Mitsubishi heat pump mini split

[Badger]

I live in Florida and use a 3.5 ton heat pump that is close to its last months and will need to buy another one. I was told an option is a Mitsubishi heat pump mini split system that would have small wall mounted units in each room that could be controlled individually. Although my home is only 1800 sq ft I would need 2 separate units due a vaulted ceiling in half the house. Since I live near the ocean the biggest problem is with the outside unit rusting. Most any system only last from 10 to 12 years before the fins and other areas on the outside unit rusts to failure.
Does anyone have experience with the Mitsubishi heat pump mini split (or other brand) system? How does the cost and life span compare with the more common heat pumps?

Cheers!

 

[freedomatlast]

We installed four Fujitsu mini splits in parts of an old farmhouse where there was no ductwork a few years ago. They were great for A/C, not quite as good for heat when it got really cold. We weren't near the ocean so I can't comment as to how well they hold up in a salt air environment. However, from a component standpoint, they are both made from the same types of materials, so I would think the salt air would have a similar effect on both.

In your case, since you have existing ductwork, I'd probably stay with a conventional system rather than a mini split just to avoid having the unsightly inside units hanging from the walls, especially if it's a higher end home.

 

[ncbill]

Of the mini-splits Mitsubishi is purportedly one of the longer-lasting brands.

With an average service life of roughly a decade versus half that for lower-end competitors, but IDK if that also applies to a marine environment.

 

[Happyras]

Boy this is a tough call. Since you are not going with a DYI install, you are going to pay a lot for a mini split replacing the existing system. I suspect some up selling going on, but if it were my decision, I would strongly consider replacing the existing outdoor condenser and be done. If the air handler is over 20 years old, then that is an issue to consider. Typically you can do an ASHRAE match on the existing indoor coil and air handler and upgrade your outdoor to an 16 SEER unit. The HVAC cartel would have you believe its rocket science, but you should be able to buy a 3.5 ton Condenser of good quality for 3 to 4k, and replace your existing for about 4 hours of tech time. https://iwae.com/shop/heating-air-c...s/condensers/heat-pumps/?cooling_capacity=100

 

[Happyras]

BTW, I am a fan of mini-splits. I just installed another one 2 weeks ago, I think that's my 4th system. Before those I have installed 6 ducted systems/condensers/upgrades on my various properties. All pretty easy to DYI, but if you you have to hire some one, get bids. Most do not repair/replace, and rarely do they miss a chance to upsell. As for life of a mini in general, you can expect 10 to 12 years, whereas a ducted system the condenser is generally a more robust system and should last 20 years or more, except in marine climates......

 

[38Chevy454]

I agree that conversion from your current conventional ducted system will likely be more expense with the mini splits vs just staying with conventional since you already have it set up for that. Mini splits will require additional electrical wiring, mounting the outside compressor, running the lines up and through the wall, mounting inside fan unit, etc are all required.

As for mini split corrosion life near the ocean, my snowbird place is approx 4 miles from the saltwater. My mini splits are also Mitsubishi and are currently about 10 years old and have no bad corrosion on outside units. They work great when heat pump mode, but that is fraction of the time. Mostly are in A/C mode.

 

[pb4uski]

I agree that conversion from your current conventional ducted system will likely be more expense with the mini splits vs just staying with conventional since you already have it set up for that. Mini splits will require additional electrical wiring, mounting the outside compressor, running the lines up and through the wall, mounting inside fan unit, etc are all required.

As for mini split corrosion life near the ocean, my snowbird place is approx 4 miles from the saltwater. My mini splits are also Mitsubishi and are currently about 10 years old and have no bad corrosion on outside units. They work great when heat pump mode, but that is fraction of the time. Mostly are in A/C mode.

This is exactly what my trusted HVAC guy told me just this week. While my conventional 2006 HVAC is still working well we both sense it is a year-to-year decision to replace it.

I asked about a mini-split and he said I'm better just staying with a conventional HVAC system, especially since I'm in a second floor condo unit.

 

[Badger]

Since the mini split appears to have a longevity that is not much different than a conventional HVAC system AND I am 2 blocks from the ocean AND I need 2 systems where one will be on the east side of the house and the other on the west side AND the cost will be quite a bit more than a conventional HVAC system it seems that I should just continue with what I have been using. There will be a greater expense on the install for a mini split too it seems and I am not able to DIY.
I was hoping there would be a better longevity but if that isn't the case then no sense in paying more for something that will still need to be replaced in 10 to 12 years from corrosion.
Thanks for the info.

Cheers!

 

[Piper20]

Badger most manufacturers make costal heat pumps to resist the salt air.

 

[Happyras]

Badger most manufacturers make costal heat pumps to resist the salt air.

Problem with them, like Trane, they use an all aluminum condenser coil. The claim is the galvanized steel enclosure resists the air salinity. I am more worried about pin hole coil corrosion, and aluminum (while great conductivity) is not suitable for this environment. Now if they made a 2205 SS or 2101 LDL coil, that would be coastal and certainly beyond the normal residential budget. Cheaper to replace every ten years than upgrade specs.

Back to the OP post, in all these discussions there are always so many facts that need to be interpreted to make a real recommendation. Most can only comment on their experience and there is not that much history out there in the US on Mitsubishi mini splits in service. Internationally, certainly more data in all brands.

 

[Joylush]

I live in Florida and use a 3.5 ton heat pump that is close to its last months and will need to buy another one. I was told an option is a Mitsubishi heat pump mini split system that would have small wall mounted units in each room that could be controlled individually. Although my home is only 1800 sq ft I would need 2 separate units due a vaulted ceiling in half the house. Since I live near the ocean the biggest problem is with the outside unit rusting. Most any system only last from 10 to 12 years before the fins and other areas on the outside unit rusts to failure.
Does anyone have experience with the Mitsubishi heat pump mini split (or other brand) system? How does the cost and life span compare with the more common heat pumps?

Cheers!

This cracks me up. My AC contractor said the same thing 12 years ago when I had him start installing Mitsubishi mini spilt systems. He wasn’t sure how they hold up being a few miles from salt water. I had to mention to him they were developed by Mitsubishi (Japanese ) and have been used extensively for years in Japan which is an island surrounded by salt water so I figured we were safe. Mine are twelve years old now and I’ve never had a problem with any of them.

 

[JP.mpls]

FYI:. Mitsubishi now makes a ceiling mount unit, that basically looks like a large vent.
I just had one of these installed in my Minneapolis home.
I think they they are way less obnoxious looking.
JP