Anyone a self proclaimed hydronics/solar expert?

[Speedbag]

Bravo.

Perhaps you will offset my gigantic carbon footprint.

[Speeddog]

What power density are you using for the incoming sunlight?

IIRC from way back in school, 100 Watts/ meter^2 is a typical number.
A Google didn't support that....found a wide variation. 
Perhaps that was what a PV array could provide.....

[mitt]

What power density are you using for the incoming sunlight?

IIRC from way back in school, 100 Watts/ meter^2 is a typical number.
A Google didn't support that....found a wide variation. 
Perhaps that was what a PV array could provide.....

W/m^2 depends on collector angle, time of year, and your latitude right?  Probably the reason why the wide variation.

mitt

[Speeddog]

Well, I was seeing numbers from ~100 to ~1000... 

[mitt]

Well, I was seeing numbers from ~100 to ~1000... 

that would be about right I think.  Take a look at these maps

http://www.nrel.gov/gis/solar.html

just for the yearly average in the US map it is 90 to 280 W/m^2 if I am doing the math right [  (2.2kWh/m^2/day)*(1day/24h) = 92W/m^2  ]  So peaks and lows world wide would probably be from 0 to 1000 depending on location and time of year.

mitt

[Popeye the Sailor]

Have you considered a wood stove? 

[rgramjet]

Talk to the engineers at Schuco.  I sold their solar thermal dhw systems for awhile.  Didnt get into radiant heating applications because the company that I sold for wanted to keep it simple.

There is a diagram on their website that shows the solar panels feeding a storage tank and boiler system.  I'm assuming it could be fed through a manifold to temper a slab.

Solar thermal hot water systems give best bang for the buck......until cheap thin film pv systems are perfected.

What exterior wall thickness are you going with?  Insulation type and R values?

Good luck!

[Speeddog]

Have you considered a wood stove? 

Might not be a good plan in a haybale house.

[Popeye the Sailor]

Might not be a good plan in a haybale house.

Oh, I'm so going to huff and puff at DIMBY.

[ducpainter]

Have you considered a wood stove? 

For the past 23 years I've been looking at and feeding those make the beast with two backsing things. If I had a wood lot I would still consider a form of wood heat. Buying wood today saves nothing and is still more work than it's worth. If I want to see flames...I'll start a fire...or install a pellet stove.

Talk to the engineers at Schuco.  I sold their solar thermal dhw systems for awhile.  Didnt get into radiant heating applications because the company that I sold for wanted to keep it simple.

There is a diagram on their website that shows the solar panels feeding a storage tank and boiler system.  I'm assuming it could be fed through a manifold to temper a slab.

Solar thermal hot water systems give best bang for the buck......until cheap thin film pv systems are perfected.

What exterior wall thickness are you going with?  Insulation type and R values?

Good luck!

I'm using a wall system you're probably not familiar with. It's called a REMOTE wall. It's very effective in cold wet climates. It's widely used in Alaska on retrofits. The idea of it is to move the condensation point outside the sheathing to prevent mold and mildew. I'm also going to use the airtight drywall approach. The house will be tight...I'm shooting for way less than .5 ACH. There will be a suitable HRV.

Framing will be 2x4 unless there is some code in the state that says I can't. We have no code enforcement in my town anyway except the fire chief will inspect a 'boiler'. I don't think I'm going to have an actual boiler and he's an asshole anyway...make the beast with two backs him. 4" of rigid outside and 3 1/2 fiberglass inside. Those numbers fit into the REMOTE system and should give me close to an R-30 wall. I can't afford much more. The roof will have 12" of either cellulose or fiberglass with an additional 2-4" of rigid on top. No penetrations through the roof other than the plumbing vent. Also no can lighting.

Oh, I'm so going to huff and puff at DIMBY.

I am so not afraid of you.

[OT_Ducati]

another rescource
http://www.americansolartechnics.com/index.html
well insullated storage tank

[ducpainter]

What power density are you using for the incoming sunlight?

IIRC from way back in school, 100 Watts/ meter^2 is a typical number.
A Google didn't support that....found a wide variation. 
Perhaps that was what a PV array could provide.....

I'm not using any power density...that's math.

I'm using the premise that with a large storage volume and collectors facing true south at an angle of latitude+15 degrees it is going to make hot water when the sun is out. Because of the storage volume and the low temps required for radiant heat I see no reason it won't be effective.

another rescource
http://www.americansolartechnics.com/index.html
well insullated storage tank

I think some of you are missing the point. If I wanted to purchase a manufactured system it would be simple. I want to build as much of this as possible because I can't afford to do what I want with factory manufactured parts. I can insulate a tank, one much larger than what I can buy, and I also think I can make collectors with close enough performance to factory built to justify the reduced performance with the cost savings. I can size the system to make up for shortfalls in performance.(I know there is at least one person that thinks I'm wrong...sorry Frank  )

Also most hot water systems are sized to do DHW only. I want a system that will do radiant heat also....think bigger...much bigger.

I'm looking for help with numbers to prove that I'm either right or wrong, and also for which widget goes where and how many I need. I already know I'm going to need a bunch of thermal sensors, pumps, and tempering valves. I also would like some input as to whether I'm thinking correctly in using a drainback system, or should I, because of the cold use an antifreeze system which is less efficient. How far can the tank be from a drainback collector before freezing is an issue at -20F if the piping is buried and well insulated?

Stuff like that.

[The Architect]

(I know there is at least one person that thinks I'm wrong...sorry Frank  )

I don't always practice what I preach or practice whats good for me.  I have a plan for domestic hot water and it doesn't involve a manufactured collector     even though I know they're more efficient and easier to control.............

[ducpainter]

I don't always practice what I preach or practice whats good for me.  I have a plan for domestic hot water and it doesn't involve a manufactured collector     even though I know they're more efficient and easier to control.............

I'll give you more efficient if you give me more expensive. 

Why easier to control?

[The Architect]

Any thoughts on those solar pool heater mat collectors?

http://cgi.ebay.com/4x20-Swim-Pool-Solar-Heater-Panel-w-Diverter-Kit-/180357483220?pt=LH_DefaultDomain_0