I found this recently published policy piece from RMI on reducing the northeastern region's carbon footprint by displacing heating oil with heat pumps on-target (they're singin' my song!)  Given the comparable levelized cost of energy of ductless heat pumps and geo, it seems silly to be subsidizing them at radically different levels.  (See figure 2, page 6.)

It's my understanding from insider scuttlebutt that MA will be subsidizing ductless heat pumps a bit more next year, but I seriously doubt it'll be anything close to the Federal GSHP tax subsidies to date, and unlike the Federal subsidy, the higher MA subsidy is likely to be available only to those heating with resistance electricity.  

Previously ductless systems have enjoyed a mere $500 subsidy through the state, whereas GSHP systems have had 0%/7 year money available and often utility/other subsidy in addition to the hefty Federal prop.  This year ductless mini-splits also qualify for the 0%/7yr money, but the $500 direct rebate is still the current max.  (MA residents can review what weatherization & HVAC subsidies are available in their community at MassSave.)

BTW:  A Deep Energy Retrofit on a Worcester, MA 3-family I was advising on last year is having an open house on 6 April 2013 between 10AM & 2PM @ 29 Crompton Street, Worcester, MA 01605. (Apparently some of the subsidizing utility program mucky-mucks and the local US congressional rep will be there making presentations too.)  It's being heated/cooled with 1 mini-split per story, all oversized for the loads IMHO, but not grotesquely so.  (Not all of my advisin' was taken verbatim, eh?  But I still saved him tons of cash as well as tons of heating/cooling load over the course of the project. )

nit: you may want to replace "ductless" with "air source". I think the government can safely stay out of the decision to use ducts or not.

I find it interesting that they consider the operating costs of ASHPs and geo equivalent (IMO, geo is lower).

If you read their analysis, they are specifically referring to primarly VRF ductless, not ducted air source systems for their numbers. (Yes, they do mention ducted VRF, but don't cite efficiency numbers separately.) A typical bang/bang ducted ASHP system in this region would come in at 1.5-2x the operating cost of geo, even if it hits the standalone SEER/HSPF numbers on a test bench. The few ducted ASHP systems tested by Ecotope in the NEEA Northwest Ductless program came in under 2.0 for a seasonal COP, compared to a 2.7+ average for the ductless systems in the regions with winter temps comparable to New England, and 3.0+ in the regions comparable to the warmer edges of PA/NY. System efficiency matters, and like GSHP, it's pretty easy for sloppy designers to bring even the best heat pumps to their knees on net efficiency, where it takes a genius to screw up a canned system like a mini-split (but those geniuses DO exist, eh? ;-) )

The operating cost numbers on each they give are a range, and while we might disagree with the authors about exactly where the 1-sigma numbers are for operating costs for either GSHP or VRF-ASHP, it's clear that they will overlap. Yes, GSHP will be more efficient in the colder parts of the Northeast, but in the warmer parts of PA/NY it's still possible for mini-splits to beat ducted GSHP, even if they get clobbered by better-designed better-implemented hydronic GSHP systems (that come with a higher than typ system cost.)

The levelized cost of energy (LVCoE) for GSHP cited in the RMI piece is 17% higher than that of the VRF-ASHP, but ends up within the high/low operating cost bands of the VRF-ASHP. Even if you posit that the GSHP will be substantially more efficient on average, the LVCoE is still comparable due to the much higher capital cost of GSHP. This wasn't a "beat up on geo" piece, but more of a "what does it really cost to move off of oil when natural gas isn't available" piece. The numbers used for the heat pump technologies are still reasonable, if you assume mini-split type efficiencies & costs for the ASHP.

While there will be outliers on both efficiency & cost with heat pump systems, the central points of heating with heat pumps vs. the LVCoE of heating with oil and pellet-boilers/stoves rings true. (I really don't care if better GSHP systems hit an average COP of 4+, if the small-sample-set averages used for regulatory estimation purposes by the NH state gov assumes a net COP of 2.5 for GSHP, or 1.5 for ducted ASHP. Both 2.5 and 4.0 for GSHP "true", in their contexts, and mini-splits are still in the range, even in a NH climate, even though I'm sure you can find some installed mini-splits that won't even hit 2.0.)

I would be interested in seeing more actual data on room by room temperatures in ductless homes (or perhaps homes with just low CFM air quality/HRV ducts). But I'll stick with ducts/no ducts and geo/air source as being orthogonal issues (at least in theory, even if not seen in most systems that we have today).

What is the net benefit to the mass of tax payers to subsidize so few?
If the money is to be spent, would it net a better return if spent on r&d?
Just wondering.

Subsidizing early adopters is part of R&D...sometimes called Beta testing.

Early adopters take certain risks so deserve certain rewards for being guinea pigs in the effort to translate lab data to real results in the field.

Why is this mini split coming up again and again. We get it that you are a big fan of it. One mini split per floor? Don't you have bedrooms, bathrooms or other rooms where it is desirable to close a door?

The Passive House crowd thinks that heating loads in perimeter rooms of suitably tight houses can be met by a combination of ventilation, internal loads and solar gain. Fascinating, but I haven't been able to work a parallel in Florida.

rooms where it is desirable to close a door?

The theory is that once the load is low enough (ie, lots of insulation, great windows), the heat/cool transfer through the interior walls and a small amount of ventilation (high and low baffled ducts and/or HRV) is enough, even with the door closed. Such a design might require exterior shades to prevent overheating from solar gain.

I think that in a few cases, subsidies have been useful in encouraging enough adoption to bring prices into the cost effective range. Or balance out the hidden subsidies that fossil fuels get :-)

Posted By docjenser on 03 Apr 2013 04:20 AM
Why is this mini split coming up again and again. We get it that you are a big fan of it. One mini split per floor? Don't you have bedrooms, bathrooms or other rooms where it is desirable to close a door?

Where else to bring it up? I have lobbied for an airsource forum and mods don't even dignify the suggestion with a response. There is no doubt in my mind airsource has applications, but we suffer anecdotal claims vs vastly experienced pro's contributions.

Joe....nice avatar. I think the mods on this board are non existent .

Posted By FBBP on 02 Apr 2013 10:05 PM
What is the net benefit to the mass of tax payers to subsidize so few?
If the money is to be spent, would it net a better return if spent on r&d?
Just wondering.

I guess it depends on what you mean by "benefit" and "so few".   The net outflow of cash from the region to oil & propane supplying regions/country is HUGE (Venezuela's oil indutry is a big beneficiary of the northeasts' heating oil hunger.)  Mini-splits are popping up like mushrooms after a rain in some places, and to my mind it's a GOOD thing. I'd rather give the money to the local/regional utilities & natural gas suppliers (most of which is domestic). 

The R & D is done- GSHP & VRF-ASHP systems work, and work well. Spending the money on accelerated IMPLEMENTATION has more benefit than handing it over to a bunch of nerds to test over & over again.  Heat pumps are mature technology (even mini-splits, which have a 40 year track record in Japan.) 

Between the regional outflow of cash for oil ($14,000,000,000 USD per year, according to the RMI analysis) and the much lower carbon footprint of heat pumps relative to oil or propane (even at the current northeastern grid mix), the benefit is to the 50-80 million regional residents as well as the world as whole.  The immediate benefit to the 6-million MA residents is in the local economy, and the local air quality. The benefit to the local utilities is lower summertime peak loads, reducing the need for building new low capacity-factor high cost peak generators to handle the peak loads of 2 million crappy low efficiency window air conditioners being ramped-on in rapid succession between 3-5PM during the work week. The benefit to the ratepayer is lower rates from lower imported peak power from remote grids. They've studied the hell out of it, and calculated the avoided capital costs,which why they contribute directly to the subsidy- it's a better investment for them than new peakers in the MA regulatory environment.  (I can dig up some the studies for you if you like- they used to be online as of 18 months ago, probably still are.)

MA has long subsidized higher efficiency heating systems for all of the previously stated reasons, (including condensing natural gas systems) but only very recently has this been applied to air source heat pumps. (IIRC it's new this year, though it may have started in 2012).  Previously the efficiency levels weren't deemed high enough, and the economic loss of high heating oil prices wasn't as egregious as it has become for the past 5 years.  Even ducted air-source heating systems can now qualify for the MA 0% loan subsidy, but mini-splits can also get a $500 direct rebate subsidy for units with HSPF>10 & SEER>20, largely courtesy of the grid operators.

In my mind the 30% Federal subsidy of GSHP systems seems more directed to "the few"- it's subsidizing the already well-off who can actually afford to drop 30 grand on a heating system rather than 4-5 grand on a mini-split to offset a 4 grand/year heating bill for blue-collar Mainers. It's taking from the 99% to subsidize the 1%, with a lower immediate bang/buck, even if it has a comparable levelized-cost-of-energy outcome.  The numbers of GSHP installations nationwide are what, a couple-hundred thousand per year, directed primarily toward our wealthier citizens? 

That's kewl and all but, the ROI on that for the climate or the country isn't necessarily the best short-term bang/buck.  To subtantially reduce the rural New Englanders (and NY/PA) high-carb high-cost heating oil diet takes a much lower cost of entry than GSHP systems.  Even when it's not a total solution, reducing household oil consumption by more than half can usually be had for $5 grand's worth of mini-split, and the effects on the regional economy would be significant. Reducing the $14B-USD outflow for heating oil by half is still more than a drop in fairly large regional economic bucket.  The personal reduction in out flow for who can't muster the cash or credit for GSHPis VERY significant for those with no options other than electricity/oil/propane.  The efficiency vs. cost of mini-splits means the MA 0% / 7year loan is immediately cash-positive for displacing oil heating for a mini-split, but not for a $25K (max MA loan subsidy) for a GSHP- it's a much longer term investment that the cash-strapped simply can't make.

Posted By joe.ami on 03 Apr 2013 09:33 AM

Posted By docjenser on 03 Apr 2013 04:20 AM
Why is this mini split coming up again and again. We get it that you are a big fan of it. One mini split per floor? Don't you have bedrooms, bathrooms or other rooms where it is desirable to close a door?

Where else to bring it up? I have lobbied for an airsource forum and mods don't even dignify the suggestion with a response. There is no doubt in my mind airsource has applications, but we suffer anecdotal claims vs vastly experienced pro's contributions.

And mind you, the paper cited wasn't mini-split specific- it was about getting the northeast off the oil habit with heat pumps and biomass to keep the money from draining the economy while heating the planet. I invite docjenser to actually read it.

I personally know people who can't afford to heat the whole place with oil, who are essentially point-source heating by only running single zones, or using woodstove-only until the outdoor temps are in the teens and worried about the pipes freezing, or keeping the place a tepid (even chilly) 60-65F during the day, setting back to 55F at night.

Most of those people would find a significant upgrade in comfort & economy with one mini-split per floor, even in crummy not-so-tight antique housing. And I'm sure NONE of them will be in the GSHP market any time soon, as nice as that might be for them.  Subsidizing cash-flow-positive loans for mini-splits seems like the right thing to do- the taxpayer/state is only giving up the interest, but gaining the regional cash retention (and probably lowering health-care costs.)

Point-source heating isn't nearly as onerous as it might sound. Since installing a wood stove I've turned off the bedroom zones just to see where they settle, and if anything my family sleeps better at 60-65F temps, which is where it hangs when the overnight lows are in the 20s. With the doors open to the main space it stays warmer in the bedrooms, of course.  (This is not a superinsulated or even code-min house, it's a 1923 timber-framed antique.) It's not any cheaper to heat the primary zone (mostly open) with an ~80% effciency wood stove, but it's made the slightly overheated living room more comfortable for my mother-in-law than the radiant floor zone in the (somewhat cooler) family room (and has proven to be a good way to keep both the ol' lady and the 12 year old separate & content.)  But unlike somebody who filled up at $4.50/gallon oil, I have no hesitation about cranking up the temps of the gas-fired heating system for comfort when the temps drop below 0F, even though it would clearly be tolerable with only the wood stove, with the doors to the bedrooms left open.

The few ducted ASHP systems tested by Ecotope in the NEEA Northwest Ductless program came in under 2.0 for a seasonal COP, compared to a 2.7+ average for the ductless systems

Given that the typical, non super insulated house cannot use a ductless system (although a mixed system might work), higher efficiency ducted ASHPs might be something to encourage with subsidies. I can't believe that it is difficult (edit: for a manufacturer) to change a ductless ASHP into a ducted design.

I can't believe that it is difficult to change a ductless ASHP into a ducted design.

D'you mean like just by adding a plenum and a fan or something like that?

I don't question that minisplits have their application, nor do I think it matters what the report is specific about, but you continue to hail mini splits as an all solution which they are clearly not. You are a very theoretical guy, with a lot of good theoretical knowledge, but sometimes not so familiar about what works in the field and what does not.
What usually does not work well for customers as well as myself for example is to leave bedroom doors open so the bedrooms get heated better, I am married and have kids, and so do most of my customers!
What works for you sometimes does not work for everyone else!

"I can't believe that it is difficult to change a ductless ASHP into a ducted design."
Sure you can, simultaneously tanking the efficiency.
The greater efficiency of ductless is due in large part to being "ductless". Larger or second fans, friction loss etc. is why you don't achieve the same performance once ducts are involved.

"Joe....nice avatar."
Thanks had a trip down memory lane recently.

"I can't believe that it is difficult to change a ductless ASHP into a ducted design."
Sure you can, simultaneously tanking the efficiency.

Compared to oil heat, the cost of running a fan is approximately free. Those watts go into heating the house at a $/btu similar (sometimes less) to oil.

One could use a hybrid system to eliminate ~2/3 of the additional fan energy - ductless for all the open areas and ducts for the closed ones. But I'd like to hear more from Dana regarding how to make ductless more practical.