Mitsubishi mini-split 26 SEER

techntrek

I've been doing a lot of research on mini-splits since learning about them on the Sanyo mini-split thread. I found the Mitsubishi product line last night and wanted to pass on info on their highest-SEER model, rated at 26 SEER. 2800 to 9000 btu cooling, 3000 to 18,000 btu heating, guaranteed 70F output @ -13˚ F, 100% output @ 5˚ F. The page below shows a wattage range of 160-650 cooling and 150-2250 heating.

For comparison the Sanyo numbers: 16-20 SEER, 3000-9000 btu cooling, 3000-12,200 btu heating, 0 F minimum outside temp, 250-755 watts cooling, 250-995 heating.

They appear to have the same operating modes, fan speeds and most of the same programming options. One downside - unlike the 2 smallest Sanyo models which operate from 120V AC, all Mitsubishis require 208-240, which may be a problem for off-gridders. As expected, the Mitsubishi costs more by approximately $400.

Model MSZ-FE09NA
http://catalog.mitsubishipro.com/item/mr-slim-m-series-heat-pumps/msz-wall-mounted-inverter-heat-pumps/item-1386

JESSICA

Re: Mitsubishi mini-split 26 SEER

Fujitsu also has a similar unit (26 SEER), but sadly, it is a 240 volts model too.

techntrek

Re: Mitsubishi mini-split 26 SEER

I'll have to check it out, I'm definitely getting one for a room in my house where 240 won't be a problem. I may have to stick with the Sanyo for my travel trailer project (described on another thread). A shame since 90 fewer watts would mean fewer batteries to take along.

JESSICA

Re: Mitsubishi mini-split 26 SEER

http://www.fujitsugeneral.com/wallmounted9-12RLS.htm

techntrek

Re: Mitsubishi mini-split 26 SEER

I walked into Home Depot and to my surprise, a Mitsubishi mini-split was up on a wall near a regular air-sourced A/C. Maybe they will finally go mainstream in the next few years.

Ralph Day

Re: Mitsubishi mini-split 26 SEER

I went with the Mitsubishi. With only a xantrex 4048 I had to use a spare t-240 autotransformer to get the 120v house supply up to 240. No problems at all. When I want the heatpump on I turn on the breaker on the t-240. I am amazed at how little power it consumes when operating in a/c mode. It uses much more when heating, but then the temperature differential between outside and inside air is far greater when you're heating than cooling. (heating...20C inside, -5C outside. Cooling...25C inside, 30C outside)

Ralph

H2SO4_guy

Re: Mitsubishi mini-split 26 SEER

I went with a Mitsubisi Mr. Slim 9000 BTU 26 SEER heat pump. I can run it on cooling from an Exeltech XP-1100 or an Outback VFX-3600 as long as they go through an Outback PSX-240 transformer to get to 240 VAC. I do usually run it through the Outback just so I don't have to run the Exeltech's at full tilt. On heating it draws about 1230 watts vs 930 or so in AC mode. Two things I don't like are it Never shuts off so I usually use the timer. I also wish the remote was backlit so you didn't have to get a flashlight or turn a light on. Other than that, it is awesome. When I build upstairs, I intend to have 2 more of them so I can zone control tempature. I would buy it again, but there are often newer units that offer different advantages.

peakbagger

Re: Mitsubishi mini-split 26 SEER

I just installed a 12000 watt high efficiency mini split. I have excess generation on my on grid system so it is going to be used in place of wood for shoulder seasons and when I am not home. Both Me and NH utilities have or had rebates and compared to oil they are lower cost. Arguably if you look at the initial cost to install a on grid PV array and mini split, the mini split is cheaper than a supplemental pellet heater. The down side is the output drops as the unit gets closer to -15 degrees F. My unit does run a blower at very low speed all the time but it doesn't seem to draw much. It has a power outage reset so a timer may be the better option for those off grid.

One caveat is that the units are intended to be run for long periods, they put out warm air. not hot.

I installed a dedicated KWhr meter on mine for monitoring purposes. I plan to do take some data from it under controlled conditions but for now it seems to be a low cost way to run

Blackcherry04

Re: Mitsubishi mini-split 26 SEER

Keep some long johns handy at -15 deg F.




Attachment not found.

http://www.nrel.gov/docs/fy11osti/52175.pdf

BilljustBill

Re: Mitsubishi mini-split 26 SEER

I suggest you talk to the Pros in your area about which A/C brands do what they say and have a good record for few problems. Mitsubishi has some of the best DLP television pictures on the market, but their "after the sale" side is very, very poor. It is so bad that their consumer complaint division's website has a terrible maze of steps just to address warranty issues, taking MONTHS to reach a repair or adjustment compensations.

Apples to Oranges in comparing products, but they come from the same company tree.... Plus, unless parts and assembly are done here in the States, Japan's future, in view of FOUR Fukushima damaged and dangerous nuclear reactors spewing into the air and ocean, is declining....

A good sampling of the local commercial repair guys can tell you what they face daily, how long to get repair parts, time required to get the old part out and the new one in, and which brand they would buy for themselves.

techntrek

An update on specs I found today on the Mitsubishi line.  The MUZ-FH09NA outdoor unit with the MSZ-FH09NA indoor unit is rated 30.5 SEER and 13.5 HSPF.  Output for heating:

100% heating capacity at 5° F outdoor ambient82% heating capacity at -4° F outdoor ambient62% heating capacity at -13° F outdoor ambient

Dave Angelini

I just installed a Fujitsu for a friend.
http://www.fujitsugeneral.com/wallmountedRLS3_specs.htm

Blackcherry04

A lot of word smithing going on in their specifications, 100% capacity at 5°f. Is that what they said or really did they say the Maximum Capacity is 100% ?? Their specifications say the maximum capacity is 10,900 btu. It just doesn't say where it comes from, the compressor and or the heat strip or both.

http://www.mitsubishipro.com/media/946493/fh_product_guide.pdf

Dave Angelini

The Fujitsu all comes from the compressor, no heat strip. They have a model that is rated for lower temps but I really was not interested in that anyway. I doubt anyone is using heat strips for heating is these price ranges Blackcherry04. The HSPF on both the Mitsu and Fuji are close to 15. Pretty amazing actually.

techntrek

Looking at the specs in that link, I agree it is hard figuring out what they mean.  Different sets of numbers at 47 F, 17 F and 5 F.

Dave Angelini

The heat strip is probably the warming coil for the compressor and not for heating the house. Just guessing. You will get less heat out indoors as the temperature outdoor declines.

Blackcherry04

I looked at another .pdf where they showed the watt load it was like double at 5 deg, that what makes me wonder if they are including some axillary heat.

Here is some verbiage from their literature.
 

Ductless Heat Pump How it Works

In the cooling mode, a ductless heat pump operates in essentially the same way as an air conditioner. The inclusion of a reversing valve allows the refrigerant to flow in either direction, which provides both heating and cooling from a single ductless system.

When considering the installation of a ductless heat pump, it is important to understand the relationship between heating efficiency and the outdoor ambient temperature. In general, a heat pump operates most effectively in mild climates that rarely reach the freezing point. An electric heat strip can be installed to provide supplemental heat when necessary.

http://mitsubishiacdealers.com/info/how-does-ductless-work

Dave Angelini

Best not to get to electric heat at that stage of outdoor temperature, use something else, or move. 

LucMan

Blackcherry04 said:

I looked at another .pdf where they showed the watt load it was like double at 5 deg, that what makes me wonder if they are including some axillary heat.

Here is some verbiage from their literature.
 

Ductless Heat Pump How it Works

In the cooling mode, a ductless heat pump operates in essentially the same way as an air conditioner. The inclusion of a reversing valve allows the refrigerant to flow in either direction, which provides both heating and cooling from a single ductless system.

When considering the installation of a ductless heat pump, it is important to understand the relationship between heating efficiency and the outdoor ambient temperature. In general, a heat pump operates most effectively in mild climates that rarely reach the freezing point. An electric heat strip can be installed to provide supplemental heat when necessary.

http://mitsubishiacdealers.com/info/how-does-ductless-work

Mini split HP use inverter compressors,  which means that they are capable of running at variable rpm to meet the current load.
More RPM=higher power consumption. At 5 degrees the compressor will be running at it's max speed to output the rated BTU.
These units with todays technology are capable of running in lower temps than 5 degrees they just can't get keep up with the heatloss of the room that's why you need an auxillary heat source if you live in a cold climate. Even at 5 degrees the COP is around 2, electric strip heat has a COP of 1. The other issue at cold temps is that the out door condenser needs to go into a defrost cycle (cooling mode) to melt the ice off of the coil to allow sufficient airflow through the coils. The colder it is outside the more the unit defrosts, when it defrosts it is in cooling mode, which means no warm air is being thrown indoors.
None of the current residential mini splits have installed electric supplemental strip heaters. The compressor has a crankcase heater used to keep liquid refrigerant from accumulating in the oil. Some of the newer units have a pan heater installed in the drain pan under the condenser coil to keep ice from accumulating during the defrost cycle. These 2 heaters are electric resistance heaters and consume approximately 300 watts.

inetdog

LucMan said:

 The compressor has a crankcase heater used to keep liquid refrigerant from accumulating in the oil. Some of the newer units have a pan heater installed in the drain pan under the condenser coil to keep ice from accumulating during the defrost cycle. These 2 heaters are electric resistance heaters and consume approximately 300 watts.

I hope that these are thermostat controlled so that they only turn on for cold weather.

LucMan

I just checked the schematic on the new Fujitsu 15RLS3H low temp model (-15 F rated), the pan heater is rated at 150 watts with a temp limiting thermostat (130 F) and it looks like they no longer use a crankcase heater. The power for the heater comes from the logic board, so it may be possible that it only operates during the defrost cycle. I'll have to wait untill I attend the next training class to find out for sure. The mini split models from all the manufacturers change yearly so it's hard to keep up with all the changes. 

LucMan

Pan heater is energized continuously below 36F.

Dave Angelini

LucMan said:

Pan heater is energized continuously below 36F.

Any chance of checking if the models for warm climates like below use the heater. I have not been able to get heating info for cold weather as we have not been below 32F yet. When we are close it has been poor solar weather for electric heating.

Still even offgrid, if you have the ability to heat in winter this way, then you have a large enough system not to worry about 150 watts. I know the LG's do not use one but they are not rated for really cold weather.
http://www.fujitsugeneral.com/wallmountedRLS3_specs.htm

LucMan

I checked the schematic on the 15RLS3, no crankcase heater or drainpan heater shown. They must have elimated the the crankcase heater on the more recent models, most likely they are not needed because the refrigerant system pumps down before deenergizing the compressor.

techntrek

Interesting.  Another energy saver.  I was just talking to someone about turning off an A/C (not heat pump) main breaker over the winter to save some bucks.

LucMan

techntrek said:

Interesting.  Another energy saver.  I was just talking to someone about turning off an A/C (not heat pump) main breaker over the winter to save some bucks.

If the condenser has a scroll compressor most likely it has no crankcase heater, so no standby energy use. 

Dave Angelini

very nice! Thx.  

techntrek

Test.  Posted two items on this thread that haven't appeared after pressing Post Comment.

techntrek

If anyone stumbles on this thread in the future, make sure to read the study posted on this thread:

http://forum.solar-electric.com/discussion/350124/mini-split-cold-weather-efficiency-study-by-carb

techntrek

<removing triple post>

Dave Angelini

The link requires you to join to see it. The last time I did that I got a virus.
Anyone not getting the idea that a mini-split is not going to heat well as the temperature declines deeply or cool well when it is 130F really should have a secondary source of conditioning a room like many offgrid folks do.