Eric, your advice was good until you started about me singing. Really, that's not what you wanna endure :-)
About the thermal mass. Do you think concrete walls (ICFs) and a concrete floor will give me enough thermal mass? BTW those scissor trusses look great it gives a nice classic look to a house.

ICF and concrete floors combined would give you more than enough thermal mass.
Cheers,
Eric

Even on cool summer nights the amount of humidity in outdoor air in that part of the country is too high to be comfortable or healthy.  The average mid-summer outdoor dew point in Connersville IN is about 65F/16C.  Moving that air into a 75F/24C room raises the relative humidity to a sticky unhealthy 71%, a humidity level at which mold grows rapidly, and humans are more susceptible to fungus infections of skin & lungs.

A heat recovery heat exchanger on a wood-stove flue will cause excessive accumulation of creosote, increasing the fire risk.

Solar thermal heating panels operate about 50% average efficiency.  Photovoltaic (PV) panels would operate at about 20% efficiency (if you pay a bit extra for high-efficiency version).  Leveraged at 3:1 or better with a mini-split, you get more than 60% efficiency out of the same amount of roof area.  Solar thermal panels for space heating require "heat dumping" for 4-5 months out of the year to keep the system from overheating when the heat is not needed, which uses pumping power.  PV panels could be running your mini-splits in cooling mode during those months rather than overheating your thermal storage tanks.  PV is simpler, cheaper (in lifecycle energy output) and lower maintenance than solar thermal panels.

At TODAY's $4/watt cost for grid tied  PV the US, the full levelized lifecycle cost is about 18-22 cents/kwh. (Where US Federal/state/local subsidies can be applied it's even cheaper.)  At Germany's  current $2/watt installed cost it's about 12-14 cents/kwh.  (You get slightly more out of the PV array in Indiana than in Germany, due to different weather conditions.)  The cost of solar is continuing to fall, which is putting the utilities at considrable risk, since by 2025 new grid tied PV will become THE LEAST EXPENSIVE FORM OF ENERGY OF ANY TYPE.  The notion that energy prices in the US will only rise from current levels or that it can rise by much is not well founded.  The financial analysis from the Sanford Bernstein investment bank predicts broad energy price deflation to begin sometime around 2025, as a direct result of very low cost PV.



The analysts at Barclays agree.

If electricity prices rise to anywhere NEAR current NL or German levels, it will become cost effective to unplug from the grid entirely (something that is on the brink of happening in Australia and Hawaii today!)  The Edison Electric Institute believes that electric cars will be able to keep the demand high enough to avoid large numbers of people from going off-grid, but that is independent of the actual price of electricity.   When electricity prices rise above the falling cost of PV such that it makes it cost effective for a house to unplug from the grid, it will also be cost effective to charge your car with off-grid power.

Bottom line, there may be some amount of energy price inflation in the US for then next 5-10 years, but there is a strong economic wind pushing back on electricity prices.

In an Indiana location geothermal will not beat the efficiency of mini-splits enough to rationalize the much higher cost.  With new construction spending the cost difference on  improving the thermal performance of the house will yield a greater reduction in power use.  All geothermal systems are custom-designed one-of-a-type, that come with some design risks, whereas a mini-split is a highly evolved highly engineered "system in a can".  It's pretty hard to screw up the efficiency of a mini-split, but it's pretty easy to screw up the efficiency of geothermal systems.

Cooling your house with geothermal systems by cooling off a large surface (floor, ceiling or wall) works fine for sensible heat (temperature), but does nothing for managing the latent heat (humidity).  In Connersville IN there are extended periods of  time during hot outdoor weather when the outdoor dew point is over 20C, even over 22C, which means a cooled slab would collect liquid condensation on it.   This method of cooling can work pretty well in most of Europe, or in the western 1/3 of the US where summer air is sufficiently dry, but it would not be very good in Connersville.

I have known Dutch people living in the US who returned to NL years later for the health care benefits.   It is legal in the US to hold full dual citizenship with most European countries, being a full citizen of both.  I don't know if Dutch law allows that, or if there would be any restrictions.

Dana,
I agree with everything you said except for using solar PV for the DHW. In a heating dominated climate there isn’t a very effective, moderate cost way to leverage it (that I know of). You can of course use a heat pump water heater powered by PV, but then in the winter you need to also reheat the air with a minisplit. You could use a geothermal system+ desuperheater, but for an efficient house this is overkill. I agree that Solar space heating, other then passive is a tough sell and not cost competitive compared to PV. Localy the numbers I have gotten are around 3.50$/watt installed in CT.

Cheers,
Eric

Dana,
Clear:
- Mini-split is the top choice
- Surface cooling is asking for problems. Health and mold problems. So certain cheap cooling comes at a high cost.
- PV panels have less efficiency than heat panels but that's leveraged away by the mini-split COP. (I'm ashamed I overlooked something so extremely basic as adding the COP into PV performance)

I think that's a correct summary.
I'm not sure I completly understand your explanation about PV vs electricity prices.
I understand the util companies don't dare to overask because they clients will run off. But OTOH what can they do? Their electricity is often generated using fossile fuel, of which they don't control the price. So can they really lower their prices, assuming they don't make extreme profits right now? I'm sure the PV price per watt will drop but I fear the utils companies are lobbying full time to get rid of tax credits. That would offset lower PV prices for quite while I think. $4 installed cost. I could install it myself but likely nu tax credit then. Are this good PV prices? http://www.wholesalesolar.com/gridtie.html




When I would hold full dual citizenship will I also be able to get tax credits for PV panels. Or is that only for the full blood Americans?

Posted By Eric Anderson on 11 Aug 2014 02:35 PM
Dana,
I agree with everything you said except for using solar PV for the DHW. In a heating dominated climate there isn’t a very effective, moderate cost way to leverage it (that I know of). You can of course use a heat pump water heater powered by PV, but then in the winter you need to also reheat the air with a minisplit. You could use a geothermal system+ desuperheater, but for an efficient house this is overkill. I agree that Solar space heating, other then passive is a tough sell and not cost competitive compared to PV. Localy the numbers I have gotten are around 3.50$/watt installed in CT.

Cheers,
Eric

Is it *possible* to heat water with a mini-split? I'm fairly sure my natural gas system can only do one task at the same time. It keeps the boiler hot or it heats my house. Giving hot water priority that means when showing the house isn't heated. But (in this climate) that's no problem unless I shower for hours.

Only indirectly,
IE use a heat pump water heater which cools the air and heats the water, then reheat the air via a minisplit. Seems like a bad idea to me, even though the cop will still be north of 1.
there are air to water heat pumps, but I know nothing about them other then the tank DHW models.
cheers,
Eric

You don't even need to be a citizen (or even a legal resident!) to collect US Federal tax subsidies on PV systems, but you DO need to be a legal US taxpayer, and the PV system must be installed in the US.

Electricity rates in the US are regulated in each state by state utility commissions, and the utilities can only raise rates if the regulators allow them to. But the fact that PV is less expensive than the retail rate in some locations now, and will be less expensive everywhere in only a decade or so is a problem for the utilities, who still have to pay off the capital costs of their generators whether they use them or not. Tax credits no longer drive this market- the raw cost of solar is already cheap enough to compete at expensive-state prices without tax subsidy. Going forward this will be true everywhere in the US. In Australia the electricity rates are comparable to NL, and even without net-metering at the residential retail rate rooftop PV is competing with the grid, reducing overall demand for power from the grid, and now they have too much coal fired capacity to be economic- the utilities & regulators either didn't see it coming, or they were in denial, but it's now a mess.

This is a looming and quite serious problem that most utilities and regulators in the US are not equipped to deal with. If they don't figure out how to keep rates low enough, the utilities will go bankrupt as people begin to leave the grid, which will make it even more expensive for those who do not have solar. The transition is going to be disruptive, but it doesn't mean energy prices will be going up. The falling cost of solar places an upper bound on energy prices. That upper bound that is becoming lower over time. So while there may be some price volatility during the disruption phase, energy prices are not going to rise very fast or very far, and in the longer term should fall.

Different states have different rules, and it gets pretty complicated. But most local & state utilities/regulators will not allow DIY installations of grid-tied generating equipment by unlicensed non-certified installers. It's more than just a tax-credit issue.

You can't heat water directly with a mini-split, but heat pump water heaters that extract half of the heat going into the water from the room air can work.

Posted By Eric Anderson on 11 Aug 2014 04:06 PM
Only indirectly,
IE use a heat pump water heater which cools the air and heats the water, then reheat the air via a minisplit. Seems like a bad idea to me, even though the cop will still be north of 1.
there are air to water heat pumps, but I know nothing about them other then the tank DHW models.
cheers,
Eric

In Indiana there are 4+ months to the cooling season, 4 months when a heat pump water heater will be lowering the cooling loads of the house, taking some of the cooling load off the mini-split.

Air to water heat pump water heaters using outdoor air do not have an annual efficiency advantage over a mini-split + heat pump water heater.  I have yet to see one of those installed here. 

The Daikin Altherma air-to-water system used for both space heating & hot water is pretty effective, but it is dramatically more expensive than mini-splits, and has some issues surrounding managing the latent load in a muggy-sticky place like Connersville.

Thanks again Dana.

You brought up the humid climate several times. I'm wondering how a mini-split dehumifies. Isn't it just an outdoor unit with refrigeration lines to an indoor cassette. How is the water removed from the air and transported outside?

The water condenses in the indoor unit, and goes out through the same condensate drain that the A/C mode uses.Something to bear in mind- you have to have a condensate drain, and if gravity-fed isn't possible, you will have to add a condensate pump to carry the water out. It is basically air conditioning, only somehow they have figured out a way to minimize the cooling aspect. The owners manual does say that the room may be cooled 'slightly' when in dehumidifier mode. Mine sort of goes into dehumidify mode automatically. Even when it is cool out, the unit runs very slowly and dehumidifies without cooling. Mine is set to 'cool' and is set for 76 F. We had a couple of days that stayed below 70, but the house stayed around 76, and the unit kept running. It was rainy, so there was a lot of humidity to manage. The sensor on the Mitsubishi measures humidity as well as temperature, and regulates itself accordingly. It can also be set to sense the warmest part of the room, and direct the A/C in that direction. Certainly a smart little heat pump!

So the automatically keeps the humidity and temp down at user set levels? I don't have to switch manually trough all sort of modes/programs.

MINI_SPLIT

I think I need about 8 indoor units. I've looked a bit around and it seems that the more units can be connected the higher the tonnage. That's logical in most cases I assume.
I will have 2 or maybe 3 guest rooms which need no or very little heating/cooling when they are not in use. Keeping the humidity in check to avoid mold and above freezing will do most of the time. Not very cost effective but I think there is no other way.
The temp in my bedroom is only of importance when I'm actually in that bedroom. When I'm not there the heating/cooling requirements are low.
Likewise the temp in the living, kitchen, library, etc isn't that important when I'm sleeping.

I did a quick check on the Mitsubitshi site which outdoor units supports up to 8 indoor units. It's a 3 ton device.
What tonnage does each indoor unit have?
Can a single cassete deliver 2 ton heating in my living room while the other 7 cassetes use the remaining 1 ton to keep the other 7 rooms within reasoneble temps?
That may sound like an odd question but consider this:
Assume my house is 4000 sqft. But during day time only 2000 sqft is used and during night time the other 2000 sqft. Or even less when there are no guests.
Then maybe only a 1.5-2 ton unit is needed.

In the same line of thought. During extreme cold an outdoor unit may not perform well enough to keep my whole house heated. So I could either buy a bigger unit that too big 99% of the year or I could use some sort of backup heater. But if I could route all power to my living space units my outdoor unit would be big enough.

All the above obiously greatly depends on how much capacity can be rooted to a single indoor unit


???

You can determine the tonnage by the BTU. 12,000 BTU= 1 ton.

A few things about mini-splits: The multi-head units aren't as efficient, and don't have the low temperature capability of single units. We were originally going to use a multi-head, but I wanted the low temperature capability, and didn't want the effiiciency hit. Our house is 1300 square feet indoors, and we have one 12K unit in the main part of the house, and a 9K in the master suite. I have found that the 12K unit easily keeps the entire house cool and dry, even on hot days. The hottest day we've had so far was 98 F., and the unit still only ran on the low fan setting. I keep all of the interior doors open (actually, I don't HAVE interior doors yet!). At night, I just run the 9K unit. The 9K will keep the whole house cool during the day, but the humidity seems to creep up, probably because it is not centrally located. By running the 9K at night, the bedroom is nice and cool (my wife would say cold) since the unit is really way too big for the space. I've read that mini-splits aren't too bad when oversized, as they simply run slower, and draw fairly low power. When you oversize a conventional ducted A/C system, they don't run often enough to dehumidify properly. Later I'll post my floor plan with the mini locations so you can see what we have.

I know about the tonnage. But right now that's not really important because I'm still designing my house. sqft, number of floors, amount windows, flat ceiling or cathedral, etc is still not decided.

8 single-head units likely are far more costly than one big one. Outdoor units for 161sqft rooms don't even exist I think?
Doors open isn't a real solution. Many people want a bit of privacy in a bedroom. Plus as I wrote in my previous post I want different temps in the house. But that wish is partly to cost (energy) costs.

Unless you have an enormous house, you wil not need eight units. If the house is tight & well insulated the temps will be constant throughout.

It's not the amount of sqft but the number of rooms.
Overly simplified I have living area. A door to a hallway which connects to bedrooms, bathroom etc

Posted By NewHoosier on 12 Aug 2014 02:22 AM
MINI_SPLIT

I think I need about 8 indoor units. I've looked a bit around and it seems that the more units can be connected the higher the tonnage. That's logical in most cases I assume.
I will have 2 or maybe 3 guest rooms which need no or very little heating/cooling when they are not in use. Keeping the humidity in check to avoid mold and above freezing will do most of the time. Not very cost effective but I think there is no other way.
The temp in my bedroom is only of importance when I'm actually in that bedroom. When I'm not there the heating/cooling requirements are low.
Likewise the temp in the living, kitchen, library, etc isn't that important when I'm sleeping.

I did a quick check on the Mitsubitshi site which outdoor units supports up to 8 indoor units. It's a 3 ton device.
What tonnage does each indoor unit have?
Can a single cassete deliver 2 ton heating in my living room while the other 7 cassetes use the remaining 1 ton to keep the other 7 rooms within reasoneble temps?
That may sound like an odd question but consider this:
Assume my house is 4000 sqft. But during day time only 2000 sqft is used and during night time the other 2000 sqft. Or even less when there are no guests.
Then maybe only a 1.5-2 ton unit is needed.

In the same line of thought. During extreme cold an outdoor unit may not perform well enough to keep my whole house heated. So I could either buy a bigger unit that too big 99% of the year or I could use some sort of backup heater. But if I could route all power to my living space units my outdoor unit would be big enough.

All the above obiously greatly depends on how much capacity can be rooted to a single indoor unit


???

You absolutely DO NOT want to install 8 indoor units!

If you do, each one will be ridiculously oversized for the heating & cooling loads, and they will not operate efficiently. It would cost more up front, and provide less comfort, and much lower than rated efficiency.

The smallest cassettes out there in Mitsubishi's product line are rated 6000 BTU/hour (about 1760 watts of output) for cooling, the heating output will be slightly more than that at your 99% outside design temperature.  If a room doesn't have at least 4000 BTU/hour of heating load it should not have it's own head.

A 9000 BTU/hr mini-duct cassette can have it's output split into multiple short duct runs without a huge drop in efficiency- it's a reasonable way to go if you're building a code-minimum type house instead of a high-performance house.  A typical 4000' code-min  house will have a heating load of about 40,000-50,000 BTU/hr @ +5F/-15C which is your approximate design condition, but it is neither difficult nor expensive to design & build it to under 30,000 BTU/hr.

A total heat load of 30,000 BTU/hr @ +5F is within the range of a 2-ton or 2.5 ton Mitsubishi capable of handling 3-4 heads/cassettes.  A 3 ton unit would be oversized, and run less efficiently, even if the interior heads were appropriately sized for their room/zone loads.

Before choosing a heating /cooling solution you need to calculate the actual room-by-room heat loads, as well as the whole-house load.  And since the room loads can be changed during the design phase it can be optimized.

That's the whole point Dana.

Many rooms don't have a fixed heating load. If a guest room is only occupied 1 month a year should it be part of the load calculation? Why heat a room if nobody will enter that room the next 2 months?
That was the whole point of my post. I don't really want 8 unit to use them all for heating. I only want them for flexibility. A 2 ton unit with 8 heads.
One of the (advertised) advantages of a cassette is that each room can have its own temperature. That sounded energy efficient to me. But basically the advise given is: Heat the living room and let the heat 'escape' to all other rooms. The result will be 'overheated' bedrooms.

Most bedrooms are 15m2/161sqft. Walls will be R30. Ceiling R40-50.

BTW I'm not really choosing/sizing a heating system right now. I'm exploring. Maybe mini-splits are not for me...

EDIT
I always assumed oversizing was only based on the outdoor unit.

Here is my analogy. Take a cooler and fill it part way with ice. Now put a cardboard box inside the cooler. Even if you don’t put ice in the cardboard box, it stays the same temp as the rest of the cooler. Now move the ice to one side of the cooler, no difference. This is a well insulated house. Now open the lid of the cooler and leave it open. This is a poorly insulated house. Now you need to put ice in the cardboard box to keep it cool, even though there is ice in the corner of the cooler
A well insulated house is the same way IF the Shell is much more insulated than the interior partitions, the interior temp stays close enough that comfort is not compromised . 2 layers of drywall is about~ R 3 so a standard partition wall has about 3/ 40 the R value of the outside wall. An individual room that does not have too much exterior surface area and a fair bit of wall area with a heated space will remain at about the same temp or close enough.

You can't realy not heat a room (cardboard box) if it is inside the cooler (envelope)

The reason a large minisplit with lots of heads is bad, is that if you have a 36000 btu outoor unit, the minimum output is likely around 9000 btu’s/hour rate when the room may only need 500. Now each zone calls for heat independently for 2-3 minutes at a time- This leads to lots of short bursts of heat which is very inefficient

Better to have 2-3 right sized, standalone units that are more efficient- but more costly.

Cheers,
eric