Does that axe-equipment carry an ASME label, so's it can meet code, huh, huh, HUH!? ;-)

No, but every time the inspectors are due out, I just get out the axe and start sharpening it, you know; to show them I am serious and committed to my backup heat source.

They always just want to sign off real quick and leave, so it must be working.

New= from store or vendor who backs product and warranties.
Crapshoot= purchased on line from unknown vendor who may or may not back the product in timely fashion when it breaks.
Crap shoots are available on all products btw which suggests that if we want to delve into the maybe new/used/stolen discussion it will offer discounts on all technologies.

Buying at  wholesale rates through the local distributor is possible in some cases, but DIY installation may void warranties unless commissioned by a certified installer.  There seems to be an avid hobby-community of DIY mini-split installers out there though.

About half the installation-labor cost of a mini-split is the electrical work- it may be only a half-day's work (usually less), but you still have to pay them to make the trip.  Depending on how cozy you are with the installer there may be some DIY discount to work there too.

My bad, Lee. Try this one: http://www.ebay.com/itm/Mitsubishi-Mr-Slim-Heat-Pump-MUZ-MSZ-GE18NA-17-2K-BTU-/280724737852?pt=Air_Conditioner&hash=item415c7f8f3c#ht_2929wt_1109

Ignore the post above. Wrong thread.

In a life cycle cost analysis, paying so little that you can replace it several times and still save money is just as viable as buying top of the line. Actually, it's smarter because it is by definition the smaller mistake if something goes wrong. The fellow with the biggest pile of money at the end is the fellow who made the smallest mistakes.

Online sellers are usually dealers. The key is to get the manufacturer's warranty.

DIY Daiken is out. Dealer has to be certified by manufacturer to purchase equipment.

Todd- here's wishing you big "piles" .

Yep, I am all for a low energy shell and ductless mini splits fit the bill, but we are in NH in a Zone 5 with about a 6500 degree day heating climate. Also we need to consider a back up heat source to use during loss of electric power situations. Installation of a wood stove or pellet stove will provide the gross BTU's to take the major part of the heating load. The pellet stove can run on a power pack with inverter for 6 hours or so.

Posted By Dana1 on 29 Mar 2012 03:23 PM
But seriously, the notion that it takes a 4+ ton Altherma to meet a 25K heat load at 0F running a radiant slab is a bit silly. Both the output & COP at a given temp are determined by the required water temp. You get a lot more out of them with a low-temp slab than in the panel-radiator temps at which most Asian & European users will be using (and at which the specs were drawn.)

A 2.5 ton Mr. Slim (PUZ-HA30NHA, if you want to look it up) would support a 25K load @ 0F with margin to spare for half the money of any version of Altherma, if you can part with the cozy-toesies concept of radiant floors. (32K out @ +5F with a COP of ~1.5, 22.5K out @ ~ -13F breaking-even, installed cost under $10K, usualy under $8K.)

You brought up the Altherma, and I am trying to educate myself a bit more on central ASHPs, so I pulled the engineering data and the performance tables on page 88 (intergrated values) for the largest model E(D/B)LQ054BA6VJU, and it showns 26.6 KBTU/H at 5F outside and 23.88 KBTU/H at -4F, both at 86F load supply temperature. How much lower do you want to go to heat your floors? Any explanation why you call it silly? This is not about COP, which is still impressive at those outside temps, but about total capacity.

http://www.ebay.com/itm/DAIKIN-FTXS18HVJU-Ductless-Mini-split-Heat-pump-include-HVAC-installtion-/120842042873?pt=Air_Conditioner&hash=item1c22bf3df9#ht_6335wt_1202

The (many) Daikin listings on eBay are sold with installation. Where that is impossible, take the listing to your local dealer and ask why he can't make money at the same price. Did that with cabinets, showing them the wholesale price of soft-close slides, for example, and asking them to explain their times-three markup. The buyer is king in this economy. Act the part.

Posted By toddm on 01 Apr 2012 09:40 AM
http://www.ebay.com/itm/DAIKIN-FTXS18HVJU-Ductless-Mini-split-Heat-pump-include-HVAC-installtion-/120842042873?pt=Air_Conditioner&hash=item1c22bf3df9#ht_6335wt_1202

The (many) Daikin listings on eBay are sold with installation. Where that is impossible, take the listing to your local dealer and ask why he can't make money at the same price. Did that with cabinets, showing them the wholesale price of soft-close slides, for example, and asking them to explain their times-three markup. The buyer is king in this economy. Act the part.

So then you agree that there is no DIY Daiken?
Ebay vendors see you as a piece of meat, not a King.

Struggling with the pertinance of your direction here............

This is not about COP, which is still impressive at those outside temps, but about total capacity.

I think you are neglecting to note that the Altherma unit you are jousting at ships with a 6kW built-in resistance heater. The capacity values you are quoting are without the additional resistance heating capacity.

Posted By docjenser on 31 Mar 2012 01:08 PM

Posted By Dana1 on 29 Mar 2012 03:23 PM
But seriously, the notion that it takes a 4+ ton Altherma to meet a 25K heat load at 0F running a radiant slab is a bit silly. Both the output & COP at a given temp are determined by the required water temp. You get a lot more out of them with a low-temp slab than in the panel-radiator temps at which most Asian & European users will be using (and at which the specs were drawn.)

A 2.5 ton Mr. Slim (PUZ-HA30NHA, if you want to look it up) would support a 25K load @ 0F with margin to spare for half the money of any version of Altherma, if you can part with the cozy-toesies concept of radiant floors. (32K out @ +5F with a COP of ~1.5, 22.5K out @ ~ -13F breaking-even, installed cost under $10K, usualy under $8K.)

You brought up the Altherma, and I am trying to educate myself a bit more on central ASHPs, so I pulled the engineering data and the performance tables on page 88 (intergrated values) for the largest model E(D/B)LQ054BA6VJU, and it showns 26.6 KBTU/H at 5F outside and 23.88 KBTU/H at -4F, both at 86F load supply temperature. How much lower do you want to go to heat your floors? Any explanation why you call it silly? This is not about COP, which is still impressive at those outside temps, but about total capacity.

This is a bit of a quibble but on p56 (.pdf pagination), left hand column, the ERLQ054BAVJU they're alleging it delivers 28.5KBTU/hr @ +5F with 86F output about 7% better than 26.6KBTU/hr number cited. (Different versions of the spec, perhaps- the document in link above is dated April 2011, on the last line of the last page.)

That's a guaranteed output, which presumes a high dew point relative to the outdoor temp for highest capacity loss to defrost cycles. Peak output at +5F is 32KBTU/hr, and typical real-world performance is in-between (it's not always snowing or foggy at +5F, usually not.) 

But point taken, it's not  really as silly as implied- I was jumping the gun (mea culpa!)

But there are other factors of spec-manship at play. What IS a 4.5 ton, or 3 ton ductless ASHP?

Calling it a 54KBTU/hr unit is a matter of how the manufacturer specifies the nominal ratings for the compressor, which does vary between manufacturers (even those with the identical Fujitsu compressors under the hood.) The output of the 54K Altherm doesn't break 54K output with with 86F water until it's 45F outside, and at typical-air-to-air output temps it's output is only ~50K @ 45F.

A Mitsubishi or Fujistu air-to-air ductess with similar output would usually be rated at LEAST a half-ton lower than that, and probably more than a ton lower:

The output of any H2i series @ 47F is typically ~7-10% higher than Mitsubishi's nominal rating, and that 47F rating is at roughly half-power, which implies that they intentionally limit the max output at those higher temps by design/control. (That is probably to preclude it from running at a lower max speed/lower COP during warmup ramps when heating loads are presumed to be light.) Mitsubishi might have called it a 48K or even lower, but other vendors would have given it a MUCH lower nominal rating:

As independently tested the max output of a 1-ton Fujitsu at 45F is about 20K, not 12K, (see figure 3, page 16, .pdf pagination ), and still over 12K@ -4F. But those are max ouput, not discounted for defrost.  As rated by the manufacturer it's 47F capacity is 16K, 33% higher than it's nameplate rating.  Fujitsu might have rated the 54K Altherma at 3-tons, since most of their ductless units carry a nominal rating 25-30% under the 47F max capacity, and put out more than the nominal nameplate rating at +15F.

So like anything else, you still have to read the specs before deciding which unit to install in to a given application, since they're not describable by one number, and the single-number description isn't fully standardized in the industry, particularly in heating mode.

There are many units that can and do deliver 2+ tons at +5F, and many houses in US climate zone 5 with +5F outside design temp that can be economically retrofitted to heat loads that low.  The lower the design temp, the lower the COP, lower the output capacity, and the more expensive that retrofit becomes.  Most ~2500' homes in US climate zone 4 (even the cold edge of zone 4) are pretty easy to get within the +15F output ranges, which is a colder US zone 4 outside design temp.  In US zone 5 it's not as easy or cheap or easy to get the design condition heat load under mini-split outputs at that temp, but it's often possible.   In US zone 6 heat loads that low are rare in single-family houses, and design temps are below where ASHP manufacturers bother to rate their output, since performance at -25C or less is so low.
 
IIRC NRT.Rob's experience was that his Altherma installation (at the warm edge of US zone 6) handily outperformed the both the average and low-temp spec, but I'm not sure how close his application is up against the stops in terms of heat load. He speculated that the building envelope was outperforming Manual-J by quite a bit as one possible explanation for the higher than expected performance.

Posted By Dana1 on 02 Apr 2012 12:18 PM

Posted By docjenser on 31 Mar 2012 01:08 PM

Posted By Dana1 on 29 Mar 2012 03:23 PM
But seriously, the notion that it takes a 4+ ton Altherma to meet a 25K heat load at 0F running a radiant slab is a bit silly. Both the output & COP at a given temp are determined by the required water temp. You get a lot more out of them with a low-temp slab than in the panel-radiator temps at which most Asian & European users will be using (and at which the specs were drawn.)

A 2.5 ton Mr. Slim (PUZ-HA30NHA, if you want to look it up) would support a 25K load @ 0F with margin to spare for half the money of any version of Altherma, if you can part with the cozy-toesies concept of radiant floors. (32K out @ +5F with a COP of ~1.5, 22.5K out @ ~ -13F breaking-even, installed cost under $10K, usualy under $8K.)

You brought up the Altherma, and I am trying to educate myself a bit more on central ASHPs, so I pulled the engineering data and the performance tables on page 88 (intergrated values) for the largest model E(D/B)LQ054BA6VJU, and it showns 26.6 KBTU/H at 5F outside and 23.88 KBTU/H at -4F, both at 86F load supply temperature. How much lower do you want to go to heat your floors? Any explanation why you call it silly? This is not about COP, which is still impressive at those outside temps, but about total capacity.

This is a bit of a quibble but on p56 (.pdf pagination), left hand column, the ERLQ054BAVJU they're alleging it delivers 28.5KBTU/hr @ +5F with 86F output about 7% better than 26.6KBTU/hr number cited. (Different versions of the spec, perhaps- the document in link above is dated April 2011, on the last line of the last page.)

That's a guaranteed output, which presumes a high dew point relative to the outdoor temp for highest capacity loss to defrost cycles. Peak output at +5F is 32KBTU/hr, and typical real-world performance is in-between (it's not always snowing or foggy at +5F, usually not.) 

But point taken, it's not  really as silly as implied- I was jumping the gun (mea culpa!)

But there are other factors of spec-manship at play. What IS a 4.5 ton, or 3 ton ductless ASHP?

Calling it a 54KBTU/hr unit is a matter of how the manufacturer specifies the nominal ratings for the compressor, which does vary between manufacturers (even those with the identical Fujitsu compressors under the hood.) The output of the 54K Altherm doesn't break 54K output with with 86F water until it's 45F outside, and at typical-air-to-air output temps it's output is only ~50K @ 45F.

A Mitsubishi or Fujistu air-to-air ductess with similar output would usually be rated at LEAST a half-ton lower than that, and probably more than a ton lower:

The output of any H2i series @ 47F is typically ~7-10% higher than Mitsubishi's nominal rating, and that 47F rating is at roughly half-power, which implies that they intentionally limit the max output at those higher temps by design/control. (That is probably to preclude it from running at a lower max speed/lower COP during warmup ramps when heating loads are presumed to be light.) Mitsubishi might have called it a 48K or even lower, but other vendors would have given it a MUCH lower nominal rating:

As independently tested the max output of a 1-ton Fujitsu at 45F is about 20K, not 12K, (see figure 3, page 16, .pdf pagination ), and still over 12K@ -4F. But those are max ouput, not discounted for defrost.  As rated by the manufacturer it's 47F capacity is 16K, 33% higher than it's nameplate rating.  Fujitsu might have rated the 54K Altherma at 3-tons, since most of their ductless units carry a nominal rating 25-30% under the 47F max capacity, and put out more than the nominal nameplate rating at +15F.

So like anything else, you still have to read the specs before deciding which unit to install in to a given application, since they're not describable by one number, and the single-number description isn't fully standardized in the industry, particularly in heating mode.

There are many units that can and do deliver 2+ tons at +5F, and many houses in US climate zone 5 with +5F outside design temp that can be economically retrofitted to heat loads that low.  The lower the design temp, the lower the COP, lower the output capacity, and the more expensive that retrofit becomes.  Most ~2500' homes in US climate zone 4 (even the cold edge of zone 4) are pretty easy to get within the +15F output ranges, which is a colder US zone 4 outside design temp.  In US zone 5 it's not as easy or cheap or easy to get the design condition heat load under mini-split outputs at that temp, but it's often possible.   In US zone 6 heat loads that low are rare in single-family houses, and design temps are below where ASHP manufacturers bother to rate their output, since performance at -25C or less is so low.
 
IIRC NRT.Rob's experience was that his Altherma installation (at the warm edge of US zone 6) handily outperformed the both the average and low-temp spec, but I'm not sure how close his application is up against the stops in terms of heat load. He speculated that the building envelope was outperforming Manual-J by quite a bit as one possible explanation for the higher than expected performance.

You are siting performance for split systems, while I was citing the performance for hydronics. I simply grabbed the data for the largest Altherma unit they make, and wanted to see if it could heat the house on the colder days of the year.
To Todd: The electric heat element adds 20KBTU/H in capacity, so you could get to 45 KBTU/h at around 0F outdoor, but that would run then at full capacity, essentially heating 45% with electric resistance heat. And keep in mind, 0F is the 97%tile load design temp, what do you do if you run into the other 3% bin hours where temps drop down below 0F? You cannot design a system which maxes out for full supplement heat at 97% design temps.

A 97th percentile outside design temperature of 0F is well into US climate zone 6, which is hands-down NOT an ideal climate for air source heat pumps. 

But even in those climates  there are existence proofs of deep energy retrofits to 99th percentile heat loads of 25KBTU/hr or less on homes that started out at 50K or higher. But it's expensive in zone 6, and a it takes a sharp pencil and careful energy use modeling to determine the net-present-value of just the cheap & easy envelope improvments + 3.5-4-ton geo vs. major envelope improvements and an Altherma (or mini-split.)

FWIW, there are relatively few regions in NY state's zone-6 areas where the 97th percentile design temp is 0F or lower, although there are many with  99th percentile design temps that low. (Adding 3F-8F to the 99th percentile numbers correlates roughly with the 97th percentile in most cases.)

The straw-man case previously presented was  "Even if I get it down to 40 KBTU/h, the 25 KBTU/H from the largest Daikin is not gonna heat the house." at a 0F design temp.  This is distinct from the case I had been bringing the design temp load down to under 3 tons (for less than the cost of geo for the pre-retrofit load)  in places like Wayne PA,  (US climate zone 4) the case that prompted this thread.  In that location the 99th percentile outside design temps are about +15F (the 97th would be about +20F)  and and the output of the biggest Altherma is well over 2  tons at panel-radiator type operating temps, no slabs or other low-temp radiant approach required.

Note, a house that has a heat load of 40K @ 0F (fairly easy to hit, even as retrofit) already has heat load of  only ~31.5 K @ +15F, and with a few judicious upgrades that are only slightly more aggressive (use BeOpt to figure out the cheapest way to get there), can bring that down to the 2-ton range, if the Altherma is deemed preferable to an air-to-air ductless solution of higher capacity. 

The additional delta in cost for getting it down to 2-tons @ +15F design temp will nearly always be less than the difference between an Altherma and 2.5-3 tons of geo.  (And WAY under the cost of the difference between a 3-head 2.5 ton multi-split capable of handling the load.)  But subsidies may still tip the balance toward geo in some cases.

I wouldn't make too many assumptions about geothermal pricing. For example, open loop systems can be very simple (with existing well and somewhere to drain). Water hardness is more likely to be a geo cooling problem.

Posted By Dana1 on 04 Apr 2012 12:50 PM
A 97th percentile outside design temperature of 0F is well into US climate zone 6, which is hands-down NOT an ideal climate for air source heat pumps. 

But even in those climates  there are existence proofs of deep energy retrofits to 99th percentile heat loads of 25KBTU/hr or less on homes that started out at 50K or higher. But it's expensive in zone 6, and a it takes a sharp pencil and careful energy use modeling to determine the net-present-value of just the cheap & easy envelope improvments + 3.5-4-ton geo vs. major envelope improvements and an Altherma (or mini-split.)

FWIW, there are relatively few regions in NY state's zone-6 areas where the 97th percentile design temp is 0F or lower, although there are many with  99th percentile design temps that low. (Adding 3F-8F to the 99th percentile numbers correlates roughly with the 97th percentile in most cases.)

The straw-man case previously presented was  "Even if I get it down to 40 KBTU/h, the 25 KBTU/H from the largest Daikin is not gonna heat the house." at a 0F design temp.  This is distinct from the case I had been bringing the design temp load down to under 3 tons (for less than the cost of geo for the pre-retrofit load)  in places like Wayne PA,  (US climate zone 4) the case that prompted this thread.  In that location the 99th percentile outside design temps are about +15F (the 97th would be about +20F)  and and the output of the biggest Altherma is well over 2  tons at panel-radiator type operating temps, no slabs or other low-temp radiant approach required.

Note, a house that has a heat load of 40K @ 0F (fairly easy to hit, even as retrofit) already has heat load of  only ~31.5 K @ +15F, and with a few judicious upgrades that are only slightly more aggressive (use BeOpt to figure out the cheapest way to get there), can bring that down to the 2-ton range, if the Altherma is deemed preferable to an air-to-air ductless solution of higher capacity. 

The additional delta in cost for getting it down to 2-tons @ +15F design temp will nearly always be less than the difference between an Altherma and 2.5-3 tons of geo.  (And WAY under the cost of the difference between a 3-head 2.5 ton multi-split capable of handling the load.)  But subsidies may still tip the balance toward geo in some cases.

While I respect your expertise to improve the envelope, and I agree that preservation and load efficiency are the key steps to take before worrying about how to heat the house. However, while COPs are impressive for those low air temps, total capacity is still an issue. I brought up the 97%tile since Todd mentioned the 6 KW supplement heat. However, the design should be such that the HP capacity plus the supplement heat capacity carries you to the possible min temperature, not to the 97%tile. Unfortunately, the heat is the least when you need it most. And no, I do not consider ductless systems an alternative to comfortably heat your house in cold climates.

And no, I do not consider ductless systems an alternative to comfortably heat your house in cold climates.

Unfortunately for your theory, the NW Ductless Heat Pump Initiative has now installed more than 15,000 ductless minis in WA, OR, ID and MT with a remarkably high customer satisfaction rate.

Maybe you are thinking more about the high end of what might be considered a "cold climate"....

Again, in new construction one has the opportunity to decide where to spend premium dollars: paying extra for HVAC or paying extra for the envelope (not merely lip service "improving it.") If the premium involves high mass, as in ICF or other concrete systems, the design day temp matters less than the average daily temperature. As Dana notes, premium insulation could reduce the load to the point that GSHP wouldn't make sense financially. As always, every case is unique. GSHP is an excellent last resort, but one should not reach automatically for a bigger hammer.

high mass, as in ICF or other concrete systems, the design day temp matters less than the average daily temperature.

I agree that a "design day average" might be of some use in sizing systems for high mass buildings.

Posted By ICFHybrid on 05 Apr 2012 12:34 AM

And no, I do not consider ductless systems an alternative to comfortably heat your house in cold climates.

Unfortunately for your theory, the NW Ductless Heat Pump Initiative has now installed more than 15,000 ductless minis in WA, OR, ID and MT with a remarkably high customer satisfaction rate.

Maybe you are thinking more about the high end of what might be considered a "cold climate"....

I would assume that docjenser's attitude is that those aren't cold climates.

Resistance electric backup is dead-cheap for handling 99.99th percentile heat load on something that has a 97th or 99th percentile heat load of 25-30KBTU/hr and has an ASHP that meets that load at design temp.  Two $50 oil-filled radiator type space heaters @ 1.5kw each put out another 10,200BTU/hr., so even if the ASHP is only delivering 70% of that 25-30K (17.5-21K) at the absolute 25 year low it would take no more than 3, or $150 worth of equipment to handle the absolute peak.

Designing the heating system or the 100 year peak load leads to ridiculous oversizing & expense. The current 99th percentile design temp in Worcester MA where I currently live is +5F. The century-low is -24F, but I'm not going to design for that.  The coldest temperatures I've seen in 2 decades of living here is in the negative teens.  At -15F the heat load is only 30% higher than what it is at +5F, and that's beyond a 99.9th percentile number.  At -15F a Mitsubishi H2i is still putting out over 65% of nameplate rating, so a 30K Mr. Slim is delivering 20K.  If the place has been tightened up to 24K @ +5F, and  the mini-split is oversized a half-ton to 30K (to reap the higher average COP),  the heat load at -15F is about 31K, so 2 space heaters would cover the shortfall even at the 99.9th percentile condition.  If the mini-split is sized for exactly 24K @ +5F, the output at -15F is  only ~16KBTU/hr, a 15K shortfall, so it takes three $50 space heaters, not two.

And that's if you feel the need to keep the whole damned house at 70F for those few hours of absolute peak load.

Retrofitting a 2500' century old house to 24KBTU/hr @ +5F isn't trivial, but it's do-able.  Getting there economically takes some careful analysis, and the details and costs will vary.  Getting it under 36K is much easier target, and usually doable for less than the typical cost-delta between a 3-ton multi-split vs. 4 ton geo.  The resulting house is usually more comfortable at design temp than the 4-ton geo solution, and uses about the same annual power than the geo solution in climates where +5F is the design temp. In places where +15F ior higher is the 99th percentile the design temp (most of US zone 4)  a similar reduction in load would result in the ASHP using significantly LESS power than the larger geo solution.