Where to Vent a Multiplus Inverter

[daleyocum]

My Multiplus 3000 inverter is installed in the curb side compartment under that twin bed in a FC25FBT. See picture. Most of the time it’s fine unvented but there are times it runs hot, like when running the AC. For now I have to remember to open the outside hatch to let it breathe. I’d like to install a thermostatically controlled exhaust fan but am having a hard time finding a place for it to exhaust TO.

I obviously don’t want to cut a new exhaust hole in the side so that has me exploring cutting a hole DOWN into the area below that compartment. Any idea what’s down there, close to the sidewall? How close am I to the water/waste tanks?

Any other ideas of places to vent to? I considered the adjacent hot water heater but that’s surrounded by sheet metal.

[Tyler2you]

Originally Posted by daleyocum

My Multiplus 3000 inverter is installed in the curb side compartment under that twin bed in a FC25FBT. See picture. Most of the time it’s fine unvented but there are times it runs hot, like when running the AC. For now I have to remember to open the outside hatch to let it breathe. I’d like to install a thermostatically controlled exhaust fan but am having a hard time finding a place for it to exhaust TO.

I obviously don’t want to cut a new exhaust hole in the side so that has me exploring cutting a hole DOWN into the area below that compartment. Any idea what’s down there, close to the sidewall? How close am I to the water/waste tanks?

Any other ideas of places to vent to? I considered the adjacent hot water heater but that’s surrounded by sheet metal.

If you can find room, you might consider cutting a hole in the panel that the MultiPlus is mounted to and install an inline duct fan in the adjacent compartment near the 12v distribution box. Cut a new hole in the floor and route the exhaust out near where all the wires exit. You might not even need a hole in the panel where the MultiPlus is mounted as it will probably pull air pretty well from everywhere under the bed anyway.

https://www.amazon.com/Hon-Guan-Extr...5&sr=8-13&th=1

[daleyocum]

Originally Posted by Tyler2you

If you can find room, you might consider cutting a hole in the panel that the MultiPlus is mounted to and install an inline duct fan in the adjacent compartment near the 12v distribution box. Cut a new hole in the floor and route the exhaust out near where all the wires exit. You might not even need a hole in the panel where the MultiPlus is mounted as it will probably pull air pretty well from everywhere under the bed anyway.

https://www.amazon.com/Hon-Guan-Extr...5&sr=8-13&th=1

That’s a creative idea, cutting near the wire pass through. I was hoping to avoid having the exhaust port exposed to the elements but that may be the best I can do. That’s why I was hoping to dump the hot air down in the layer where the water and waste tanks are but I certainly don’t want to hit one!

[Tyler2you]

Originally Posted by daleyocum

That’s a creative idea, cutting near the wire pass through. I was hoping to avoid having the exhaust port exposed to the elements but that may be the best I can do. That’s why I was hoping to dump the hot air down in the layer where the water and waste tanks are but I certainly don’t want to hit one!

Maybe some kind of vent shroud would help keep out water/debris/bugs.

[Slimpockets]

How much heat do they put off? Would a vent to the inside work?

[daleyocum]

Originally Posted by Slimpockets

How much heat do they put off? Would a vent to the inside work?

Most of the time mine is fine just venting into the cabinet it’s in. That is until it’s hot outside and maybe the batteries are in need of a charge, and the AC is running. Then it was getting hot enough I couldn’t keep my finger on the case when I forgot to open the flip down external compartment door. Opps!

Usually it gets hot when the AC is running so in those cases venting to the living space wouldn’t be ideal!

[AppFan]

If it were me, I'd look to put a vent shroud on that hatch door. I'd be more comfortable cutting a replaceable hatch than I would be cutting into the floor.

Regardless, you may want to consider some form of a temperature controlled fan. I've used these boards on several other projects, to control 12v fans.

[JCRC]

I had to replace my first inverter (Victron multiplus 3000) with a new one because it overheated and burned at least 2 diodes. I had installed it horizontally on a shelf in the bathroom closet in my Argosy, which did not allow for good airflow. The fan is supposed to be on the bottom to help the heat rise out of the top. I also used 2/0 battery cables, which I think contributed to the overheating. I also used to leave it on inverter even plugged into 30amp. It didn't last a year. It was not covered under warranty. I originally had just installed it using the wires from a previous inverter that was "professionally" installed. After much research, I removed all of the old wiring, built a place to install the inverter vertically with the fan on the bottom, vented the closet more, and used 4/0 battery cable. I now only use inverter mode when plugged into less than 30amp or when not plugged in. It barely even gets warm now even with heavy load.
Be careful with the boost feature. It doesn't like switching when you are using more than the 3000w it is rated for. I now turn off large amp draw appliances if I need to use more than one (turn off A/C briefly to use coffee maker), and it seems way happier. Just some thoughts.

[daleyocum]

Originally Posted by AppFan

If it were me, I'd look to put a vent shroud on that hatch door. I'd be more comfortable cutting a replaceable hatch than I would be cutting into the floor.

Regardless, you may want to consider some form of a temperature controlled fan. I've used these boards on several other projects, to control 12v fans.

Good point about the door being replaceable. Might be the best solution.

Yes, I’d be looking for a module to control the fan. It looks like that particular one, from the description of one of its siblings, doesn’t remember its setting when the power goes out. Is that true?

[daleyocum]

Originally Posted by JCRC

I had to replace my first inverter (Victron multiplus 3000) with a new one because it overheated and burned at least 2 diodes. I had installed it horizontally on a shelf in the bathroom closet in my Argosy, which did not allow for good airflow. The fan is supposed to be on the bottom to help the heat rise out of the top. I also used 2/0 battery cables, which I think contributed to the overheating. I also used to leave it on inverter even plugged into 30amp. It didn't last a year. It was not covered under warranty. I originally had just installed it using the wires from a previous inverterhttps://www.airforums.com/forums/f44...on-243603.html that was "professionally" installed. After much research, I removed all of the old wiring, built a place to install the inverter vertically with the fan on the bottom, vented the closet more, and used 4/0 battery cable. I now only use inverter mode when plugged into less than 30amp or when not plugged in. It barely even gets warm now even with heavy load.
Be careful with the boost feature. It doesn't like switching when you are using more than the 3000w it is rated for. I now turn off large amp draw appliances if I need to use more than one (turn off A/C briefly to use coffee maker), and it seems way happier. Just some thoughts.

Yes, I’ve been learning a lot this trip about the limitations of the Victron Invert function. I used to think there wasn’t much point in the “Charge only” setting but was sure wrong about that. Leaving it on “Charge only” when we have 30a plug-ins seems to be a lot better and doesn’t discharge the battery for no reason under loads in the 2kw and higher range.

It does get pretty warm when charging a well-discharged battery as well. I need to monitor that.

Next time it’s getting hot I’ll remember to check the temperature of the power wires. There are only a few inches of them exposed in that compartment. If I flipped it right side up I’d have a lot more wire in there and would need to go to 4/0.

[AppFan]

Originally Posted by daleyocum

Good point about the door being replaceable. Might be the best solution.

Yes, I’d be looking for a module to control the fan. It looks like that particular one, from the description of one of its siblings, doesn’t remember its setting when the power goes out. Is that true?

I can't speak to this exact module. Unfortunately, the unit I used is no longer available on the amazons, however they look to be essentially the same. The unit I used does retain its settings between power cycles. I'm using it to vent heat in my 3D printer enclosure. Here's a vid of it in action.

I believe I do have a spare as I was planning on using it for a project I've since abandoned. Send me a PM if ya want it. It's yours if you cover postage.

[daleyocum]

Originally Posted by AppFan

I can't speak to this exact module. Unfortunately, the unit I used is no longer available on the amazons, however they look to be essentially the same. The unit I used does retain its settings between power cycles. I'm using it to vent heat in my 3D printer enclosure. Here's a vid of it in action.

I believe I do have a spare as I was planning on using it for a project I've since abandoned. Send me a PM if ya want it. It's yours if you cover postage.

Thanks SO much for the offer. I’m still figuring out if I want to saw a hole in the door or just remember to open the hatch when there’s a lot of activity. I might just use the Cerbo’s temp sensors to alarm me that the hatch needs to be opened. I’ll reach out if I decide to go the route of a separate board.

[Tyler2you]

Here's a source for IP68 rated fans if you go that way

https://orionfans.com/ip-rated-harsh-environment-fans/