AC_Hacker installs a new Mini-Split

[AC_Hacker]

I installed my original mini-split in around 2009, before I started my Homemade Heat Pump Manifesto project. The heat pump I installed then was a Sanyo KS0971 (+ C0971
+ CL0971). It had what I considered to be a respectable SEER rating. I didn't know as much about these matters at the time, so it seemed like a reasonable choice. Over the years, it has been an extremely reliable performer, kept me comfortable, and saved me a lot of money, compared to the more conventional heating & cooling systems. However, last winter, it went into serious decline nd failure. I have decided to replace it.

I have learned quite a bit about these matters in the intervening years. One thing I learned is that the salesmen & saleswomen don't know as much as they should to properly advise a customer. Of greatest importance to me was that They only mentioned SEER ratings to denote quality. None ever mentioned the rating HSPF (Heating Seasonal Performance Factor). SEER ratings are of greatest concern when the cooling performance of the mini-split ids of greatest importance. Likewise, HSPF ratings are of the greatest importance when heating is the primary concern. I have learned that SEER ratings and HSPF ratings are not necessarily related, and that a higher SEER does not necessarily indicate a higher HSPF, and vice versa.

So, this time, I did not shop for the best price, but for the highest HSPF, because my concern is for heating performance, and now also with a keen eye on the burden I place on the environment

The model I ended up choosing is a Fujitsu Halcion Model AOURLS3, rated at 3/4 Ton ((9,000 BTU). It was the very best I could find. My house is small and very well insulated, and this size works just fine.

As a comparison, my old Sanyo had the following specs:
SEER = 16
HSPF = 7.7

The new Fujitsu has the following specs:
SEER = 33
HSPF = 14.2

With regard to the HSPF ratings, they can be expressed as COP (Coefficient of Performance) by dividing the HSPF number by 3.12

So the old Sanyo had a COP of 7.7 / 3.12 = 2.47 (pretty good)

the Fujitsu has a COP of 14.2 / 3.12 = 4.55 (jaw dropping performance!)

The amazing performance does NOT mean that I will get more heating or more cooling, but it does mean that the power this Fujitsu uses will be much smaller. I'm less impressed by the lowered cost of energy it consumes, as I am by its greatly reduced load on environmental resources, and a lessened impact on the climate crisis.

It is also interesting is that the Sanyo cost $1300 ten years ago, and the Fujitsu cost $1600 today.

Quite a bargain, I think.

[pinballlooking]

Nice specs. That should serve you well.
That is a Great COP number.

[Daox]

Very interesting performance and price comparison. I wonder what things will be like in another 10 years.

[MN Renovator]

I've been looking at installing this model on my house but instead going with the 12k BTUhr unit to better cover a majority of the cooling needs instead of replacing my slightly oversized 2 ton(a 1.5 ton would be perfect for my house) central air unit. If I put it in my bedroom and aim it down the hall, it would cover the upstairs for a majority of the days and I'd still use the central air here and there to spread the cold air through the rest of the house and cover design days, likely 2 hour runtime at most on hottest days.

In the winter, I plan to shut the bedroom door, keep the rest of the house cooler and use the mini-split to specifically heat the bedroom to a comfortable temperature while I'm on the computer, watching tv or sleeping. Normally during the workweek I'm usually in the bedroom most of the time anyway and during the weekend I'm often not home for a good chunk of the time and spend more of the time in the bedroom anyway. It seems this unit is one of the best for this type of use. I've also looked into the comparable Mitsubishi and Panasonic units as they have progressed in HSPF, SEER, and 17f heating performance numbers, it seems they swap around with who performs the best. I think that Daikin, Mitsubishi, and Fujitsu share the role in the most reliable equipment and are all great choices, but I'm looking to buy based on performance and Fujitsu is there right now.

Can't wait to hear about how it performs on the coldest nights of winter for your home.

[pinballlooking]

I don’t have one of those brands but I do have inverter tech in my bedrooms. They can be over sized and work very well in the bedrooms. In three bedrooms here two of them are over sized 9K units but the inverter units still works very well.

That COP is getting real close to GEO.



Mine is Tranquility 30 Q-Digital Series

[AC_Hacker]

Originally Posted by pinballlooking

....They can be over sized and work very well in the bedrooms. In three bedrooms here two of them are over sized 9K units but the inverter units still works very well.

Yes, they will work well. But if the situation is such that if you can plan for it, slightly undersizing will be more power efficient.

That COP is getting real close to GEO.

That is why it is so jaw-dropping. In this area, the COP exceeds previous GSHP units. The HSPF is based on a yearly average. And it's obvious that when outside temps go down, COP will also drop, the more "lifting" the unit has to do, the lower the COP.

I think that if the same attention was given to GSHPs as has been given to ASHPs, there would be big improvements there too. The physics of extracting heat from deep ground contact is absolutely better than extracting heat from ambient air. It's a matter of refinements, in my opinion

I'm fortunate to live in an area with fairly mild (low 40s to mid 30s), usually even winters. Which favors ASHPs. However, occasional dips, when an Alaskan cold front drops temps to low teens, for a few days, then the ASHPs are working hard.

-AC.

[Fionn]

Any updates on the installation or performance?