First time poster here. I tried to search the forum but my specific questions remain unanswered so I thought I would post. I live on 3 acres at 53' Lat. -40C in the winter is not uncommon. I bought a 1300 sq/ft bungalow 2 years ago that was built in 1974 and I am the second owner. The attic and walls were all R9 and I have since upgraded the attic to R50. I don't there is anything I can do about the walls easily. The basement was uninsulated and now my biggest heat loss in the house. The house is shaped like an L with a living room on the short part of the L. This is the coldest room in the house. I am planning on building a 10KW solar hydronic heater with a massive outdoor thermal battery buried 8' underground. That plan isn't totally finalized as I need to finish my house upgrades before I attempt that. With the house I want to insulate and finish the basement and at the same time add radiant heat on both floors. I was planning on adding PEX tubing in between my joists for the upstairs with a layer of roxul for insulation and sound proofing. In the basement I was going to make the walls R15 with rigid interior insulation and then add 1" of XPS then lay 7" strips of 5/8 plywood with a 5/8 gap in between to run my pex. I would then put a thin subfloor on top of that. My specific questions are as follows: If I want to heat my basement and my upstairs, do I need to install the tubes in the basement or is there a way that I can heat my upstairs floor and have the heat come down to the basement while not making one way hotter. If I did use roxul, would I still have to use heat transfer plates or would the roxul be enough to make the heat go to the floor. If I do have to put tubes in the basement floor, instead of putting heat transfer plates that bend around the tube, can I just lay sheets of aluminum on top before I put my subfloor on? This way the top of the pipe would touch the aluminum and any heat that radiated off the sides would want to go up because of the thermal break below it. If I did this, what thickness of aluminum should I use? Is there any other thoughts or considerations anyone has?

Sorry for the jumble. It won't show my paragraphs.

First a finished envelope with window size, quality and location. Then the finished R value of walls. The depth of basement below grade?

The type of sub-floor radiant system is dictated the room-by-room heat load. If you are in Canada, with the exception of the lower East and West coasts, then extruded aluminum plates are in order, some of the best being made engineered and sold by Radiant Engineering out of Bozeman, MT but manufactured in Alberta I believe.

You must insulate between floors since you cannot control the heat flux in either direction without it.

We have heated many ancient homes here in Minneapolis, which are on the National Register, which are impossible to insulate. Even with un-insulated stone and block walls we heat them with carefully engineered radiant floor systems but plates and proper controls are always in the mix.

For basement floors XPS is good with plates and tube. There are products on the market to do this but heat loads dictate which is best.

That ratio of heat needed in the basement to upstairs changes widely with outdoor temperature - as MA says, thermally separate radiators with separate thermostats. For best heat transfer, you should have good thermal contact between PEX and aluminum.

R9 in the walls, and -40C? Sounds chilly Can you add more to the walls? Insulation is probably going to be the most effective tool in combatting this. In resisting the flow of your heating dollars to the outside, it may also pay for itself the quickest in terms of cost and overall comfort.

Heat transfer is about time, temp difference, flow and probably most importantly surface area and the conductivity of that surface material. No metal = very little heat transfer. Metal only in contact with top of pipe, better, but not all that great. Far better is a plate stamped to fit in the grooves and that the tube presses/snaps down into the groove. This places more than half the tube surface in contact with the metal plate for more efficient transfer.

Google Warmboard. They make a product for retrofit/remodel it is a solid aluminum top skin stamped to fit the tubes and bonded to structural ply. Comes in 4X8 sheets and attaches like any other subfloor material.

It does sound like you need to do a heat loss study. Have you looked at the heat loss calculators at Borst Engineering? They are pretty easy to complete and will give you an idea of what heat source you will need to make this work. It also makes it easy to play with the insulation levels and see how that effects required heat. Don't forget to look closely at air infiltration. You need a certain ammount for healthy living, but as the insulation levels increase air infiltration quickly becomes a major player in overall heat usage. here is a link to the heat loss calculator. It is only one page with 15 pieces of information to enter. You take some measurements in your house, do a little math to calculate areas and volumes, READ the instructions and they will walk you right thru the process. Once you have the house info there, you can vary insulation and infiltration and environment to see how that effects heating requirements. One of the easiest to use calculators I have come across.

Good Luck.
http://www.borstengineeringconstruction.com/Heat_Loss_Analysis_Calculator.html

Yet another pseudonym?

Posted By BadgerBoilerMN on 13 Jun 2015 05:07 PM
Yet another pseudonym?

So you think I am someone else? I have seen you attack her so many times that it didn't take much for your pseudonym remark to register thru my overly thick skull, who exactly you are refering to. I have always wondered why you have such an obsession with her. I have never seen her try to be anything but helpfull, but you attack her(and apparently anyone who you think might be her) at just about every opportunity you can. If I am a pseudonym, I am a dam elaborate one:) Nope, my user name is a combination of my first and last name(Ron Marlett) and I live in Port Angeles WA, I have been registered here(and a few other forums under that name) for quite a while now. If you search out my user name here, you will see I am working on a new ICF house and have posted in many areas of this forum, not just this one. I have found her calculators usefull over the past few years, as the O.P. might also. The math seems pretty solid and the price was right(dam nice of her to do that don't you think?). I actually got aquainted with the Borsts thru a micro-cogeneration forum a few years back as we both built the same type of slow speed diesel generators, and I am recovering the waste heat from mine.(basic power necessities AND domestic hot water and some heat, all from a 6HP/3KW generator)... Sorry I allowed myself to be drug off topic...

I beg your pardon.

Non-the-less you have never "seen" me "attack" "her" or anyone in person or on line. I do admit to being tired of hearing about the much overrated "free" software and the several names she has used to truly attack anyone and everyone.

Thanks Everyone for the replies. Yes it is a 2X4 wall with batt insulation so I am guessing R9. It doesn't go below -40 all the time but it's not uncommon. I don't really know how I could upgrade my walls without committing to some serious renos. I did the calculator as best as I could. I don't know if this looks right, I think I may have calculated the heat loss from the basement incorrectly: Window Heat Loss (BTU/Hour) 10045 Wall Heat Loss (BTU/Hour) 7229 Door Heat Loss (BTU/Hour) 441 Ceiling Heat Loss (BTU/Hour) 2548 Floor Heat Loss (BTU/Hour) 1411 Infiltration Rate (CFM) 88 Infiltration Heat Loss (BTU/Hour) 9349 Total Heat Loss (BTU/Hour) 31024 Total Heat Loss (BTU/Day) 744571 Total Heat Loss (BTU/Hour-Deg F) 317 Looks like after I insulate the basement, windows is next on the list.

I would not fret about the walls. The next best thing is to increase fuel efficient with a condensing boiler, and properly set up the on-board outdoor reset feature. Beyond this a properly programmed Nest, EcoBee or equivalent.

As for the heat load, the basement will be in the single digits. DIY heat loads are seldom accurate regardless of the cost.

Your basement should be in the single digits and the heat load for the entire structure may easily be handled by a comb-water heater if the radiation is designed for it.

Again, though the house is modest the complexity requires some experienced evaluation.