New Home - What Would you do Differently?

[fowlerrudi]

Hello folks,
I am a lurker - been absorbing the wealth of knowledge you all have. I don't think money can buy the education one can obtain on the Internet. Whether its a good education or not....

Anyway, my wife and I are planning on building an off-grid home next summer. I will be a handcrafted log home and will be powered by water turbines on off a river that runs by. We are currently living in an off-grid home and use wood heat and ceiling fans to get the job done.

Here is my plan for the new home, call me a dreamer:

Froling 3000 Turbo - with storage - how much - I do not know. I like what Justburnit did - inspirational! But is bigger better?

Warmboard throughout the home - Check out the Breckenridge on this site - (broken link removed to http://www.yellowstoneloghomes.com/floor.html)

I would like to run Pex in parts of the basement (not the mechanical room) and then on the main and upper floor run Pex in Warmboard (which requires different temps).

We would like to have a loop for an outdoor hot tub (currently heat with a Japenese Chofu heater) - and also would like to put PEX in the slab of the garage - all running from the basement Froling boiler.

I am thinking of putting unpressurized storage under the basement floor (built into the basement floor) perhaps using ICF blocks and a pool similar to Justburnit.

This winter it went to -40 C. That -40 F as well.

In the future when I am too old to handle firewood - I am thinking I can just swap out the firewood boiler for a pellet boiler (P4 looks nice).

So how can I build this with min amount of circ pumps since I am offgrid (check these out - http://www.grundfos.com/web/homeuk.nsf/Webopslag/DMAR-6EGDHG)

I don't completely understand why I would go pressurized or not however I do like the simplicity of non-pressurized storage at the moment - add a loop in the tank for supplement solar for after DHW tank is hot - add a loop for hot tub, etc.

Please comment

 

[stee6043]

If I could start from scratch I would most certainly go pressurized storage inside the basement or a workshop (less parts, higher usable temp, arguably more efficient??). 1,000 gallons minimum but I can't imagine using more than 1500-2000. I'd want a much larger boiler if I ran any more than 1,000 gallons. My EKO 40 seems almost borderline big enough to charge 1000 gallons in two loads of wood when also heating the house. I seem to be more like 2.5 loads most days. An EKO 60 would probably have been better for me since I really like getting two good loads in per day.

In floor radiant everywhere would be my choice. With forced air as a back up (and for Air Conditioning). Honestly - if I were building a house and I was able to add on a workshop/second garage I would likely go with a Garn. A big one...

 

[Justburnit]

I had given thought for a new house to make the basement walls deeper, such at 12'. Insulating and capping this to provide the true basement floor. This would provide a large storage with the secondary use of having a cistern for fire fighting water. For the site I was looking at this would have been of value. This tank could be under ether the basement or garage keeping either relatively warm.

Part of the goal with large storage is to be able to use solar as an input. Unfortunately we do not have good sun up here and I expect you have less up there. Trying to get more than DHW and the Spa heated gets frustrating.

For your needs a pressurized system reduces pumping loads. All of your general heating loops run with same water. The real benefit is you can store hotter and use less of this heat since you have no transfer losses.

Now depending on how much streamflow you have for the hydro you might not have much restriction in power. If you can get 400 to 600 watts of power you will be in quite good shape. You just need to control the run time of each circulator so they do not eat into your stored electricity.

 

[DaveBP]

If you're running AC motors through inverters any time you can run DC right out of the generators or battery bank(I don't know how your hydro will work) I think you'll be more efficient. I'm not very up to date on that stuff. Our photovoltaic days were decades ago. Laing makes high efficiency DC circs for solar and hydronic systems:

http://www.lainginc.com/pages/laing.htm

Radiant floors are not only extremely cozy and efficient but have the advantage of using lower temp water so more 'usable' BTUs can be stored if you have heat storage on a hydronic boiler/solar heating system.

Personally, I'm very skeptical about the insulation value and air infiltration claims I've heard from those who sell log homes. Awesomely beautiful, but the few folks I know who have them use a lot more heat per square foot of floor than they want to. Especially those big cathedral ceilings with glass to the top. Beautiful though.

 

[fowlerrudi]

Thanks for the friendly replies,
Anytime switching from AC/DC will cause efficiency losses yes, and possibly would be smart to run DC circs. Justburnit - sun is scarce in the winter as you predicted, I would be impressed if I could heat a spa with solar hot water alone. It would be nice to have hooked up with valves so one could choose where the solar hot water would put it's energy - if DHW is hot, divert to spa - if spa is hot, divert to storage. Good point on the pressurized storage - I need to learn more about this. I have a 500 gallon propane tank, but am thinking I could probably build something three times the size depending on my needs. Its nice to plan ahead having not built a house yet. I am clearing land now.

There are lots of opinions on log homes and such, tons to learn.

No one seems to be running this Froling 3000. Is it too new yet that no one has one? I am very fresh to the whole idea - but how else to have radiant heat in an off grid home? Wood rocks (I wasn't saying that growing up doing my parents wood)!

The stream I am living by has a ton of potential for bringing an an easy 1000 watts continuous and still leaving thousands and thousands of GPM in the river- which is enough to power almost any home. As long as I can get the intake right and prevent freezing - I should be ok - a project for this fall. However - even though I could have tons of power from the stream, I would like to design the heating system with using absolutely no more juice than I need to. So if pressurized storage would help accomplish this then great!

 

[Gooserider]

Sounds like power isn't a big issue for you compared to most off-grid folks, but if I was looking at an off-grid setup I would be giving some serious consideration to using a Masonry Heater instead of / in addition to any wood boiler setup...

There is a fair bit of stuff on MH's scattered around the forum, I'd use the search to find more info and threads that have resource links, but in short they combine the clean burn and high efficiency of a gasser with not needing a bunch of juice to run the boiler, circs and so forth. If you haven't looked at them, it might be worth investigating and considering the idea.

As to the Froling - definitely seems to be like a very nice unit, problem is that you are also looking at a BIG price tag - the rough numbers I've seen are that the Froling is about 50% more than an EKO or Econoburn, and I think there could be considerable question about how much extra benefit you get for a big price jump...

Gooserider

 

[jebatty]

Be very sure you do an accurate heat load calc before making any decision on heating system, and if you are planning high cathedral ceilings, that you plan very well for moving all that hot air that collects at the top - summer and winter. Our neighbors continually curse their decision on 2+ story cathedral ceilings; too hot in the second story loft and bedroom area in both winter and summer (solar heat gain). Now they've put blinds over the full frontage glass to cut the solar heat gain which has turned out to be nothing but a pain for them. Kind of funny to spend big money on big windows and then cover them all up. As to heat load calc, doesn't wood have about an R value of 1 per inch of wood? You may need more heat and cooling that you think. Also, moisture control should be researched carefully; lots of shrinkage and expansion with logs as moisture changes.

 

[Justburnit]

I notice on that boiler that they call for 240V input. Are you going to have other needs for 240 Volts to make it worth the added inverter?

On my Tarm Solo series it draws 38 watts with the blower running. That plus the 80 watts of the circulator is not out of hand. But I have seen draft inducers that draw 4.5 amps. I would sure check on what the draw of this unit is. It is probably not bad but needs to be known.

 

[fowlerrudi]

You are right, I know on the froling the draw for the "Turbo" alone is 180 watts, which is pretty significant when it is running. Lack R value of log homes is replaced by the thermal mass of them. I guess you could say it works on the same principle as the masonry heater - or is supposed to. What do you guys think of that new Alpha2 Circ pump? I believe it is only in the UK at the moment, thus works on 50 hz, but it wouldn't be an issue to make 50 hz either - even at 220-240V. A second inverter is probably wise in a large system to provide the 220-240. Not sure what exactly it would be used for though, as most 220-240V devices seem to use an element - which is almost not allowed off-grid due to the power consumption of an element. In the place we are in now we run 240V into the panel (like a regular home I assume) - but I suppose most places aren't making 240V at their power source...

I was looking at "A Simple Pressurized System" in the stickies - I'm not counting many circ pumps there - it looks efficient.

 

[Justburnit]

Lack R value of log homes is replaced by the thermal mass of them. I guess you could say it works on the same principle as the masonry heater - or is supposed to.

Yes, but is that thermal mass responding to the outside air or the inside air?
Having worked for decades in structures with high thermal mass and seeing frost on a wall in a heated room makes me question this.
When one is building for efficiency we do the best to eliminate thermal bridging in a wall, that bridge is the wood structure.

 

[Nofossil]

I'm assuming that peak power consumption is a specific concern. In my system I have one circ for each heat source, and only one runs at a time. That keeps the peak draw fairly low. The EKO itself is only around 40 watts with the fan running.

If total power consumption over time is also critical (as when running from batteries) consider that the hotter water withdrawn from storage, the less time you have to run a circulator to extract a given amount of heat. That suggests that pressurized storage would have an advantage, and that stratification saves circulator power consumption.

I'm also playing with intermittent zone circulation, in which you run water through a zone long enough to flush out the cold water, then stop and let the hot water sit for a while. This returns water to storage at a colder temperature and reduces circulator run time. It also reduces average heat output for the zone and causes the return side baseboards to get less heat, but it could be an option in some circumstances.

 

[SolarAndWood]

Our neighbors continually curse their decision on 2+ story cathedral ceilings; too hot in the second story loft and bedroom area in both winter and summer (solar heat gain). Now they've put blinds over the full frontage glass to cut the solar heat gain which has turned out to be nothing but a pain for them. Kind of funny to spend big money on big windows and then cover them all up.

This is one of the things we addressed in our rebuild. 50 feet of floor to ceiling glass facing SSW heats up the house pretty quick regardless of the time of year. I designed the overhang on that side to shade the summer sun while still allowing the winter sun. The trusses went up last fall and we are enjoying the benefits this year. No more drop the blinds before we go to the office and get the heat out of the house at the end of the day rituals. A nice side benefit is we can leave the windows open during storms. Good luck with your project.

 

[fowlerrudi]

Sounds like that frosty wall couldn't have been very thick? I have been reading - is it possible to design a complete system to run off of 1-2 circ pumps?

http://www.pmmag.com/CDA/Archives/BNP_GUID_9-5-2006_A_10000000000000044355

Also, how are you adding solar and spas to pressurized storage? I suppose you could add the spa as a zone, but what about solar? Design a heat exchanger into the storage tank?

It sounds like a good overhang will be crucial to keep the shack cool in the summer. I was thinking one could pump river/well water through the system to cool the home - but the condensation could ruin hardwood. Just a thought.

We plan to have a wood stove on the main level as backup.

Another thought - could one perhaps swap the 180 watt fan motor out on the Froling 3000 for a similar spec brushless more efficient motor to conserve power? The controllers wouldn't know the difference I wouldn't think. Could be a warrenty voider...

 

[Hansson]

If I where to build a new house and have some money I have build something like this.

Smart guy

http://translate.google.se/translat...rsörjande huset"&sl=sv&tl=en&history;_state0=

 

[Justburnit]

Sounds like that frosty wall couldn’t have been very thick?

The wall is 10". It was cold out, very cold.

 

[jebatty]

It sounds like a good overhang will be crucial to keep the shack cool in the summer.

It is more than critical to avoid excessive heat. Get a sun angle chart for your area, also a chart that shows average hour of sun during the year, and dig out your trig book, if needed. Summer is usually the focus, but depending on your orientation, spring and fall can also produce far more passive solar gain that you will want. Winter likely is OK, so long as your house is large enough to handle the solar heat gain. Also be sure your glass is UV blocking to minimize UV fading/impact on everything that it falls on.

We have 8' walls, SSW orientation overlooking a lake, nearly all glass front, 4' eaves, and lots of deciduous trees in front. Didn't plan it that way, just got lucky. The solar happens to work out perfectly with a plus, in dead of winter we also get sun reflection off the lake ice/snow and get a boost on solar gain when needed. Late spring, early fall, and all summer 0 to minimal solar gain.

 

[coolidge]

I know if i was thinking about a place like this my GF would want to know when i was starting. Anyway wouldnt a concrete floor hold heat better than the Warmboard? I would put 7" closed cell foam in the roof. And look at upgrading windows here. alpeninc.com

 

[fowlerrudi]

You mean your GF would like it? I didn't get that comment. You could use thin concrete I believe - but I wasn't that keen on putting concrete all over the place. Warmboard is the subfloor as well and doesn't require super hot water to work. I feel like I'm sold on it already just from reading about it. Worst thing is it's price. Interesting link on the windows, I will check that out.

 

[SolarAndWood]

It sounds like a good overhang will be crucial to keep the shack cool in the summer. I was thinking one could pump river/well water through the system to cool the home - but the condensation could ruin hardwood. Just a thought.

Shading is key. I used a solar calculator I found online. You put in latitude, direction, window height etc and it gives you the overhang. I think I found it on NREL's site.

The place for the river water to be run is through chilled beams. This is a story about a company here in Syracuse that is interesting. While he is taking an active approach, you will find links to passive applications online as well. Greatly reduced electrical demand, zoning and no air handler/ductwork/AC smell are pretty appealing.

http://blog.syracuse.com/green/2008/11/room_by_room_company_breathes.html

 

[tom in maine]

Before you start talking about any heating system, start by thinking about insulating the whole building to R-60 with foam.

All your other choices will be a lot simpler. Your heating system will be smaller, heat distribution system will be smaller and the storage tank will be tiny by comparison to what a lot of folks have to use when they retrofit an older home or a home that is not well insulated.

The attention to detail-- making sure it is tight, using high performance windows and not over-glazing the house will also have a big impact.

You cannot plan on buying a lot of fuel forever and any extra cost of insulation, etc. will have a much, much better payback than anything else you do.

And you will be comfortable!

 

[fowlerrudi]

Hey Tom - I'm reviving an old post. Its log so R60 all around is out of the question except for the ceiling / roof. Our white/red pines are about 1.5 R per inch - with min being 12" in the walls, max being about 24" Here is a good article giving logs some points for efficiency:

http://www.loghomes.org/uploads/The Energy Performance of Log Homes1.PDF

I would like to hear "Tom in Maine" and "nofossil" duke it out over pressurized vs. non-pressurized. I am leaning towards pressurized right now, but was almost convinced after visiting your website Tom. I feel the set-up of pressurized will be longer but will be worth it. I know there are a few threads here on comparing the two that I will look for.

 

[tom in maine]

From my point of view, there is nothing to duke out.
It depends on the application. There are places where pressurized might make sense.
Unpressurized offers convenience and simpler installation. (And maybe cost if you are paying someone to install your system).
If the heat distribution system can use low temp water, we can squeeze a lot of energy out of an unpressurized tank.

We are finishing up development of an unpressurized gasifier boiler (all non-ferrous) that is designed for use with our tank.
The beauty of such a system is the low cost, inherent safety and simplicity.
Whether we ever get the money to get it tested and into the market (we are in the process!),
remains to be seen.

We have a storage system that works well with existing hardware. It is not an exact fit for everyone, but it ain't bad.

I am not crazy about wrestling big tanks around, which was the genesis for our tank business.
I also want everything to be serviceable since eventually everything needs some kind of attention.

One size does not fit all. That is what makes the marketplace great.

 

[fowlerrudi]

I admit I like the idea of building a tank right in the basement while I am pouring the basement this spring. To be honest the extra circ pumps scare me, but so do three 500 gallon propane tanks!

 

[Frozen Canuck]

Have to agree with what has been said Re: the thermal performance of a log home, over the years I have lost track of how many (log homes) I have been in to see the owners about a reno/retrofit because while they may be comfortable in the interior of the home, water will freeze anywhere near the exterior walls of the home & quite frankly they want a more "livable home" not easy, not cheap & bye bye log look at least on the interior. If you are in love with the log look I suggest you use it as siding on the exterior & as paneling on the inside over a much more efficient structure, SIPs if you can fit them into your budget would perform best over time. Trust me on this, logs homes look wonderful (when they are new) but perform only slightly better than concrete. Good luck with your project. BTW the more energy efficient your home....well the less energy & time you will spend keeping it warm. Forever.

 

[101x81]

if i will built a new home, she will be very well insulated with 2x8 walls, R50 in the roof and basement insulated with 2 inch of sprayed foam. brick wall outside. hydronic running in all floors. good orientation of the house to benefit of the solar heat in winter.
a big garage attached to the house and all the wood and heating system underneath the garage. a solar system to heat up the dwh in winter and the pool in summer. my dream