mini-split indoor unit filter box

[bruce_taylor]

I am installing a mini-split in my new garage, I noticed that the unit has a filter around the coil but it us a bit cheesy, I do alot of wood working for dust is an issue even with dust collector and filters, it's dustier than normal, I am contemplating wrapping the top of the mini-split indoor unit and adding a couple 20x20 maybe 24x24 filters as prefilters for the unit in hopes of extending the life of the coil, has anybody else done this or had issue with the coils on these units getting dirty?

 

[The Cobbler]

I watched a video on yutube where a guy had built a large filter assy for a mini split

 

[Jackfre]

there are many mshp systems operating in like environments. I think for the health of both yourself and the unit you should look into improving your dust collection. Both at the tools and with an ambient air filter box. I run one and it makes a big difference in the airborne particulate. Also, these are not hard to clean. They are a pita to clean but it is not difficult. Have your contractor show you how to remove not only the lid covering the filters but the whole cover and instruct you on how to go about it. Cleaning the coil is important, but you have to get to the blower wheel as well. building a filter box to prefilter will only diminish the units performance.

 

[finn]

Just my opinion, and despite the hype they receive here, mini splits aren’t really well suited for a dusty shop environment. I get that they are cheap, efficient, and easy to install, but the lack of adequate filtration is a major drawback in some situations.

Don’t get me wrong. I have three Mitsubishi mini splits in a couple of houses, but for a shop, I would look into something with better filtration designed in rather than cobble something after the fact.

 

[rlitman]

Just my opinion, and despite the hype they receive here, mini splits aren’t really well suited for a dusty shop environment. I get that they are cheap, efficient, and easy to install, but the lack of adequate filtration is a major drawback in some situations.

Don’t get me wrong. I have three Mitsubishi mini splits in a couple of houses, but for a shop, I would look into something with better filtration designed in rather than cobble something after the fact.

+1 Mini splits have fans that are not sized to handle the flow losses from the restriction of filters and ducting.

There are better options for this.

 

[Jackfre]

“Dusty shop environment” Humans are not designed for a dusty shop environment either. The amount of accumulation in any equipment sets the maintenance schedule. To the OP, how large is this space? It’s location being FL de-hu & cooling are its primary jobs. I was looking over Fujitsu’s site the other day. They have just introduced a multi-position ducted air handler in 24, 30, 36 & 48 btu sizes that match up with the inverter condensing units.

 

[mhejl]

I tried a 12x24 filter on my 18k with an adapter box. It reduced flow enough to cause the evaporator to freeze up.

 

[bruce_taylor]

I'm looking at building a box to house 4@ 20 x 20 inch units, that is what will work I have been told, Should allow plenty of air to pass, The building is 34 x 60, metal quonset hut, will have 2+ inches of closed cell foam sprayed in, along with dust collectors and shop vac's, and air cleaners, but wood working is a dusty environment

 

[DHCrocks]

get these. I have been using them on the top of my mitsubishi since I got it installed in 2016 and no problems. They work really well and everytime I check the stock internal filter is always clean, I never had to wash them out. I change the filter every 6 months. When the AC guy comeout to clean my blower wheel since it was gunked up with mildew he said it was ok to use filter and actually recommended it said for a garage its helpful since all the dust will clog the ac unit since the stock filters don't really do much.

I just cut it to cover the entire top and lay it on. I think 12"x42" or something like that. It comes with velcro strips that I **** on the edge to hold the filter in place so it doesn't fall off. from the ground you can't really see anything except for the edge of filter but its white and only aoubt 1/8" thick so doesn't look too bad.

https://www.amazon.com/gp/product/B079MCBJWR?pf_rd_r=6SYRP5R56QJ16QNRAZCR&pf_rd_p=5ae2c7f8-e0c6-4f35-9071-dc3240e894a8&pd_rd_r=ffaf1136-709e-4c14-9b22-8e09977b1896&pd_rd_w=65Xcb&pd_rd_wg=QGlyu&ref_=pd_gw_unk

 

[The Cobbler]

the video I watched on You tube, the guy had massive square footage for filters, essentially making a no restriction filter .

 

[drspencer5]

I live in South Florida and have this issues as well. On one hand, It's nice to have a cool garage but I shouldn't weld with the garage door closed. I built a 24" square box with a blower fan in it. It has 20" filters on either side of it. I also have a toolbox with the lower portion cut out for a blower with filters on 3 sides. Keeps clean air moving around. I haven't gotten to the mini split yet but there's no way the blower in mine could pull air through a filter the way the filter was designed.

 

[jjrbus]