Mini Split Location
Looking for some advice on location for a single zone non ducted mini split for the open portion of the house. The other end is bedrooms and for now I'll keep them with the window units. I have marked the layout and then the camera views for each spot, red arrows refer to the pictures and the blue stars refer to the possible mini split locations. My wife will kill me if she knows I put pictures of the messy house online..shhhh it will be our secret. I can't put the mini split on the big wall with the "Home" decorations because I have an addition in the works and that wall will be gone. Area to be cooled is 600sq ft, but 400 sq ft has that 12' cathedral ceiling. In doing basic calculations depending on various assumption I'm getting either a 18k BTU or 24k BTU capacity. All I know is that 14k window AC near mini split location #1 normally keeps everything cool, but as the outdoor temps approach 90 the room temp drifts up.
Aesthetically I would prefer mini split location #3 or #4, but not sure it would cool the whole area. Thoughts?
Comments
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It’s going to be ugly no matter where you put it. A bigger consideration is running the lineset.
Are you sure you don’t need two heads?I think the ideal spot is right where you show the decoration 'Home'.
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It's not ugly when it is quietly spewing cool air onto you that's for sure. The "Home" wall is not available he said.
NJ Steam Homeowner.
Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
See my sight glass boiler videos: https://bit.ly/3sZW1el1 -
Don't put a 24000 in under any circumstances. You should be able to do 600 sq ft/ton12,000btu. What temperature are you expecting? If the 14,000 won't do it something is wrong unless you have no insulation.
Cathedral ceiling has little effect on the load as the space above your head stays unconditioned when on cooling. You really don't have a good spot to do this with one head. I would use 2 6000 btu or a 6 & an 8 if available. 2 tons for 600 square feet is crazy
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We have it set for 70 degrees. Insulation is R19 batts in the walls and two crisscrossing layers of r30 batts in the ceiling. Where would you recommend puting two heads, at locations #1 and #3?
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I agree 2-Tons is way too much.
Where is this house? 9000 - 12,000 MAX!
That kitchen creates other issues.
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New Hampshire
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What issues were you thinking the kitchen creates?
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Grease!
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Will this be the only heat source?
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I don't plan on using it for heat at all really. Looking at the tax credit/rebate it appears the only models that qualify are the ones with low outdoor temperature heating.
I just did a natural gas boiler with hot water storage tank with the help of this forum last year and that works great.
https://forum.heatinghelp.com/discussion/196165/help-me-with-the-basics#latest
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If you were i would recommend 2 systems. But it's fine to use it during the shoulder seasons.
Cooking can plug the evaporator quickly, that leads to more expensive maintenance. Keep the head as far away from the stove as possible.
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And heat
NJ Steam Homeowner.
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See my sight glass boiler videos: https://bit.ly/3sZW1el0 -
If these were my choices for location I would put it at #1 and adjust the airflow to only blow into the living space so its not blowing at that wall, and I imagine your cats will want you to move the cat tree
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70 deg is too low. normal design is 74-76. Are you sure the 14000 unit is not icing up?
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I like locations 2 and 3.
It'll get the cool air mostly where you want it and make running the linesets and electrical easy.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Looking at the two Mitsubishi units below, do I size based off the max output or the rated output? Is the max there as surge capacity for your upper 10 percentile days?
Mitsubishi MSZ-FX06NL & MUZ-FX06NLHZ
Min 1700
Rated 6000
Max 14000
Mitsubishi MSZ-FX09NL & MUZ-FX09NLHZ
Min 2500
Rated 9000
Max 15000
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For that location 6000. Do they make a 6000 single?
Who's installing this?
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Using Manchester NH as a design location (looked like the hottest temp choice for NH on my software) and putting all your windows in as 4' tall, excluding the room at the bottom right, and using the generic add on values for a normal kitchen and living room, with 4 people in the space, my software is telling me 1.39 tons to maintain 70 degrees inside (and design day is 89f there so not taking into account your over 90 days..). Honestly I was on board with everyone else saying a 1 ton unit would work great in that space. I think if it were for me I would still be on board for 1 ton, but its not for me its for you. So with that I would say a 1 to 1 18k mini split, but definitely get a good one with a wide modulation range because this will be sizing for a colder than normal indoor temp, and for a hotter than design day outdoor temp.
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1 1/2-Tons for a tight 600 Sq Ft in NH?
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A couple of windows are probably smaller than what I have on the document, and the kitchen/living assumptions are probably too high. But then again the weather the OP is experiencing is also above any design day I have for NH I tend to believe these numbers, I was expecting it to be lower. This isn't including the little room at the bottom of the plan either
like I said I would put a 1 ton if it were my house, there is some fudge factor in there for sure.
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The 6k and 9k I listed are available as singles
Me, myself, and I inc. will be installing this haha. In all honesty it will probably be similar to how I did the boiler where I did all the electrical and plumbing and had a licenced plumber run the gas line. So in this case I'd run everything and let the plumber took in the refrigerant lines and pressure test/vacuum them.
As far as outside temperatures, I've been in the house for 15 years and overall outdoor temp is definitely creeping up. Used to get feet of snow in the winter and now I only use the snowblower a couple times a season. In the summer hving a day above 90 was rare, let along having almost a week straight. Course now it's back to low 70's, welcome to New England.
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I haven’t seen a 6000 except in multi zone applications
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I wouldn’t go over 1-Ton
Again huge issues not letting them run 100% as often as possible.
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Yea, at the time I verified it wasn't
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To be fair my design temp is 72F and I run 68F at times.
I've never found it to be too low. With a txv the system has no issues controlling humidity. Not sure with minisplits and their EEVs but id hope it does as good or better than a TXV.
74F is too warm for me and forget 76.
I was thrilled my system was able to achieve 75 when it was 100 outside but I'm much happier with it cooler especially in the bedrooms.
I have a freezestat on my evap just in case but it's never been needed in 8 years so far.
That said... Even in my drafty uninsulated house I'm only at 533sqft per ton.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Thanks so much for doing those calcs.
On that addition I plan to take that wall with the "home sign" and set it back 4' to 6'. It will now be an inside wall and lose the windows so will would that be enough to offset the increase in cooling area or would that tip me over into say a 15k but unit?
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a good explanation on why you don’t want to oversize a mini split.
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1/3 of your loss is in the glass if @GGross's calculations are close and even good windows are worse than a terrible wall so if you get rid of some of the windows with an addition your heat gain (and loss) go down significantly. You have a mostly outside walls and a lot of glass, I believe the calculations that show your btu/ft^2 is unusually large.
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Yeah it is unusually high, it's a small space with a full kitchen, set up for about 4 people or so, and 3 screens. I do want to emphasize that this load calc would be worst case scenario, someone on the computer, couple people watching TV and someone cooking up a storm in the kitchen. If you add to that people going in and out of the house more than normal on a humid day I could see the load being slightly higher than whats on the page. I'm kind of assuming that the worst case scenario happens on occasion since the existing window unit won't keep up, I would expect it to personally
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does the window unit still have all if its charge?
cooling also has a lot less fudge factor than heating because the delta t is much smaller so small changes in your assumptions have relatively big effects.
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Are you able to do something like this? A ceiling mount.
You can run the tubing and wiring with the joists out to the condenser.
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All of those require a pump (built in), no?
If that's the case I'd only use those as an absolute last resort, especially in a finished ceiling/
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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As well as a Maintenance nightmare!
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In a commercial environment someone probably has a lift somewhere. in a home servicing those off a 12' stepladder will be dicey.
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Seems like a good argument against 12' ceilings in a house, actually.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Cassetts come with a condensate pump but I don't think it has much head capacity. Enough to get the condensate out of the cassette then you have to have gravity or another pump. I wouldn't use them unless you had a drop in ceiling so the tiles could be replaced if needed so they are not good for residential except for maybe a basement ceiling.
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to be on the safe side I always assume that the built in pump can just get the condensate up and out of the unit, and go gravity drain the rest of the way. My first classes on my brand the guy wouldn't call it a pump and tried to drill that into our heads so we didn't try to pump too high.
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The several cassettes I know of use a slinger-style pump that'll give you up to IIRC 26" of lift, then they're supposed to gravity drain from there. They'll easily lift to a Little Giant sitting on top of the cassette. More than that, not so much.
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Wanted to follow up and saw thanks to everyone who educated and helped me.
I ended up going with the a Mitsubishi FX 15k BTU. The minimum cooling is 3700btu vs the 12k has a minimum of 2500btu and the max is 19k btu vs 16k btu. The thing that pushed me up to the 15k is the 12k is only pre charged for up to a 25' line set and the 15k is good for 50'. The indoor unit will be at least 20' horizontally from the outdoor unit and that's not even taking account the elevation change. Since I'm doing this myself it saves me the hassle of trying to convince a contractor to recharge/add refrigerant to a homeowner installed system.
I also think it's going to go into position #4. I was told the cat tree wasn't moving so position #1 was no go.
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