Re: Portable heater

by burlingtonboaby Tue Feb 27, 2018 3:09 pm

Not all vans have the same heating as yours CC, I did in my Sigma and Nuevo, however my Duetto has an Eberspacher airtronic diesel heating system.
Boaby

by Paulmold Tue Feb 27, 2018 3:10 pm

daisy mae wrote:
CC wrote:Why don’t others just use their onboard heating when it’s cold? Ours is switched on permanently during cold spells like this when on the driveway and just set it to low on the thermostat...
Because if the heater gets a fault or breaks down it is cheaper to replace a portable heater than it is the on board fire.

Absolutely, with Truma combis costing over £2000, a little oil-filled rad cost is nothing by comparison .

by burlingtonboaby Tue Feb 27, 2018 3:12 pm

daisy mae wrote:
CC wrote:Why don’t others just use their onboard heating when it’s cold? Ours is switched on permanently during cold spells like this when on the driveway and just set it to low on the thermostat...
Because if the heater gets a fault or breaks down it is cheaper to replace a portable heater than it is the on board fire.

I concure Daisy Mae ,used the Screw fix heater in the coachbuilt vans at home and used the onboard heating when touring.
Boaby

by Gromit Tue Feb 27, 2018 3:21 pm

I'm not even sure if it's advisable to heat vans at home? scratch head

Warm air can hold a lot more water vapour than cold air, so there's an argument in favour of leaving the van cold.

Don't know, but it's a sure fact that those on dealers' forecourts won't be heated.

by rogerblack Tue Feb 27, 2018 4:02 pm

We do sometimes leave our onboard heater on overnight on the 500W setting with the thermostat fairly low but it's only really effective if we also have the fan on, which sounds unbelievably noisy in the quiet of the night. Also, even with external screens etc, the cab end of the van can get a bit chilly. Our little DeLonghi Bambino oil filled radiator is silent and placed at the cab end gives enough background heat on a low setting to keep the chill off overnight. Then in the morning, we switch on the onboard at 1000 or even 2000W with the 'stat set high and the fan on full, which quickly gets the van toasty for getting up, performing ablutions and getting dressed.

by daisy mae Tue Feb 27, 2018 7:03 pm

rogerblack wrote:We do sometimes leave our onboard heater on overnight on the 500W setting with the thermostat fairly low but it's only really effective if we also have the fan on, which sounds unbelievably noisy in the quiet of the night. Also, even with external screens etc, the cab end of the van can get a bit chilly. Our little DeLonghi Bambino oil filled radiator is silent and placed at the cab end gives enough background heat on a low setting to keep the chill off overnight. Then in the morning, we switch on the onboard at 1000 or even 2000W with the 'stat set high and the fan on full, which quickly gets the van toasty for getting up, performing ablutions and getting dressed.

I do the same as above, when away.

I keep my van heated all the time in cold conditions, on the drive, because I use it everyday, and it is more comfortable to get in to than a very cold van, I never have had condensation. I keep bedding and everything in van apart from fresh food. so keeps everything aired.

by CC Thu Mar 01, 2018 2:22 pm

I understand others comments about being worried about their onboard heating developing a fault... But then rationally thinking about it, that’s a bit like not running your home central heating in case your boiler breaks down or not running your heating when away in the Motorhome incase the combi develops a fault shrugg

I don’t have the heating high, the thermostat is only set on 1.5 and the lower 1 bar electric setting, with Gas assistance (needed in this weather) so actually cuts in very little, and it’s only on during really cold snaps like we are currently experiencing, just cautionary in case there’s a small qty of water left behind in the pipework to prevent anything freezing, used in conjunction with a small dehumidifier.

I agree with Dave probably totally unnecessary but whatever floats your boat, surprised that a little oil rad (we used to use one in our Trident btw) would be sufficient to do much in a van the size of say a Broadway.

by Peter Brown Thu Mar 01, 2018 4:42 pm

Gromit wrote:I'm not even sure if it's advisable to heat vans at home?

Warm air can hold a lot more water vapour than cold air, so there's an argument in favour of leaving the van cold.

Don't know, but it's a sure fact that those on dealers' forecourts won't be heated.

Sorry Dave, I replaced the max/min thermometer i keep in the van a couple of months ago, the one I now have also measures max/min humidity. I found that the humidity goes up drastically as the temperature falls and reduces as it increases; I googled and found:

"When the temperature is low and the relative humidity is high, evaporation of water is slow. When relative humidity approaches 100 percent, condensation can occur on surfaces, leading to problems with mold, corrosion, decay, and other moisture-related deterioration. Condensation can pose a safety risk as it can promote the growth of mold and wood rot as well as possibly freezing emergency exits shut."

So in the past, whilst on the drive, I just used the oil filled radiator when the temperatures was forecast to be at or below zero for a few days, I'm now looking to keep the temperature over 5 deg to reduce humidity.

by Gromit Thu Mar 01, 2018 5:40 pm

Interesting Peter. It seems to defy logic.

I thought I understood the physics, but I'm not so sure now - and that description you found isn't exactly crystal clear.

Evaporation of water is obviously slow when the temperature is low, and it's equally obvious that condensation can occur when the relative humidity approaches 100%. What else does the description tell us, other than that condensation causes problems? (No surprise there then! )

I'm not sure how much of an insight it gives as to what actually occurs inside an unheated van in winter.

Or am I being dense? Whistle1

by Peter Brown Thu Mar 01, 2018 6:01 pm

For a certain quantity of water in a certain amount of air, in higher temperatures the air will retain the water and at lower temperatures it will 'off load it'. Take a van with freezing temperatures outside and moderate temperatures inside, the inside surface of the outside wall will be a lot cooler than the inside of the van. The air inside the van retains the water till it touches the inside of an outside wall where, the colder temperature allows the air to discharge water to the surface - condensation. This water can be absorbed by adjacent fabrics such as seat backrests - if you live in the van in a cold climate you will notice this.

This effect will occur even if the inside of the van is unheated and ventilated as, because of the chill factor of any air movement, the outside surface of the van wall will always be colder than the inside.

If you want to confirm what I say, buy one and try:

https://www.amazon.co.uk/gp/product/B01H1R0K68/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

by Lorfal Thu Mar 01, 2018 6:01 pm

Well, I have my oil radiator and fan heater, ready to go.......but trips all cancelled for weeks now, so Likely heating will be fixed now before the trip !!! But ! I have taken on board the comments about using them anyway instead of on board stuff. Makes sense

by rogerblack Thu Mar 01, 2018 6:12 pm

During my long career in industrial measurement instrument technology, I sat on the Humidity Groups at NPL (the National Physical Laboratory at Teddington) and HEVAC (Heating, Ventilation & Air Conditioning building services association).

Humidity (or more correctly hygrometry, the measurement/determination of humidity) is a complex issue, difficult to condense (see what I did there!) into a short post here, so don't worry, I'm not gonna bore you all to death now; there's loads of info online for anyone interested.

The terminology commonly used doesn't help. The key parameter determining condensation is Dewpoint level, however this is difficult to measure accurately without using expensive chilled mirror technology. Lower cost instruments such as wet & dry bulb thermometers can be used to measure RH (relative humidity) from which Absolute Humidity can be determined using complex hygrometry tables. Nowadays, electronic instruments capable of doing the calculations are available.

The humidity in your freezer will almost certainly be lower than that of the air in your warm kitchen whilst cooking on the hob, which is why food will dry out if not wrapped well. Low temperature in itself needn't cause dampness; it's the phenomenon that warm air is capable of holding more absolute moisture than cold air that means if warm moist air is cooled quickly the moisture vapour will then condense out.

I also use low level heating in our motorhome over the colder months, more to keep it snug for when we use it than anything else. I also monitor the internal and external temperatures & humidity, as well as the energy consumed, using electronic data-loggers so I can keep it comfortable without going over the top.

by Peter Brown Thu Mar 01, 2018 6:15 pm

rogerblack wrote:During my long career in industrial measurement instrument technology, I sat on the Humidity Groups at NPL (the National Physical Laboratory at Teddington) and HEVAC (Heating, Ventilation & Air Conditioning building services association).

Humidity (or more correctly hygrometry, the measurement/determination of humidity) is a complex issue, difficult to condense (see what I did there!) into a short post here, so don't worry, I'm not gonna bore you all to death now; there's loads of info online for anyone interested.

The terminology commonly used doesn't help. The key parameter determining condensation is Dewpoint level, however this is difficult to measure accurately without using expensive chilled mirror technology. Lower cost instruments such as wet & dry bulb thermometers can be used to measure RH (relative humidity) from which Absolute Humidity can be determined using complex hygrometry tables. Nowadays, electronic instruments capable of doing the calculations are available.

The humidity in your freezer will almost certainly be lower than that of the air in your warm kitchen whilst cooking on the hob, which is why food will dry out if not wrapped well. Low temperature in itself needn't cause dampness; it's the phenomenon that warm air is capable of holding more absolute moisture than cold air that means if warm moist air is cooled quickly the moisture vapour will then condense out.

I also use low level heating in our motorhome over the colder months, more to keep it snug for when we use it than anything else. I also monitor the internal and external temperatures & humidity, as well as the energy consumed, using electronic data-loggers so I can keep it comfortable without going over the top.

I love it when this happens!

by Gromit Thu Mar 01, 2018 6:18 pm

I was going to say the same as Roger, but I didn't want to show off!! Whistle1

by Cymro Thu Mar 01, 2018 7:27 pm

Seeing Rogerblack's contribution above yet again made me think "what a wonderful Forum"! We seem to have all sorts of experts, benignly prepared to share their expertise.

Which reminds me: time to make another donation, which is a small price to pay for such a great resource and unmet friends.
Cymro

by JohnsCrossMotorhomes Thu Mar 01, 2018 9:59 pm

Not the cheapest but

http://www.johnscross.co.uk/products/streetwize-700w-oil-filled-radiator.html
Portable heater - Page 2 1805_ful1__39535.1455895334.1280.1280

Portable heater - Page 2 1805_ful1__39535.1455895334.1280.1280

700W Oil Filled Radiator
The low wattage of this Streetwize Oil Filled Radiator means that you don't have to worry about overloading the hookup point at your campsite. It's ideal for use on a campsite, or for use in the garden or home.
• 7 Elements/Fins.
• Illuminated on/off rocker switch.
• Variable temperature delay.
• Economical to run.
• Compact and robust design.

by Paulmold Thu Mar 01, 2018 10:21 pm

I've had my 700w oil filled radiator in the van since Tuesday. Temp dropped to minus 7 last night, checked this morning, van at 5 degrees. Just hope any residual water has been kept from freezing.

by rose49f Sat Mar 10, 2018 12:32 pm

I never heat my van at home. Was told it causes more condensation. Just had my hab check and no damp. Don't use the van in Dec and Jan but take him out for a couple of runs so he feels loved. Just been out today to the shop. He hasn't been out since before the bad snowy freezing weather and started first time. I love my Kevin

by MikeJJ Fri Mar 30, 2018 8:35 am

WORD OF CAUTION:

Having read this thread and thinking what a good idea I purchased a 800W, 6 fin small oil filled radiator. There seem to be dozens of obscure brand names for what looks like the same machine. I purchased from a reliable online retailer.

Over 2-3 days testing I found that the radiator was cycling on and off NOT on the thermostat but on the thermal safety cut-out ie it was overheating and unsafe.

I explained this to the retailer and they promptly refunded the purchase price and asked me to dispose of the unit (nearby Council tip).

If you have one of these units please check its operation. Maybe this was a one-off faulty unit but I suspect it is more a case of bad thermal design trying to get too much heat out of a unit with too little surface area.

To replace this unit I have replaced it with a De'Longhi Nano which functions correctly.

by daisy mae Fri Mar 30, 2018 8:51 am

That is why it pays to buy a good reputable one , cheaper in the long run.

Pleased you are now sorted.

Best wishes, Could have been nasty.
Margaret

by JandL Tue Apr 17, 2018 4:48 pm

MikeJJ

How do you check it cuts out on the cut-out rather than stat?

by MikeJJ Tue Apr 24, 2018 3:13 pm

Hi JandL,

Just back online and seen your post. When it cutout on the safety cut-out the whole unit is "dead" and rotating the thermostat will not have any effect. When it cuts out on the thermostat then often rotating the thermostat to a higher setting will cause the unit to switch on again. On mine I would set the thermostat about half way and after 10mins or so it would cut out completely.

by JandL Tue Apr 24, 2018 6:06 pm

Thanks, will check mine in the house. A useful safety check.