Including defrost cycles?

Ayup.

Posted By ICFHybrid on 22 Jan 2011 05:29 PM

Including defrost cycles?

Ayup.

If this means yes, how can this be given that defrost cycles are dependent on outdoor temperature at the time of the cycle?  Does it also include auxiliary heat strip engagement during the defrost cycle?

Maybe you should ask Rob. Doesn't he have one harnessed up in his shop?

Alternatively, you could look up a Daikin engineering manual and see that it gives integrated values for heating capabilities.

Posted By ICFHybrid on 22 Jan 2011 03:08 PM
The new air source heat pumps that have been thrown around still deliver a COP of just about 3.0 at freezing and 2.0+ all the way down to 0F. However, the heat output is about 70% of rated output at freezing and about half down at 0F.

Half the capacity at 2/3's the efficiency sounds like manufacturer double speak for many times less useful at 0 degrees.
ASHP manufacturers will continue to be suspected of smoke and mirrors as long as they continue to make claims like this one that suggests satisfactory performance at 0*.

Geo obviously loses capacity at lower temps as well, be we can dictate minimum EWT.

ASHP may still be a good fit for OP, but a local designer on the hook for performance would be far superior than internet advice.
j

thanks for the replies.
Any thoughts on the more "DIY" approach? Meaning supply the products and just hire out the install? I have subs that can do vertical wells, grouting and hooking them up to the system for about $2k per well. I am not sure how many I need just yet, dependings on the depth obviously. It looks like I can buy everything I need for 8k or less. Plus wells and install costs, I am probably around 15k or less, maybe.

Opinons on ASHP vary by everyone in this area. Most push dual fuel, but the choice being gas. When I replaced the the furnace in my current house a guy bidding suggested what I am asking, ASHP with air handler and electric strip. He gave an arguement showing numbers how this route would be cheaper then the gas in my area, which is pretty resonable. Unfortunately the site does not have gas, but room for geo for sure.

Nothing wrong with DIY, but you have much more research to do if you think you can get everything we've discussed for "8k or less".
Most HVAC pros get burned on their first geo or two by unanticipated expenses (even the thermostat may cost $150 more than you expect).

It becomes increasingly difficult to offer you much guidance as you introduce multiple systems (with or without in floor radiant), multiple (unqualified or itemized) quotes and now possible DIY with arbitrary numbers and unspecified system type.

You are getting to the point of asking what a new car should cost (without qualifying features) but suggesting the sum of all parts is 15k or less.
Can't help you without you pinning a few points down.
Good luck,
joe

I understand its hard to compare nothing to nothing...I am working on getting everything I need to post accurate info to look at.  For DIY, I am looking at several out there, including the Terrasource, which from my readings is a better system then the Ingrams one.  I will contact them for an exact quote, but off of their site, generically, they are showing $8500 for a 3 ton dual stage, desuperheater, heat strip, variable speed fan, horizontal loop, thermostat, etc.  13500 installed...I would still need to add an HRV to that, pex in the slab, air filter, etc.  So another 3k total there I would guess. 

I will post the info I get from the bids when I get them.

google "trouble with _______" (either of the systems you are looking at). problems are not true of every install but it will give you some looks at what could go wrong.
if you want to get sweat equity in a project, i suggest you speak first with the local guys so that you have support when something goes wrong. we offer design to turn-key to our customers as I hire out digging, electrical and often plumbing.
If you go geo you only save 70 cents on the dollar so a few extra bucks could be cheap insurance to the job's success.
j

ASHP manufacturers will continue to be suspected of smoke and mirrors as long as they continue to make claims like this one that suggests satisfactory performance at 0*.

"Satisfactory performance" is a very subjective term. It might be different for different people and different situations. The fact remains that once resistance heat comes on you are getting that heat at a COP of 1.0. Even half the capacity at 2/3 the efficiency is better than that and indicates that high performance ASHPs are going to find their way into an increasing number of applications. Like my home, for instance.


BTW, Daikin is a $10 billion diversified corporation with a substantial reputation in engineering innovation and I do have confidence in the Daikin specifications.

Daiken is a big Corp with an aggressive position on marketing ASHP's. Their business model is to make everything from the ground (refrigerant) up. They are among the first examples I've seen of electric (variable) TXV's in the field.
I have looked at Daiken for one or two projects.
That said, they are marketing hard but continuing to make watersource products as even they recognize ASHP's aren't a good fit everywhere.
1/2 the heat at 2/3's the efficiency means the other half of your heat comes at 1/3 the efficiency. While it is an oversimplification, if you live in a climate with low temps, you may be doing much of your heating at a 1.5 COP. That is very different than the advertised peak efficiencies. To the folks who miss this subtle distinction and expect 3 COP, their heating bill will be roughly twice what they anticipated.
My biggest concern is when they are not explained well to people in which case expectations will not be met (which has been true of geo and other products as well). There are certainly great applications for all products.

ICF I hope you will be very happy with your Daiken and I'm sure they will be deligted to meet you on ASHP Talk Forums.
joe

While it is an oversimplification, if you live in a climate with low temps, you may be doing much of your heating at a 1.5 COP.

I think that statement could be applied to just about any heating unit with resistance backup. Once parameters are met (or a malfunction occurs) the resistance heat will go on in an attempt to maintain design temp and the overall COP will head towards 1.0 with the accompanying higher electrical bill.

These new high-efficiency ASHPs are feasible where you see deep winter lows of 0F. At those temps you still get a COP of 2.0 or better from the heat pump. What that probably means is that you have many more days in the twenties where the COP is 3.0 or higher. That opens up a much larger range of environments where they can compete with geothermal heat pumps.

ICF- do you know what a HP like this runs compared to a "standard" HP from Lennox, Trane, whomever?

Also while I understand 1.5-2 COP is less then advertised, the alternative (non geo) standard HP stop at around 30 degrees and heat strip kicks on. 1.5-2 COP at 0 is still a lot better then full heat strip, if you compare it to that way.

However if you go with one of these more "DIY" packages and still hire out the install for safe measure, its still coming in slightly higher then the standard ASHP quote. with tax credit, it would be less. With that being said, I can not imagine even the Daiken would be a good idea as I assume it costs a bit more then even a high end Lennox or Trane.

Also, I redid my heat loading since we added some more north glass.  Looks like if I want it to condition the entire upstairs, down stairs, and bonus room over the garage, I would at 29,500 BTU heat requirment.  This is for about 3000 sqft total.  Looks like a 3 ton 2 stage is really what I probably need after all....

Not so fast Ize, you need a comprehensive design with op cost calcs. you may find a 2 ton with aux usage designed in (air source or geo) a more economical fit. Running an extra large compressor all the time to cover a little extra aux use is seldom the best answer. Based on the 29,000 btu load I think 2 ton is likely still the best fit (at least in geo in my AO), but it depends on many things.
You really need better design advice than you have now. Don't let the cart lead the horse.

Daiken equipment tends to be higher than conventional, but can save you money on a duct system.
No tax credits apply. Especially if home has a generally open floor plan so that few airhandlers are required.
j

Posted By lzerarc on 24 Jan 2011 10:32 AM
ICF- do you know what a HP like this runs compared to a "standard" HP from Lennox, Trane, whomever?

I can tell you about our spring 2009 quotes:
Two Geo units - $25,000 total before tax credit.  $17,500 after tax credit.  30 EER, COP 5

Two 13 SEER Trane units $10,000 no tax credit (I don't recall the COP.)
Two 19 SEER Trane units $19,000.  Maybe $1,500 tax credit at the time? - net $17,500 (I don't recall the COP.)

I also wonder if Daikin is more expensive?  Does a person need a Daikin unit in just about every room of their house that they want heat or AC in (compared to a vent over hidden ductwork)?  If so, I'd have a hard time selling that to my wife (in a house) unless it is twice as efficient as a geothermal system, or 1/2 the installed cost (or both.)

ICF- do you know what a HP like this runs compared to a "standard" HP from Lennox, Trane, whomever?

Oh, there is no question that they are more expensive. They represent a step up in technology, and of course, early adopters are going to pay more. You can't really buy them "by Internet", so I couldn't tell you what the wholesale costs are. But, if you are talking a bunch of holes at $2,000 a pop, they might be back in the game. You'd have to have a dealer do the info for you.

Running an extra large compressor all the time to cover a little extra aux use is seldom the best answer

Inverter heat pumps are now in use. The ductless mini-splits are based on them. They run more efficiently over a range of outputs widening the number of situations in which a larger unit might be suitable.

Does a person need a Daikin unit in just about every room of their house that they want heat or AC in (compared to a vent over hidden ductwork)?

Are you talking about "ductless mini-splits" in general? If so, Daikin is only one manufacturer of them Fujitsu, LG and Sanyo come to mind as well....

If so, I'd have a hard time selling that to my wife (in a house)

That's what my architect said before we had a field trip and showed him one in operation... :-)

Posted By geome on 24 Jan 2011 02:51 PM

Posted By lzerarc on 24 Jan 2011 10:32 AM
ICF- do you know what a HP like this runs compared to a "standard" HP from Lennox, Trane, whomever?

I can tell you about our spring 2009 quotes:
Two Geo units - $25,000 total before tax credit.  $17,500 after tax credit.  30 EER, COP 5

Two 13 SEER Trane units $10,000 no tax credit (I don't recall the COP.)
Two 19 SEER Trane units $19,000.  Maybe $1,500 tax credit at the time? - net $17,500 (I don't recall the COP.)

I also wonder if Daikin is more expensive?  Does a person need a Daikin unit in just about every room of their house that they want heat or AC in (compared to a vent over hidden ductwork)?  If so, I'd have a hard time selling that to my wife (in a house) unless it is twice as efficient as a geothermal system, or 1/2 the installed cost (or both.)

curious...was your prices including ducting and everything as well?  Or just equiptment?  I got a quote from a climamater 3 ton 2 stage HP, desuper heater, horizontal wells installed for 13,500.  Ducting, HRV, filtrations would need to be added to this as well.  However it is my understanding that the credit only applies to the 13,500 number, not the total number (say another 6k for the rest?)
However your EER and COP is higher.  EER is 25 and COP is right around 4.0. 

Posted By lzerarc on 24 Jan 2011 03:59 PM

curious...was your prices including ducting and everything as well?  Or just equiptment?  I got a quote from a climamater 3 ton 2 stage HP, desuper heater, horizontal wells installed for 13,500.  Ducting, HRV, filtrations would need to be added to this as well.  However it is my understanding that the credit only applies to the 13,500 number, not the total number (say another 6k for the rest?)
However your EER and COP is higher.  EER is 25 and COP is right around 4.0. 

Ours was a retrofit.  Adequate duct work was already in place.  It included labor, two geothermal units, horizontal loop, 2 DSH's, and everything else that was needed for the installation.  No HRV.  I bought electrostatic filters on my own (not included in the pricing given.)  We did go with top of the line WF Envision units.