New Home HVAC System

[kf4uda]

We are in the planning stages of building a new house. My original thought was to have a standard central air and heat ducted system using heat pump with propane backup. We also will have non vented fireplace with gas logs for supplemental or backup heat if the power goes out.

In talking to a friend who retired from the HVAC world he suggested looking at a Mitsubishi Multi Zone Mini Split System. Multi-Zone Cooling and Heating Outdoor Units | Mitsubishi Electric

Are any of you guys using a system like this in your house or have any knowledge of it? I have studied it some and it certainly looks interesting. I like the idea of each room/area temperature being controlled independently. I also like the idea of no duct work as well.

 

[EddieWalker]

I'm not a fan of them. I've worked on quite a few homes that people have added them to an existing system for rooms that where converted from storage areas, like attics and garages, into living areas. They work OK in those areas, but you can tell the difference when you want through the house and into those areas. I've also been in small homes where they had three units for the entire home. Each room had one. In those cases, it was a lot of money for basically what a window unit does. I was told the advantage was in saving money on electricity over window units, but in both of those homes, they didn't stay there long enough to make back what it cost to buy them.

I would never contemplate replacing a central unit with a bunch of mini split system when building a new home.

If you are planning on living in this house the rest of your life, I would still factor in what resale value will be if something comes up in your life that you never imagined happening. It happens a lot. How much money will you lose when selling the house because of the mini split systems over a central HVAC system?

 

[pjigar]

Resale is the only problem with mini-split HVAC. We built our forever home in the country and opted for individual mini-splits rather than multi-zone mini-split. The single units are more efficient and cheaper to replace when they break plus you won't be without HVAC in the whole house when they break. There are added benefits of mini splits: Your house would have fewer air leaks, Rodents can't chew the ducts!

We have 5 units: 2 for living areas and one for each bedroom. Bathrooms have fan heaters for winter. Remember to upsize the living area units. Our units are 21 SEER and I paid less than $5000 for the material. You may feel the temperature difference from room to room but it's a feature to me rather than a downside.

PS: Multi-units were cheaper since I installed them myself. If you pay someone then multi-zone might be cheaper. They were way easier to install DIY than ductwork would have been.

 

[forgeblast]

we have the Mitsubishi mini splits with the heat pump. Life changer especially in an aframe that has no windows upstairs. We use it all year long. I cannot say how much it has improved our home.

 

[wagne223]

I don't think I would choose mini splits in lue of a central system. A central ducted system is great at moving air throughout the house and seems to balance temp good.

That said, mini splits have their place and I really like them.
I have 3 in addition to the central system for the following reasons.
- They are DIY friendly.
- They are great assist to central in rooms that have a high sun load.
- at night I can keep the Master bedroom cooler and comfortable for sleeping without having to keep the whole house that cool.
- They are Generator friendly. During power outage from Hurricanes I can run the 3 minis, the fridge, lights and TV on a 3500 watt inverter generator.
-should the central fail, you can take your time and shop around. It is not an emergency even if it is 100 degrees out.

 

[Buppies]

I agree with Eddie we have two units one up 2 ton heat pump 16 seer. Downstairs 3 ton heat pump backed with propane 18 seer. These units are 5 years old even air flow works well when propane people do not let me run out

 

[dodge man]

For a new house I would go with some form of forced air, but that is my preference. Tennessee is far enough south heat pumps are probably viable. Better yet look at geothermal. There were and may still be some very big tax breaks. We also pay a few cents less per kilowatt hours for our geothermal. A HVAC guy with the right software can break down each system and the return on investment for geothermal.

 

[Popgadget]

It’s hard to beat the mini splits. They are very high efficiency, generally over 20 SEER, extremely quiet, inside and out, and much better zoning than you would get with ductwork and dampers.

As far as multiple outdoor units vs multi head, that depends greatly on the installation and how the line set would run. Multiple units give you redundancy, which is a good thing.

 

[riptides]

Really depends on your floorplan. I have on 960sq foot building with a minisplit wide open floor plan. Works perfect. House with multi zoned HVAC...works as advertised.

I like the minisplit better. I could probably replace my downstairs zoned HVAC as the floorplan is only three rooms.

 

[jk96]

No reason you can't zone your home with a central air system. We have geo. 2 units, total of 6 zones with independent thermostats for each zone. Now with scroll compressors that can ramp up or down on demand zoning has gotten even easier. Also btw sensi makes a nice wifi tstat if you are running multiple zones. I have the 6 tstats on the house and 4 more for my business all at my fingertips in an easy to use app.