Mini split choice

[ericm]

I got a quote for two 24k mini splits for my 2260 sq ft shop in Oregon. They quoted two different units and I'm trying to decide which to go with.

Daikin 22.0 SEER2, 12.0 EER2, 10.0 HSPF2 R-454B
RXM24WVJU9 and FTXM24WVJU9

For $600 more:
Mitsubishi 23.5 SEER2, 13.35 EER2, 10.5 HSPF2 R-454B
MUZ-FX24NLHZ and MSZ-FX24NL

The units in the house there are Daikin.

My load calc shows that heating is significantly more important than cooling. I'll only need < 20k btus to cool at the 98% design temp but will need 44k to heat. In comparing the units I see that the Mitsubishi heating capacity is 19800 btus while the Daikin "heat pump BTUs" is 24000. HSPF is not that much different between the two units. I'm kind of doubting those heating numbers since the info for Daikin also said its output can vary from 9k to 32k, and I would expect the Mitsubishi to also have a range of output. Both units are rated to make full heat at 5 degrees which is sufficient for this area. But if the Daikin heats more I'd go with it to have more of a reserve when I open a garage door.

 

[pcmeiners]

You are correct in concentrating on HSPF numbers. Get the highest HSPF that you can afford.

FTXM24WVJU9
Noise level is pretty high
Energy star qualified=no ?

Now I would rate the linked AHRI cert below as totally useless, no specific data, not that I trust AHRI that much, AHRI is the JD Power and associates of the HVAC industry.

https://documents.alpinehomeair.com/product/daikinahricertificate212494260rxm24wvju9-ftxm24wvju9_A1958A27-E934-47DD-AC1E-F0004711BB5E.pdf

If you get an energy star rated split you get 30% back from the feds, more if you utilities have a rebate.

 

[pembol]

Unfortunately that Daiken combo isn't on the NEEP cold climate heat pump list just yet. What it your 'typical' low temperature? At 5F the Daiken will put out 24000 BTU/h at a COP of 1.8 whereas the Mitsubishi will be 26,600 at a COP of 2.1 so the Mitsu low temp performance is a little bit better.

If you get this done by September 30, December 31 you may be able to get a 30% tax credit on the Mitsu as it is Energy Star cold climate rated which would make it much cheaper. It looks like the Daiken also meets the specs, but may not have the certificate yet, so it is less of a sure thing to get the credit.

 

[pcmeiners]

What does Sept 30 have to do with the tax breaks ?, the tax break ends Dec 31 2025

 

[pembol]

What does Sept 30 have to do with the tax breaks ?, the tax break ends Dec 31 2025

You are right - EV related tax credits end 9/30, heat pump credits are the end of the year.

 

[ericm]

Unfortunately that Daiken combo isn't on the NEEP cold climate heat pump list just yet. What it your 'typical' low temperature?

Lowest temp this last winter was 15. Record low is -3. Average low in January is 32.

At 5F the Daiken will put out 24000 BTU/h at a COP of 1.8 whereas the Mitsubishi will be 26,600 at a COP of 2.1 so the Mitsu low temp performance is a little bit better.

Sounds good! Where did you find this? I must not be looking in the right places.

If you get this done by September 30, you may be able to get a 30% tax credit on the Mitsu as it is Energy Star cold climate rated which would make it much cheaper. It looks like the Daiken also meets the specs, but may not have the certificate yet, so it is less of a sure thing to get the credit.

Unfortunately it looks like the EEHIC tax credit is for installs into existing homes, not new builds like this one. Maybe there's other tax credits but that's all that I find. The solar and batteries credit does apply to new construction.

 

[pembol]

Lowest temp this last winter was 15. Record low is -3. Average low in January is 32.



Sounds good! Where did you find this? I must not be looking in the right places.



Unfortunately it looks like the EEHIC tax credit is for installs into existing homes, not new builds like this one. Maybe there's other tax credits but that's all that I find. The solar and batteries credit does apply to new construction.

Given your milder winters, the 17F numbers may be your best point of comparison - for the Mitsu the max output is 29.2 kBTU/h with a COP between 2.25 and 3.

ASHP

ashp.neep.org

For the Daiken at 17F the output is 26.1 kBTU/h with a COP between 2 and 2.7 (this spec may be a slightly different model though)

ASHP

ashp.neep.org

It looks like the Mitsu is still the winner on performance - as it produces more heat, it will also be able to run at a lower speed to maintain temperature which typically means it is running higher in the COP range.

The tax credit is a tricky one - we just built a new home (completed in 2024), but then we had a detached garage/shop built (completed in early 2025). I have purchased and will soon install an Energy Star cold climate heat pump for the shop, which my understanding is eligible for the tax credit as per the IRS you are eligible if the project is for "An existing home that you improve or add onto, not a new home". Depending on how your construction is phased you may or may not be eligible for the credit. In my case it is only about $600, so not a huge factor either way.

 

[ericm]

Wow thanks for the detailed response and the links. Yea the Mitsubishi looks like it's the winner.

Reading your post I realized that technically the house is a remodel as we kept the basement. So we might qualify for the rebate on the house mini splits and maybe the shop too.

 

[Torque&Recoil]

I have LG units, so no personal experience with either Daikin or Mitsubishi. However... I have a good friend who has bought and installed, 3 USED Mitsubishi's. No problems whatsoever after several years of second-hand usage (no idea how many years the original user ran these things for). It seems like Mitsubishi is a pretty high quality unit. I probably should have bought Mitsubishi, but I got the LG's at a good price. Hope I don't regret that decision down the road... I'd go Mitsubishi.

 

[bluedog225]

I didn’t realize the tax credit expired (permanently) this year under the new law. Have to hustle.

 

[pcmeiners]

"For the energy efficiency home improvement credit, the home must be:

• Located in the United States
• An existing home that you improve or add onto, not a new home

Seems a new home is designated as a new build before the actual purchase, as noted further down in this post.


So you can take the credit for a new add on garage, even if the garage is not totally finished you can take the credit. With a garage, if you get the energy complaint doors and windows wiring for the minisplit you can take for the credit credit up to the limit.
Shame the government does not allow carry over to the next year's taxes.

This is an AI answer to adding a minisplit to a newly purchased home which sound correct, but needs to be checked....................

"In most cases, individual homeowners are not eligible for the tax credit for newly constructed, energy-efficient home. However, homebuyers can still claim tax credits for qualifying improvements they make to a new or existing home after the purchase."

The critical point to this is the minisplit must be installed after the home purchase, if installed before the purchase the contractor gets the benefit of a tax break.


Oregon utility rebate.......

https://www.oregon.gov/energy/Incentives/Pages/home-energy-rebates.aspx

Nice utility rebate !

Lastly if you can afford a Mitsubishi minisplit go for it, not only are a better unit they are well supported. You might look into Fujitsu minisplits also a top end unit.

 

[Mikes61]

I’m about to buy a 24,000 BTU mini split for my new garage. I’ve talked to numerous people about which one to pick. Two of my frineds are HVAC guys and they both said get the Mitsubishi.

Also, we have two mini splits in the building that I work in. They have been running non stop for the past 15 years that I have worked there.

I’ll be getting a Mitsubishi, now just have to decide which model.