Options to Install Aircon in Van for High UK Temps

[Keep Right On]

Been looking at various options as this year's Uk temps have been on the high side in the van.
Have dismissed portable options and so want to go installed. I presume they will only work on EHU as leisure/solar will kill power? Is there an option that will switch from leccy to gas as the fridge does?

 

[TerryL]

Sorry, never heard of an aircon unit that runs on gas. The refrigeration unit is not the same as a normal, i.e. 3-way m/h fridge. It'll be a compressor type which will only run on leccy. Someone will correct me of course if I'm wrong.

I removed our aircon unit as it was never used (rarely on hookup) and replaced it with a Maxxfan that runs off the vans 12v system. Its NOT a cooling unit but a very efficient roof mounted fan which in our case gets used all the time. I will admit though in the extremely high temperatures we've suffered over the last two days in Germany/Netherlands it's struggled.

 

[Keep Right On]

Sorry, never heard of an aircon unit that runs on gas. The refrigeration unit is not the same as a normal, i.e. 3-way m/h fridge. It'll be a compressor type which will only run on leccy. Someone will correct me of course if I'm wrong.

I removed our aircon unit as it was never used (rarely on hookup) and replaced it with a Maxxfan that runs off the vans 12v system. Its NOT a cooling unit but a very efficient roof mounted fan which in our case gets used all the time. I will admit though in the extremely high temperatures we've suffered over the last two days in Germany/Netherlands it's struggled.

Doesnt it hammer the van battery?

 

[Figaro]

Doesnt it hammer the van battery?

Yes it would. I think there are some models that can run from the leisure batteries via an inverter but your going to need an awful lot of solar and a very big battery bank to run it.
Not achievable for most, so it's EHU or get a fan.
No aircon run off gas as far as I know

 

[TerryL]

Nope - even at 100% it only uses 4-5 amps and you would never leave it on that high - that's the "hurricane" setting.
Last night I left it on overnight at 20%, almost silent and it was drawing less than 1 amp. It was enough with another roof vent cracked open to provide a light airflow that kept us cool enough to sleep well.

Edit, just seen Figaro post. He's talking about a proper aircon unit which would indeed kill the batteries if you could make it work. I'm talking about the Maxxfan unit.

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[Neil n Pat]

Go Green, train your wife to be one of these https://en.wikipedia.org/wiki/Punkah to operate a manual fan. She may need a refresher course if the MH is stored over the winter though. If you require 24/7 operation your wife working in shifts with your mistress is a good solution.

 

[funflair]

Yes it would. I think there are some models that can run from the leisure batteries via an inverter but your going to need an awful lot of solar and a very big battery bank to run it.
Not achievable for most, so it's EHU or get a fan.
No aircon run off gas as far as I know

If you set the aircon to low fan speed it doesn't use as much power, ours will run at around 400watts which is less than 40A DC so you could easily get half of this direct from solar.

 

[Paul F]

If you set the aircon to low fan speed it doesn't use as much power, ours will run at around 400watts which is less than 40A DC so you could easily get half of this direct from solar.

The lowest setting on our Dometic unit still pulls 60A if run through the inverter Martin, but as you say the solar can provide a good piece of this. Our unit also has a fan only setting, and this provides a good flow of air for only 3A of power. It saves having to store a separate fan and works surprisingly well if batteries are getting low.

Alternatively as TerryL says, the Maxxfan units use a tiny amount of power for the same effect.

 

[funflair]

The lowest setting on our Dometic unit still pulls 60A if run through the inverter Martin, but as you say the solar can provide a good piece of this. Our unit also has a fan only setting, and this provides a good flow of air for only 3A of power. It saves having to store a separate fan and works surprisingly well if batteries are getting low.

Alternatively as TerryL says, the Maxxfan units use a tiny amount of power for the same effect.

Which unit do you have Paul? I put ours on yesterday and it started at around 900W but then dropped to around 400W on lowest fan setting, quite possibly depends on the outside temperature as well.

I do agree though that a Maxxfan is very effective, we only have the Dometic version but still very effective.

 

[EuroTrotters]

Had rooftop and underfloor ducted.

Ducted has been superb for us . Can be used whilst driving too

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[Paul F]

Which unit do you have Paul? I put ours on yesterday and it started at around 900W but then dropped to around 400W on lowest fan setting, quite possibly depends on the outside temperature as well.

I do agree though that a Maxxfan is very effective, we only have the Dometic version but still very effective.

We have got the Freshjet 3000 unit which has a cooling capacity of 2516w according to the manual, but that also says it is rated at 7.5a - so not sure how they work that out! I make 2516w at 240v to be 10.5a - maybe the 7.5a is an average.

I suspect the ambient temperature, and the temperature you are trying to achieve have a significant impact on power consumption too.

 

[funflair]

We have got the Freshjet 3000 unit which has a cooling capacity of 2516w according to the manual, but that also says it is rated at 7.5a - so not sure how they work that out! I make 2516w at 240v to be 10.5a - maybe the 7.5a is an average.

I suspect the ambient temperature, and the temperature you are trying to achieve have a significant impact on power consumption too.

The amperage difference is due to it being a heat pump so the output power is not directly related to the input, I think you will get between 2 and 3 times more watts out than you put in, we have the same unit now after our Freshjet 2200 was replaced as it was faulty, these units have a variable speed compressor so yes the more work they have to do the more power they will draw.

 

[Orion]

Can’t comment on other units but our Truma Aventa 2400 has a ‘ventilation only’ setting which has the fan running but not the ac compressor.

Forum member Ditcha kindly provided the consumption figures when used in the various modes:

“We run our Truma Aventa compact when off grid, using just vent on low fan it uses 4amps climbing to 9amps on full fan if you use the compressor for cooling it uses about 45amps which in sperts is manageable once the batteries are full with solar it's free.”

which makes it entirely feasible to run it when off grid provided you have the battery capacity and solar available. Although I’ve not yet fitted an inverter to run it like that I did experiment when on EHU in a hot and sweaty Athens, and found that in top vent mode, along with the Truma blown air doing the same at low level and the manual roof vents cracked open, it was perfectly comfortable overnight. Win, win IMO - full ac when on EHU and vent only when off grid.