New Build, need opinions

[petawawarace]

Hey guys I'm new to the site, I have already done some looking around and have found alot of info.

Here is my situation.

We are building a new house on a 15 acre bush lot. The house will be 1700 sq ft main level with a full basement. There will be an attached garage 32' deep by 24' wide. This garage is for the wifes car, kids bikes, ect. I will also have an detacted garage 30' wide by 40'. I will likely add storage off the back that is not heated (or even completely closed in)

Natural gas is not an option or I would have gone with it right away. And a geothermal/heatpump is going to be too expensive to buy and operate. I don't mind the work involved with wood, but at the same time I want to minimize the mess and the amount of times I handle the wood. I also dont want to be a slave to wood. I want to be able to leave the house for the weekend, and not have to worry about heat in my house. Or worry about the wife adding wood.

I am thinking I could put a propane boiler and propane DHW in the house as the main heating source. It would supply the house and the garage (all with radiant floor heating by the way). I could then put the wood gasification boiler (and storage tanks) in the storage area behind the detached garage. It would keep the wood mess and the tanks away from the house. I could also store quite a bit of wood there as well. I think this idea would require some extra piping or atleast some trick valving to get it working properly from 2 separate boilers on the same system.

I plan on insulating the house and garage extremely well.

My main questions are:

#1. Does this sound like a decent idea, and does anyone else have something similar?
#2. What would be my best choice for A/C???(House only) I'm not sure if I can cool the house with the radiant lines??? too much condensation??
#3. do you think I could do this for under 20k??? I can build my own storage tanks too thats no problem.

Thanks for the help guys

Jeff

 

[blades]

You will need separate duct work from a stand alone AC system if relying on floor radiant heating. As long as you still need the duct work you might as well install a hot water coil there also, just for those really nasty cold days, this depends some what on your location. I have a friend with a beautiful home all floor radiant, his wife is always bitching in the winter that shes cold. Winter here can get a might chilly when we get to the negative numbers in the evenings, sometimes days also, plus the windchill factors. Your radiant system is not designed for cooling. Radiant heating from the floor is nice but addition items are needed to prevent stratification in the home during the heating season.

 

[petawawarace]

I also forgot to mention that I will have an airtight woodstove and a propane fireplace inside for extra heat if needed.

 

[Clarkbug]

Just some thoughts...

You mentioned that on the detached garage you would have storage that wouldnt be heated or even closed in, but then you said thats where you wanted the possible gasification boiler to go... If you are going to put your boiler and hot water storage there, you will definitely want that enclosed and insulated if at all possible.

How far away from each other will all of these buildings be? Are you pumping water a significant distance?

Since you are running radiant, you can use lower temperature water than if you had baseboard heat. You could even use solar collectors to pre-heat or provide all the heat you would need on a sunny day. With storage tanks, that might be just the ticket.

As blades mentioned, you would need to use ductwork for your A/C, so you are adding costs for initial installation. You could try to do radiant cooling, but its waaaaaay to easy to get condensation, and its probably not worth the hassle.

Its possible to heat with two boilers with some simple control logic. Lots of folks on the board have wood as a primary source and oil/propane/NG as their backup source. The fact that you will have a woodstove as further backup is also a nice thing. What would you use for backup in the garages to keep the wood boiler from getting too cold? That would be my biggest worry if you travel for an extended time frame and dont have heat in that space.

Keep the thought process rolling, add schematics and pictures, and Im sure as the temps drop more people will come in and comment.

 

[Floydian]

Hi Jeff,

What stage of design/building are you at with this project?

It could be extremely worthwhile for you to spend some time here:

http://www.greenbuildingadvisor.com/

search: Pretty Good House

Super insulate, build tight,ventilate right, stay nice and comfy, and eliminate the time/effort/$ it takes to heat a house with an envelope that is not up to snuff.

A gassifier+storage may yet be the right choice but not at the expense of your building envelope.

Radiant floors are for houses that don't have enough insulation (like mine).

Good luck with whatever you decide as this is your house and needs to be right for you.

Noah

 

[BoilerMan]

.
Radiant floors are for houses that don't have enough insulation (like mine).

Noah

Whats that supposed to mean? Like saying baseboard is for tight houses, or panel rads, or old cast iron rads.......

Radiant is and excellant low temp emitter as are panel radiators.


TS

 

[JP11]

Sounds like you're on the right track. Propane for DHW in the months when you have a huge tank of hot boiler water may not be fun after a while. I would recommend a solution like a tankless DHW heater for the months when you don't wanna fire the boiler. Then you aren't wasting propane in winter months just for DHW.

My oil boiler is wired to NOT come on to heat the home if my storage tank is above 135 (I have radiant, so 105, or 135 or so depending on which floor is calling for heat.) I have an indirect for DHW that's set to 132 degrees. Oil stays off if wood boiler storage is hot.

This winter will be my first winter with it. But I THINK it's gonna be a good setup. Make your wood in an area where you can drive a tractor or ATV right IN to where you store it. I'm using pallets in a U shape. I never touch the wood after the splitter till it goes in the boiler.

JP

 

[infinitymike]

Welcome aboard.

Theres a lot of extremely intelligent people with a lot of experience in designing and building a heating system. Stick around they will start to come around when the temps get colder.

Noah asked a great question "what stage of design are you in?" If you have the time, then take it. Don't rush just for the sake of getting it done. I know,...I did, and now I need to redo a few things. Has much as it did get me through the very mild winter. I don't know how well it will do if we get hit with a cold one.

Its pretty easy to set up two heat sources. A little plumbing and some wiring, a couple relays...simple as ABC.
I have what is called a Primary/Secondary loop. I have my oil burner and wood burner tied into this Primary loop and the zones(secondary loop pull off the Primary loop. If my wood boiler drops below 150* the oil burner comes on automatically.

Where you live will also make the design easier to figure.

 

[petawawarace]

Yeah I may have to put some more thought into the dhw system to optimize it. I love the pallet idea. so do you have several pallets made up, and after you cut the wood, you stack it in the pallets and let it dry...then just move it near the boiler and fire it in???

I have a good amount of time to plan. we are looking at building next year so just trying to sort out things ahead of time

 

[Fi-Q]

Take your time, and once you think hour good, re think again. I was planning the build for years, but man, I wasn't ready.... But thats another stroy.....

Are you going with a full basement ? I did put a 8 foot full basement. But with 4 in of foam, 4 in for the slab, and lose another 3 in for the ceiling, I am down to 7' 1'' of overhead clerance in the basement. Not bad, but I should have went an extra 6 or 12 in with the basement.

 

[JP11]

Yeah I may have to put some more thought into the dhw system to optimize it. I love the pallet idea. so do you have several pallets made up, and after you cut the wood, you stack it in the pallets and let it dry...then just move it near the boiler and fire it in???

I have a good amount of time to plan. we are looking at building next year so just trying to sort out things ahead of time

Yes. 3 pallets in a U. Braces across top corners. They hold about 1/3 to 1/4 of a cord. I've got 40 something U's of this year's stuff. 16 so far of red oak for future years. Forks on the tractor (Green Oak is pretty heavy, need a descent size tractor)

I've got a hand pallet jack to move the pallets around in the boiler room. I've got 3 in there now.. I think I will squeeze a forth in depending on how much of a PITA it is to free them from frozen gravel in winter.

I'll echo others comments. Share drawings, heat loads, ideas here. keep reading. Don't get too bogged down on the "Ford vs Chevy" debates. You need to burn wood and heat water. Store hot water... and use it when you want. LOTS of ways to skin that cat.

JP

 

[Floydian]

Whats that supposed to mean? Like saying baseboard is for tight houses, or panel rads, or old cast iron rads.......

Radiant is and excellant low temp emitter as are panel radiators.


TS

Hello Taylor,

I completely agree about radiant floors being a great low temp emitter. A few years ago I started researching gassifiers,storage, DHW and low temp emitters to take full advantage of storage. This will be my first winter with my new set up which consists of a Vedolux 37 with 1000 gallons, 7 loops of radiant floor(tube and plate installed over the subfloor, good for about 30 btu/sq ft/hr with120 deg water at design). Each loop has a non electric capillary tube TRV for individual room control. Constant circulation with a Grundfos Alpha and a 3 way Taco ivalve with outdoor reset to modulate supply water temp based on outdoor temp. Obviously I can really geek out on hydronics and I am really excited about this heating system.

Simultaneous to remodeling my house and installing this system, I was designing a new house for my folks. Originally it was going to be standard 2x6 construction,
Andersen/Pella double pane windows etc. with basically the same heating system I put in my house.

Then I started reading up on super insulation and talk about a game changer. The single biggest advantage of a super insulated house is that they just don't require very much energy to stay warm/cool. They also don't require complex, expensive heat distribution systems to achieve comfort.

So, in a super insulated house with a design heat load of less than 10btus/sq ft/hr a radiant floor would would be about 5 degrees warmer than the inside temp at design.
Which means for most of the winter the floor is only 2 or 3 degrees warmer than the inside temp-basically the floor just wont really feel warm. Not a good investment IMO.
That money should go toward a better envelope, the single most important part of any house.

My folk's house is currently in the rough in phase of things. Main level and a full basement are 2200 sq ft total. 2x6 walls with damp spray cellulose in bays, 2.5" of Poly Iso outside of the sheathing, vertical rainscreen attached through the foam, whole wall R value of over 30 after figuring in the framing factor. Thermal bridging is nicely addressed and the framing of the house stays a nice even temp like the inside of the house. Happy structural framing.

And of course the windows play a big part in the comfort/efficiency game of any building. We ended up choosing Inline Fiberglass windows out of Toronto. Triple pane glazing with whole window U value of .2 (R 5) with high solar heat gain on the south facing glass and low E on everything else.

R 20 for everything below grade and R60 in the attic in a 5300 Heating degree day location.(2400 ft elevation)

Annual heat load of about 15 million btus NOT counting the moderate solar gain the house will receive.

A mini split heat pump on each level, centrally located and a wood stove in the basement and a little supplemental heat in the bathrooms is all the house should need.

Obviously I can really geek out on super insulation as well, and sorry for the long winded response.

Noah

 

[dogwood]

Noah, what is the " vertical rainscreen" you refer to?

Mike

 

[Floydian]

Noah, what is the " vertical rainscreen" you refer to?

Mike

Hi Mike,

It's been awhile! The rainscreen is basically the gap created when attaching 1x4 battens through exterior foam, to every stud, on layout. Now there is a place to hang the siding to, and any water that gets past the cladding has a nice place to go and not be a problem assuming everything is properly flashed. This ventilated (or not) gap can really help natural wood and fiber cement sidings last longer. Typically vertical battens for horizontal siding and angled (45*) or horizontal battens for vertical siding. And of course this also
creates more details and the project drags on and on.

Noah

 

[dogwood]

Thanks Noah

Mike

 

[rkusek]

You may want to consider a standard air source heat pump (not geothermal) as your base system. It can cover all your cooling and also the heating needs when out of town, etc. and unless you live somewhere with extremely high rates it would a decent overall option should you not be able to burn wood for some reason. I went that route because I didn't want propane and electric resistance (expensive) would have been the only other option.

 

[BoilerMan]

Floydian:
Your folks construction sounds almost exactly how I built my house three years ago. 2x6 with standard R19, 1.5" polyiso, 3/4" varticle airspace, then drywall/ pine etc. North wall same but with 2" polyiso. Ceilings same way, 1.5" polyiso, and R 38 fiberglass, for a total of R 52. Total wall R value is 32 and 36 on north. All triple glazed casements from Paradigm (Portland Maine) with similar U factor. The only diff was I'm on a slab on grade which is 8" thick. I placed the tubing 3" up from the bottom of the slab to take advantage of the huge "flywheel effect" of this mass of concrete. 2,200 square feet of heated slab. I supply the water to the slab at 115F and see very little chage in surface temp or room temp, but the house can go for several days w/o a fire and drop only a degree a day or so if it's above zero outside. You never notice the floor being warm or cold, it just seems like it's there and nice. I was told I was crazy when I was doing it, but I in effect have built storage into the floor. I have a big enough indirect to make it between fireings so DHW is also taken care of completly by wood. I have not burned a drop of oil to heat the house ever. I have a stand alone oil DHW setup for the summer only. To satisfy the insurance I put in 16' of electric baseboard (two 8' sections in different locations) as "backup heat" it was cheap and maintainence free, and hey I'm an electrician! But as rkusek said it is the most expensive heat, but that was not a concern for me as it's not really needed. They're set on 45F and have never come on......

To the OP, there are many ways to skin a cat, and if you super insulate, you WILL be happy for a long time to come. Welcome to Hearth, and gather as much info as you can, and talk to people we are happy to share what we have and what we would do differently if we could.

TS

 

[heaterman]

Peta......It would be really helpful to know where you are located. An air to air heat pump with a hot water coil in the duct might be a good choice for you but it really depends on the heating degree days you will normally encounter. My brother just built a new house a couple years ago and I put on of those in for him along with a gas furnace that automatically switches from the heat pump to gas. We found that the heat pump would take care of his heating load all the way down to the 35-40* range with no assist from the gas side of the system. He put in a sealed combustion fireplace insert to supplement during the January -March time frame and burns less than 400 gallons of LP for the entire year. That for all heating, cooking and hot water in a 4,800 sq ft house.

 

[rkusek]

peta...You really have quite a few building options and if you go super insulated, ICF construction would be something to consider. We looked at a new house locally in 2008 but went with conventional 2x6 stick construction mainly because of price. That contractor was one of very few around here building that way, was swamped, and never returned my calls which was another concern. Wife was also unsure about the thick walls but just because it was something she had not seen. If you haven't already broke ground it may be worth a look. I don't believe this home had one but you would definitely want a ventilation system because the house would be so tight. They say you can heat those homes with a "match", you certainly would not need a boiler. www.ourcoolhouse.com has a good story of a self design (not ICF though) with an interesting monitoring system caught the attention of the geek in me. Their home uses one of those ERV (exhaust recovery ventilation?) systems that exhanges outside and inside air and does it without losing much heat.

Mine ended up being 2x6 stick with R19 walls, R19 batts +R30 blow in the ceilings. We liked the Pella windows and doors because of the blinds behind the glass and they seem to perform great but I'm sure a true triple pane fiberglass like Floydian mentioned would be much better. The air to air heat pumps with the electric back up can work simultaneously down to probably 10 degrees where the air to air HPs with propane backup it's either one or the other. My first winter 2009 I did not have UG boiler lines to the house yet so we heated exclusively with the HP and the compressor would still be running when it was 0 outside. Propane has more than doubled here in the last 10 yrs and is subject to every oil shock like gasoline but the electric companies here really push HPs giving big winter rate discounts (about 1/2 over summer rates) because most homes here heat with natural gas and they have to utilize their capacity needed for the hot summers. Since you need AC, I think one of these 2 types would be your best choice, affordable to install, satify your insurance co. and lender, and still allow you to heat with wood using a water to air HX in the ductwork, radiant floors, or radiant panels. This covers the situation in case you ever need to sell the home, get injured and can't tend the wood, etc. This would allow you to do some of the boiler install and radiant work yourself after you move in, save more money, etc. as long as you get the pex layed right in the concrete of course. I plan to finish the basement myself with staple up pex & plates on main floor and radiant walls in the walkout basement. Hopefully this will utilize my storage more than the W/A HX even though I have been impressed with the way it operates now. The radiant for me will be more for comfort and give me an option to heat in a doomsday (no power grid) situation. Your detached garage sounds like a great place to put the boiler and keep the mess out of the house but check your building codes. I'm sure you will need to put in a separate room from the cars. Insurance wise, it may be better to build a separate building like a garden shed where the boiler, storage tanks, and a supply of wood could be housed. I get a little wood mess and smoke occasionally while loading the boiler in my pole barn but I'm glad it's there rather than in the house. If I could do over I would build an insulated "garden shed" and have a pole barn free of boiler, wood mess, and propane tanks.

 

[petawawarace]

Thanks for the help guys,

I am going to super insulate for sure (including the detached garage). I believe it is now code here for new builds to have R29 walls, but I will likely go more.

I am located about 2 hours northwest of Ottawa.

I want to stay away from the air style heat pumps because of the cold temps here, and they are still just an electrical device and power is not cheap here.

 

[rkusek]

2 hrs NW of Ottawa makes a difference. It looks like you still have hot, humid summers (according to Wikipedia) with heat indexes of 86-104F? I never would have guessed that and I'm sure you will see nights below -25F in winter. It sounds like you won't be able to get away from installing ductwork and running a compressor for your cooling, dehumidification needs however.

 

[petawawarace]

Yeah get some pretty hot spells in the summer and yeah the nights can get pretty cold too

 

[petawawarace]

Ok so after doing some learning this is what I have come up with. Please tell me I am out to lunch if I am. Also my drawing skills may not be the best.

The wood Boiler and Storage tank is out in the detached garage. The propane boiler is located in the basement of the house.
I would like to only heat the storage tank from the wood boiler. This design means I will have to run 4 lines total from the garage to the house. 2 main lines when the wood boiler/storage tank is in use, plus the 2 lines for the loop of the garage itself regardless of which boiler is running.

The idea here is that the wood boiler heats the storage tank and it feeds the heating load. If the storage tank is above ~120F V-1 and V-2 will be open to the storage tank and the load circ pump will circulate the water to the zone valves that request it. The propane boiler will be disconnected from the system. When the storage tank drops below ~120F, V-1 and V-2 will switch and connect the system to the propane boiler. The wood boiler/storage tank will be dissconected from the system.

I am new at this, but willing to learn, please let me know what you think.

Thanks,
Jeff