Use of the 12v system in the move

Discussion in 'Tech/Mech General' started by PP Bear, Oct 6, 2014.

  1. PP Bear

    PP Bear Funster Life Member

    Joined:
    Apr 5, 2013
    Messages:
    2,082
    Likes Received:
    6,036
    Location:
    UK
    If we can successfully use the alternator to charge the batteries and cool the fridge when on the move, then why doesn't it have a system to heat the water on the move too :)

    With a battery to battery charger "tricking" the alternator system into producing lots of useful electricity, then surely it wouldn't be beyond the realms of a manufacturer to introduce such a system? :)
     
  2. dave newell lvs

    dave newell lvs Trader-Vehicle Services

    Joined:
    Oct 31, 2008
    Messages:
    2,513
    Likes Received:
    3,318
    Location:
    Telford, Shropshire
    The simplest way to generate hot water while driving is via a "calorifier" which is simply a heat exchanger connected to the engine's cooling system. They are available but not cheaply as far as I know and installtion can be time consuming so expensive in labour terms too, probably why most motorhome manufacturers don't bother with them although a few do/did.

    D.
     
    • Like Like x 1
  3. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,466
    Likes Received:
    16,915
    Location:
    YO11 2BD
    Because 12v will never heat a usable quantity of water.

    I tried one of those stupid 12v cup immersion heaters......after 25mins with the engine running the cup of water was just luke warm.

    With a heat exchanger the engines cooling water can be made to heat the domestic hot water to a point.
     
    • Like Like x 3
  4. peterc10

    peterc10 Funster

    Joined:
    Jul 5, 2013
    Messages:
    3,208
    Likes Received:
    2,287
    Location:
    Tunbridge Wells
    Errrr .... why not leave the truma on when you are driving?
     
  5. Snowbird

    Snowbird Funster Life Member

    Joined:
    Apr 24, 2009
    Messages:
    10,141
    Likes Received:
    16,391
    Location:
    Liverpool.
    My Alde does heat the water whilst driving through a heat exchanger. At first it would not have been my choice, all those joints to keep tight and with potential leeks,but after some use I would not change the system now.
     
  6. Tootles

    Tootles Funster

    Joined:
    Sep 14, 2013
    Messages:
    8,990
    Likes Received:
    30,882
    Location:
    Lancaster
    You might need a very long mains lead.....Or leave the gas on, not really a good idea on the move.........
     
  7. peterc10

    peterc10 Funster

    Joined:
    Jul 5, 2013
    Messages:
    3,208
    Likes Received:
    2,287
    Location:
    Tunbridge Wells
    Always have the gas on when on the move. It is supposed to be safe with the securemotion regulator (not sure if that is the right name). Only time it is off is when I am refilling gas bottle or in the tunnel.
     
    • Like Like x 1
  8. Snowbird

    Snowbird Funster Life Member

    Joined:
    Apr 24, 2009
    Messages:
    10,141
    Likes Received:
    16,391
    Location:
    Liverpool.
    I was told by a Truma fitter that all motorhomes are designed for the gas appliances to be used whilst the vehicle was in motion. As most American RV fridges are mains and gas only, with no 12 volt, the fridge works on gas whilst on the road.
     
    • Like Like x 1
  9. Bailey58

    Bailey58 Funster Life Member

    Joined:
    Jun 23, 2010
    Messages:
    6,363
    Likes Received:
    9,640
    Location:
    Norfolk and Toftir.

    We bought one for our long journeys up to Scrabster for the ferry, used to plug it in after leaving Jedburgh on our lunch break and it still wasn't hot at Inverness. :ROFLMAO:
     
  10. Tootles

    Tootles Funster

    Joined:
    Sep 14, 2013
    Messages:
    8,990
    Likes Received:
    30,882
    Location:
    Lancaster
    Sorry, I thought it was standard procedure for MH and Tugs when on the move, in case your involved in an RTA.
    I know its a strong recommendation from the fire brigades. o_Oo_O
     
  11. jockaneezer

    jockaneezer Funster

    Joined:
    Dec 12, 2010
    Messages:
    1,593
    Likes Received:
    3,067
    Location:
    Cumbria
    If you draw power from your alternator whilst on the move, your engine has to provide that power in the first place ( you get nowt for nowt in the energy game, first rule of something or other ) bit like how your mpg drops when you switch the aircon on. A heat exchanger from the vehicle’s cooling or exhaust system would provide “free” energy though.
     
  12. hilldweller

    hilldweller Funster Life Member

    Joined:
    Dec 5, 2008
    Messages:
    26,432
    Likes Received:
    25,111
    Location:
    Macclesfield
    You've had the heat exchanger explained.

    Electrically. The shear scale of the amps. Water takes a lot to heat it ( if I remember physics from 50 odd years ago, it takes more energy to heat water than anything else ), so you'd end up with much bigger alternator belt, alternator, cabling. You'd see this in fuel consumption.

    The real crunch is that many people go an holiday and stop driving. All that investment wasted.
     
    • Like Like x 1
  13. scotjimland

    scotjimland Funster Life Member

    Joined:
    Jul 25, 2007
    Messages:
    28,934
    Likes Received:
    25,574
    Location:
    .
    It would need at least a 600 watt element , this would use 50Amp..
    does your alternator have that capacity spare.. ?

    but irrespective of the wattage, .. there is no such thing as a free lunch.. it would use extra fuel to drive the alternator..

    just noticed Brian beat me to it
     
    • Like Like x 1
  14. mariner

    mariner Funster Life Member

    Joined:
    Nov 21, 2013
    Messages:
    1,284
    Likes Received:
    3,798
    Location:
    Isle of Dogs, but mostly Artola Spain.
    Elgena do a lightweight water heater that heats on 240v but also has a 12v element to keep the water hot when traveling.


    :cooler:
     
    • Like Like x 1
  15. Minxy Girl

    Minxy Girl Funster Life Member

    Joined:
    Aug 22, 2007
    Messages:
    8,537
    Likes Received:
    9,915
    Location:
    E Yorks
    Alternatively get one of these and put it out where the sun (yes we do get it occasionally!) can get at it - it's surprising just how quickly it get hot, we've used one to warm up water for washing up, hair washing, washing smalls etc ...

    solar-20shower.jpg




    the only problem is ...




    ...




    ....





    that you have to ......






    .....






    remember to use the bloody thing! :rolleyes:
     
  16. jonandshell

    jonandshell Funster

    Joined:
    Dec 12, 2010
    Messages:
    5,261
    Likes Received:
    7,881
    Location:
    West Norfolk
    24volt FFR Rover gennie and a BV!

    Call yourself a craftsman?!:reel:
     
    • Like Like x 1
  17. Forestboy

    Forestboy Funster Life Member

    Joined:
    Jul 31, 2007
    Messages:
    4,941
    Likes Received:
    7,686
    Location:
    Forest of Dean
    Same here.(y)
     
    • Like Like x 2
  18. Daifuse

    Daifuse

    Joined:
    Feb 20, 2013
    Messages:
    184
    Likes Received:
    310
    Location:
    Milford Haven
    A great many narrowboats have calorifiers (heat exchangers) fitted as standard and they are surprisingly efficient, utilising the waste heat from the engine, but unless you spend a lot of time on the road or you're prepared to run your engine when on site just to get hot water, I don't think it's a particularly efficient way to go.
     
  19. eddievanbitz

    eddievanbitz Trader - Funster

    Joined:
    Oct 4, 2007
    Messages:
    3,550
    Likes Received:
    11,063
    Location:
    Taunton Somerset
    What about vehicles powered by LPG? My RV works on 220VAC and gas, no 12 volt option. Again most RV's are or offer "on road" hot water option. Most European motorhomes that have Alde heating have it or again have the option.
     
    • Like Like x 2
  20. Tootles

    Tootles Funster

    Joined:
    Sep 14, 2013
    Messages:
    8,990
    Likes Received:
    30,882
    Location:
    Lancaster
    Yes, Eddie, but if I wanted to power my LPG car on bottles, would that be allowed/legal??
     
Loading...

Share This Page