Let's get right to the point: when it’s hot out, you’ll want to use your air conditioner. Whether you're plugged into shore power or living off grid and using your batteries, there are a few tips to help things go smoothly.
Strategies for Cooling Your Van
When your van gets very hot, it can be difficult to cool the interior. In the heat, the BEST strategy is to:
- Pre-cool the van with the cab and house air conditioners while you have you are driving/the engine is on
- Limit cooling to the smallest volume of air possible (e.g. only the bedroom)
If possible, try to keep the van from getting very hot in the first place. When it has been baking in the sun all day, it becomes heat soaked and the interior may be hotter than the air outside. Not only is the air in your van hot, so is everything in it. Metal, plastic, wood, your belongings, water in your water tank ...everything in your van can store thermal energy.
These materials with stored thermal energy will heat the air in the van as they cool down when you turn on the air conditioner. This radiant heating will continue until the materials are cool enough for the air conditioner to keep up. Only when this happens will the air conditioner start to cool the air in your van.
Imagine heating a pot of water on the stove, and you just shut the stove off. The pot and water will feel hot for a long time. In your van (2nd/3rd generation revels) you have 20+ gallons of water alone that may be heat soaked. As it cools, just like the pot of hot water on the stove, the water in the van's tank will add heat to the cooler air/materials around it for a long time.
This is why pre-cooling the van while driving will make a massive difference in comfort when you park in hot weather then continue to use the AC.
Running the Air Conditioner When Using Batteries
1st Generation Revels owners: with your upgrade, you can now run your A/C when not plugged into shore power. Heck yeah!
The amount of time you can use your A/C depends on A LOT of variables: how many ah of storage do you have? Is the van directly in the sun? Are the windows covered? How charged were your batteries before starting the AC? Are there other loads on your system?
The BEST way to get extended run time is to block off parts of the van so you are cooling a smaller volume.
In general, we advise planning for 1 hour of run time per 100ah of storage. That is a safe bet that assumes worst case conditions. However, the reality is that run times can be much longer. If you are judicious with use and primarily use it on low at night when you are sleeping and there’s no sun beating down on the van, the number can be 2-3x higher.
Since many variables can affect A/C run time, learn about monitoring your battery power so you can make sure that you do not overuse the AC (or any other appliance) and reach the system’s low-voltage shutdown.
Running the Air Conditioner on Shore Power
When running air conditioning on shore power, you may be limited by your shore power connection:
- If you are on a TRUE 30A connection with good wiring, then you can charge your batteries AND run A/C at the same time. Easy.
- If you are on a 20A connection with good wiring, you will have to wait for charging to finish (Amps = 0 on the Victron app) before running your A/C.
- If you are on a 15A connection, you may have trouble running the A/C. You MUST make sure charging is finished.
Regardless of connection, you can never run the electric water heater and A/C at the same time. Learn more about using shore power here.
RV parks in the summer can be a challenge since EVERYONE will be using a lot of power and so the voltage (power available) can be low. If you are having issues running your A/C, follow these steps.
Other Hot Weather Considerations
Solar panel efficiency decreases in hot weather. If you have any solar panel shading or other blockage, that will also decrease what the panels can generate.
Always monitor your power, including voltage, to ensure you have enough power to run your system. Unless you are plugged in or regularly doing long drives to deep charge your system, you must also check voltage to ensure your batteries are not depleting. If voltage is 12.2 or lower (even if SOC is high), your batteries are depleted and you should charge immediately via shore power or driving. Read our Victron Battery Monitoring Guide to understand why.