Mini-split A/C

[attilathehun1]

Hi, In thinking about new construction, 3000 sq.ft. with a full basement, and wanting to avoid duct work, does mini-split A/C make any sense? Looking for pro and con on this. This for a ranch style home in North Carolina. Thank you for any input.

[DNT1]

Mini splits work well but with 3000 sg ft you will need multiple units and the cost can be pretty expensive. What is wrong with duct?? (Sheet Metal Worker here LOL)

[TigerDunes]

attilathehun1

I don't like this idea for several reasons. I am not clear why you would even consider this.

1.Comfort

2.Cost. Your upfront cost on the mini-splits will not save you any $$$ and definitely would be more expensive to operate than a high efficient conventional heat pump system including a properly configured and insulated ductwork system.

3.How do you plan on heating home? With heat pump mini splits?

4.Resale of home down the line. Who would want to purchase your home at a later date?

My opinion.

[Lugnut]

One drawback of mini-splits is inadequate air circulation to evenly cool the house. With a central air and duct system, you have vents in every room.

For example, are you going to install a mini-split in the bathroom, and several more, one in each bedroom? I don't see anyway to cool the bedrooms evenly unless each room has it's own system. That's when the cost of the system begin to soar.

[danski0224]

If you are trying to accomplish a zoned system, the cost of a few mini-splits might be a wash in comparison to a properly zoned system. Less complicated, too.

Does a condenser farm in the backyard appeal to you?

I would consider a well designed conventional duct system with the most energy efficient equipment you can afford. Consider ground source geothermal heat pumps.

Zoning with dampers adds complexity and cost, and few savings. Multiple small systems is the way to go. Two small efficient systems cost less to operate than one big one with a bunch of complicated dampers. Complete failure of multiple systems at the same time is not as likely as the one big one going out to lunch.

Make sure the system(s) and duct are properly sized, it is much more expensive to fix it later. The last 3000 sq ft ranch that a friend of mine looked at was screwed up by the rule of thumb guy. Big bucks to fix what should have been done in the first place.

Give up some of the eye candy like granite and stainless steel for now. Consider the cost of ownership in your HVAC equipment, not just the upfront cost. Energy costs are not going down. Granite and stainless can be easily added later. Mechanicals cannot.

Expensive energy efficient equipment needs good clean power. Get a whole house surge protection system.

[GregH]

Sorry about what yer hearin'............. lots of air movement people here. :D
It's generally accepted that air movement in a hvac system is a good thing.

If you describe the home in greater detail maybe more specific suggestions can be given.

[DNT1]

You might consider a commercial type system where one large condensor (probably a cooling tower type) would supply all evaps (one in each room) with refrigerant on a as needed basis. Lots of refrigerant piping and extra electrical service but none of that nasty ole duct. All heat transfer would be thru the line sets. Note: there is a reason that 99% of residential systems uses a duct ditribution system and of course that is COST You did not mention cost as a factor maybe you just want something unique and really do not care about cost?

[attilathehun1]

Thanks to one and all. The plan [we are in the early planning stage] calls for building with ICF's and using a geothermal source with in floor heating. If there is a way to cool the house with out ducts [without spreading the cost of ducts over heating and cooling]we'd like to learn about it. There is a system made by a US company using Convection Valances which have been used in commercial buildings, and are now being used in residential applications. There is also some new data coming out of Korea where hydronic heating is in wide use, that avoids the condensation problem connected to infloor cooling. Thanks to all once again.

[GregH]

Ok, I understand.

There have been many advances recently in high technology as it relates to residential hvac.
However, I think you must balance these ideas with todays tried and true methods.
I know of several who have installed "cutting edge" only to find something better not too far down the road.