Mini split or new ducts?

[aafadca]

I'm renovating a 1930's house that has oil heat but with vents only down stairs! Ive spoken to a few a few HVAC people on the phone about adding new ducting upstairs. There seems to be space in the attic if needed. A couple said a mini split may be the way to go instead of new duct. HVAC people, what do you think?

 

[Bretny]

If your attic is unconditioned i would not put a unit in the attic. Think about it. Your wanting the coldest air possible and your putting it in the hottest place in the house just out of convience of the installer.

 

[dcg9381]

I think you mean doing a wall-mount ductless system over a conventional ducted system in the attic.

In this case, my answer is "heck yea" - you'll get better SEER out of a ductless (per dollar) and you won't be pumping your cool air through the hottest part of the house (the attic).

The downsides: ductless systems, IMHO, are really not built for component repair. They seem to be built cheaper with more moving parts than ducted AC systems. I don't think you're going to get 10+ years out of them.

You've got a heat pump and you're in VA. If you need heat out of them, pay attention to which ones are efficient when it gets really cold out.



Advantage: You can cool individual room(s) to desired temperature. Probably easier to install than trying to ductwork. More efficient.

 

[yeldogt]

I'm renovating a 1930's house that has oil heat but with vents only down stairs! Ive spoken to a few a few HVAC people on the phone about adding new ducting upstairs. There seems to be space in the attic if needed. A couple said a mini split may be the way to go instead of new duct. HVAC people, what do you think?

Not enough information -- how many rooms up?

Insulation ? how much renovation .... heat/cooling load

 

[fitter30]

There is another option a high velocity duct system, this is just one brand.
http://spacepak.com
Mini splits are good but they have some drawbacks that I've found out and i have two multi head systems. In heating when in defrost no heat. Look at you tube videos cleaning a wall unit. Parts may not be stocked in your town and can be a few days away. Count how many indoor units everyone has blower moter, damper motor ,circuit board, drain piping/ condensate pump and two refrigerant connections.
Pluses- quiet, zoned, energy-efficient, no duct loss and got a rebate from my electric company.

 

[aafadca]

Mini split in older home

I recently bought a 1930 2 story house. It has an oil furnace for the lower floor but no ducts upstairs! I'm thinking of a mini split system for the upstairs. There are 2 bedrooms (roughly 10x11) across from one another and a "sitting room/small hall" in between. It's a Craftsman style house if you're familiar with that style. I would like to at least put heating/cooling in each room. There's no air in the house. The most important thing is heating since there is none. Does anyone know if there are DIY systems with multiple air handlers? Any other ideas for heating? This will be a rental house.

 

[aafadca]

2 bedrooms across from one another, small hall in between. Not well insulated yet but im working on that. Would want it mainly for heat since its in the mountains. It will most likely be a rental or something similar. I just started a similar thread (because i forgot about this one) and asked about mini splits with multiple air handlers.

 

[aafadca]

There is another option a high velocity duct system, this is just one brand.
http://spacepak.com
Mini splits are good but they have some drawbacks that I've found out and i have two multi head systems. In heating when in defrost no heat. Look at you tube videos cleaning a wall unit. Parts may not be stocked in your town and can be a few days away. Count how many indoor units everyone has blower moter, damper motor ,circuit board, drain piping/ condensate pump and two refrigerant connections.
Pluses- quiet, zoned, energy-efficient, no duct loss and got a rebate from my electric company.

Ive read about those. Very interesting but I think they're pretty expensive

 

[Jackfre]

There is another option a high velocity duct system, this is just one brand.
http://spacepak.com
Mini splits are good but they have some drawbacks that I've found out and i have two multi head systems. In heating when in defrost no heat. Look at you tube videos cleaning a wall unit. Parts may not be stocked in your town and can be a few days away. Count how many indoor units everyone has blower moter, damper motor ,circuit board, drain piping/ condensate pump and two refrigerant connections.
Pluses- quiet, zoned, energy-efficient, no duct loss and got a rebate from my electric company.

The hi-V systems are much less efficient than the mini splits. Back when the 13 seer requirement came in the Hi-V folks took a “space restricted” loophole to not even make 13 seer. They can be good, but the ducting must be about perfect or that thing will whistle like crazy.

 

[SALIV8]

The hi-V systems are much less efficient than the mini splits. Back when the 13 seer requirement came in the Hi-V folks took a “space restricted” loophole to not even make 13 seer. They can be good, but the ducting must be about perfect or that thing will whistle like crazy.

Thanks Jackfre did not know that

 

[danski0224]

The hi-V systems are much less efficient than the mini splits. Back when the 13 seer requirement came in the Hi-V folks took a “space restricted” loophole to not even make 13 seer. They can be good, but the ducting must be about perfect or that thing will whistle like crazy.

Yeah, and an advertised "18 SEER" split system hooked up to existing ductwork with no changes is certainly making label efficiency... not.

Yes, ductwork in an unconditioned attic is just about the worst thing that can be done for HVAC stuff.

Yes, the high velocity system requires pretty intense attention to detail for a properly functioning installation.

I wouldn't dismiss a high velocity system based on the way outdated slam on the SEER loophole above.

I do know that while mini splits seem to be all the rage, for most purposes, they are essentially not repairable by the end user, and the high end stuff pretty much requires factory level service. The average HVAC/R shop will NOT have the computerized diagnostics to get into the system, and when they do, good luck getting parts on a timely manner.

 

[Jackfre]

Outdated perhaps, but also correct. HV systems in my experience require a greater level of care, which only comes with experience, in the installation and as importantly, the lay-out of that duct work than any product in the hvac field. I know. I represented Spacepak in a 6 State area. I saw plenty of it and given that they are generally installed in tight areas repair is difficult. in today’s world everything is PCB driven and the service side of any of the hvac products can be pretty tough. Hvac distributors don’t carry the parts they used to because the money is no longer in it. You wait for almost everything and yes, it is complicated.

 

[justinjoyal]

The downsides: ductless systems, IMHO, are really not built for component repair. They seem to be built cheaper with more moving parts than ducted AC systems. I don't think you're going to get 10+ years out of them.

We see 15+ y.o. mini-splits regularly.

They are perfectly repairable, you just gotta stick with the main brands to ensure parts availability.

There are not really more moving parts than in a regular split system... a bit more electronics than the standard non inverter splits but that’s needed to achieve the higher efficiency. High performance inverter split systems have electronics too.