[Telstar]

Greetings all! I am seeking advice regarding a couple of different mini split 3 zone heat pump/ac systems that I'm looking at installing in my 100 year-old home. I've been looking at several different posts, on different sites but have yet to uncover much info based on experience, rather than informed speculation and/or prejuducial responses from HVAC pros that seem to have little actual experience with these. My basic home stats are as follows:

My home is located in memphis, TN. It has 2 stories plus a semi-finished attic room. The exterior walls are uninsulated (and probably won't be anytime soon), balloon 2x4 frame, with plaster walls and approx 4-5-inch thick limestone facing on the exterior of the first floor, slate tiles on the 2nd floor (which doesn't get nearly as cold as the 1st floor in winter!). The attic is insulated, and I have r-30 insulation under the ground floor (crawlspace, which incidentally has a plastic sheeting for a vapor barrier over the dirt).

The rooms I'm looking at for the 3 zones (what we can afford right now) are downstairs -room 1 is 15' x 15' with an 11' ceiling (2 exterior facing walls), room 2 is 14' x 14' x 11' (2 exterior facing walls), room 3 is 18' x 12' x11' with one (8' x11') exterior (south facing) wall. All of the windows are single pane, wood set in masonry, 3' x 6'.

I did a rough estimate of my whole house heat loss using the caclulator located at builditsolar.com/References/Calculators/HeatLoss/HeatLoss.htm and came up with a heat loss figure of about 117,000 and some change. This doesn't take into account our current heating, as we'd like to use that as little as possible once this other system is in. The total heat loss (according to the calculator, which I suspect may be on the high side) for the 3 rooms we're looking to heat is around 40k BTU.

We have 2 gas logs at present, which aren't really doing the job, probably partially because we have such high ceilings and standard-height (80” -ish) openings between rooms, as well as a front room staircase that may as well be a chimney for the way that it funnels heat from one of the gas logs upstairs. And in spite of MLGW's laughably fictitious claims to the contrary, using natural gas here is insanely expensive, so we'd reaaally like to get off the stuff if possible. The two outdoor units we've been looking at are the LG and Mitsubishi multi-zone units (36000 BTU) with a matched combination of (2) 18K BTU indoor units and (1) 12k BTU unit. (see typical online package offers below)

e-comfortusa.com/products/lg-lmu365hvlmn125hvlmn185hvx2--wall-mounted-tri-zone-heat-pump36000btu/3492

e-comfortusa.com/products/mitsubishi-mxz4a36namsza12namsza15nax2wall-mounted-tri-zone-mini-split-32400btu/3436

Is there anyone out there who has experience with this type of system in a multi-zone application and can give me an idea if this would be a decent heat setup for my type of house and climate? I have a friend who is an HVAC guy who highly recommends mini splits and has installed several single zone systems, but he hasn't installed a multi-zone system before. He will be helping me pressure test and evacuate the system. Also, any advice regarding the heating performance of ceiling cassette units vs wall mount units?

I'm pretty set on putting a mini split system in, as having a central unit put in isn't really an option, nor is it something I'm really interested in due to the mess that installing the ductwork would make of the walls, floors, and/or ceiling (not to mention the 3 x 6' hole in the 100 year-old foundation I'm told would be required to fit the main trunk for a package unit).

I'd love to hear from someone who has installed one or more of these multi zone units in a similar scenario(s) and can give me an idea of how well they work for heat...Thank you in advance for any information that y'all can provide, and please hit me up if I can provide any additional information about my home...