Mini-spits: LG, Daikin and Mitsubishi oh my...

[riojaonly]

I bought a foreclosure with 8' ceilings and a poured slab between 1st/2nd floor (so no trusses for duct work). House currently has four 2 ton traditional central air sys with horrific drop down soffits for the duct work (makes my 8' ceiling 7').

Plan is to do mini-splits on 1st floor so I can remove the soffits/duct work and keep the central air upstairs. But the question is which brand? Everyone seems to be manufacturing mini splits these days (Sanyo, Fujitsu, Friedrich, YMGI, LG, Daikin and Mitsubishi to list a few) but finding a contractor in South Florida who is really well versed on them is proving to be a challenge.

The kitchen and Master BR each have an adjacent sun room which make good locations for ceiling cassettes (also only place in the house where I have plenty space above ceiling). The kitchen and Master BR are on opposite end of the home split down the middle by a great room that allows no attic access to run lines. So may need two separate outdoor units, one for each end of home with 2 to 3 indoor units each.

So the question is, outside of trying to learn the difference between VRF and Flex Multi systems on this site, what should one focus on when determining brand other than the low hanging fruit of SEER and price?

[ChaseAir]

You may want to look on angies list to find a reputable contractor. They should do areal load calculation. I am putting a Sanyo three zone in my home this weekend because they had a 1.5 ton that could have three indoor units. I thinking sizing the unit properly is key to savings. This unit has a .85 shr sensible heat ratio, so 1.5 tons will be more than enoigh for my 1280 sq ft house in jax, fl.
stay away from lg. Mitsubishi, fujitsu, daikin, sanyo...find the right size with the right amount of indoor units. Wall hung are the most efficient. My unit will ramp down to 50% capacity during low load times.

[riojaonly]

Thanks ChaseAir!
Sanyo definately seems to have some of the most reasonable pricing.

Why stay clear of LG, Daikin and Mitsubishi? Pricing, performance, or both?

[stonewallred]

I sold 4 Comfortstar systems, and am having major issues getting the equipment, or the heads for them at least.
The OD units, line sets and internal condensate pumps are sitting at the supply house waiting for the heads to show up.
The supply house has none in stock except at a few branches on hold for customers, and the folks who have them won't get off of them.
It seems to be a manufacturer issue, which since I had to talk to their tech support folks when bidding on the job, doesn't surprise me.
I won't submit another bid using the equipment unless every piece of the system is in stock at the warehouse and under a hold.

[skippedover]

You may want to look on angies list to find a reputable contractor. They should do areal load calculation. I am putting a Sanyo three zone in my home this weekend because they had a 1.5 ton that could have three indoor units. I thinking sizing the unit properly is key to savings. This unit has a .85 shr sensible heat ratio, so 1.5 tons will be more than enoigh for my 1280 sq ft house in jax, fl.
stay away from lg. Mitsubishi, fujitsu, daikin, sanyo...find the right size with the right amount of indoor units. Wall hung are the most efficient. My unit will ramp down to 50% capacity during low load times.

Spoken by an ill informed amateur. Our company is a Mitsubishi Diamond dealer and we have tremendous success with the products. We've installed others over the years and some have been great, others not so great. 50% of capacity on a mini-split is really pitiful compared to a Mr. Slim. Their products turn down to less than 33% of full capacity and many have greater than rated capacity for exceptional days. If properly sized and installed, the systems work extremely well. I'd recommend the OP go to the website of the brands in which he's interested and use the dealer locator as an assistant.

[mchild]

I bought a foreclosure with 8' ceilings and a poured slab between 1st/2nd floor (so no trusses for duct work). House currently has four 2 ton traditional central air sys with horrific drop down soffits for the duct work (makes my 8' ceiling 7').

Plan is to do mini-splits on 1st floor so I can remove the soffits/duct work and keep the central air upstairs. But the question is which brand? Everyone seems to be manufacturing mini splits these days (Sanyo, Fujitsu, Friedrich, YMGI, LG, Daikin and Mitsubishi to list a few) but finding a contractor in South Florida who is really well versed on them is proving to be a challenge.

The kitchen and Master BR each have an adjacent sun room which make good locations for ceiling cassettes (also only place in the house where I have plenty space above ceiling). The kitchen and Master BR are on opposite end of the home split down the middle by a great room that allows no attic access to run lines. So may need two separate outdoor units, one for each end of home with 2 to 3 indoor units each.

So the question is, outside of trying to learn the difference between VRF and Flex Multi systems on this site, what should one focus on when determining brand other than the low hanging fruit of SEER and price?

A little confused about ChaseAir comments as he states he is installing a Sanyo system in his home but then says to stay away from Sanyo products.

You will have a well made system from any of the major Japanese manufacturers - Mitsu, Daikin, Sanyo (recent acquired by Panasonic) and Fujitsu. The Koreans and Chinese are still working on their quality to match the Japanese. But, as with any system, make sure you have a top notch contractor for the installation. Each of these manufacturers offer VRV/VRF (Variable Refrigerant Volume/Flow) systems that allow up to eight (8) indoor units to be connected to single outdoor unit. Each indoor unit will perform as a stand alone system with individual temp settings and such. Indoor units can be mixed and matched with ductless and ducted units. The only thing between indoor and outdoor units are the refrigerant lines and a two wire communications cable.

One of the benefits of these types of systems is they allow better for building diversification. That is, the difference in the load on the home under differing conditions. Such as the west side of the home needing much more cooling than the east side in during the summer in the late afternoon. Both sides of the home may need a maximum of 2 tons of cooling but not at the same time. Thus, the indoor units can be sized for the maximum load but the outdoor unit only has to be sized for the maximum load at any point in time during the day which will allow for a smaller and more efficient outdoor unit. Assuming you need a maximum 8 tons of cooling as you have now (and this is a big assumption that should be thoroughly understood with a detailed load calc including building diversification analysis), by factoring in building diversification you may be able to meet the load with 6 tons.

With VRV/VRF systems the indoor units combined capacity can exceed the outdoor unit capacity by 30% - 50% depending on manufacturer. Outdoor units can normally slow to about 25% of rated capacity.

Finally, it is difficult for ductless indoor units to comfortable condition more that one room. In some large rooms where you may want to ductless units you would be better served to have two units - one on each end of the room. Of course, ducted units can serve several rooms and would be my personal choice if at all possible.

[riojaonly]

Excellent stuff Mchild! Thank you.

Did not realize the indoor units of VRF could exced the capacity of the outdoor

In your opinion, are the VRF systems worth the extra $ over a flex/multi system to obtain the greater efficientcy?

[ChaseAir]

Sorry about my poor english, what I meant was stay away from lg. I base this on local dist testimony, poor warranty service. All the other jap products are no doubt great. I like mitsubishi. Wow someone is a diamond dealer, that means you like took a class or something, can I hang out with you at the expo?

Load calcs (extremely detailed) are totally necessary. Dont spend all that money and guess at the size. The Sanyo system had a .85 shr which made a big difference. I am pretty sure the unloading capability is different for each btu and model.

[SoFlaDave]

Its still such a new concept and sometimes people get sticker shock on the estimates. Lots of copper, wiring, and set up. We've only done one VRF system so far in a store front in Palm Beach using Sanyo Mini Eco's. 2 condensers 5 airhandlers internal pumps and one central control.

My only gripes with the system is that the controls were not very intuitive but the system set up and ran beautifully. I only went back for some drainage issues with the pumps.

I've worked on Mitsus, Samsung, Sanyo, and Comfort Stars. Had quite a few issues with Samsungs. Board failures seemed pretty common although some of the problems were due to FPL stepping up the voltage to 250V and general power fluctuations.

The Comfort Stars have been surprisingly reliable so far but I don't think they have any Multi zone equipment.

There is alot of training involved with these systems and most companies are a bit behind with getting with all these mfg's, mine included. But the operation is essentially the same between all of them.

[riojaonly]

I found some interesting comparisons of the different brands on the following thread:

http://hvac-talk.com/vbb/archive/ind.../t-172361.html

[mchild]

Excellent stuff Mchild! Thank you.

Did not realize the indoor units of VRF could exced the capacity of the outdoor

In your opinion, are the VRF systems worth the extra $ over a flex/multi system to obtain the greater efficientcy?

I don't know the price differences but I do know the VRV/VRF systems are the absolute top on the product lines for each manufacturer. You will have more leeway with the design and use of the system. Most multi-head systems (non VRV/VRF) have a lower limit on the number of indoor units, connection ratio is limited to 1 to 1 (i.e.: indoor unit capacity can not exceed outdoor unit capacity), and the selection of indoor units that can be used is more limited.

With VRV/VRF systems the total system capacity increases with a higher connection ratio (use the max if at all possible) and the operating efficient goes up too. With my 4 ton Daikin system my total cooling capacity is nearly 5 tons at my design conditions. And the system will operate when the load is as low as about 1 ton.

Over the last several days we have had relatively low temps, overcast and high humidity (around 80%). I maintain indoor temps of 76-77*. My Daikin system has run almost continuous as I have put each zone in dehumidify mode which has kept indoor humidity at about 40% with minimal overcooling as most zones are within a one degree of the set point.

[ampulman]

Will a kind soul please explain how the condensate is handled, that is, how is it transported from the wall units and disposed of?

As mchild stated: "The only thing between indoor and outdoor units are the refrigerant lines and a two wire communications cable." So, are there condensate lines (going up and out) from each indoor unit?

[mchild]

Will a kind soul please explain how the condensate is handled, that is, how is it transported from the wall units and disposed of?

As mchild stated: "The only thing between indoor and outdoor units are the refrigerant lines and a two wire communications cable." So, are there condensate lines (going up and out) from each indoor unit?

Most if not all indoor units have built in condensate pumps. Condensate lines from each indoor unit will exit the building however is best for any particular unit. Some wall mount unit ductless units the condensate line will exit directly behind the unit through the exterior wall. For the recessed ceiling ductless type which are normally placed near the center of a room, assuming the room has an outside wall then the line would to that wall and out.

I have ducted units and don't use the condensate pumps as condensate lines are available from previous cooling equipment and gravity works just fine.

[Workahallick]

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[jpsmith1cm]

Workahallick

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