Mini-Splits vs Conventional for hard-to-reach room

mjacksonw

Hey folks,

We have a 1920 colonial in the Boston metro, and we're exploring getting air conditioning going. There's no existing ductwork, so we'd initially figured that mini-splits would be the best bet. ~2600sqft over three levels, with an unfinished basement and a partially-finished third story.

Two of our quotes so far have suggested an all-ductless strategy. The big challenge is that on our first floor, the kitchen (which covers most of the rear of the house) has no room for an air handler of any size – it's all either windows or cabinetry. So both ductless proposals have two units on that floor, one in a small office connected to one side of the kitchen, and the other in the living room pointing into the kitchen from the other side.

The third proposal suggested a hybrid approach, with a conventional system for the first floor and ductwork in the basement, using mini-splits for the upstairs rooms. He said that the office and living room would likely be cold as they try to push air into the kitchen, or the kitchen would be warm as the other two rooms optimize for their own temperature.

The pricing is fairly similar, though the conventional system wouldn't qualify for the same rebates as the ductless system would. And I'm not sure if it'd qualify for interest-free HEAT loans since the system is has an SEER of 12.

Any thoughts about the validity of the concern? It seems to make sense, but perhaps it's not as much of a problem in practice as he'd suggested?

Thanks!

JUGHNE

Do you heat with steam or hot water now?
How high of a SEER is needed for the HEAT loan?

It doesn't take much to bump a system up to 13 SEER.
But beyond that maybe so.

HVACNUT

Can you post some pics of the kitchen?
No matter what route you take, I would get a head or ducts into the kitchen. Anything under the kitchen. Summer cooking. Most
used room in the house.They do make units that can be ducted short distances, using a ductless system. Is there room under the kitchen that can be ducted to floor registers?

mjacksonw

Necessary SEER is 16, which seems far off. They just go based on the equipment's rating certificate.

Attached are a floor plan of the first floor and a photo of what the floor plan calls the kitchen/breakfast room. The proposed two mini-split units would be on the living room wall facing into the breakfast room, and in the dining room (office for us) facing toward the foyer.

I'd been interested in ducted mini-splits, but basically everyone has refused to quote me on them.

The basement is underneath the whole first floor and is unfinished, so there's definite potential for ducting floor registers, which is what the contractor proposing the conventional system wants to do.

HVACNUT

What was the proposed BTU's for the first floor?
Doesnt seem like there's feasible locations for 2 heads in the living room.
If you've got an unfinished basement, your not confined to exterior walls. Mounting on inside walls are easily done if your willing to have sheetrock repairs. (Hope it's not still plaster.) Its done all the time.
What's that between the bath and peninsula? Desk? Open wall space above it?
Is there enough width for a 9K head in the kitchen on the wall back to back with the China cabinet?
BTW, 16 SEER central air systems are common and shouldn't be hard to come by.
How is the home heated?

JUGHNE

I would suggest 4 units all mounted on inside walls.
One on the back side of the dinning room china hutch shooting towards the kitchen.
One on the short wall shooting towards the breakfast room.
(Optional, depending upon solar heat gain from those windows, IMO)
One on the inside living room wall shooting towards the door going into the sun room.
One on the dinning room wall shooting towards the window on the right.

These lines can be fished up the inside of the wall just like wiring, just a bigger hole. The inside unit would cover up any wall opening needed for the lineset.
The condensate drains could go to a basement floor drain or outside to daylight.
Going to inside walls keeps the outside of the house from lineset clutter for that floor. You will have some showing for the 2nd floor though.

BlueGreen

If you could drop the ceiling of your central stairwell/lav/closet area and put ductwork in there with supply registers high on the inner wall of the surrounding rooms and a large return in the center or wherever you can, even additionally upstairs, you could have a nice unobtrusive and quiet conventional system. You could have the air handler preferably above in the attic that could also serve the upper floors. Good supply to kitchen is key but at least there is only one window there.

This is the near exact arrangement in my house. Google long-throw duct work for some more explanations. I have experience with high quality mini-splits at a shared home and they are noisy and distracting, not to mention all the filters that need cleaning and unit cleanings every few years. Too many points of failure.

Ducted mini-split terminals and/or ceiling cassettes might be a reasonable compromise, but then you have condensate drains, electrical, and line sets to go everywhere.

Ducts insulated on the inside really keeps noise down.

Don't forget the laundry chute.

STEVEusaPA

I'd also go higher efficiency conventional in the basement for the first floor, and a 2nd unit in attic for floors 2 and 3.
If the 3rd floor is partially finished, might not be as hard as you think to get the duct work accomplished.
Also not too much more expensive to make them heat pumps, and add heat strips. Then you can use the heat pumps in the shoulder seasons (if electric rates permit), and have back up in the winter if your main heat fails.
I just don't like the mini-splits for many reasons, some already mentioned. There's a whole town here next to the airport where the airport put mini splits in all the homes, and you see all the enclosed line sets running up the exterior walls...looks ugly.

NY_Rob

@ThomasMiller1
Are you a robot, AI or company shill?

Your posts generally seem like long and winding pre-canned responses that don't address the OP's situation.

I also noticed you embedded the same links to a commercial HVAC sales site again....

HVACNUT

Ha! It reads almost like those Time/Life books for DIY folks from years back.