Preparing Old AC Bay for Mini Split

[Glennman]

I've been reading quite a bit about the mini split systems picking up a lot of road dirt. I plan to install mine in the old AC bay like most converters. The bay has a few baffles in it at the bottom, and the bay was full of dirt on every horizontal surface. What are you guys doing to prepare the bay for maximum air movement, but also to prevent dirt from the road from entering. I was thinking of adding more baffles. Thanks everyone in advance.

[richard5933]

Did your bus have a filter screen on the intake door?

My GM has a metal mesh filter screen, and it does a pretty good job of keeping out debris and larger dirt without blocking the airflow. I've been in that compartment a few times to flush out the condensing coil, and it's usually just the very fine dust which gets through.

My impression is that the coil fins on a mini split are much finer than the ones on an OEM condensing coil, so this finer dust will likely be more affected by it. Might be a good idea to use a mesh screen to keep out the larger debris, and then plan on doing at least periodic cleaning of the coil using a safe cleaning solution and then a water flush. Not sure you'll keep out the finer dust without negatively affecting the air flow.

[sledhead]

I put a furance type stainless steel washable filter before the split unit and so long as I remember to clean it out all is good

if you look at the pic the filter on the left than it goes to the split unit condenser ( in the next bay ) then to a 12" inline duct fan then out the bottom of the coach . when the condenser fan would turn on the duct fan would as well
a head of the filter I had a honda 7000 watt inverter genny on a roll out and that took up the rest of the space in the old condenser bay 

[epretot]

I picked up my minisplit today. I will have this in the rear bay. I'm saving the old ac bay for my generator if I ever find one.

I have read a lot about negative air pressure. I have come to the conclusion that I'm not going to worry too much about that right now.

Obviously I have a plan if that ends up being an issue. However, I'm of the opinion that one can't really guage whether this will be a problem until the systems are in place and you drive down the road.

I have read that some have no problem at all with the mini or generator regarding negative air pressure.  I have also read that some have. Seems bus specific.

I think there is too much space in the old ac cabinet for just the mini. Perhaps the propane bottles can go in there as well.

Maybe it's a pipe dream, but I'm trying to keep all of the mechanicals in the rear bay. Propane bottles being the exception.

WHO DEY!

[Glennman]

I'll see if I can devise a filter system. If that doesn't work, I'll go to plan B (once I have a plan B!). Thanks everyone!

[mqbus767]

Are you talking about the condensor (outside) part of the mini-split? If yes, I did this:

https://www.busconversionmagazine.com/forum/index.php?topic=33689.msg407893#msg407893

The unit is on rails and flex hoses so it can slide out. This gives me lots of access around the unit for repairs and washing down the coils. I don't think it's going to get that much road grime on it. Probably what you saw was accumulated over many, many years.

[richard5933]

Another thought...

If you've been operating without the OEM unit in that compartment for some time, you've had the bottom of the compartment open to the outside. Likely a lot of the dirt and buildup you're seeing came up from the road that way.

One you get the unit installed, you'll likely be closing in portions of the bottom as you won't need that much air flow. It will be much easier to direct the airflow if you don't have it swirling around in there and can control it with partial closure of the opening.

Your baffling will be part of this partial closure, no doubt. Depending on how much vertical space you have you might be able to shield the actual exhaust flow this way to avoid road debris/dust/spray from coming up.

[luvrbus]

The factory Air over powered that space with high amp high hp motors dirt and dust wasn't a big problem, splits will take some modifications along with careful planning

[Glennman]

These are all some really good points. I don't believe the original equipment worked for a long time. Plus by the time I minimize down the opening on the bottom, that may reduce the amount of dirt entering the space. Thank you everyone, I got some pretty good ideas from you guys.