Blown Air Heating

[Gagakev]

Was looking at a new van yesterday and inquired about the heating, no fire in the van so I was thinking must be the Alde system.
Was told there is no fire ( How far behind in this modern world am I ?) Only the blown Air System through the built in vents.

So my question is, Has any one had any experience of this system and does it really work and is it sufficient ?
Van was Bailey Pegasus Bologna.

I'm sure some one will have a view, thanks in advance.

 

[otherclive]

I’ve got a blown air system from a “ conventional “ Truma gas/electric heater and it’s very effective. Sounds like yours is a bit different what You wouldn’t get is heat from the heater into the lounge should the fan not work. But there’s no reason it shouldn’t be effective. Mine has no exposed ducting underneath to chill the air. Some vans do have external ducting, my last Bailey did. But insulating it gave a noticeable improvement.

 

[Gagakev]

I’ve got a blown air system from a “ conventional “ Truma gas/electric heater and it’s very effective. Sounds like yours is a bit different what You wouldn’t get is heat from the heater into the lounge should the fan not work. But there’s no reason it shouldn’t be effective. Mine has no exposed ducting underneath to chill the air. Some vans do have external ducting, my last Bailey did. But insulating it gave a noticeable improvement.

Hi OC, my current van has the Truma gas/electric with blown air as yours, so yes the heater into the van to benefit, BUT the blown air is quite useless, hence why i'm asking about just the newer blown air version's.
It was stated the newer vans were very well insulated in this day and age.?

 

[Hutch]

Kev ours is the blown air, from the Truma combi unit gas and 4 /8 amp electric. Work perfectly a fraction noisey when going from say 8c to 18c but only for about 5 minutes then dies down to a hum. Then a gentle waft of warm air.
I really like ours. I have changed the elements once in 8 years. Last year.

 

[ProfJohnL]

Hi Gagakev.

Without knowing what the problem you are presently having with the blown air system is, it difficult to say whether the newer Combi systems will or won't suffer from the same issues.

What I do know is a well installed and properly adjusted blown air system can be very effective, Its perhaps a bit more difficult in longer caravans, but as I say correctly adjusted a relatively small temperature differential can be achieved through out the caravan.

As Otherclive has suggested, many caravan manufacturers fits a length of hot air duct under the caravan, If that is not properly insulated that can make a noticeable difference at teh farthest point on the system.

Also air flow is impleaded by every bend in the ducts, so keeping them as straight as possible can make a surprising difference.

In one make of caravan, customers were complaining the end bathroom was not getting warm. We were asked to investigate. We found the caravan manufacturer was using a tee fitting in the duct close to the heater. The hot air entered the head of the Tee, and the straight ahead out put went to a vent, the remainder of the duct to the bathroom was on the leg of the Tee Swapping the vent and the bathroom duct over made a massive difference, directing more air flow to the bathroom.

Also regulating down the output flows through vents closer to the heater improves the flow to the extremities - without losing too much room temperature closer to the heater.

Its all about balancing the system.

 

[Thingy]

My last caravan, a Challenger Sport had the blown air and no fire, we found it worked perfectly and warmed the van efficiently. We always carried a very small fan heater to boost it until it warmed up if the weather was very cold.

Actually, it was my last two caravans, the prior one was a fixed bed affair, and on that model the heating pipes ran under the caravan, and as many others did, I insulated these pipes and it increased the efficiency tremendously.

 

[JezzerB]

WE had a PEgasus VErona-so very similar-end bathroom was always a bit cooler than the rest of the van-adjust the front flaps to close off a bit of air so it forces the warm to the end of the van. BUT it was a great system-fast warm up-esp on combined gas and electric and we were never cold even in the middle of the winter, with no back up heat. One air tube did pop off the heater unit once-easily popped back on!

 

[Buckman]

On a previous caravan we had blown air heating. Next caravan had ALDE heating. In comparison we thought that the blown air heated up a caravan quicker, but you had cold spots. After a about a year ownerhsip we found that the ALDE had not been installed as per the manufacturer's specifications and we had to have a modification done. ALDE brilliant after that and now we would not be without ALDE heating.

 

[Beachball]

My present van has a fire and blown air heating it seems to warms up quickly when it was checked at it service and we have so far been very happy with it

 

[Dustydog]

Kev

Your potential new baby will have one of these or a variant. Note all air pipes are internal, as is my 12 year old Wyoming. This system takes you into another dimension and without the worry of changing heating fluids every two years!
The video explains all. I like it👍👍👍

View: https://www.youtube.com/watch?v=SeBHBgAU6UA

 

[Sam Vimes]

Having jut got back on the road after an 11 year absence its remarkable how somethings have changed like the heating. And of course some things are still the same.

I'd got use to the big old brown things that sat in the middle of the van and got nice and hot and reasonably quiet. Always seemed to have some residual heat when you turned it off.

Now our little van has an underslung heater which while very efficient at heating its like being in a small jet aircraft when blowing at full bore. Being underslung the floor of the van acts as a sounding board. The controls are simple, which I'm all in favour of, and after a while you get used to get the optimum settings for heat and the least noise.

Seems these days you have to have internet or bluetooth to control anything. My motto has always been KISS - Keep It Simple Stupid.

As Beachball would say 'To each their own'

 

[otherclive]

Fundamentally I prefer the resilience and in depth redundancy of the older style blown air with separate water heating. If you lose 240v you still have gas for heating the caravan and water, vice versa if you lose gas. If the heater 12v fan should fail you still have a source of convective warmth from the lounge heater on either gas or electric. But as old habits die hard, I see that technology moves on; but to whose benefit?

 

[otherclive]

Having jut got back on the road after an 11 year absence its remarkable how somethings have changed like the heating. And of course some things are still the same.

I'd got use to the big old brown things that sat in the middle of the van and got nice and hot and reasonably quiet. Always seemed to have some residual heat when you turned it off.

Now our little van has an underslung heater which while very efficient at heating its like being in a small jet aircraft when blowing at full bore. Being underslung the floor of the van acts as a sounding board. The controls are simple, which I'm all in favour of, and after a while you get used to get the optimum settings for heat and the least noise.

Seems these days you have to have internet or bluetooth to control anything. My motto has always been KISS - Keep It Simple Stupid.

As Beachball would say 'To each their own'

Or "the better is the enemy of the good enough" attributed to Sergey Gorshkov.

 

[Dustydog]

Is this all the same as reinventing the wheel🤔🤔🤔

 

[Mel]

Our 2019 Bailey has a blown air system. Truma job. No fire. Think they stopped putting them in some time ago. It is a bit of a curates egg. Good in parts. The good part is that it heats up the van very quickly and is not particularly noisy. The water is always red hot. The bad part is, that the heat doesn’t get to the end bedroom ( one of these middle washroom layouts where you walk through the washroom to get to the bedroom). If it wasn’t such a big van, it would be OK.
Our tiny tourer has the Whale blown air heater and again no fire. Hot and toasty in no time. However with a shipping length of under 5m, a large candle would probably heat it just as well 😀.
Mel

 

[CustardAvenger]

I've had to add additional insulation to the hot-air pipe that runs to the rear washroom, as it runs externally for about 2 meters, and never really gets warm. (2020™ has meant the mod hasn't had a proper test)

However, the internal routed vents kick out a lot of heat. I've had to open windows in -1°c weather as I've set the heating too high.

 

[Gagakev]

Hi Gagakev.

Without knowing what the problem you are presently having with the blown air system is, it difficult to say whether the newer Combi systems will or won't suffer from the same issues.

What I do know is a well installed and properly adjusted blown air system can be very effective, Its perhaps a bit more difficult in longer caravans, but as I say correctly adjusted a relatively small temperature differential can be achieved through out the caravan.

As Otherclive has suggested, many caravan manufacturers fits a length of hot air duct under the caravan, If that is not properly insulated that can make a noticeable difference at teh farthest point on the system.

Also air flow is impleaded by every bend in the ducts, so keeping them as straight as possible can make a surprising difference.

In one make of caravan, customers were complaining the end bathroom was not getting warm. We were asked to investigate. We found the caravan manufacturer was using a tee fitting in the duct close to the heater. The hot air entered the head of the Tee, and the straight ahead out put went to a vent, the remainder of the duct to the bathroom was on the leg of the Tee Swapping the vent and the bathroom duct over made a massive difference, directing more air flow to the bathroom.

Also regulating down the output flows through vents closer to the heater improves the flow to the extremities - without losing too much room temperature closer to the heater.

Its all about balancing the system.

Hi Prof,
Every time we tried to use it entering the van which had no heating on it is quicker to warm the van just useing the heater, the duct's always seemed to blow cold air for some time before warming up so defeating the object really. None of the pipes run externally.
But not really a concern anymore as we now leave the heating on if we go out on a low setting and toasty when we return.
The question really was to get others views and opinion's and the majority seem to like it, perhaps it's me behind the times as my van is 11 years old and I had heard about the Alde system but not the blown air without the fire/heater in the van.
And watching the video Dusty posted it goes on to say about phone apps and bluetooth, oh my ............. more things to go wrong!!

 

[otherclive]

Hi Prof,
Every time we tried to use it entering the van which had no heating on it is quicker to warm the van just useing the heater, the duct's always seemed to blow cold air for some time before warming up so defeating the object really. None of the pipes run externally.
But not really a concern anymore as we now leave the heating on if we go out on a low setting and toasty when we return.
The question really was to get others views and opinion's and the majority seem to like it, perhaps it's me behind the times as my van is 11 years old and I had heard about the Alde system but not the blown air without the fire/heater in the van.
And watching the video Dusty posted it goes on to say about phone apps and bluetooth, oh my ............. more things to go wrong!!

My handbook recommends initially putting the heater on and then when it is connecting warmth to then turn on the fan. It works very well and avoids the initial cold droughts.

 

[Gagakev]

Kev

Your potential new baby will have one of these or a variant. Note all air pipes are internal, as is my 12 year old Wyoming. This system takes you into another dimension and without the worry of changing heating fluids every two years!
The video explains all. I like it👍👍👍

View: https://www.youtube.com/watch?v=SeBHBgAU6UA

Hi Dusty, we actually fell into this van by mistake!!
After the atrocious weather we had last week and spending copious amount of time in the van Mags and I got talking and decided that we are in future to be fair weather tourist, to do this we would look to book the same week as going away after looking at the forecast for that week.
We also wanted more weekend's away and the only real answer was to go back to our idea of a while back and change over to a motor home. So Monday we go shopping for said motor home and after visiting two dealers and entering numerous vans which were all brand new as the mid price range ones have all been sold. We finally decided that we were not paying for brand new,( apart from the fact we cant afford one!) and the space inside really is very limited. Claustrophobic comes to mind.
So we decided to stick with a caravan BUT downsize from our current 6 birth to perhaps a 2 or 4 birth, to make easier getaways, they had no stock of them either!So went into the Pegasus as it was RAINING and fell in love with it And cheaper than even a 2nd hand Motor home.
Even sat down with the salesman and at the last minute decided we would think about it
Wow that was close, suppose to be down sizing!!
But started the thread as am sure other vans will have the blown air heating.

 

[Gagakev]

My handbook recommends initially putting the heater on and then when it is connecting warmth to then turn on the fan. It works very well and avoids the initial cold droughts.

My point exactly OC, the van is already warm with the heater then no need for the fan.

 

[otherclive]

My point exactly OC, the van is already warm with the heater then no need for the fan.

But without the fan the bathroom shower and bed end don’t get comfortable.

 

[Hutch]

The bathroom and shower in our Coachman gets toasty, one vent even blows onto the toilet roll.
I do wish it had fan controls, so that you could blow cold air around when its a hot summer night. But 12 inch fans do that instead.

 

[ProfJohnL]

Hi Prof,
Every time we tried to use it entering the van which had no heating on it is quicker to warm the van just useing the heater, the duct's always seemed to blow cold air for some time before warming up so defeating the object really. None of the pipes run externally.
But not really a concern anymore as we now leave the heating on if we go out on a low setting and toasty when we return...

I do appreciate you no longer have the offending caravan, but very much as OC suggests its a question understanding how to get the best out of it, and you found your own way. But I have to point out whatever system you have, it will take some time to heat its self before it can produce any practical heat into the caravan, and some will be quicker than others.

Assuming you had a Truma SL 3002 on full setting it produces 3.6kW of heat. If all of that is convectiing through the front grille, yo will see a rapid and big temperature rise above the heater . but the rest of the caravan will be somewhat colder. The heat will tend to spread like a mushroom cloud with floor and extremities being the last to warm up.

Because the heater has a finite maximum output (3.6kW) The use of a blown air system will take a significant proportion of the heat and blow it around the caravan . Tests I have carried out in an environmental chamber shows how evenly you can get the whole caravan to heat up. so yo wont get such hot spot right by the heater. but the whole caravan warms - yes it don't get the instant burst of warmth , but that would apply to any heating system.

I think it was more a question of not meeting your expectations, and whether that was the heater or the way the manufacturer fitted it I couldn't tell you.

 

[Woodentop]

The OP should look on the back of the heater unit where he will find there is a 'diversion' flap that steers the air either to the front or rear pipe - by default the flap is central. Try moving it to give preference to the bathroom about 2/3-1/3. You can do with a little less heat in the living area to give a warmer bathroom. We had exactly the same issue with our Pegasus 462.

Also, per the outside pipe, I got some large pipe insulation, cut it neatly down the length in a straight line, and fitted it over the external pipe holding it in place with zips. It was only when I went to fit it that I found the external pipe is actually double insulated!

 

[JezzerB]

And of course the beauty of the Truma blown air system is that you can blow cool air-ie heat off fan on-when it is hot out there-or should I say if. Fortunately with Alde we now have an omnivent that can do that. Not using it much though!