PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

aglicknmexaglicknmex Solar Expert Posts: 40 ✭✭✭
Hi folks,

I would just like to get out the word on how well some of the new products for heating/ cooling/ water heating, are working!!

I have been running 2 inverter style, variable speed, Mini split heat pumps all summer from 6500 w of PV One is 15K btu and one in bedroom a 9K btu. Thats all little over 1.5 tons cooling. It cools the entire 1700 foot house. With the record rain here in SW NMex and all the clouds and humidity, most folks are suffering from damp houses. I cant say enough good about these Mini Splits. Several brands are available, but all are fantastic for anyone producing power from PV. Folks who come to my house, see the units, and want to have one!!
I am a small time mister fixit type guy out in the boonies of SW new Mexico, near the town of Glenwood(300 people) I have installed 7 of these Mini splits, in the last 6 weeks and I am a lousy salesman!!
I just want to get the word out to the solar community, that you can live in comfort winter and summer, using PV to power a Mini Split heat pump.

That said, a new product for heating Water is just coming on the market. Same concept, just heats water instead of air. Fujitsu is the only one I know of right now, but the other vendors will soon have them available, Im sure. I have not gotten info on price/ availability, but the concept is fantastic. I would much rather use it to heat water than the 13 water heating solar panels that I now must maintain. They spring leaks, pumps fail, air lock etc.

Im not trying to sell anything, but just want people to know how efficient these Minit splits are. My 15K unit draws about 400w set on a medium fan speed. It doesnt stress the inverter at all. I would be glad to share my experience with anyone who is interested.

Al from New Mexico

Comments

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    some of us in the northern areas will have some difficulty in ever coming close to heating our homes exclusively with minisplits, let alone having enough solar to keep them going. southern states will certainly fair well in most cases.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    My mini-split does great cooling when the sun is shining with just 1000 watts PV, and the PV still has to run two freezers and a fridge. I also use it for heat in the Spring when the sun is high overhead and no longer shining heat in my south facing windows like it does all Winter. The mini-split gets a lot of use cooling on warm Fall days when the sun does hit the windows. I've had to play with the thermostat so as to have it run on half or less power draw, but once I get the new 900 watts PV installation completed, I expect to be able to go full power. I don't run it off battery power alone very much because the batteries have enough to take care of already.
  • aglicknmexaglicknmex Solar Expert Posts: 40 ✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    Hi Niel,
    The cold north is tough any way you approach it. takes alot of btu,s

    Did you read the part about the new inverter style air to water heat minisplit? It would sure beat frozen pipes etc, and pv works decently in overcast conditions. My solar thermal panels dont do much with any clouds. Fujitsu has the new air to water coming out soon. Its called "WATERSTAGE"
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    another option in its delivery is nice, but heat is heat. if the air gets heated then pipes there get heated too and don't freeze. most of us in the north know the pipes should be located strategically so as to avoid the pipes freezing. outer walls or unheated crawl spaces are most likely going to bust your pipes in very cold weather.
    but then i would assume you know that already being from ohio previously.
  • stephendvstephendv Solar Expert Posts: 1,571 ✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    Very happy with our daikin mini-split for cooling and the occasional heating. But on the topic of hot water heating, just did a quick search for air source hot water heat pump, and bumped into this product: http://www.plumbnation.co.uk/site/stiebel-eltron-wwk-300-a-domestic-hot-water-heat-pump/

    At that price, wouldn't it be better to invest in more PV and a cheapo immersion heater instead?
  • peakbaggerpeakbagger Solar Expert Posts: 341 ✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    A local utility in Bangor Maine (definitely not a summer climate) is paying incentives for mini splits for heating in their region. The new Fujitsu's and Mitsubishi units put our heat to below zero (albeit the efficiency is low), they don't represent them as a primary heat source but folks who use them have cut way back on their oil or wood usage. In reality a lot of the savings are related to the fact that Maine is predominantly oil heat and many houses have one heating zone. By putting in a mini split the majority of the house can be kept cool with the living area supplied heat from the mini split.

    I am waiting for an estimate for installation for one on my house in Northern NH. Installation on the units is somewhat backwards for a predominant winter use, the outdoor unit is intentionally placed on the southerly exposure of the house preferably where it catches the morning sun. Obviously this impacts summer efficiency unless shading with deciduous trees is used but given the split between heating and cooling in Northern New England its good tradeoff. Our area also has high summer humidity so the AC is used as much for dehumidification as for cooling.
  • aglicknmexaglicknmex Solar Expert Posts: 40 ✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    Having multiple cooling and heating zones without ductwork, in my spread out ranch house, is a big plus. Here in New Mexico at 5000 ft, we use both heating and cooling, but we do try to keep the units out of summer sun since it is very intense!! PV works incredibly well here.
    check out the air to water unit from Fugitsu: http://www.fujitsu-general.com/global/products/atw/
  • aglicknmexaglicknmex Solar Expert Posts: 40 ✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    Immersion as in electric water heater?? It sure would work, but inverter load would really jump up unless you used low wattage element. Heat pump load is 1/4 to 1/2 draw of resistance heating. I suppose it depends on the system and amount of sun. In my case I would need to add another inverter if I used resistance heating. Could run a heat pump though----Always interested in what others have done.
  • BB.BB. Super Moderators, Administrators Posts: 31,784 admin
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    What "aglicknmex" says... As I recall, the GE Geosprings is around 500 watts on heat pump mode and would be the equivalent of ~1,000-1,500 watts of heat going into the tank (depending on efficiencies and ambient temperatures--warmer rooms, more efficient for heat pump).

    A typical AC water heater is ~4,500 Watts or more (in US). Of course, a 1,000-1,500 watts heat pump output is still going to take a lot longer to heat 30-50 gallons of water vs a 4,500 watt element. If you have teenagers that like to drain water heaters--The following family members are going to have to wait or take cold showers (got one of those--and even with a "California Special" natural gas water heater, we have to way 40 minutes for the next shower).

    -Bill

    PS: California Special--"They" have reduced burner BTU size to gain a bit in efficiency and run the combustion temperatures cooler to reduce Oxides of Nitrogen (air pollution).

    Around 36,000 BTU with catalytic burner vs >40-50,000+ BTU water heaters from 40 years ago.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Ralph DayRalph Day Solar Expert Posts: 947 ✭✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    I'm with Wayne. I can start the Mitsubishi unit for cooling, set the fan speed to low, the temp to what I want (probably 2C higher than the room temp at turn-on) and the pv will run it, the house loads and still do a full charge cycle...eventually (if it's sunny). Getting ahead of the curve with an early start is the key. Wait until you "need" the cooling and your into much more of a power demand.

    Ralph
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER
    Ralph Day wrote: »
    I'm with Wayne. I can start the Mitsubishi unit for cooling, set the fan speed to low, the temp to what I want (probably 2C higher than the room temp at turn-on) and the pv will run it, the house loads and still do a full charge cycle...eventually (if it's sunny). Getting ahead of the curve with an early start is the key. Wait until you "need" the cooling and your into much more of a power demand.

    Ralph

    Exactly! Get ahead of the curve and let it run on low all day and the PV has no trouble at all as long as there's sun. It's awesome! Love it!
  • Gila DaveGila Dave Registered Users Posts: 1
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER
    aglicknmex wrote: »
    Hi folks,
    ...
    Folks who come to my house, see the units, and want to have one!!
    I am a small time mister fixit type guy out in the boonies of SW new Mexico, near the town of Glenwood(300 people) I have installed 7 of these Mini splits, in the last 6 weeks and I am a lousy salesman!!

    Al from New Mexico

    I have one of the Fujitsu mini-splits installed by Big Al. I've only had it for a year and a half, and LOVE it for summer use. The quiet, both indoors and out, is such an improvement from my old window A/C. Grade: A+
    However, winter is another matter. I live down in the valley bottom, where the cold air settles. [Most mornings Nov - mid-Apr are below freezing, with some in single digits.] This cold time is when I need heat most, but the little mini-split just can't get the job done. Grade: C-

    Well, heck, it's only rated at 12kBTU. With a desired indoor of 70 and an outdoor of 15, it needs to maintain a delta-T of 55 degrees. In Summer, with a desired indoor of 75 and outdoors 95, it needs only maintain a 20 degree difference.
    I have a perfectly good little wood burning stove that keeps me warm in winter. Don't take me wrong - the unit DOES work when it's teens outdoors, but I'd rather throw another few sticks into the woodburner than depend on the feeble heating of the mini-spit.
    Early fall and late spring, to take the chill off, fine, but the next 4 months, nope.
    - Gila Dave
  • solar_davesolar_dave Solar Expert Posts: 2,381 ✭✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    I have a 3 head wall units with a single outdoor compressor in my office/shop building. They easily keep up in summer months with the cooling load on this well insulated structure, even when outside is 115F and interior are 78F, no issues and power consumption is much less than the main house 3 ton Trane units. In winter the few times I wanted heat they work great, but then again the lows here rarely go below freezing.
  • H2SO4_guyH2SO4_guy Solar Expert Posts: 213 ✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    I have a Mitsubishi mini split that is wonderful......except that it Never shuts off. I suppose that is what a heat pump is supposed to do, but it does have a timer on it. Now I am in a 175 sq ft living quarters with R21 in the walls and R30 in the floor and ceiling. 9000 BTU works great for me so far. I have even started heating only with the heat pump. I'll run it for 20-30 minutes and it will last one to many hours. It runs on my $1300 used battery pack just fine. (99 KWH) In the summer when the outside temp was 96 outside, I got the inside living quarters to 62 degrees. Why not, there was extra power?

    I still have panels to put up, but have about 9k making power. Now to get the Whiz Bang Jr's installed and configured to do something 'Extra'.....
    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
  • halfcrazyhalfcrazy Solar Expert Posts: 720 ✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    My mom has 2 of the Fujitsu units on her old farmhouse here in Maine. I am logging one with the Ted5000 and I got to say I will have one here before next winter. It is plain amazing at how cheap she can heat her old farmhouse with Electricity....
  • LucManLucMan Solar Expert Posts: 223 ✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER
    halfcrazy wrote: »
    My mom has 2 of the Fujitsu units on her old farmhouse here in Maine. I am logging one with the Ted5000 and I got to say I will have one here before next winter. It is plain amazing at how cheap she can heat her old farmhouse with Electricity....

    There's dec. & jan. coming up, electric consumption will be going way up and comfort will be going down as the units won't be able to keep up because of the low outdoor temps.
  • halfcrazyhalfcrazy Solar Expert Posts: 720 ✭✭✭
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    Yes she is aware that when the temp drops to say -10F the mini splits will not contribute. She has baseboard hot water in the dwelling to. It is fun to watch the Mini Splits on the Ted5000 though. It is actually pretty impressive for an old uninsulated farmhouse how little it costs to run them
  • Tonyc@alpinemech[email protected] Registered Users Posts: 1
    Re: PV powered MINI SPLIT HEAT PUMPS FOR AIR AND WATER

    Hi There......Tony from Phoenix and i just wanted to give you an FYI to let you know that Daikin has an air to water heat pump system on the market. They are very pricey though. Very big in Europe, Its called the Altherma model of Daikin equipment and can also be used to cool water to act as a mini chiller if you will.

    Thanks

    T
    Alpine Mechanical & Service Inc
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