Solar to indoor thermal mass ideas

I'm about to start building the second half of our cob and timber frame house (I owe many a debt to you good folks on this forum for ideas on that front!).

To make a long story short, my plan to have a large thermal mass bookshelf/bench exposed to winter sunlight through the day may not pan out as I had intended because of dimension/orientation issues, but I'd still like to make use of a thermal mass in the home to help in the winter. I'm considering a rocket mass heater too, but that's not what this post is about. What it IS about:

Has anyone tried encorporating a solar water heater design into a thermal mass? I'm thinking of a closed system of black tubing filled with water/antifreeze that gets heated outside and runs indoors and is encorporated inside some sort of a thermal mass bench/bookshelf structure. I've attached a basic sketch (forgive the mediocrity- done on the phone).

We're heating the house with a wood stove, so it's not like I'm expecting such a structure would do the whole job, but I figure every little bit helps in the winter. If you've tinkered with plans like this or seen something like it done, how does it perform?

Arkady Schneider wrote:I'm about to start building the second half of our cob and timber frame house (I owe many a debt to you good folks on this forum for ideas on that front!).

To make a long story short, my plan to have a large thermal mass bookshelf/bench exposed to winter sunlight through the day may not pan out as I had intended because of dimension/orientation issues, but I'd still like to make use of a thermal mass in the home to help in the winter. I'm considering a rocket mass heater too, but that's not what this post is about. What it IS about:

Has anyone tried encorporating a solar water heater design into a thermal mass? I'm thinking of a closed system of black tubing filled with water/antifreeze that gets heated outside and runs indoors and is encorporated inside some sort of a thermal mass bench/bookshelf structure. I've attached a basic sketch (forgive the mediocrity- done on the phone).

We're heating the house with a wood stove, so it's not like I'm expecting such a structure would do the whole job, but I figure every little bit helps in the winter. If you've tinkered with plans like this or seen something like it done, how does it perform?

I would search your local classifieds for used solar collectors. They pop up often as pool heaters or systems that get torn out. They will outperform dramatically the black pipe variety of collector. Also don't be afraid to search up used solar electric panels as well. You get roughly one third the energy as you would from a solar thermal panel but it's in the form of electricity which is very easy to retask in the warmer months when you don't need the heat. I add that because used solar electric panels are really cheap right now.
Cheers, David

If you haven't found it already, builditsolar.com is a great resource.

Keep an eye out for used SHW panels, as they do turn up when roof repairs are done, or houses change owners.
No reason it couldn't work, often SHW thermal storage is accomplished with an insulated water tank, which ALSO allows for a domestic hot water (DHW) loop to be heated. DHW being the main year-round heat need.

I strongly support having a radiant in floor heatint system. You can then power the system with:
- DHW
- Pellet Broiler
- LHG Broiler
- Solar-Thermal (your black pipe idea)
- Solar-Electric (regular PV panels)
- Heat Pump (SANCO2)
- Rocket Stove (boom-squish)
- etc, etc, etc
Actually you can use as many of those concurrently or backup/sequencially.

I would run a different line (pex pipe) to each room, from a central pex manifold in the mech-wall/mech-room.
Needed things: Pressure release valve, fill/empty fixture, recirculating pump + timer/switch/controller, heat exchanger,
Heat Source: solar-thermal, pellet broiler, tankles water heater (for $500 in emergencies), etc

This is an interesting idea. We're milling our own flooring, and I've heard conflicting things about the thermal properties of lumber (admittedly having researched it minimally). If I put down my OSB sub floor, then a reflective bubble insulating sheet, then the tubing, then the hardwood flooring, could this work?

Yes that would work.

I would aim for a water temp of 115F in the radiant pipe and then after giving up its heat it should go down to 100F.
With the thermostat at eye level set to 67F (floor temp will be 75F and ceiling temp will be 60F)

With the pex pipe temp of 115F, I don't see a problem with the setup.  

You mentioned that you are not too sure about the thermal properties of wood, what did you mean by that?

Wood had a a specific heat capacity (by weight) that is higher than cement/stone/tile/etc. So it still holds a good amount of heat it just doesn't releast the heat as quikly as metals/stone. And we can't dicount the fact that 1000ft of pex pipe holds 40gallon+ of water.