Given the heatwaves many are suffering ... mini AC ?

[William_H]

We have 10 fans onboard. Essential in the Tropics. We have them over the bunks (5 fans), two in the saloon, one in the nav station, one in the galley and one over the work bench in the engine room. 6 of them are Hella fans and 4 are 10" truck fans that are supper quiet and move a lot of air.
The best bit of kit though by far for a good nights sleep is the mattress cooler. On a hot night with fans running and mattress cooler, we get a great night's sleep with no need for aircon. Mattress cooler uses 8w

I wonder if geem can describe how the mattress cooler works please. ol'will

 

[geem]

I wonder if geem can describe how the mattress cooler works please. ol'will

It is an evaporative cooler that we locate in the cockpit and run the flow and return pipes (silicon rubber) out through a deck hatch to the cooling pad that goes under the top sheet of the bed. The cooling pad is a matrix containing water that is circulated by a tiny pump up to the cooler. The cooler has a variable speed fan to adjust the level of cooling provided. You fill the cooler with about 2 litres of water. It used about 1 litre per night. The water is evaporated by the fan to just wet bulb temperature. Our blood temperature is circa 37.5degC. If you can cool the water in the cooler to say 30degC due to the wet bulb temperature being lower than dry bulb temperature then the difference in the temperature of the mattress is about 7 or 8 degC lower than you body temperature. This pulls the heat from your skin. No more sweating. It uses about 8w at 12v. See mattress cooler USA on Google

 

[lustyd]

Wouldn't it be just as effective to pump filtered seawater through? If you have pipes and a pump anyway, and seawater is unlikely to be over 30 degrees in many places.

 

[Bouba]

Wouldn't it be just as effective to pump filtered seawater through? If you have pipes and a pump anyway, and seawater is unlikely to be over 30 degrees in many places.

In port it means you are cooled by sewage

 

[Baggywrinkle]

It is an evaporative cooler that we locate in the cockpit and run the flow and return pipes (silicon rubber) out through a deck hatch to the cooling pad that goes under the top sheet of the bed. The cooling pad is a matrix containing water that is circulated by a tiny pump up to the cooler. The cooler has a variable speed fan to adjust the level of cooling provided. You fill the cooler with about 2 litres of water. It used about 1 litre per night. The water is evaporated by the fan to just wet bulb temperature. Our blood temperature is circa 37.5degC. If you can cool the water in the cooler to say 30degC due to the wet bulb temperature being lower than dry bulb temperature then the difference in the temperature of the mattress is about 7 or 8 degC lower than you body temperature. This pulls the heat from your skin. No more sweating. It uses about 8w at 12v. See mattress cooler USA on Google

That sounds very interesting .... is it this kind of thing?

Amazon.de

... we had a week in Croatia on a borrowed boat where the heat was unbearable, bought a portable 220V 1200W AirCon unit and unfortunately it was just too much for the batteries and inverter so needed to be hooked up in a marina from around 3pm each day ... ran the thing permanently and the interior temperature of the boat was just about bearable. Very noisy and the exhaust hose was routed out a portlight sealed with a towel.

Really hope these temperatures don't become the norm.

 

[geem]

That sounds very interesting .... is it this kind of thing?

Amazon.de

... we had a week in Croatia on a borrowed boat where the heat was unbearable, bought a portable 220V 1200W AirCon unit and unfortunately it was just too much for the batteries and inverter so needed to be hooked up in a marina from around 3pm each day ... ran the thing permanently and the interior temperature of the boat was just about bearable. Very noisy and the exhaust hose was routed out a portlight sealed with a towel.

Really hope these temperatures don't become the norm.

Yes, thst the one! If you are dealing with high temperatures on a boat it's a game changer for us. We are in the Caribbean for the summer. Typically 32degC during the day and dropping to 28degC over night.
It takes a bit of getting used to lying on something cold. Now, after a few weeks it feels normal. If I forget to turn it on, the bed feels so hot

 

[Baggywrinkle]

Yes, thst the one! If you are dealing with high temperatures on a boat it's a game changer for us. We are in the Caribbean for the summer. Typically 32degC during the day and dropping to 28degC over night.
It takes a bit of getting used to lying on something cold. Now, after a few weeks it feels normal. If I forget to turn it on, the bed feels so hot

... it's on my shopping list. Thanks for the tip

 

[vas]

Yes, thst the one! If you are dealing with high temperatures on a boat it's a game changer for us. We are in the Caribbean for the summer. Typically 32degC during the day and dropping to 28degC over night.
It takes a bit of getting used to lying on something cold. Now, after a few weeks it feels normal. If I forget to turn it on, the bed feels so hot

geem,

I see there are two sizes .70X1.60 and 1.40X1.60, and trying to figure out what would work in my case with a v.awkward shaped plan. Is it OK to have that from the top of the bed to wherever it reaches, or should the head be left out?
Guess you just fit the sheet on top and nothing else, right? I have a custom built matress (and don't even remember what's in there, definitely lots of coconut palm whatever, memory foam and others).
Basically I'm wondering if it will feel odd to have part of your upper body on top of that and part out as in my case I'm afraid I'll have to order the .70m wide one as at 1.6m from the header I definitely don't have 1.4m width and I don't think you can fold or wrap that, can you?

cheers

V.

 

[Rhylsailer99]

In North Wales my night heater is currently running, its freezing .

 

[geem]

geem,

I see there are two sizes .70X1.60 and 1.40X1.60, and trying to figure out what would work in my case with a v.awkward shaped plan. Is it OK to have that from the top of the bed to wherever it reaches, or should the head be left out?
Guess you just fit the sheet on top and nothing else, right? I have a custom built matress (and don't even remember what's in there, definitely lots of coconut palm whatever, memory foam and others).
Basically I'm wondering if it will feel odd to have part of your upper body on top of that and part out as in my case I'm afraid I'll have to order the .70m wide one as at 1.6m from the header I definitely don't have 1.4m width and I don't think you can fold or wrap that, can you?

cheers

V.

We use a matrix that is basically single bed size but turned through 90deg for a double bed. It keeps our trunk cool. The important bit.
It sort of dangles over the side a bit one one side of the queen size bed, but it's not a,problem

 

[William_H]

It is an evaporative cooler that we locate in the cockpit and run the flow and return pipes (silicon rubber) out through a deck hatch to the cooling pad that goes under the top sheet of the bed. The cooling pad is a matrix containing water that is circulated by a tiny pump up to the cooler. The cooler has a variable speed fan to adjust the level of cooling provided. You fill the cooler with about 2 litres of water. It used about 1 litre per night. The water is evaporated by the fan to just wet bulb temperature. Our blood temperature is circa 37.5degC. If you can cool the water in the cooler to say 30degC due to the wet bulb temperature being lower than dry bulb temperature then the difference in the temperature of the mattress is about 7 or 8 degC lower than you body temperature. This pulls the heat from your skin. No more sweating. It uses about 8w at 12v. See mattress cooler USA on Google

Thanks geem I learn something new every day on this forum. Re my UK friends concerned about global warming and their own comfort, you can get used to even enjoy warm temps. ol'will

 

[Iliade]

Aircon is a power-hog just like a fan heater.
No way can a normal sized battery bank, nor even an abnormal one handle that sort of load, nor anywhere close. You need a decent generator or mains for a/c.

My MH can run our rooftop air conditioner under UK June sun for about an hour, without the engine running, before the low voltage trip switches off the inverter. (~300Ah Pb plus ~200Ah solar). With the engine running it can just about keep going; We ran it for several hours yesterday while driving up through France and the batteries were depleted, but not enough to stop it working. (Fiat 2.8 JTD)

A less obvious issue is the heat produced by the inverter has to go somewhere and my current arrangement has this going into the accommodation, which is far from ideal.

I think our little 1KW Honda will now be able to keep it going indefinitely, running in tandem with the battery bank & solar, though it definitely cannot start it on its own.

This is no 'car' air conditioning unit, it is barely adequate for a 7m MH with all sunblinds closed barring the cab windows.

However, the same animal would perform much better on the boat, as she has a smaller occupied volume and also contact with the sea, but I doubt it would survive long in the saltwater environment. If global warming continues to make our summers warm I may try it, but we had to woodburner on at the beginning of the month (August!) so I'm not panicking about that here just yet...

 

[robertager1962]

Probably a very downmarket answer, but we are currently.in Spain and it's very hot. We don't have air-con but I ha e found that running the Eberspacher on cold setting has helped over the past few nights as the air outside has cooled but the cabin has remained hot. The mosquito covers tend to keep the heat in and the cold, blown air, brings in cooler air to the cabin as my inlet is in the cockpit.

 

[pcatterall]

Looking for suggestions chinese - or other ... for a mini ac that could run of 12v / 240v .... for a modest sized 38ft sailboat ...

Not really for on-passage - but when berthed / trying to sleep ...

We have had a 'portable' 240v A/C under the steps on our Neptunian 33 for 10years now. It is strictly for when we have shore power. The vent duct goes straight into the engine bay and exits via the (raised) cover.
It has been fantastic for those really hot days in the marina and cools the small saloon really well. This type of A/C is great if you can site it and the ducting in a good place.

 

[Refueler]

We have had a 'portable' 240v A/C under the steps on our Neptunian 33 for 10years now. It is strictly for when we have shore power. The vent duct goes straight into the engine bay and exits via the (raised) cover.
It has been fantastic for those really hot days in the marina and cools the small saloon really well. This type of A/C is great if you can site it and the ducting in a good place.

Interested as to which model / brand you have ?

 

[pcatterall]

Interested as to which model / brand you have ?

Sorry, not on board and can't remember! It was a standard job bought in France at a Carfour. I cant remember the output but I Know it has to be bigger than you would calculate for a room in a house as the heat lnsulation in a typical Grp hull is very poor! We were lucky in that there was a good space where the companionway steps were located so we could duct out into the engine room. Of course we had to then vent out from the engine room We just raise the hatch cover to allow the heat to escape from there into the open cockpit. An alternative could be an insulated flue pipe up through the roof!?
It has served us well!

 

[Bouba]

Tottenham are top of the table ......Everton are bottom

 

[William_H]

Sorry, not on board and can't remember! It was a standard job bought in France at a Carfour. I cant remember the output but I Know it has to be bigger than you would calculate for a room in a house as the heat lnsulation in a typical Grp hull is very poor! We were lucky in that there was a good space where the companionway steps were located so we could duct out into the engine room. Of course we had to then vent out from the engine room We just raise the hatch cover to allow the heat to escape from there into the open cockpit. An alternative could be an insulated flue pipe up through the roof!?
It has served us well!

I imagine it is what is known around here as a window rattler. ie an a/c designed to go in a window where the hot side compressor condenser etc is cooled by a fan to outside but evaporator and fan are heat isolated to indoor part. very common. The idea of fitting it under the steps at the partition engine bay to cabin would be good buit definitely need more ventilation of engine bay to outside. They work fine in a window but are noisier than split type where compressor is remote. ol'will