Eric, that post is by far the most informative post I have read bar none. Thank You. I was struggling to get some traction and actually know what someone would suggest for what I am trying to do. You are correct....my hearts desire is to use the outdoor wood boiler, however I realize that if I am building a new home the potential for more modern insulation techniques and air sealing options and those might make the heat load of the house to low for the boiler to be a good option. Additionally I am leaning towards ICF because it seems that everything I want to do to the stick built and wood sheathed walls would be eliminated with ICF. I am not sure it's in our budget to do ICF for all the exterior walls but believe me I am very interested in using them for our house.
I will work on your list and get the info that I can from the level of design we already have and as we finalize our plans I will be able to answer more. Thanks again.

Folks here have mentioned heat storage but I'm going to offer it again because it answers your problem and makes your life easier besides. Classic homebrew is to adapt a large propane tank that is past its expiry. Or you can buy an off-the-shelf tank here. http://www.stsscollc.com/ Hook it up and your OWB sizing problem goes away, along with the pollution issues at idle, You run the boiler flat out to ashes. Because it is heating water storage rather than your house, you can make the latter as tight and well insulated as you want., The tighter it is the less work required of you. A 1000 gallon tank with a 50 degree temperature rise above HVAC operating (ie baseboards: 135-185) would store 400,000 btus. Reducing the OWB chores to every third day or so is a happy outcome in my book. I have free firewood too but, alas, not the kind that splits and stacks itself.

Thanks Todd...I see the gains from the water storage but I don't really see how starting a fire every third day and having to baby sit the furnace while it burns for 8 hours to heat all that water back up is easier than just maintaining the temp on 150 gallons. Something to consider though.

You mentioned baseboards....i assume you are talking about the kind that are connected to the furnace much like a radiant floor system? How do you like those?

Baseboards work well, a bit clunky looking, some expansion snap crackle and pops, but nice even heat. You might consider European style panel radiators as well. http://www.houseneeds.com/heating/hydronic-radiators They take up less room and look better.

The Slimline baseboards look pretty sweet....and by using the water from the boiler I think that would be a solution to my boiler draw issues? Just trying to do what's best for the overall quality of heat with the potentially TIGHT and super insulated house.

If you are going with hydronic think of it as 3 separate but inter related issues.
First is getting water hot, efficiently at reasonable cost, with minimal effort. The second is transferring the energy in the hot water to the house, third is what happens when you go away and no one is loading wood.
The combination of a wood gasification boiler with a large hot water tank accomplishes 2 of these things. Basically you load it up with wood, it burns hot and hard to complete burnout. You end up with a hot water tank with a lot of BTU’s stored up. I would probably size the boiler and hot water storage tank so that in the coldest part of the winter it needs to be fired once per day to cover your heat and hot water. The swing seasons it would likely need to be fired every 2-3 days and in the summer, you might get away with firing it once per week if it is very well insulated (and you want it well insulated). I would put a temp sensor in the tank with a readout in your kitchen so you can easily monitor how much energy is left in the tank. With a little thought and practice, you can burn like you have an outdoor reset. When it is really cold outside burn wood so that the tank gets to say 170° F and when it is not so cold out, burn wood to get the tank up to 135.
If you are using a heat exchanger coil to get DHW you will need a thermostatic mixing valve on the hot water line so you can’t scald anybody when the water is very hot. As long as the temp in the tank never gets below 120° you should be ok for hot water
Secondly as far as taking the energy of the hot water and transferring it to the house, you can use in floor radiant, panel radiators and baseboard. In the basement and shop areas, it may be easier to use hydronic fan coil heaters. They can also be oversized in the garage if you want to heat it quickly to work out there for a few hours and then let it go back to 45 or 50°
Here you are going to want to work with a good radiant designer as all the different emitters have different optimum water temperatures and transfer efficiencies.
The third part of the program is what to do when you are not around to load wood. This simplest back up is an electric boiler, but it is likely the most costly energy source.
While you are looking at wood fired heating systems, you might look at masonry heaters also as a quality heat source using wood.
Cheers,
Eric

Posted By toddm on 28 Oct 2013 07:58 AM
Baseboards work well, a bit clunky looking, some expansion snap crackle and pops, but nice even heat. You might consider European style panel radiators as well. http://www.houseneeds.com/heating/hydronic-radiators They take up less room and look better.

Fin tube baseboards are not-very-tall convectors, and only work well at water temps of 120F or higher. Below that the fall-off in heat emittance with temperature is very non-linear, and even affected by dust-kittens etc.

By contrast radiant floors and low-temp convecting panel radiators, old-fashioned column radiators, and case iron baseboards continue to deliver predictable heat at temps down to ~80F heating system water, which means the low-limit temp on your thermal storage can be much lower, with much lower standby loss.

Interesting.
I have considered the masonry heater simply because it doesn't require any electricity to run and it should do a nice job in our vaulted ceiling living room where it would be placed. Trouble is finding someone that is qualified to build one correctly.
All this water storage info has got my wheels turning. I still need to get with my architect and find out the best answers to a lot of the questionds Eric has asked. By the way Eric are you an HVAC contractor?

I have considered the masonry heater

Water stores more heat in a fraction of the area. And it's easy to distribute and control.

I believe that you can use a motorized outdoor reset controlled mixing valve to deliver a continuous, constant temperature to well balanced zone radiators to avoid the rapid and extreme changes that cause noise.

Easy, I am definitely not an HVAC contractor. Currently I am employed as a building manager, but I am BPI certified as a building analyst and am working towards starting a company to do auditing and performance contracting. Cheers, Eric

If you are in an area governed by the IRC, you will require an automatic heating system. This will require you install an electric or propane boiler as well.

Eric here is the list you had posted with the best responses I can come up with right now. I don't have everything but it should get you started. Thanks for any assistance you can offer me.

What energy sources are available to you? Electricity, Propane, wood
Do you have average costs for each fuel type in your area?
Do you require AC or is it optional. yes
What are you targeting for ACH50? Not sure what this is
What are you targeting for ventilation rates for the structure? Not sure what this means
Are there any special occupant issues? My daughter has asthma and allergies so air quality is a must.
Do you cook a lot indoors? yes
Large stove? Yes, large Viking stove
Cook with gas or electricity.
Design____
What does the house look like? Very simple farm house design with 2 full stories, and a walk out basement
Basement______How much of the basement will be underground? Will it have a walkout ie exposed wall? ½ underground and back wall and west wall will be exposed with windows
What will the R value of the foundation insulation be and what will the insulation under the slab be? Under slab will be 3 inches of PS foam/ we are planning to do radiant in the basement slab
What will the basement be used for? Rec Room, storage, gun room, bedroom, bathroom
What will the floor covering be? Carpet/exposed concrete
Garage? What will it be used for? Vehicle parking/ Does it need to be heated to 70° or are you just trying to keep it at 50-55…50-55 would be great. But there is a wall that’s shared with a bedroom so that wall will be insulated better that the exterior of the garage.
Insulation under the garage slab? Yes, same as basement
Main Living Area above ground_____
What is the wall construction and insulation plan( ie wall stack up)? 2x4 stick framed walls, wet blown insulation in all stud voids, OSB seams taped and PS foil faced foam on exterior of OSB. Foam sealed rim joists and gasket material under sill plates long enough to be tied into exterior foam board
floor coverings? Primarily Hardwood with ceramic tile in mudroom , entry way, and pantry areas.
Total square footage of windows on each side of the house,
is there shading on the east and west sides? Some shading on east side from garage positioning,
How about the south side. Home is positioned for a southwest exposure, no shade
What glazing type will you use? Not sure what to use
Ceilings What R values are you targeting? Ceiling will have 24 inches of blown cellulose with sealed seams. OSB on bottom of trusses to support insulation weight.

ACH/50 is air exchanges per hour at 50 pascals pressure, as measured with a calibrated blower door. This is the standard way to determine "tigthness" in an apples-to-apples kind of way. It has been enshrined in code- a new house built to IRC 2012 standards needs to be tested, and score below 3ACH/50. A PassiveHouse is required to test under 0.6 ACH/50 to pass that part of the certification. The ACH/50 number can be a very crude way of estimating parasitic infiltration rates that add to the heating and cooling loads, but since there is no way to know the location(s) of the leak(s), the inherent error in the estimates spans a full order of magnitude.

Ventilation rates are the average cubic feet per minute being moved in/out of the house via mechanical ventilation. Any house benefits from active ventilation, but in very tight houses it is essential. The air exchange at different temperatures has an energy penalty (about 0.018 BTU per cubic foot per degree difference), much of which can be gained back if your ventilation system has a heat exchanger (HRV/ERV).

Almost any code-legal window would gain more heat during a winter day than it loses over a winter night, but it's good do optimize it for both your winter & summer loads, and the amount of thermal mass in the house. In general, having slightly more square footage or higher gain window facing south is beneficial, since the unwanted summertime gains can be mitigated with overhangs or awnings. On the east & west sides it's better to have low-gain windows &/or less square footage to mitigate unwanted gains from low-angle sun that can't be shaded with overhangs. The loss characterisics of the window are it's "U-factor" number (lower==lower loss), the gain characteristics are it's SGHC number (higher== higher gain.) Since you are oriented for southwest exposure you'll have a harder time shading against unwanted summertime gains, so don't go too high or too high-gain on that side. You may want to go higher gain on the SE facing side as your primary passive-solar if you can. You can get rough energy use numbers related to the window by it's orientation, site location, shading factors and U-factor/SGHC numbers by using freebie download tools like RESFEN (google-it, it's on the Lawrence Berkeley National Laboratories site). In general, in a higher-R house it's appropriate to use U-0.25 or lower windows everywhere, except where intentionally used for passive solar gain. To go lower than U0.25 usually requires triple pane windows.

The thickness of the foam on the sheathing matters more than the facers. You've indicated foil-faced EPS on the exterior, but no thickness. Bloomington is on the cool edge of US climate zone 4, and you could get away with as little as 3/4" of EPS without risking wintertime moisture loading of the OSB sheathing, but that's not a very high performance wall- it's comparable to what you're putting under the slab, from a whole-assembly point of view(!). Given that you have an R80+ attic and R12-R15 under the slab, it would be appropriate to use polyisocyanurate instead of polystyrene on the sheathing, and go at LEAST 2" with it (making it as thick as a 2x6 framed wall), or a even thicker. (Over 4" gets awkward though.) A 2x4 cellulose filled studwall with 2" of polyiso comes in at about R23 after factoring in the thermal bridging of the framing. With 4" of exterior polyiso you'd be in the R35-ish range for a "whole-wall" number.

Designing your roof pitches for optimal solar gain for a future rooftop solar PV is a good idea- especially that SW facing pitch. Clean lines with few bump outs hips or dormers is the key. Currently the installed cost of rooftop tied to the grid with an inverter is averaging about $5/watt nationwide, but $4 in states where it's being more actively pursued by state utilities/regulators. In parts of Texas it's under $4, and slated to go under $2 at some point in 2014-2015 time frame (which is credible since in Germany any body can call up and get competing bids in the $2 range right now, using the same panels/racks/inverters.) If not this week, at some point prior to 2020 the lifecycle cost per kwh will be well under your retail rates, and even if YOU don't want to spring for the up-front costs, there are third party operators willing to spend the money, cut you a discount on your power rates, and sell the PV output to the grid operator. A SW facing pitch is pure-gold for them, since the output correlates better with the grid peak demand hours, when the wholesale cost of power to the grid operator is at it's max. Under current IN law if you paid for the PV you can simple net-meter: run the meter backwards, essentially developing a credit over the summer to be worked off in the winter, but the third-party installers can set up power purchase agreements with the utility for the output, and they usually have hundreds or thousands of installations to bargain with. (Peak summertime wholesale power is generally way more than the residential retail.)

What Dana said.

Anyone using forced air should be careful to keep supplies and returns balanced so that they aren't creating in/ex filtration.

Anyone burning wood should look at storing heat (probably in water) so that they are burning cleanly and don't have to refuel at inopportune times.

Resistance electric and propane - usually best not to make much use of it.

Major oversight on my part....the house will be SOUTHEAST facing....still no shade but SOUTHEAST not SOUTHWEST. Sorry for any confusion this may cause with recommendations DANA1

I'm probably not going to do the water storage simply because i cannot wrap my head around the reason for doing so right now. I just don't have any issues with the furnace needing to be loaded at a bad time. I load it once a day and it's good to go.

As for the R-23 walls....is that ok with the climate I am in? Also the R-12-R-15 you mentioned under the slab....is that sufficient or overkill with the radiant? I bet I could go lower in the attic as well just to try and save some money and gain some space, i just realized that the attic in our home design has the potential for storage space. Basically I wonder if I am over insulating???

For a climate zone 5 or higher climate the "pretty good house" rule of thumb is for R values of 5/10/20/40/80 for windows, sub-slab foam, foundation walls, above grade walls, and attic. That isn't fixed in stone, but it's the approximate values where using standard methods you optimize the energy savings for the insulation type.

You are in zone 4, so dialing that back to 4/8/16/32/64 is probably reasonably cost-effective. So, in order:

An R4 window has a U-factor of 0.25, which can be had in a double-pane. It's not a cheap window, but it's a lot less expensive than U0.20 (R5) triple-panes.

An R8 slab is 2" of EPS. But if you're heating the slab it needs to be bumped up- R12-R16 (3-4" of EPS) is still worthwhile.

To hit R16 at the foundation wall it can either be a bare-bones R16 insulated concrete form, or 1" of polyiso on the interior side of the foundation wall with an UNFACED batt-insulated 2x4 studwall, whichever is cheaper. (The ICF costs more for the materials, but it's a lot less labor.) The band-joist and foundation sill can be insulated and sealed to the wall-foam with an inch of closed cell spray foam followed by R15 rock wool (carefully trimmed for fit) as the interior side thermal barrier against ignition, resulting in a ~R20-ish stackup.

To hit R36 with a 2x4 studwall with fiber cavity fill takes 4" of polyiso on the exterior of the sheathing. If you went with a 2x6 wall 24" o.c. it takes about 3-3.5" of exterior polyiso.

An R64 attic would be a truss-roof with 18" of cellulose (20-21" initial-blow, settling to 18" in 20 years.)

Wall area is typically more surface than attic, but open-blown cellulose is a lot cheaper than rigid foam. If you want to use a sharper pencil on the bang/buck optimization, model the place using BeOpt, and punch in real numbers of different quotes.

If it's a SE facing house you can still go for a hint more solar gain (more window area) and cut back on the SW side. But if the roof lines can still get decent SE facing roof area, that's somewhat more valuable PV than a SE orientation. A hipped roof using both pitches for PV can probably have HUGE output, but may not be worth the complication & cost over a simpler gable using trusses.

Dana gave you some great advice. First off you are thinking of this before you build, so you area already ahead of the curve. His explanation of ACH50 and the problems with translating that into natural air leakage are spot on. I will try to offer advice on other pieces of the puzzle--------- In the basement, since it will be living space it will likely be heated the same as the rest of the house so R 15 under the slab is reasonable. Any carpet you use in the basement should be less than r-3 with pad if possible. If you keep the R value of the insulation under the slab ~5 times greater than that over the slab, ie carpet, your heat loss will be minimized. Since it is living space, I would look at the cost effectiveness and ease of installation of using Insulated concrete forms for the foundation. Since you are using 2x4 construction above with a couple of inches of exterior foam, you should be able to line up the exterior foam with the foam from the ICF so it looks seamless. The fact that alot of the boundation is exposed, leads me to recomend insulating it to a similar value to the walls, an R21 form would fit the bill.------- I would try to get the building air sealed to under 3 ach50. This lowers heating and cooling costs, and reduces moisture loading in the wall assemblies. It also allows you to control the flow of air into the structure. Any outside air that is brought in mechanically can be filtered. The priority would be sealing the garage from the living space to prevent VOC and CO into the living spaces. Next would be the ceiling to attic and the basement. ---------- In your case, with a child with breathing issues you are going to want to focus on indoor air quality issues. Good Air Quality is a combination of things, many of them you can deal with at the construction stage. Basically you want to prevent things that contribute to poor air quality from getting into the air, and you want to dilute out any pollutants that get into the air. --- Point sources of contamination need to be delt with at the source. The stove and oven need to be properly vented, if they are propane they should be combustion tested for Carbon Monoxide(CO) output. You want the vent hood to extend past the front burners. What you want to be careful of is the massive vents that are often sold with quazi commercial ranges. I have seen some installed in houses that were 1200 cfm on high. If you do install one of them, it needs to have a makeup air source because it causes the house to be negatively pressurized when running. Shoot for 300-400 cfm on high. --- The bathrooms should have exhaust fans that have at least 50 cfm of airflow flow. I always recommend that they be on timers so they run for a period after the shower/bath is finished, a 10-20-30 min timer is fine. If you get a quiet fan, your family is much more likely to use it. --- If you store chemicals and park in the garage, I would add a small powered exhaust fan in the garage so it is always slightly negative pressure and is constantly diluting with outside air. Something around 15-25 cfm would be good. This keeps contaminates from the house --- The last big source of contamination would be the outdoor boiler. They tend to produce a lot of particulate if they are not burning hot and hard. It should be located downwind of the house for the predominant wind patterns and the chimney should be higher than the house. Wood smoke is an asthma trigger for me, but I comfortably burn wood with a high efficiency woodstove so you can deal with it.------- Once the point sources of pollution are take care of, you need to dilute out the remaining contaminates. The best way to do this is to install an ERV or HRV and introduce a controlled amount of fresh- tempered air into the house. I would shoot for one that can run at its highest fan speed at about 2 times ASHRE 62.2 2010. It should have a hepa filter on the fresh air side. Once you are in and living in the house , you can play with the ventilation rate to get what you need. You nose is quite sensitive and you can quickly figure out how much ventilation you need for the air in the house to not seem stale when you first walk in from the outside. I would exhaust air from the laundry room, bathrooms, and kitchen, and I would supply fresh air to bedrooms and living room. I would supply a higher flow rate of fresh air to your daughter’s bedroom. ------- If you end up with some sort of a forced air system for heating/cooling, you are going to want a very good quality air filter (hepa) in the system. Make sure that you tell the HVAC guys that you are going to use a hepa filter. This is important because these filters are a lot more restrictive of the airflow than a standard filter. Basically they have to design the system to use a larger filter size to make up for the restriction or there will be too much pressure drop across the filter. ----- Because of the size of the building,I think it would probably be easier to used a ducted forced air system for cooling/ backup heat as opposed to minisplits. I would look at something like the Lenox XP21 heat pump, sized properly to manual J heat loads.------ As far as windows go, on the South East side I would probably specify high solar gain low e argon filled double pane windows Cardinal lowE-180 or similar. On the other 3 sides I would go for a low solar gain double with argon fill (or Triple if you can afford them). Generally triple panes never will payback their increased costs in energy savings. Where they are worth it is if you have a lot of windows near where you sit or sleep. Basically they increase the mean radiant temperature and make a room feel more comfortable on cold nights. It has a comfort payoff, but not justifiable on the basis of energy savings alone.------- When you are building prior to the insulation, you should blower door test the house for air leakage, and correct any problems. Because you are using osb on the bottom of the truss cords you have an easy way to establish and test the air barrier before the drywall goes up. I would use the OSB as the air barrier and tape the seams or better yet use Zip sheathing panels and tape the seams with zip tape. Much easier to deal with air leakage before insulation and drywall. ------cheers, Eric

THANK YOU DANA1 and ERIC ANDERSON. I was hoping that I could get some specifics and actual things to investigate since the market is so darn flooded with products claiming to be energy efficient and green and all that.

I do have another question. If you siggest that Forced air is probably the best way to heat and cool the house then how does the ERV/HRV work to introduce air? I assume that it's in addition to the forced air but isn't that kind of working against eachother? Not sure but aren't the HRV/ERV systems expensive? Is there one that is recommended? I haven't even began to research that set up yet.

Air-air heat pumps aren't always ducted, and the highest-efficiency versions are ductless (mini-splits). Since ductess heat pumps are point-source heaters only heating the room with the ductless-head directly (in much the same way that a wood stove is a point source heater), there can be some trade-offs affecting comfort in larger homes with a lot of doored off room. These systems get their efficiency by modulating both the compressor & blower speeds over a significant range- at least a 3:1 turn-down ratio for most of them. When running at part load the backpressure on the blowers is lower, and the coils are "oversized" for the load at that moment, making for highly effective heat transfer and high efficiency. At max-speed their efficiency is usually lower than at minimum speed, independent of outdoor temperature, but still pretty good, since there is no duct-impedance backpressure to drive.

It's important to size them reasonably correctly for the actual heating & cooling loads, no more than 1.5x oversizing or it will run less efficiently due to cycling on/off most of the heating season, with higher air volumes. In a high-R house even undersizing it a bit would be preferable from a total comfort & efficiency point of view. To size it correctly you need to do the heating & cooling load calculations on the house, and look up the output numbers for the different units at both the 99% and 1% outside design temps for your area. (In Bloomingtoon IN that's about +5F, and 92F repectively. http://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/Outdoor_Design_Conditions_508.pdf )

There are a couple of variable-speed ducted versions out there with mini-split type high efficiencies: Carrier Greenspeed, and it's cousin Bryant Evolution Extreme. (The Lenox XP21 is also variable speed, but benchmarks at a significantly lower efficiency, though still quite good compared to on/off or simple 2-stage heat pumps.) When going with a ducted system it's very important to get both the sizing and duct design right. Since it will run almost continuously during the heating season dialing in the air-volumes for space heated by each register is important to keep from over/under heating different rooms differently. (With ductless it's more immediately obvious which spaces you'll over heat, and which might run a bit cold.) The output capacity & efficiency of the Greenspeed over the range of outdoor temperatures is variable, and differs with the combination of compressor & air handler selected. They have a handy online tool for playing around with different combinations here:

http://www.tools.carrier.com/greenspeed/ (Click on the "Heating Capacities" tab, set the heating design temp to +5F, and select IN & Bloomington so that they get the weather data right.) The 3-ton (xxxxxx036A) can deliver over 25,000BTU/hr @ +5F with some of the indoor unit (air handler) options, the 2-ton is good for about 20,000 BTU/hr.

Comparatively , a better-grade 2-ton mini-splits can deliver on the order of 28,000-30,000BTU/hr @ +5F, and cost a lot less (about $5K, installed), but it's a point-source heater- the remote doored off rooms may need auxilliary space heating during the temperature extremes. That said, there are many higher-R homes in my area (where the 99% design temp is also +5F) that can be comfortably heated with just one ductless head per floor, but to get there requires some careful thinking during the design phase- it rarely works that well by accident in some random floor plan & house design.

ERV/HRV systems are best implemented with their own ducting system, since the air volumes are much lower than what's needed for peak heating/cooling, and call for smaller ducts. It's sometimes easier/cheaper to use the same ducts as the heating & cooling, duty-cycling the air handler on the heat pump to provide sufficient velocity and mixing. Good results can be had that way, but not always, and the power use of the bigger air hander cuts into the operating energy efficiency when in ventilation-only mode. An extremely simplified HRV system might be a $2.5-3K cost adder in new construction, but the average system is probably in the $4-5K range. ERV/HRV

DANA1 thanks for the reply but that was WAY over my head.

Since I'm planning to use a heat exchanger in the duct work 1 for the upstairs and one for the down stairs and radiant in the basement slab I was thuroughly expecting to have a furnace in the basement somewhere and a furnace in the upstairs somewhere. Simply becaus eof the heat exchanger duct work idea for heating with the boiler.

Do you think that there is a way to implement that and still have some energy efficiency? I don't really see another way to do the boiler unless there is a way to do it with a heat pump