
Yes radiant heating tends to directly warm objects rather than air, and the air will take up heat from the objects as a secondary heat transfer, so that bits fine, but there are real practical problems with implementing a radiant heating system in a caravan. Fundamentally , just like a light bulb, the heat from a radiant source travels in straight lines, and wont go round corners, so to benefit from it you have to be in a direct line of sight with the appliance. Only the surface facing the heater will receive the heat, so residents may well find they get hot on one side but remain cool on the other.
Caravans are by their nature quite small and there are only a limited number of places a heater can be installed. Often at the bottom of the wardrobe or in a low draw unit, which all tend to face across the caravan rather than at the seating areas, so some items of furniture will be come toasty warm but not the people.
Again regarding the condensation issue, as the radiant heater will only be operating inside the living space, and will only warm the surfaces in direct line of sight of the heater it will have no more effect on the under seat storage and closed corners of the caravan than the portable fan heater solution. so my comments regarding condensation will apply just as much with the radiant solution as the fan heater solution or possibly worse.
In practice even a radiant heater will produce some convected heat, but as its not fan assisted, the warm air will collect at the top of the caravan leading to the uncomfortable hot head cold feet syndrome.
Concerning your comments regarding floor temperatures, 27C?? comfortable for feet, I don't know what your background is but that seems on the high side to me, The flooring industry recommendations tell us
"Independent tests reveal that the most acceptable indoor climate is one in which the floor temperature ranges between 19-29°C and the air temperature at head level ranges between 20 and 24°C."
Under floor heating in caravans is rarely sufficient to provide the entire heating solution in a caravan. Manufacturers of electric underfloor heating solutions seem to limit their maximum heat output to 200W/m2 for high heat loss areas such as conservatories.But depending on floor coverings that may need to be restricted down, so lets be generous and assume we could achieve 200W/m2 in a caravan, the heating power available is determined by the amount of floor space that can be used for the heating. Practically that will be length of the saloon times its width at floor level. My guesstimate is that the average floor space width will be about 0.8M. Given those figures for a caravan with an internal length of 5M you would have 5m x 0.8m = 4m2 so at best that would be only 800W max but in most cases that may need to be reduced to only 100W/m2 because of carpet coverings probably closer to only 400W of effective heating.
It would give you nice warm feet (which is very nice) but it won't heat the whole caravan to a satisfactory level.
You also need to consider the spaces where fan heaters wont blow, and radiant heaters can't see, and it's questionable whether underfloor heating (Electric) would be safe, such as bathrooms or end bedrooms. How do you heat these areas?
Electric underfloor heating is not a realistic whole solution, it would need to be supplemented. That means the weight of two heating systems!
Thankyou for your kind comment. However, I can't agree with some of the points you make.
Yes radiant heating tends to directly warm objects rather than air, and the air will take up heat from the objects as a secondary heat transfer, so that bits fine, but there are real practical problems with implementing a radiant heating system in a caravan. Fundamentally , just like a light bulb, the heat from a radiant source travels in straight lines, and wont go round corners, so to benefit from it you have to be in a direct line of sight with the appliance. Only the surface facing the heater will receive the heat, so residents may well find they get hot on one side but remain cool on the other.
Caravans are by their nature quite small and there are only a limited number of places a heater can be installed. Often at the bottom of the wardrobe or in a low draw unit, which all tend to face across the caravan rather than at the seating areas, so some items of furniture will be come toasty warm but not the people.
Again regarding the condensation issue, as the radiant heater will only be operating inside the living space, and will only warm the surfaces in direct line of sight of the heater it will have no more effect on the under seat storage and closed corners of the caravan than the portable fan heater solution. so my comments regarding condensation will apply just as much with the radiant solution as the fan heater solution or possibly worse.
In practice even a radiant heater will produce some convected heat, but as its not fan assisted, the warm air will collect at the top of the caravan leading to the uncomfortable hot head cold feet syndrome.
Concerning your comments regarding floor temperatures, 27C?? comfortable for feet, I don't know what your background is but that seems on the high side to me, The flooring industry recommendations tell us
"Independent tests reveal that the most acceptable indoor climate is one in which the floor temperature ranges between 19-29°C and the air temperature at head level ranges between 20 and 24°C."
Under floor heating in caravans is rarely sufficient to provide the entire heating solution in a caravan. Manufacturers of electric underfloor heating solutions seem to limit their maximum heat output to 200W/m2 for high heat loss areas such as conservatories.But depending on floor coverings that may need to be restricted down, so lets be generous and assume we could achieve 200W/m2 in a caravan, the heating power available is determined by the amount of floor space that can be used for the heating. Practically that will be length of the saloon times its width at floor level. My guesstimate is that the average floor space width will be about 0.8M. Given those figures for a caravan with an internal length of 5M you would have 5m x 0.8m = 4m2 so at best that would be only 800W max but in most cases that may need to be reduced to only 100W/m2 because of carpet coverings probably closer to only 400W of effective heating.
It would give you nice warm feet (which is very nice) but it won't heat the whole caravan to a satisfactory level.
You also need to consider the spaces where fan heaters wont blow, and radiant heaters can't see, and it's questionable whether underfloor heating (Electric) would be safe, such as bathrooms or end bedrooms. How do you heat these areas?
Electric underfloor heating is not a realistic whole solution, it would need to be supplemented. That means the weight of two heating systems!
Hello ProfJohnL
Again thank you for the full and detailed contribution to this thread.
I've read on another forum that not all built-in systems perform well and many people resort to portable heaters to provide secondary heating. I assumed Freedomfairy was asking about portable heaters for this purpose. Apologies if this isn't the case.
I agree with your conclusion that electric underfloor heating is not a realistic whole solution.
But as a secondary heater, an electric under rug heater in your main living area is an excellent choice.
It will solve once and for all the 'the uncomfortable hot head cold feet syndrome' you mention which, in fact, is a drawback of all convected air systems. Forced air movement of cooler air at floor level - felt as a draught - isn't very comfortable.
Turning the floor into a radiant surface means you might even be able to set the air temperature thermostat (if you have one) for your main heater to a lower setting. Less noise, less air movement, less stuffy air.
All your figures and analysis I can pretty much agree with.
An under rug heater suitable to go on any floor surface is around 120 Watts per square metre.
A 0.5 x 1.5m under rug heater with underlay weighs around 2kg. I don't know the weight of the fan heaters and oil filled radiators I saw on sale at a caravan shop yesterday but wouldn't have thought they were much less.
Hope this helps!
Again thank you for the full and detailed contribution to this thread.
I've read on another forum that not all built-in systems perform well and many people resort to portable heaters to provide secondary heating. I assumed Freedomfairy was asking about portable heaters for this purpose. Apologies if this isn't the case.
I agree with your conclusion that electric underfloor heating is not a realistic whole solution.
But as a secondary heater, an electric under rug heater in your main living area is an excellent choice.
It will solve once and for all the 'the uncomfortable hot head cold feet syndrome' you mention which, in fact, is a drawback of all convected air systems. Forced air movement of cooler air at floor level - felt as a draught - isn't very comfortable.
Turning the floor into a radiant surface means you might even be able to set the air temperature thermostat (if you have one) for your main heater to a lower setting. Less noise, less air movement, less stuffy air.
All your figures and analysis I can pretty much agree with.
An under rug heater suitable to go on any floor surface is around 120 Watts per square metre.
A 0.5 x 1.5m under rug heater with underlay weighs around 2kg. I don't know the weight of the fan heaters and oil filled radiators I saw on sale at a caravan shop yesterday but wouldn't have thought they were much less.
Hope this helps!
Ridiculous :evil:
Come on boys. I am away in sub zero temperatures including a snow blizzard an hour ago.
We are on a 16amp EHU. It warms up fairly quickly before we turn on the air blowers. Fully agree with the Prof about warming up the hidden parts.
Once or twice this week we have also run the Truma on both gas and electric to obtain a fast warm up.
Please remember electricity costs money and even using a remote heater will erode your usable amps.
Come on boys. I am away in sub zero temperatures including a snow blizzard an hour ago.
We are on a 16amp EHU. It warms up fairly quickly before we turn on the air blowers. Fully agree with the Prof about warming up the hidden parts.
Once or twice this week we have also run the Truma on both gas and electric to obtain a fast warm up.
Please remember electricity costs money and even using a remote heater will erode your usable amps.
Ha Ha! Glad you're warm with your Truma.
Maybe I got a bit carried away but - back to the original topic - how would you help Freedomfairy? Is the best portable heater a fan heater, convector, or something else?
Maybe I got a bit carried away but - back to the original topic - how would you help Freedomfairy? Is the best portable heater a fan heater, convector, or something else?
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