Tom planted a seed in my brain after he showed me how he is using bluetooth temp sensors (Ruuvi tags) with his Victron cerbo GX which then make the bluetooth sensor available to be seen on your phone or computer via victron cerbo GX. We have had some extreme weather here with highs hovering 100 almost everyday and I run my AC for our bus off solar to keep it from cooking the inside so the inverters are making a lot of heat in a enclose compartment under hot conditions. One day I got a high inverter temp warning so I had to make something happen PDQ. The inverter bay is directly under where the kitchen cabinets are located and they have vents in the toe kick area so I drilled a 3.5 inch hole into the inverter bay from under the kitchen cabinets where I installed a 24v four inch fan to pull cool air from under the cabinets to the inverters then I put another fan in the floor pulling hot air out. Both fans are controlled by one of the Victron cerbo relays which is gets it information from the Ruuvi tag. You can program the temp settings that turn fans ON and OFF on the cerbo color screen. The system works perfectly, inverter compartment stays around 108 F. I liked it so well I bought 2 more Ruuvi tags, one turns on the 24v heaters for my lithium battery bay and the other shows me inside temp. With all this new information on my 5 inch screen it was difficult to see so its upgraded to 7 inch now. This is just what I have done with the two relays on the cerbo, there are endless possibilities. Thanks Tom!
I'm adding a schematic that I drew up for a friend who needed to control 2 12v fans in his cruisair bay to help with his AC units.
(08-29-2026, 04:10 AM)Jack Houpe Wrote: Tom planted a seed in my brain after he showed me how he is using bluetooth temp sensors (Ruuvi tags) with his Victron cerbo GX which then make the bluetooth sensor available to be seen on your phone or computer via victron cerbo GX. We have had some extreme weather here with highs hovering 100 almost everyday and I run my AC for our bus off solar to keep it from cooking the inside so the inverters are making a lot of heat in a enclose compartment under hot conditions. One day I got a high inverter temp warning so I had to make something happen PDQ. The inverter bay is directly under where the kitchen cabinets are located and they have vents in the toe kick area so I drilled a 3.5 inch hole into the inverter bay from under the kitchen cabinets where I installed a 24v four inch fan to pull cool air from under the cabinets to the inverters then I put another fan in the floor pulling hot air out. Both fans are controlled by one of the Victron cerbo relays which is gets it information from the Ruuvi tag. You can program the temp settings that turn fans ON and OFF on the cerbo color screen. The system works perfectly, inverter compartment stays around 108 F. I liked it so well I bought 2 more Ruuvi tags, one turns on the 24v heaters for my lithium battery bay and the other shows me inside temp. With all this new information on my 5 inch screen it was difficult to see so its upgraded to 7 inch now. This is just what I have done with the two relays on the cerbo, there are endless possibilities. Thanks Tom!
I'm adding a schematic that I drew up for a friend who needed to control 2 12v fans in his cruisair bay to help with his AC units.
Nice work Jack! I have been in my bay where my inverter/charger is and it can get a bit warm. Was thinking about doing a similar thing. I do have an A/C supply duct that runs through there so I may just put a small vent in the duct to blow on the inverter/charger.
i will be doing the same thing for my inverter bay. i already have a ruuvi tag sensor there and i had previously run wires from relay 2 on the cerbo to that bay to control lights. i will just move that control to a 40a relay that will control a fan i am putting in the ceiling of that bay. will be nice to control it via the cerbo vs using a disc snap thermostat i was going to use at first.
i had chatgpt design a mount for the 5.2 inch radiator fan to go over the the ceiling vent in the bay. i 3d printed it and it is perfect.
tom
2014 Haulmark 40' Super C on Freightliner Cascadia ISX15 Eaton 13 speed
Former Owner 1990 38' Newell Coach 236 8V92
Former Owner 1999 45'8" Newell Coach 526 Series 60
Former Owner 2002 45'8" Newell Coach 608 Series 60
Thanks Jeff! I would do the same thing, wonder if they make a temp controlled flapper valve? Sort of like the coolant thermostat in a car.
Tom I wish they had more than 2 relays on the cerbo. I printed the fan housings but drew mine up on tinkercad, I need a different filament as this stuff is warping already.
I’ve been using safesense tempiq to monitor our B&B . I added a sensor in the salon and one in the bay next to the Growatt. It reached 118 during the summer setting out in the sun.
1993 Newell (316) 45' 8V92,towing an Imperial open trailer or RnR custom built enclosed trailer. FMCA#232958 '67 Airstream Overlander 27' '67GTO,'76TransAm,'52Chevy panel, 2000 Corvette "Lingenfelter"modified, '23 Grand Cherokee.
(This post was last modified: 08-30-2026, 05:04 AM by HoosierDaddy.)
When I designed my cooling system for my inverter bay, I decided to use the inverter logic of my victron system cooling fans to turn on my fans, and turn off with them as well.
I did a much less elegant, though similar setup in my inverter bay. Due to the cables already in place and my lack of desire in trying to run a cable most of the length of the coach, I mounted my Cerbo way up front next to my Touch 50. The option of using the internal relays would have been difficult.
So I used a 105 degree snap disc triggering a 4” pancake fan blowing out an existing floor hole. I attached a section of dryer vent hose to the fan, terminating it just above the upper surface of one of the Quattros now in the coach. So it sucks hot air off the bay ceiling and blows it out through the floor.
Comparatively crude, but it works.
06 M450LXi 3 slide
(This post was last modified: 08-31-2026, 07:22 PM by arcticdude.)
