OK, here are some numbers I've been crunching for a potential Mini-Split install on a Sprinter Class C motorhome (Winnebago Navion).
The inspiration is the YouTube video linked below, describing a 9K Btu install on a Class C motorhome of comparable size.
Mini-Split install, what would it take?
It seems to me ( thinking out loud) that the main questions to be answered are:
1) When the sun is *not* shining, can the battery bank sustain the overall power draw?
(Ideally, batteries could go to near near-depleted state without damage)
** The size of the battery bank could be derived from the answer to that question **
2) And when the sun is shining, can the solar panels fully recharge the battery bank, while sustaining the overall power draw?
(Worse-case: batteries start from a near-depleted state)
** The size of the solar array could be derived from the answer to that question **
Now, let's draw some speculative Off-grid scenarios for a typical Class C motorhome:
* Assuming an average consumption budget of 200Ah per day without A/C, that's about 100W per hour.
* According to this video (link), a 9K Btu mini-split running 24/7, on average consumes ~239W/Hour on cooler hours (night), and ~460W on warmer hours. So let's say that's 250W from 6 PM to 8 AM, and 500W from 8 AM to 6 PM.
Nighttime Analysis (6 PM to 8 AM, running on batteries):
Consumption = (250W/Hour, A/C) + (100W/Hour, Other) = 350W/Hour total
Battery Draw (Watts) = 350W/Hour * 14 Hours = 4900W.
Battery Draw (Amps) = 4900W/12V = 408A
So let's say that's 410A drain from the batteries, and if that load were to represent 80% of battery capacity, the battery bank must be at least 512Ah. (E.g., the video claims a 600Ah battery bank is sufficient)
Daytime Analysis (8 AM to 6 PM, running on Solar):
Consumption = (500/Hour, A/C) + (100W/Hour, Other) = 600W/Hour total
Let's say that during the 10-hour period, on average, we get 5 hours at full capacity, and 5 hours with enough Solar to cover the consumption budget (600W/Hour).
So during the 5 recharge hours, the required recharge power per hour would be 4900W/(5 Hours) = 980W/Hour.
Hence, the minimum Panel Capacity = Recharge + Consumption = 980W/Hour (Recharge) + 600W/Hour (Consumption) = 1580Watts/Hour.
Based on all the above, it seems like minimum power requirements are:
1) Battery Capacity = 600Ah+
2) Solar Capacity = 1600W+ (clearly, more would be best!)
*** DISCLAIMER ***
I have
*not* done this (yet), so the points above are just my assumptions (and you know what they say about assumptions!)
009 - [Redo] Solar Mini Split Air Conditioner Runs 24/7/365 Day & Night