Alde wet central heating systems

[Royston]

I have been considering changing my present caravan Bailey Senator 2009 model to a more modern version in the new 2015 Bailey Range.
Having been to my local Bailey Dealer, noticed that all the new vans do not incorporate the fire which in my caravan I can select fire only or the fan assisted blower system.
In my experience using the direct heat (Electric) from the fire heated our caravan far quicker than the blower system.
In the brand new range you have no option but to use the Alde wet heating blower system which uses the same heater that supplies the hot water.
Question is has anybody ever experienced problems using this combined system.
I have often had to call out local fitters to a site to correct faults and replace items that have failed , just wondered if these same fitters would Know how to fix a malfunction with Alde wet system.
Many ThanksRoyston

 

[ProfJohnL]

Hello Royston,

The Alde systems have been fitted into a wider range of caravans over recent years, so any self respecting service agent should have familiarized themselves with the products.

But as ever no forum contributor can give you a copper bottomed confirmation that the agent you choose to use will be Alde competent. So the best way is to ask them when you make contact.

 

[RogerL]

Most people like the Alde - but I don't, not compared to a well-sorted Truma Ultraheat blown-air system. In cold weather, it takes a long time to warm up and the effectiveness of the heating depends on the air circulation gaps under and behind all the furniture. I find the comfort levels are more even throufgout the caravan with the Alde set to 1kw and a free-standing fan heater set to 1kw - that's despite Alde and Lunar carrying out significant modifications to my Lunar.

Like all caravan appliances, dealers can and do call in experts from the equipment manufacturer.

 

[BedfordGeorge]

The Alde heating system in my opinion is far superior to the blown air type, which on my Challenger 570 never really heated the bathroom, whereas the Alde gives a very even heat throughout our new van. You also have the option to pre set it to come on before you come back to the van, following a day out, so you can come back to a nice warm van, set to the temperature you want.
The other major advantage is the extra space for storage you acquire, as the Alde system only takes up a similar amount of space that the separate water heater used to, giving you the space that the Blown Air System used to take up.
Regarding servicing, the Alde system has been available long enough for the engineers to have acquired the knowledge to be able to service them properly, but as always it is important to find an engineer you are happy with, and to build a relationship with them.

 

[ProfJohnL]

The Alde heating system in my opinion is far superior to the blown air type, which on my Challenger 570 never really heated the bathroom, whereas the Alde gives a very even heat throughout our new van. ..........

Hello George,

The Truma/Carver systems were very capable of heating a caravan, however there were two common problems, The first is that the caravan manufacturers didn't always route the hot air ducts in the best way, often creating more bends than was necessary, and underfloor ducting without proper thermal insulation.
The second problem was the owners didn't set the hot air outlets to best effect. When both issues are managed properly the heat distribution in caravan was very good.

One problem with the wet systems is the hot air rises and collects at the top of the caravan, and it can leave cool air at floor level, Having done tests on caravans I can confirm that can led to hot head and cold feet for the occupants. With the blown air systems the air is far more evenly distributed.

 

[BedfordGeorge]

Hello Prof,

One thing I did not mention was that we only used it on the electric setting, and it never ever heated the bathroom. As far as I could see the piping was not clogged in any way, but the diameter was quite large, and possibly the fan was not sufficient to send the heat back quickly enough. It was under the fixed bed, so some heat will have been lost under it, how much I do not know.

 

[RogerL]

We normally run our Alde at 22.5 when we're in, and set it back to to 18.0 when we go out for the day - came in tonight and raised it back to 22.5, on 1kw and turned the 1kw fan heater on - the air in the caravan was up to temperature due to the fan heater BEFORE the Alde got the fluid up to full working temperature.

The only reason some Alde's can have the settings changed by phone is so you can start the LONG warm-up process and hour before you get home.

I want warm air in the caravan, not hot storage compartments !

 

[ProfJohnL]

Hello Prof,

One thing I did not mention was that we only used it on the electric setting, and it never ever heated the bathroom. As far as I could see the piping was not clogged in any way, but the diameter was quite large, and possibly the fan was not sufficient to send the heat back quickly enough. It was under the fixed bed, so some heat will have been lost under it, how much I do not know.

Well George,

The bigger the diameter the better, as it provide less resistance to air flow. but a big killer to air flow is length and the number of bends, A 90 degree bend is like adding an extra meter to the length of the duct and it slows air flow down quite dramatically. Any section under the floor should be encased in a bigger waterproof pipe and have thermal insulation around it, other wise its losing heat to the great outdoors!

The other real issue with hot air systems is when the fan unit get clogged with dust and hairs. This seriously impairs the fans ability to move air. Regular (annual) cleaning is a good suggestion.

I have refitted some systems in caravans and taken care to ensure that any tee pieces are fitted to maximise flow. In some I have created a ring main loop of duct, to provide easier air movement to all area, and take care to set the outlet registers to encourage complete distribution around a caravan, including end bathroom. It takes time to tweek a system, but the end results are very respectable. With the exception of a little more duct there were no extra parts, and installing fittings the right way round, then its up to the user to adjust the outlets to suit..

Suffice to say that with 3.2Kw output Gas heater an external ambient temperature of -5C we could raise the internal temperature of an entire 6.4M TA caravan to 19 at the coolest floor level and 25 at the hottest roof level (22+/-3C) in all habitation areas from floor to ceiling.

Similar testing of wet systems could not get same narrow band of temperature distribution, and the difference at the floor was 5C and roof level was 28C. The only practical way to improve the wet system was to run a table fan to keep the air mixing.

A wet system may outperform a poorly installed hot air system. It is less forgiving than a wet system, so it may give the sorts of results you report, but with a little effort it I am certain it could have been improved.

 

[RayS]

Before buying my current van I investigated the 'wet' central heating systems quite carefully. I came to the conclusion that they were not for me, being inherently more complicated, slower to warm up and much more expensive to maintain that a blown air system. On most of the combined systems a fault in the central unit will deprive you of both heat and hot water.
So I went for a Whale blown air system with the heater unit mounted under the floor. By and large it has been very good. in the fixed bed layout I have the air inlet is in the toilet room rather than outside so minimizing the intake dust problems. The toilet room also has an air outlet (there are two others) so by adjusting the vanes on these it is easy to get heat where you want it.
The snags are that the unit is a little susceptible to strong side winds under the van - the inlet and exhaust ducts are not necessarily exposed to the same static pressures and this causes a lockout in the control system which can be difficult to clear. There is a night setting with low fan speed and 500watt heating which is fine, and there is a nice big empty cupboard where the previous generation of heaters would have been installed. There are no annual re-filling chargers or air venting, so all in all a good unit, which I am sorry to see dropped from some new vans in favour of wet systems.

 

[RogerL]

The effect of wind can be mitigated by fitting baffles/ramps on the underside of the floor by any/all vents but still leaving them open downwards.

My Lunar had these baffles around all the gas drop holes but not by the fixed ventilation inlet - baffles were added as part of the modifications I had done to it last winter to improve the Alde performance as we were also getting cold draughts - these extra baffles work very well.

 

[Royston]

Thanks very much for all your comments, It looks like that if I purchase a newer van , Baileys cannot be included within our choice due to the complete range now only have this wet type of heating.
All of my caravanning life we have never experienced a cold caravan using the standard radiant fire coupled with the additional blower system.
I can see the advantage of having a system where you can switch it on via I pad, whether it works as well as the manual system we are used too will remain just thoughts
We are currently looking at a Coachman which has the same specification as the bailey Unicorn same layouts only difference is that Coachman still has the radiant fire blower system.
Royston

 

[CameronBurns]

We've had a Fleetwood Heritage 600-EB for around a year now and have never been able to get the Alde system to work. We've had a caravan engineer to look at the system, but he was unable to fix the problem. A reputable caravan dealer also tried to advise, but so far no luck. The problem as I understand it is that the system is constantly changing, making it hard for caravan engineers to keep up with all the variants. We also find it odd how it can't be just turned on or off, you have to program the settings, much like how your home central heating works (but with no manual override). But I'm guessing the latest version will have this feature, but be sure to check if it does before committing to buy the caravan as it's effectively useless in our caravan! We've been using a plug in blown air heater, which actually very sufficiently heats the twin axle caravan just on it's lowest 1000w setting. The wet central heating is a good idea in theory, but not absolutely necessary.

 

[MichaelE]

The system can be turned on and off quite easily, i never set the programming as it loses all its settings when the car is connected