All
Just dreaming.
In the 70s I saw book with a guy who had laid out 8″ block under his basement floor then poured 4″ of concrete over it. Then he hooked up his solar collectors to this and he would blow solar warmed air thru the blocks to store heat.
Since that time I have always wondered about different ways to incorporate thermal mass into a house.
So I am thinking of a ICF home with a single thermal mass wall down the center, or two smaller walls that are heated and cooled by either solar hydronic system in the winter and ground loop for summer cooling.
For the two smaller walls I would do a Master suite, then a thermal wall, Living/kitchen area then thermal wall then other bedrooms.
In Iowa almost all homes have a basement with a main wood joist floor. I don’t know what it would be like to live with a concrete floor (for thermal mass). I know people who work retail complain about long days standing on concrete. So I don’t know if a thermal mass in the floor would be the most enjoyable .
The thread on cooling tubes got my imagination going again.
I know Mike Smith in RI thinks a couple of window AC units would be cheaper, but here in Iowa the cooling season runs from mid June to Mid Sept, unless of course you have an all ICF home and their cooling bills are alot lower.
Like I said just dreaming and thinking. What do you think.
Rich
Replies
Radiant heat is great.
Cooling is difficult. Warm moist air condenses on cool surfaces. There have been some attempts at running cooled (ground source would be a economical way) water through the floor tubes to cool the slab. Damp on top slab was the result. I'm thinking I might use a ground source heat pump to make my summer cooling.
Using Mikes suggestion isn't too far off. Here in NW Oh where hot and humid sometimes can go for a few weeks to a month, we cool the whole house with one window unit. A dollar a day electric over the norm. Built into the hill first floor with a second story above.
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Calvin
Do you have an ICF home or is it conventional framing.
Our climate is very similar. Hot and humid for late june thru end of Aug.
It might cool alittle but it is still humid.
Rich
Nope, semi-conventional. Stepped block foundation with first fl. framing 2x10 to match up with the block.
Warm and Dry ext. foundation insulation/waterproofing.
2x6 second fl framing.
Fibreglas in walls and in attic/1'' dow with furring behind siding.
Shaded lot in summer.
2' overhangs.
Passive solar-HW radiant slab floor heat, Tulikivi Mas. Htr., HW basebd in two upstairs BR-s (a salvaged 5' in each one), one window unit in window on balcony over greatroom.
and a woman that likes it warm in the winter/cool in the summer.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Calvin
and a woman that likes it warm in the winter/cool in the summer.
We all have one of those.
I will work outside summer or winter and come home at noon and she will say "It's really cold/hot in the house"
I just keep my mouth shut.
Rich
As long as she's hot when you walk in that door, what's not to like.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
calvin
I'm not going near that one.
This is a family oriented site.
Rich
And how exactly do you think these families get started?
certainly not by osmosis.
not that there's anything wrong with that.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Calvin
The stork.
That's my theory and I'm sticking too it.
Rich
I built a house in the late 70's that was passive solar/wood backup. S.O.G., Earth bermed,with the footings sitting on and wrapped in 2" Dow X foam, entire house was thermally isolated from ground by the same 2" of X foam. Slab had 4" ADS tubes run 4' o.c. to a central tunnel under the house.
Tubes originated in a false wall at the earth bermed side of the house and at floor registers on the south side (framed side) and an integral solar glazed room (green house) as well.
Tunnel was connected to two towers within the building that reached to within 1' of the ceiling and doubled as a mechanical chase for all plumbing etc.. Each tower had a slow speed fan mounted in it to provide mechanical air movement.
Somewhere near 180 yds. of concrete in the building IIRC.
Fans were thermostatically controlled to move the air when preset temperature differentials between floor and high ceiling temps were reached. First year the house sat unoccupied for almost all winter here (Ore.) Owner reported to me he would light a small fire every 2 days to ensure it stayed warm and dry . Burned a total of 3/4 cord of wood to do that . Even the garage had a set of tubes that terminated under the owners chosen spot to park his 2 diesel Mercedes to ensure the engine oil was kept warm . I visited that owner quite a bit over the years as he was also my one of my doctors and he was always pleased with the performance of his house. Alway comfortable and pleasant temperatures inside with little effort on his part. Edit for some of the typos.
Edited 3/4/2008 3:02 pm by dovetail97128
cargin
You don't need concrete to get thermal mass.. you can use wood! another words build a timberframe or post and beam inside the ICF's
Surprisingly that is a very affordable thing to do!.. For example a 9"x7"x 9' hardwood beam is only $20 to$22. Many sawmills can make you 18 to 19 foot long beams for about $44 each.. A thousand dollars would provide you with all the timbers etc you'd need..
Like Mike Smith I too have a love of small window units installed in the wall. (I did it in my house, a combination of SIP's and ICF's) go to 85891.1 & 94941.1 for pictures.
First place the house stays so much cooler than my old stick framed house you can't believe the differance.. In the Summer (Twin Cites) I rarely need to turn the A/C on. It has to be well into the 90's for me to feel a need for A/C. Inside the house it can be 15 or more degrees cooler without A/C
With Window units installed in the walls you can get higher efficency ratings than all but the very most expensive central A/C units. Plus if new technology comes out you can easily upgrade at a modest cost compared to a large central A/C unit..
In addition not A/C rooms which are not in use saves a lot of money..
My summer long A/C cost is seldom much over $15 or $20 for the whole season!
Winter my heating bills went from $500. month dec.&jan to $200 a month for the same period.. that's in spite of using the same furnace in the house that is now twice as large with three times as many windows!!! (and my old house was carefully insulated before)!
Edited 3/4/2008 2:03 pm ET by frenchy
Frenchy
I have looked up your threads on your house. Very impressive.
Raised paneling for the bathroom. Wow. Better watch your aim.
I have also read just today how you have been preaching to people to buy wood from local mills and no one is listening.
Very few saw mills in this area, but I am not far from the Land of Lakes.
I was toying with idea of radiant heat (and solar panels) in the interior walls. Slow day around here and the mind is just fooling around with different ideas.
But I think you are right, insulate well and pay for the small amount of cooling needed.
Thanks
Rich
cargin
I know there are several sawmills in North eastern Iowa.. they aren't real big mills but that's exactly the sort of mill you should be looking for..
Worse comes to worse grab a truck and come up here to mine.. they are nice people..
PS you will love in floor radiant heat! Relatively easy and cheap to do too!
rich... in the early 80's i designed a commercial condo
4 units.... the 3 south facing units were each 30x40 and all were heated with a solar hot air radiant floor... they still are
anyways... in researching it i found a mfr in California who makes a steel form that creates a hollow concrete floor they are a series of little arches that hook together
you set them on a foam base and route the air passage , then pour your slab right on top
we blow solar hot air into the slab... it transits thru the maze.. and comes out of baseboard registers under each of the 4x6 south facing windows and at various locations around the wall perimeter
the slab gets to about a max of 80 deg... the blowere is turned on by a differential thermostat
if there is a protracted lack of sun... the thermostat calls for electric cove heaters to turn on and maintain the temp
here'sa link to the AIr-Floor mfr... pretty interesting site
http://www.airfloor.com/
I don't know too much about it, but a good friend of mine is building his house right now using a system with no concrete.
Sand.
Lots of sand.
He laid a significant bed of sand with pecks tubing running throughout.
Like I said I don't know much about the system but I'll find out more.
I'm not quite sure what you're describing, and my solar experience is entirely with passive heating not cooling.
But here's a solar collector efficiency comparison. It's hard to beat simple south windows with direct-gain solar mass.
sunspace with fan 35%
Solar & Super-Insulated Healthy Homes
Edited 3/4/2008 4:52 pm ET by Riversong
Good evening Robert
I am just fooling around with ideas. Like I said most homes in our area are built with a full basement and a wood joist main floor.
So how do you get the thermal mass on the main floor if it is wood framing?
An Iowa farmer thinks if alittle is good alot is better. If you do that with too many south windows the house can get uncomfortably hot and the glare can be uncomfortable to live with.
So I am just knocking around concepts of how you could get that thermal mass in the core of the house, either with passive solar heating or with air or hydronic tubing connected to a solar collector.
The lastest issue of JLC had a vaccum tube solar hot water heater set up. It seemed complicated but he has excess heat to deal with that was piped into a radiant slab.
So how do you get the thermal mass on the main floor if it is wood framing?
Keep the wooden floor light in color and reflective and place the mass in the center bearing partition. If there's a woodstove, use a masonry surround as combination wood heat mass and solar mass. Or just finish the center wall with tile or masonry. You can also double the drywall on direct-gain walls.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
I've read that dark tile can make a significant impact.
Any truth to that?
Too dark a surface can make the space too dark for livability. Medium colors with course texture are often best.
Solar Absorptivity factors*:<!----><!----><!---->
flat black paint .95<!----><!---->
dark grey paint .91<!----><!---->
dark brown paint .88<!----><!---->
dark green lacquer .88<!----><!---->
medium brown paint .84 <!----><!---->
medium rust paint .78<!----><!---->
red bricks .70<!----><!---->
uncolored concrete .65<!----><!---->
medium orange paint .58<!----><!---->
medium yellow paint .57<!----><!---->
medium blue paint .51<!----><!---->
white semi-gloss paint .30<!----><!---->* absorptivity below .60 substantially reduces performance<!----><!---->
<!----><!---->
for painted surfaces of equivalent lightness, hue has a substantial influence<!----><!---->
best absorbers = middle wavelengths (green & yellow)<!----><!---->
poorer absorbers = long wavelengths (red)
worst absorbers = short wavelengths (purple & blue)
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Interesting thanks
My question was more-
Is there really enough mass in a tile floor to be an
effective heat sink?
I know lots of factors to consider.
How about a south facing room say 20x20
Medium dark tile.
Glass to Mass Ratios<!----><!----><!---->
<!----><!---->
A sun-tempered house can have 7% (of floor area in) south glazing (multiply the entire window by .8 to get the net glass area) without additional thermal mass.<!----><!---->
<!----><!---->
To increase beyond 7% we must also add thermal mass, usually starting with floor mass and then walls.<!----><!---->
<!----><!---->
An additional 1 sq. ft. of south glass (beyond 7%) may be added for every:<!----><!---->
<!----><!---->
5.5 sq. ft. of sunlit thermal mass floor (up to 1.5 times south glazing area)
40 sq. ft. of floor not in direct sunshine<!----><!---->
8.3 sq. ft. of thermal mass wall<!----><!---->
The recommended maximum amount of south glass for direct gain is 12-15% of floor area.<!----><!---->
THERMAL MASS PROPERTIES<!----><!---->
<!----><!---->
High Density - The more dense the material (ie the less trapped air) the higher its thermal mass. <!----><!---->
<!----><!---->
Good Thermal Conductivity - The material must allow heat to flow through it. But if conductivity is too high (eg. steel) energy is absorbed and given off too quickly to create the lag effect required for diurnal moderation.<!----><!---->
<!----><!---->
Low Reflectivity - Dark, matt or textured surfaces absorb and re-radiate more energy than light, smooth, reflective surfaces. (If there is considerable thermal mass in the walls, a more reflective floor will distribute heat to the walls).<!----><!---->
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Edited 3/5/2008 9:10 pm ET by Riversong
I've read that dark tile can make a significant impact.
I think there are at least two schools on the tile color when it comes to passive solar heating. School1 believes in dark tile near the windows. The sun hits the dark tile and heats it up. School2 believes in a light colored tile. They feel that the light colored tile reflects the light further into the house... so they are kind of bouncing the heat further into the house (reflect off the floor and onto the wall behind it or some such).
I don't know which school is better.
jt8
"Worry never robs tomorrow of its sorrow, it only saps today of its joy" --Leo F. Buscaglia
I don't know which school is better.
Go with School B.
Putting the solar absorber around the windows will keep the heat around the windows.
Since windows are not just for solar heating, but also for views and daylighting (as well as ventilation), it's important to keep window returns light and reflective. Then put the solar collector surface and thermal mass deeper into the living space where it will surround the occupants with radiant heat.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
When I built this house I insulated all the interior walls and put in electric heat. Each room is therefore its own zone. When someone is gone to south for winter we just shut off that part of house, easy.
In summer, here about Frenchy's lat, we put in the window A/C. We didn't bother last summer. Two small ones for the whole house and that is plenty. One of which is a 5000 for my small suite.
Ceiling fans thruout and good sighting. But great insulation is the deal. We paid in advance and now 3 years later that is done and we are living free, well almost. But compared to others around here this is certainly a cheap home.
Good luck and have fun...dan
drapson
What is the rest of the insulation package like? The outside walls and attic.
Sounds like a nice comfortable home.
Rich
I did regular 2 by wall and 1/2 insulation on the outside of the osb, but I like Mike Smiths wall a lot! The attic is a raised heel truss and just blow the thing full of cellulose. R-50 or so.I did put 2" of rigid insulation on the outside of the 4' crawl space foundation. that puts all the block on the inside of the conditioned space. It puts the crawlspace into a huge heatsink. The space down there never gets below 47 degrees and never above 61. I have found the floors to be cold. I have laminate thru most of the house. One bath is electric heat embedded in tile insulated under. There are two that are carpeted. They are all right.
drapson
Thanks for the info.
Rich
cargin
Mass is mass.. tile or concrete are denser mass than wood is but wood is more comfortable than tile or concrete.
the risk of a high concrete or tiles is that the place becomes too institutional looking.. remember you may be warm enough but that isn't enough to fel comfortable and cosy..
large timbers will provide that along with a sense of security you don't get from a concrete wall..
frenchy
I wasn't thinking about leaving the wall as bare concrete. Texture it and paint it. Give it a brick or tile veneer.
In my head I was thinking about a thermal mass that was heated by roof top solar collectors either air or fluid.
Riversong makes a pretty convincing pitch to stay with passive heating. Anybody that has owned a car can tell you that the more electronic gadgets that you have the problems you will have as the car gets older. Could be the same with complicated solar systems.
Therefore it might be wise to stick with passive or air heat transfer.
Like I said just thinking out loud, and trying to get a conversation going with people who are smarter than me.
Rich
Here is a book you might find interesting:
The Solar House: Passive Heating and Cooling
by Daniel D. Chiras
http://www.amazon.com/Solar-House-Passive-Heating-Cooling/dp/1931498121/ref=pd_bbs_2?ie=UTF8&s=books&qid=1204817624&sr=8-2
View Image
jt8
"Worry never robs tomorrow of its sorrow, it only saps today of its joy" --Leo F. Buscaglia
John
Thanks. I'll give it a look.
Rich
My local library had a copy and I liked the book well enough that I bought my own copy and sent a second copy to a friend. So you might check your local library for it. Covers a variety of topics.
jt8
"Worry never robs tomorrow of its sorrow, it only saps today of its joy" --Leo F. Buscaglia
All
Bump to bring it to the top.
Rich
I was doing some soap stone carving and some reading on same. One article mentioned the Inuet ( Eskimos) used large pieces of soap stone to store heat. The heat was from a crude window built in the south and a whale oil lamp sunk into the stone.
Many places make soap stone fireplaces as it has a slow release and looks very nice. I wish I could find the link but Goggle Soap Stone fire place and look for a place in Quebec there stuff is fantastic.
Also look up the Craik Eco Project in Saskatchewan. It is a neat place. I haven't been there but a friend of mine did a lot of masonry and straw bale work.
He has since added a big room to his house with a straw bale wall and big masonry heater. All survived a tornado but the roof . truss with steel roofing. an easy fix considering all.
How about stone sills inside the windows?
Shoemaker
Thanks for the reply.
Those were interesting websites.
The Craik site was pretty weak on pictures. I wanted to see what a straw bale house looked like.
I started this thread about 1 year ago to just play around and gets some discussion going.
I (like many others) would like to build a dream home/shop with the layout we would like and an energy efficient design. I think the ICF homes offer great potential for great insulation package and thermal mass.
Mike Smith restarted the Superinsulated house thread because someone (Hudson Valley Carpenter I believe) wanted to review superinsulation threads. So I bumped this one just so it would get back into the viewing for HVC.
I keep toying with ideas about building heat storage into the fabric of the house.
Our house (an old Victorian) is paid for, so the dream house will probably have to wait for a few years. I don't want to get back into a morgage.
Again thanks for the reply and the websites.
Rich