Mini split A/C Heat Pump systems

[greenmojo]

All;

I built a temporary office up here on the property and seeing as I want to use these mini split systems in the whole house, I went with one in the temporary office to see how easy they install and to see if I ultimately liked them.

For the temporary office, I went with a 12,000 Btu Pioneer, however for the house I am looking at a few zones with a total of 54,000 Btu's with Mitsubishi units.

So far, I am really impressed with the efficiency. It is super quiet, switches from hot to cold automatically in these shoulder months where the nights get cold, and power consumption is extremely low, which is great for my off-grid system.

Any opinions or recommendations?

~Moses

 

[stuckmotor]

Moses,
Could you give us a link. I'd like to read a sales brochure.

 

[greenmojo]

Moses,
Could you give us a link. I'd like to read a sales brochure.

Of course!

Pioneer (12,000 Btu 20 SEER) unit I bought, this is the sales brochure: https://www.highseer.com/pdf/WYB-19-2014.pdf

Mitsubishi units I am going to put in the house: Wall-Mount

~Moses

 

[dave1949]

We have a Mitsubishi MSZ-FE18NA and a MSZ-FH15NA. Installed last July so not a lot of history but they have been fine so far.

The cooling and moisture removal are great. Heating is fine too but we don't use them for heating very much.

 

[greenmojo]

We have a Mitsubishi MSZ-FE18NA and a MSZ-FH15NA. Installed last July so not a lot of history but they have been fine so far.

The cooling and moisture removal are great. Heating is fine too but we don't use them for heating very much.

Did these augment your existing HVAC?

I am stoked about their efficiency and that they are ductless so not losing hot/cold through ducting.

~Moses

 

[dave1949]

Did these augment your existing HVAC?

I am stoked about their efficiency and that they are ductless so not losing hot/cold through ducting.

~Moses

We have no HVAC system, so they are it. I really should have built with an ERV based air handler system but didn't.

We were experiencing too hot and too humid inside conditions the past couple of summers. We needed a solution and these seemed to be better than back-fitting ceiling vents and ducts that would have to be in the attic since we are on a slab.

 

[SirReal63]

We have them in use in the house in Meadowlakes, a regular Mitsubishi Mr. Slim but out at the farm with we went mini split with a twist. The Guest House is being climate controlled with a single 48VDC mini split from HotSpot Energy. I am thoroughly impressed with it, and being a 48VDC unit, it runs from the solar batteries, no A/C power to it at all. A single 1-ton unit is cooling the 24x24 insulated metal building with 14' walls with ease. That is a lot of volume for a 1-ton unit.
Solar & DC Air Conditioners | 48v DC Solar & Telecom Air Conditioner Heat Pump | Off-Grid Air Conditioning

When we get the main house constructed, I think we will go with a mini split chiller system. No freon lines to run, just water lines and very high efficiency.
Small Heat Pump Chillers | Chiller Air Conditioner For Home or Office | Residential Ductless Mini Split Chillers
Other than the high efficiency, anyone who can run water lines can install it.

 

[TomSeller]

They are going to make a big dent in the traditional market for cooling and heating homes.

 

[greenmojo]

We needed a solution and these seemed to be better than back-fitting ceiling vents and ducts that would have to be in the attic since we are on a slab.

Exactly! I'm building a home up here in central WA and wasn't interested in running ducting, especially considering the energy losses involved. When I started to look at these ductless systems, I was surprised at their efficiency and technology overall.

We have them in use in the house in Meadowlakes, a regular Mitsubishi Mr. Slim but out at the farm with we went mini split with a twist. The Guest House is being climate controlled with a single 48VDC mini split from HotSpot Energy. I am thoroughly impressed with it, and being a 48VDC unit, it runs from the solar batteries, no A/C power to it at all. A single 1-ton unit is cooling the 24x24 insulated metal building with 14' walls with ease. That is a lot of volume for a 1-ton unit.
Solar & DC Air Conditioners | 48v DC Solar & Telecom Air Conditioner Heat Pump | Off-Grid Air Conditioning

Interesting! I didn't even consider an all DC system... The electrical building will need something to keep it cool this summer now that all of the inverters are installed and running. Now, some reading to do!

They are going to make a big dent in the traditional market for cooling and heating homes.

I agree! No ducting, means more energy is making it to the right places.

I called the local county inspection office and talked with them about kicking my HVAC plans to the curb, and wanted to know what was involved with them in regards to switching to these zone-based ductless systems. To my surprise, they said it simplifies the whole process. They only wanted to know if it met the minimum HSPF of 8.5 and that was it (my proposed model numbers are 10 and 9.5 HSPF).

Because they are inverter based, and can move as little or as much air as needed to stabilize the environment, the county didn't care about over sizing, unlike a traditional over sized HVAC system that might exchange the air so quickly that the bones of the house remain less affected, causing the HVAC to cycle more frequent as the bones transfer the temperature back to the internal air.

Inspector told me that if we go with the ductless solution, that my mechanical inspection is just a simple walk through the house.

~Moses

 

[hslogger]

I have heated with wood for decades, wood furnace,and or Jotul, et. al. After watching Japan wash away a few years ago, we noticed so many of their structures had ductless heat pump systems and decided to look into it. Our power provider came out and we consulted about efficient energy use. The information shown to us brought us to the conclusion that a ductless heat pump system would be the way for us to consider as we weaned off of exclusive wood burning.

We agonized over giving up some old ways. We did not remove our wood furnace or ducting, nor our wood stove. We did have four mini splits, Mitsubishi brand installed and have not regretted it yet. It IS an exchange system, and when it is really cold, twenties and teens it doesn't keep the place toasty at all, and we fire up the Jotul. We are pleased with the efficient use and the opportunity to utilize the cooling aspect when we have hot summer temperatures.

 

[Redneck in training]

We heat and AC our house with geothermal heat pump. When we built our house about 10 years ago I was familiar with the mini split units but they were not readily available on the market. We also worried about operation at low temperatures. We built a shop building two years ago and my office and guest room are heated/AC by Halcyon mini split unit. I think they are phenomenal. If we build our house today we would install mini splits only. It would cost less than half of geothermal and the saving could be used to install about 10 kW of solar panels.

 

[Coyote machine]

2 Fujitsu mini-splits, good for providing heat to -15 F, and AC.
Wall Mounted 9 - 15,000 BTU Hi SEER - Fujitsu Ductless Mini-Splits
Subsidized through Efficiency VT. $1,200 cost reduction direct rebate against installed cost.
They work excellently.

 

[forgeblast]

Once we refi on thursday I will be ordering the Halcyon, Halcyon Hybrid Flex Inverter -  Fujitsu General Ductless Mini-Splits we are going to go with a 3 zone set up.

 

[tamu94]

The minispilts are great technology. I installed a dual zone Mr Slim at our ranch cabin and we are very impressed with the efficiency and quite operation.

If I build a new home I plan to look very closely at them. Be warned that many installers charge a small fortune to put them in. I do not know why as they are easy to install.

 

[IXLR8]

We installed a Mr. Slim about 5 years ago, we have been happy with it. We use it for AC in the summer and heating in Fall/Spring. Doesn't do much for heating when the outside gets below 20dF. We fire up the wood stove and run it for heat from Dec to March. The Mr. Slim unit we have doesn't put out much heat below 20dF, the new units will put out heat to -15dF, but much below 20dF their efficiencies drop off rapidly. Costs about $1/day for heating in Spring/Fall, about $10/month for AC in the summer. We were going to do geothermal for retirement home in NC but now are thinking going mini-split w/solar power instead.

 

[greenmojo]

We agonized over giving up some old ways. We did not remove our wood furnace or ducting, nor our wood stove. We did have four mini splits, Mitsubishi brand installed and have not regretted it yet. It IS an exchange system, and when it is really cold, twenties and teens it doesn't keep the place toasty at all, and we fire up the Jotul. We are pleased with the efficient use and the opportunity to utilize the cooling aspect when we have hot summer temperatures.

That's precisely what I would like to do. We have 2 wood burning fireplaces in the house plans, and my plan is to use 7 Mitsubishi units throughout the house, which will give us control as well as more than enough Btu's. I was looking at Mitsubishi's new HYPER units, which they claim will work down to -15f. If not, or when it does get that cold, we'll just augment with the fireplace as usual.

~Moses

 

[Sigarms]

Mitsubishi units I am going to put in the house: Wall-Mount

~Moses

You probably knew this, but the MSY models are AC only.

 

[greenmojo]

You probably knew this, but the MSY models are AC only.

No! But you just scared me. I went back and checked my model numbers I have selected and they are all MSZ. Slight panic. All good now. ;-)

 

[greenmojo]

We heat and AC our house with geothermal heat pump. When we built our house about 10 years ago I was familiar with the mini split units but they were not readily available on the market. We also worried about operation at low temperatures. We built a shop building two years ago and my office and guest room are heated/AC by Halcyon mini split unit. I think they are phenomenal. If we build our house today we would install mini splits only. It would cost less than half of geothermal and the saving could be used to install about 10 kW of solar panels.

I don't know much about geothermal. I have plenty of land to do a shallow system over a large area, but I don't know enough about it to know how I would use it.

2 Fujitsu mini-splits, good for providing heat to -15 F, and AC.
Wall Mounted 9 - 15,000 BTU Hi SEER - Fujitsu Ductless Mini-Splits
Subsidized through Efficiency VT. $1,200 cost reduction direct rebate against installed cost.
They work excellently.

Yikes, I'd love to get some of that cash, but I'm not connected to the grid... Entire property is alone on the mountain.

Once we refi on thursday I will be ordering the Halcyon, Halcyon Hybrid Flex Inverter -* Fujitsu General Ductless Mini-Splits we are going to go with a 3 zone set up.

Fujitsu is another of the big name brands that I like.

~Moses

 

[Sigarms]

It IS an exchange system, and when it is really cold, twenties and teens it doesn't keep the place toasty at all, and we fire up the Jotul. We are pleased with the efficient use and the opportunity to utilize the cooling aspect when we have hot summer temperatures.

People never look at the ACTUAL heating capacity down to 0, and generally only concern themselves with the SEER rating and cooling capacity. Mini splits now don't come with strip heat so heating in colder climates (even here in NC) is more important than cooling when it comes to a mini split being a primary heat source.

One particular 3 ton multi zone mini split unit at 5 degrees outside air temp can produce over 45k of heat. Thing is, a mini split inverter compressor is rated at 60 hertz by national standards, but has the capacity go much lower and as high as 120. When you're looking at the max rating, it's not coming from an agency, but from the manufacturer who is letting the HVAC contractor exactly what the max output of the system is.

Think - size for heat first, cooling second, and don't get hung up on SEER. There's no ductwork