I have been reading and researching for about 18 months. I need to replace a forced air oil furnace that heats my 850 sqft home. The technologie appears to have matured to the point where I am prepared to buy in. Problem locally is there is only one Mitsubishi dealer and no running units with clients to talk to.. although he talks a good game and has a unit heating his shop the installation appears designed to ensure it can't fail. It is insulated and sealed to near passive house specs, has very few Windows and being his proof of concept building is built waaay beyond my homes standards even with my planned improvements. So that said what I need to se a minisplit that has been running over our winter in a typical -not super- insulated home in southern Manitoba or northwest Ontario (postal code p9n0e7) I know I will need supplemental heat for a few weeks and I have an electric furnace for that in storage... I hope to add a dc motor to continuously circulate th air as well... But bavk to the question... has anyone got a system I see eee annd ask questions about?

I don't have a reference of any you can go look at near Winnipeg , but Fujitsu has released a new cool-temp version of the popular Halcyon AOU-xxRLS2 series( designated xxRLS2-H) in Canada & US that are fully rated down to -26C, and will keep running below -30C.

http://www.thermoco.ca/nouvelles/111/Nouvelle_thermopome_Fujitsu_RLS2H.html

http://smartgreenbuild.com/pdf/Fujitsu-RLS2H.pdf

It has some nice features specific to very-cold temp operation, such as a pan heater to keep the defrost melt-water from building up ice in the bottom of the outdoor unit before it drains. It also has a motion-detector auto-setback function for saving a bit of power when the room is unoccupied. (I assume that can be disabled if desired, since recovery ramps can be long at the temperature extremes.)

Bottom line, true cold climate mini-splits are no longer just a Mitsubishi -FExxNA show.

wow...excellent information...now to find a Fujitsu that's up and running... any insight there...I am visiting ND/SD/MN/MI this summer so I can expand my range to see one

Though it's a moving target, with incremental improvements in efficiency from year to year without changes in model names/numbers, as of a couple of years ago the -xxRLS2 serise were somewhat more efficient across the board than the -FExxNA series, even though the FEs had lower specified operating temp. See:

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

I'm not sure how different the RLS2 is from the RLS2H, but the power used by the pan heater has to cut into COP somewhat, if not capacity.

I suppose you could use internet searches or the manufacturers' "installer finder" to get telephone numbers people installing them, and ask them if they have a client willing to show you one and give performance feedback, etc.

Run a careful load calc with particular attention paid to infiltration and fenestration (window) perfromance

Hey kenora...I know this is an older post, but we are also building a house here in Kenora and are looking into the mini-split heat pumps. Did you end up installing one? I'd love to know how it worked out. We are also having a hard time finding someone to design the system for us--it will need to be very carefully planned since the house is so airtight, and it will need to coordinate with the HRV and wood stove. Anyway, if you are still following this thread and have any input, it would be much appreciated.

I'll post asap...

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NO I haven't found anyone using a ASHP (in particular a Mitsubishi) to talk to yet :(

If you do please chime in what you learn... our climate is drastically colder than most of the kind folk S of the 49th.

sorry to take so long.. I got tied up changing the heat trace line to the lake...it cratered and cost me $1700 to fix... :(

Anyway for the benefit of all that might be in our little corner of the world I'll post a reply here instead of sending a PM.

There are two ongoing giant challenges as you already know when building a "different" structure out of the..

#1- "NORM" (2x6 wood frame) up here (Frosty Canada away from major centers like Toronto)

#2- "heating" it with something other than the traditional three (NatGas (not avail to me), Oil (using it now and its NUTS expensive) or Elec resistance (forced air elec furnace) or baseboards, neighbors with a double wide trailer are on the budget at $600/month for their all electric house) ouch.

I've been reading the posts here in all the forums paying most attention to how I can expand my existing home (2x6 wood) to add another 800 sqft over a new walkout basement. My reading leads me to this..

I will strip the existing siding (vinyl) off the existing house and add 4" EPS (R20 + R17ish for foam) from the roof line to the existing footings. (++I have had CONSIDERABLE PUSH BACK FROM BUILDERS (framers) about this EXTRAVAGANT USE OF FOAM, they want to add 2' at most++)... they don't use it so they don't want to use it... given a choice and appropriate screws I would add 6" of EPS... but try to find the screws!!!) I will most likely do this myself.

Since the plan for this area changed with the expansion I will remove all the windows/doors and replace with the best I can afford (probably GeldWen tripane low E argon in all but the S facing windows...those will be designed for solar gain; I wanted Accurate Door/Windows (fiberglass) but the 2x $$$ was over my budget)

Since I won't tear into the existing walls more than necessary I will air seal as best I can around new windows/doors.

I will blow an additional R30(ish) on top of the existing roof insulation (R40 very poorly placed pink batts); that's all that will fit on the flat roof side, the cathedral side remains as is (R40 batts).

The new addition looks like it will be 2x6 at 24 centers with 4" EPS on the exterior.

4" EPS from the footers to the roof line.

R20 or better under the slab; I have found a source of 3" XPS in CYWG but it appears overpriced so off to Menards I go... for that.

I will have Large windows facing S with overhangs to keeps out summer sun and allow winter sun.

Removable insulated shutters (R20 EPS) for "most windows...I built the prototype and I'm happy with it so I will include mounting hardware to all windows.

R80 roof in the addition with energy heel and parallel chord truss (vented cause no one builds a hot roof here?!!)

MAX attention (by me) to air sealing.

Now heat...

I have tried a variety of the Manual J free calculators and can't get a load that seems reasonable...I think I'm missing some data. My load appears (????) to be about 38000btu at outside temp of -30c; I don't think this is correct as I have an 80000 btu oil furnace now for the existing house. I think its that size cause that's all they had when the house was built in 1997).

I will somewhat reluctantly talk to the owner of CUSTOMVAC (CYWG on Logan) maybe its just me but I found that he was both enthusiastic about the technology (ASHP) and reticent to share much info about it... Since he seems to still be the only Mitsubishi dealer in our neck of the woods I will get him to calculate Manual J and size ASHP mini-splits. He is the one I mentioned in post #1

My current PLAN is to use three ASHP mini-splits (or three heads of a larger unit). Build is next summer...

1- on existing side converted to three bedrooms a (existing) bathroom and a large en-suite (hey my wife is the boss) an ASHP in the hall proving heat/cool. Since two of the bedrooms will be for guests those doors will be closed most times reducing the load on the existing side by about 1/3.

2- New construction Main floor on south face of loft (tiny at about 80 sqft) that backs onto existing building.

3- New construction Walk-out basement level on south exterior wall facing sunroom.

4- Electric heated tile at main entrance, walkout basement entrance and en-suite.

5- HRV to ventilate the house.

6- Old fashioned baseboards to take over when the ASHP hit their bottom limit (around -25c)

7- Electric appliances.

8- Small high efficiency wood stove as back-up if the grid goes down (I’m on 8 acres of wood)

9- Last but not least a 2kw Honda or similar gas generator (in the detached garage) to power the lights (all LED) if the grid poops out at night (night is nearly 16 hours long in February).

FWIW, my next door neighbor is in the concrete business (in CYQK) if you need a lead. He will be doing my foundation and concrete floor)... another neighbor (across the lake (I’m on Alcock Lake just N of 17a)) had gone off grid with solar (by Raysolar in CYQK) and seems very happy to be off the HydroOne teet J

Solar (net Metering) is my next project and can be added after I see what my actual KW usage is.

This site is the best I’ve found for exploring these new technologies and I read every post here. There is also excellent info at ecorenovator(dot)org see the forums there...

cheers

 

 

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I am in Buffalo, NY, and I am bias (disclaimer!), since I am designing and installing geo systems. Out of curiosity I put a new mitsubishi unit into my office for A/C purposes (old building with radiant heat), and turned the unit on at 5 degrees F outside temp. It was spending 45 min per hour in defrost mode, and during that time it did not heat the space. After a couple hours I got cold and turned on the radiator, since the heat output was essentially non existing. Make sure you have another efficient source of heat at the time your ASHP spends a lot of time in defrost mode....but again, I admit I am bias!

I am in Buffalo, NY, and I am bias (disclaimer!), since I am designing and installing geo systems. Out of curiosity I put a new mitsubishi unit into my office for A/C purposes (old building with radiant heat), and turned the unit on at 5 degrees F outside temp. It was spending 45 min per hour in defrost mode, and during that time it did not heat the space. After a couple hours I got cold and turned on the radiator, since the heat output was essentially non existing. Make sure you have another efficient source of heat at the time your ASHP spends a lot of time in defrost mode....but again, I admit I am bias!

Which model?

docjenser... yes please, which model...

Thanks for all the info., Kenora! On the subject if concrete...yes, if you have a concrete contact that would be fantastic (pm me?). We are doing a short stem wall with concrete slab. The slab will be our finished floor, but we haven't been able to find anyone to finish it (nothing too fancy, just a little nicer than a garage floor).

We are building a superinsulated bungalow (26 x 42', no basement) just off the Redditt Rd. Walls will be R-52 polyurethane Raycore panels (probably more like r-42 once you account for the thermal bridging of the studs). Roof is raised heel scissor trusses with blown in cellulose to at least r-60. Floor is slab with 4" of foam underneath on an ICF stem wall. Right now I am looking into air barriers...thinking of the airtight drywall system with huber zip panels on the ceiling (covered by t & g pine)...kind of nice because we could avoid the polyethylene vapour barrier altogether (Raycores have a foil vapour barrier on them already). We have had a VERY hard time finding contractors who understand green building around here, so I think this build will need to be much more hands-on (on our part) than originally anticipated.

As for the heating, more and more, I'm thinking we should install some baseboard heaters (which we'd need anyway below -25) and see how we do for hydro bills. Our main heat will be a high efficiency wood stove (we have 10 acres), and an energy efficiency consultant calculated our heat load as 16,500 BTU at -36 C, not too bad at all! We could always add the minisplit later on.

Do you ever sell your insulated shutters? I know quite a few people who are looking to buy/install some!

EMT.. I sent you pm

Posted By jonr on 08 Nov 2014 05:00 PM
Which model?

MUZGE18NA - MSZGE18NA

I installed a Mitsubishi MZFE18NA system in my old (small and well insulated/sealed) farmhouse in Missouri in July of 2013. So far this winter I have run the backup heat for about 20 hours. The Mitsu unit keeps us comfortable down to about -5 ambient, and can't keep up below that. Right now, it is a balmy 6 degrees outside. My wall thermometer says 72.2, and a nice warm stream of air is flowing out of the heat pump. This heat pump is one of the smartest purchases I ever made.

I have trouble understanding how an ashp could spend over 40 minutes of an hour in defrost. I think most of them are on timers.

The amount of time it spends in defrost is a function of the humidity of the air. While dumb timers are common for defrost cycle on old-school heat pumps was/is common, I don't know of any modulating mini-splits that run that way.

If it's actively snowing an sucking snow into the coils you can sometimes have very high duty-cycle in defrost mode at +5F. But if it's not snowing the humidity in the air is quite low, and if the thing is in perpetual defrost mode there's something wrong with it. High defrost duty cycles are much more common in rainy/foggy areas with mid-winter temps in the 35-40F range, since the raw volume of water in the air is an order of magnitude higher than when it's +5F out, and the coil is well below freezing.

The -GE18 is a lousy choice for heating in a Buffalo location, since it's minimum wet-bulb operating temp is -5º F (-21º C) WB.

http://www.mitsubishipro.com/media/456672/msz-ge18na-8~muz-ge18na-1%20submittal.pdf

The -FE18 would have made much more sense, since it's designed for -15ºF (-26ºC) WB operation. The past 5 weeks have seen over 100" of snow in Worcester, MA (way ahead of Buffalo for the season) and temps have dropped below (dry bulb) -5F multiple times, yet the three FE18s heating a friends 3-family rental have been performing flawlessly.

http://ecomfort.com/PDF_files/Mitsubishi/Mitsubishi_MSZ-FE18NA_Submittal.PDF

If you're going to use a mini-split for heating in a US DOW zone 5 or colder climate it's worth using an appropriate cold-climate model. Hopefully docjenser sprung for the appropriate drain pan heater (Mitsubishi MAC-642BH-U) to keep the GE18 from self-destructing on the block of defrost re-freeze in the bottom of the pan, if it's actually spending that much time in defrost mode for a reason other than malfunction. In a snowy cool lake-effect Buffalo climate they probably won't warranty that type of damage without it.

Congrats paulm! Is that a 1.5 ton unit? Is it heating your whole home (til-5) ? You must have done a good job insulating and airsealing. How big is your home?

Posted By Dana1 on 27 Feb 2015 02:31 PM
The -GE18 is a lousy choice for heating in a Buffalo location, since it's minimum wet-bulb operating temp is -5º F (-21º C) WB.

http://www.mitsubishipro.com/media/456672/msz-ge18na-8~muz-ge18na-1%20submittal.pdf

I actually bought it for A/C and only turned it on for curiosity. Any reason a HP rated for -5F should not work in +5F? Plus any reason the defrost should be less?
You guys are always fixated how they perform in rated conditions but there are the following facts: ASHP’s (in contrast to ground source heat pumps) are subject to stark seasonal climate variations. They are rated by ARI 210/240 method in climate zone IV, which is not representative of most heat dominated climate.
In addition, the defrost operation is typically based on the compressor runtime in real systems. The ARI procedure assumes there is no defrost operation below 17ºF where defrost operations will, in fact, often be triggered due to extended compressor operation (see Section 4.2.1.3, ARI 210/240).
Although the vast majority of air-source heat pumps operate auxiliary strip heat during the defrost cycle to prevent "cold blow," the ARI procedure specifically requires that strip resistance heaters be prevented from operating during the frost accumulation test. (Section 4.2.1.3). This is important since such operation of strip heat during the 3-10 minute defrost cycles satisfies part of the house heating load at a lower efficiency that is not reflected in the ARI procedure.
An ASHRAE study examined the impact of climate on air source heat pumps (ASHP). The study found that ASHPs perform with a 25% performance penalty for example in the Detroit, MI climate in heating mode (HSPF of 5.8 instead of 7.8 nameplate), and a 10% performance penalty in cooling mode (SEER of 10.7 instead of 12 nameplate).
"Climate Impacts on Heating Seasonal Performance Factor (HSPF) and Seasonal Energy Efficiency Ratio (SEER) for Air Source Heat Pumps. ASHRAE Transactions, June 2004, by Fairey, P., D.S. Parker, B. Wilcox and M. Lombardi, American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc., Atlanta, GA, "

There is no reason why the GE18 would not work at +5F dry bulb temp, and there is no reason why it should be in defrost mode 45% of the time (under any temperature & humidity condition). As I stated previously:

"...if the thing is in perpetual defrost mode there's something wrong with it."

In my experience, this does not happen (ever) with the FE18, nor does it happen with the Fujistu -12RLS2.

There are multiple (and more current) long-term in-situ monitoring investications by 3rd party investigators to demonstrate that the HSPF hit in colder climates with mini-splits is nowhere near as severe as the the June 2004 Fairey et al publication. eg:

http://apps1.eere.energy.gov/buildings/publications/pdfs/building_america/monitoring-mini-split-ductless-heatpumps.pdf

http://neea.org/docs/default-source/reports/ductless-heat-pump-impact-process-evaluation-field-metering-report.pdf?sfvrsn=31