Gone a week in winter - no heat - no freezing - a Testimonial to a bermed home

Testimonial for our bermed home in the Maine foothills - Closed it up on a Monday morning - no furnace - drapes pulled 1/2 way - temperatures ranged from the low 30's to single digits at night - and it snowed about 10-12 inches one day with wind - we returned in the middle of the night on the next Saturday - living room was 63 degrees and the back bedroom was 61.  Can anyone beat that?

When is 62 degrees F not cold inside?

When you wake up to 0 degrees F - no furnace running and one firing of the Tulikivi the night before - the wind howled all night (gusts to 40 mph according to weather men). This is when 62 degrees is really not cold!

Today the sun is to shine - although temps are to stay below 20 degrees. Oh well, sun means warmth in our house! Still loving the passive solar solution.

And the garage - also bermed but only on 1/5 sides - no heat at all was 45 degrees at 7 am. This can be the solution to a huge portion of our energy crisis.

Technorati Tags: sharonbetts passivesolar bermed Tulikivi

Ready to burn

It's done - we have the wood ready for this winter and next (actually starting the stock for 2010-11.
There is this winters pile - about 2 cords split and stacked in the attached garage - ready to burn in the Tulikivi (thank goodness for it, and its clean wood-saving burn).
We should make it through the winter with this - way less than 2 cords - and no furnace. We only supplement the back shower room with a boost from the electric heater occasionally before morning showers.


Stored in the back garage to finish drying over this winter. Dave built two woodbins that sit by the south facing windows. Using the solar design as a winter drying facility. Yet another use for the sun and our berms.

And outside is the beginning of the next pile - quite a system.


sharonbetts
tulikivi
passivesolar

Passive Solar Works - Build a Fire!

Its a rainy Spring day in Maine! The temperature is 30 degrees higher than the sunny day I blogged about no heat last January. What little sun we have today only comes into the house about a foot inside the southern windows. Due to the height of the sun, the berming and the depth of the overhang, it all works to keep summer heat out. Last winter, we had rays bouncing off the back living room wall (18 feet into the room). Being a fringe season (Spring, Fall and Mud), we are cool and actually started a fire in the Tulikivi. Not a problem, as we didn't use as much wood as we had estimated and there is still some stacked in the attached garage. Rather burn it than have to carry it back outside. That will keep the house around 70 - very comfy.

Another success is the tile flooring. It is nearing completion, too. Not only do they serve as heat storage during the winter and remain cool to the touch throughout the summer, during these rainy days it is easy to mop the puddles left by 245 pounds of wet double coated dogs! Doesn't do much for the perfume of wet fur - but is certainly easy to sop up.
I highly recommend it to anyone with 4 legged pets.

sharonbetts
passive+solar
tulikivi

Building further south?

So long between posts - guess this long winter is getting to my enthusiasm. But, finally some of the over 100 inches of snow are melting.

We had another request for some info - but way south of Maine:

I live in Spartanburg, SC where most of the time it's in the 40's & 50's during the winter days and in the 30's at night. It does dip in the mid to upper 20's at night but not very often.  I would really like to build an earth shelter. My plans are similar to yours except my front garage corner will not angle away from the front but will angle towards the front, giving me a workshop inside against the back wall. Planning on 3 bedroom, 2 bath. It'll come in somewhere around 2700 sq.ft. not including garage/shop. Plenty of south facing windows where the bedrooms & living room will be.  Also planning on radiant floor heating to the bathrooms, kitchen & TV room using Thermomax.  What's the square footage of yours & how much heat is generated thru the windows? Winter? Summer?  Are all those windows a big source of heat leakage? Do you have any sort of ventilator installed or mainly rely on opening the windows?

Wow, with those temps, there are times I  think we should head south....  Here is the answer - most of the items were mentioned in a blog post during construction.
Your questions are all good ones.  Our house is around 1900 sq. ft.  Two bedrooms, two baths and a study in the 'kink'.   We wanted to get our house size down to something easy to maintain and clean, etc.   The ten large, fixed windows are 46"X72" each.  They are a commodity item used in sliders and commercial store fronts.  We paid around $125 per window, which is way less expensive than a ready to hang window unit.  These come with just a rubber or butyl liner around the edge, you have to build your own jams.  So, how much they leak sort of depends on how well that is done.  Mine aren't done yet, just some caulking most of the way around them.  I think we most notice the radiant losses at night, like standing next to any large window.  Thermal drapes would stop a lot of that, but I don't know if we will get those.  We also have four casement windows for ventilation and fire escape code.  The large window glass is clear with no inert gas between the panes.  That may not be the correct thing for your climate.  I chose clear due to the higher light transmission compared to low-E coatings.  A really important aspect of windows is your overhang width.  26"-28" is considered optimal for this latitude - just under 45 degrees.  Yours would be different.   You definitely want to keep direct summer sun out of your rooms.   The heat gain in winter is phenomenal, if anything, it can be too much on a crystal clear day in Jan.-Feb.  We have some roll-up bamboo blinds we lower once in a while.  The house will go up to 80 degrees no matter the temperature outside on a clear inter day.  We crack a few windows open as needed.  The temperature drops back to low to mid 70's by early evening.  We have only lived here one summer,  we did use fans to stir the air during warm spells.   I suspect there is a fair amount of radiant heat gain through the windows in summer even though they are shaded by the overhang.  Of course, heat in Maine is relative.  We get so used to moderate temps that 85 deg. is a scorcher here.  It rarely hits ninety, maybe 6 days per summer, sometimes it never hits 90 all summer.  In any case, summer is short here, so we just put up with it.  Based on our experience and trying to guess about your climate, I think you would make different choices on windows.  We optimize for winter here.  I wish I had a more technical answer.  It pays to read up and talk to people in your local area.  We were able to visit three homes of this style before committing to the design, that really helped to frame our expectations.  Ventilation in these homes is very important.  For the first 6-12 months they are loaded with residual moisture in the concrete.  We have interior plaster and it also takes a while to really dry out.   For ventilation we have an outside air inlet for the wood burner, a high capacity kitchen range hood fan than vents to the outside and four fans in the ceiling that exhaust into the attic space.  There are attic exhaust fans at each gable end of the house that are controlled by a thermostat switch.  The four ceiling  exhaust fans are on individual switches.  The attic exhaust fans turn on around early afternoon on hot summer days.  They pull air through the soffit vents to cool the attic space.  The four ceiling exhaust fans are used only in summer.  We open windows in the evening and let them pull fresh, cooler air into the house.  That air pressurizes the attic space and pushes air out through the soffit vents.   With so little air infiltration through exterior walls, getting air in is really something to plan for.  Are you planning on air conditioning?  I think it would be a good idea just to control summer humidity.  You don't want to have moisture build up through condensation, which will happen in rooms that are on the 'back' side of the house.  The earth berm will keep those walls and floor pretty cool compared to the outside temperature.  For heat, we have a radiant heat system installed that rarely gets used - thank goodness, given the price of propane.  I ran a couple zones for about 4 hours twice this winter during an extended cloudy period.  We burn just under two cords of wood in the fireplace stove.  It is a Tulikivi soap stone masonry type stove.  There are over three tons of soap stone in it, once it is warm, it radiates heat for the next 20 hours or so.  We usually burn it once per day but skip a day now and then depending on sunshine.  For the bedrooms and bathroom in the far end of the house, which don't receive much heat from the wood burner, we use electric heaters to take the chill off during cloudy spells.  That is less expensive than running the radiant heat - go figure.  I really think our house would never go below the mid-fifties with no added heat, just the sun.  I haven't tested it since sitting around in a house that is in the low sixty range isn't comfortable.  A regular framed house around here will freeze up solid in about 2 days with no heat. Given the cost of a radiant heat system and your climate, it must be hard to choose.  I think our radiant heat was really not a good use of the money, it works just fine, but is not really needed.  When you consider we can go for weeks at a time here where our high temperature for the day is well below freezing, and we hardly use the radiant heat, your climate may not need any sort of central heat in a solar house.  Maybe electric heat combined with an air conditioning system would be better in SC?  Our water heater is a zone on the boiler, someday I might get into a solar pre-heat set up.  We have a propane range/electric oven combination.  For hot tap water and stovetop cooking we use about four and one-half gallons of propane per week.  A flow through on demand water heater might save a little, but our tank is well insulated and the boiler hardly ever runs unless someone is using hot water.  One thing that takes getting used to is how earth sheltered homes don't fluctuate in temperature very much and certainly not quickly.  We can go to bed after being too lazy to make a fire in the Tulikivi with a temperature of 68 or 69 degrees; it will be 64-66 degrees the next morning with no heat on anywhere.  That's with an outside temperature in the low teens.  It really demonstrates what thermal mass does.  Well, I hope I answered your questions helpfully.  Good luck with your project.  We really like our house, and the higher fuel goes, the more we like it!  I would be glad to answer other questions you may have.  Have you considered earth sheltered roofs?  I have never been sure which is better - bermed walls and regular roof or go all the way and have an earth covered house with just the southern side exposed.  While I was cleaning the record amounts of snow and ice off my roof this winter, I was sure the sod roof would have been the way to go - Ha! Regards 

Updates on Perfect Passive Solar Day

Since the berm construction is pretty well complete for the house and the detached garage only needs a ceiling and insulation, I haven't posted much lately. But today is just too good to pass up. It is 12 degrees outside with the sun shining - our house is around 75-78 inside with no heat . smile.

Work on the interior is progressing also. We are finishing the ceilings followed by the woodwork. Nearly all of the ceilings are tongue and groove - which means some sanding, staining and poly before putting them up. Since I am still working, the actually hammering is only on weekends. Even at that, we finished the study and are now working on the dining room.
Floors will break the monotony of ceilings. There are still quite a few concrete floors - which although utilitarian, are not very attractive. The tile is ordered for the study and should arrive in the next week or so. We have picked all the others out -some slate and some tile.

I plan on posting more information about "rural Maine living" as Spring approaches - and promise more updates on the finishing touches of the house.
More pictures of everything at our Gallery.
sharon+betts
bermed
Maine

Reflections posted

I was in the process of posting some reflections on our home when I asked my husband for some references. He promptly jumped in and wrote his thoughts which I have published on the right. Just click on the Scribd to enlarge. I think he said it all - at least from the "construction" side.


passivesolar
bermed
sharonbetts

Supplementing the Sun

There are so many factors involved in the amount of supplemental (or central) heat necessary for any passive solar home - especially one of bermed construction that I wouldn't even consider trying to recommend any. However, here are my thoughts after being in our house for a year.
1 - Design We opted for a modified design (usually for full passive value, you would build in modules with all rooms open to the sun and each other). You can see from our design that we placed baths and laundry behind a hallway as a personal preference. The shower bath therefore is the coolest location in the house and I like to supplement it for those early morning showers.
2 - Building style - insulation, amount of thermal mass concrete, amount of windows, sides bermed, preparation of the slab (see previous posts during construction).
All of these add to the retained heat .
3 - Window treatments - we do not yet have any insulated window treatments to withhold the heat during the night. We may add these later.
4 - Resale - it can be very difficult to get a mortgage for a house without central heat. We never use our radiant heating system though and at times feel it was wasted money.
5 - Type of wood stove. We chose a Tulikivi (because I fell in love at first site). It gives a slow radiant heat - no major hot spots and is great for our living area. We could have also installed a small wood stove in the back of the house and probably only supplemented with wood.

So, in our situation, we do need our Tulikivi. Only for the times that we have more than one day without sun. If during those dreary weeks we wish to have the bedroom and shower room above 64 or so, we also need additional heat at the west side of the house. Do we need or use the radiant heating system - no.

68 - possible?

Had a question from a reader yesterday that I would like to answer here:
I live in NH and would like to know if it is possible to have a bermed home that stays around 68 degrees with simple supplemental heat.

My thoughts after living in ours for a year:
Yes, of course it depends on two things - the amount of sun and your interpretation of supplemental heat. We find that if we get even two hours of sun in a day, the temp will remain a comfortable mid-sixties through the nights with no additional heat. We may even be a bit over-glazed and it will get up to the 80s until we open the windows (regardless of the outside temps - have had them open with single digits), Our supplemental heat sources consist of the soapstone Tulikivi and stand alone electric heater. Although we have radiant istalled, it is much cheaper to run electric for several hours than to pay for propane.

There is so much more to this answer - it could be a thesis. I would appreciate any further questions or comments.

Conversation with interested reader

1. Have you continued to have a good experience with the house? Absolutely - I would never live in a "standard" house again!
2. Have you found that you are using significantly less fuel to heat your home while still remaining comfortable (of course, I can use significantly less fuel in my 190 year old house, but I have been VERY cold!)? We only use wood and a few hours of an electric space heater in the back bathroom. And the Tulikivi only needs to be fired once or twice a day which cuts way down on the amount of wood (and time).
3. Have you resolved the condensation issue? It is much better this winter - the only condensation we have had so far is a small amount on the windows if someone showers at night. No longer an issue.
4. Have you had any problems with leaking? No
5. Do you find that the windows drain a lot of heat at night during cold weather? And do you feel that you need to remedy this with insulated blinds or drapes? Are the windows double-glazed or triple-glazed? The windows are double - actually they are replacement panes for sliding doors. They obviously cool at night, but the concrete holds so much heat that we haven't seen much. We have installed some bamboo blinds for the intense sun on sunny days which makes it nearly impossible to read or work on the computer.
6. How comfortable is the house in the summer? Its fine. Did it get very hot? Not really - we have two attic fans during the day. At night we run the exhaust fans installed periodically through the house to bring in the cool air. Living in the foothills - there was only 1 night that I can recall last summer being overly warm at night.
7. Who was your contractor? A local builder - individual, not a firm. Did he have experience with building this type of home? None Who designed your house? We did.
8. Are you considering including your house in one of the solar home tours? Perhaps when it is finished.
9. And finally, would you do it all over again? Absolutely If so, what would you do differently? That's a hard one as we really love it. Ask me in another year or so.
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Passive Solar 1; Propane 0

Its November. The leaves have all dropped and we still have not needed any heat - as a matter of fact, I have had to open the window at night.

We have had nights below freezing, but enough sun during the day to warm everything up above 75 degrees. Dave did cut enough wood for the winter (it is in the garage) and the pile for next year is started too. But, so far no need. I am actually getting the urge to light the Tulikivi - but it has been too warm in here. Gotta love the sun.

With these shorter days comes thoughts of starting inside house finishing again. First on the agenda -- wood ceilings in the study and living / dining room. I also want to get that final kitchen cabinet made and hung now that we have a design. Then a little paint - and on to the tile floors that are still concrete. Time changes tomorrow night - that makes it dark during the evening news (or before). Ugh.

sharon+betts
passive+solar
Tulikivi

Maine Metal-roof torture.

An interesting effect of a metal roof and the passive solar design in an ice storm.

About 1:30 am this morning, we heard a crash that brought both of us and all three dogs out of a nice winter sleep with a vengeance. What? could be some wood checking in the new house? A couple of shakes from the dogs, a roll over from us and everyone back to sleep. For 10 minutes - another crreech - crash! Back up - Sophie at the bedside to let me know something just isn't right (she is my nervous Nelly about any loud noises - thunder, gunshots etc.) Then the third - brrrrrrr-crash! Aha - ice sliding off the metal roof in sheets and landing against the aluminum at the top of the foundation - due to the southern breeze.
And on it went - rain coming down - freezing on the roof - sliding down the slope and crashing on the aluminum. A fantastic method of natural sleep deprivation. At 2:00 am, I gave up and took the whimpering Sophie to the living room. Banjo and Milos managed to groan at each disturbance, but go back to sleep. Every new bang, Sophie would look up at me and I would reassure her and back to dozing in my chair. At 4:15, I finally went back to bed as it seemed to have slowed down - or I just got so tired it didn't matter. So, build a steep metal roof at your peril.

sharon_betts passive_solar metal_roof

Watch that thermometer

Since we blew in all that insulation - wonder how we are doing? Today was the first day the furnace came on for the radiant heat zones! Impressive. We haven't had extremely cold weather, but it has gotten into the high 20s at night and we are cozy here in the berm.

All it takes is a bit of sun during the day and those thermostats jump right up to the 80 mark. I can see where we may be running around in shorts if we have a sunny week this winter. But - no complaints from me.

We do notice that when the temp does begin to drop, it slows down as it approaches around 68 degrees and then stays fairly stable for 6 - 8 hours. There is one more bit of insulation to install which will wait until next Spring. We need to put the styrofoam from the outside walls out and cover it with stone. I believe it goes out 6 - 8 feet. It is quite a process, but looks to be well worth the effort. I will update occassionally as the weather chills.
berm passive_solar insulation sharon_betts

Warm and cozy

The attic insulation is done! We ended up with about 18 inches of blown in cellulose insulation.

We chose loose-fill cellulose for several reasons. In reading, it seems that it out performs fiberglass batts. But, even better, cellulose contains more than 75% recycled material, primarily newsprint. So, it not only saves energy, it helps the environmental waste disposal challenges.

Rented a blower and Ken (contractor) and Dave broke up the bundles into the hopper while they snaked a long tube to Jason (works for Ken) in the attic. Jason was dressed in a paper coverall and all wore masks. The material looks a lot like the padding in those envelopes for pictures. And it goes pretty much everywhere. Especially when the hose plugs and then pops off the hopper - blowing the garage in the process.
You can read more about this type of insulation at the Cellulose Insulation Manufacturers Association (http://www.cellulose.org/index.html).

The good news - the furnace has not come on today (temps are in the high 30s) and we seem to have the "excess" all swept up - at least what we can see.

passive_solar
sharon_betts

Plastering

They are very busy plastering and it is a messy business. They arrive around 6 am - Milos shows exactly how we all feel about that. Finishing the walls is starting to make the house really take shape. It is quite interesting and a long process. We have a challenging house with the concrete topped with framing - they are doing their best. First they "paint" the walls with a bonding agent, then apply a base coat (some times several to smooth the flaws). That is all followed with a final coat of white plaster. They work extremely well as a team - but, there is plaster everywhere. Thank goodness the first thing they did was cover all the floors.

You can view other pictures by clicking the word: Gallery.

Concrete Done

The concrete is finally complete -- You can see the step down to the garage floor (which took another couple of trucks). They have even started the framing for the south wall. The results are laying on the house floor. As you can see, we are finally having some nicer weather. But, we still get showers about daily. Now that all those layers are covered, it is difficult to remember what all is under that slab.

45 yards later

The trucks started rolling in around 8:30 today - and 45 yards of concrete later, we have a floor. The house is completed, but they plan on pouring the attached garage floor on Thursday. We ended up going with 8 inches due to the need to cover all the paraphanalia that is incorportated into this slab.
Stone, 2 sheets of black plastic, 2 layers of styrofoam, rebar (on 2 inch chairs), the PEX tubing -- and then we placed styrofoam around the concrete walls to separate the floor from them and thus deter heat loss.
The pour went well - the last load was a bit wet, and the concrete crew is presently working to make certain that ends up the way we want it. Dave was in the middle of the job allong with 5 others.
The garage siding (on the detached building) was also making major steps today and is nearly completed -- gray siding with white trim. All are documented in our Gallery. It was great to be home and see all the progress. I still can't believe we are on the move. As a matter of fact, the contractor left to order some lumber and we should see a start on the south wall framing next week.
Progress is sweet.

PEX not PEZ

Long time - no postings. We had a delay with the progress on the slab the last week or so. Finally, Dave ended up laying the rebar himself (with the help of a neighbor teenager). Today, we had the heating contractors and they have the radiant heating tubes (PEX tubing) nearly finished. I meant to put a link on the previous post for information on the Slab-Shield we used. But forgot so check out this site if you are interested. We read alot on radiant heat and PEX was most accepted as the best material for the slab. Cross-linked Polyethylene.
There are a few more pictures in the Gallery - and check out Dave's wall.

So, now if we can just get the rebar chairs to lift the rebar above the slab shield, we can POUR THE FLOOR!!! Stay tuned.

Major Preparation

We are spending a lot of preparation time on the floors and walls. If you want to live in a bermed house, you need to insulate yourself in all the correct places. So, the concrete is first covered with two layers of heavy black plastic, followed by two layers of styrofoam.
After major plumbing lines are in place, the floor is covered with stone, two layers of plastic, the styrofoam and then Slab Shield. After that, we call the concrete team back for the rebar before the heating contractors come to lay the radiant heating piping. WHEW. Documentation with pictures in the Gallery.

Plumbing and insulation

The concrete forms on the walls are finally gone. Today, the plumber worked (along with Dave and Ken, the general contractor). Having a concrete floor and walls means alot of planning and a slab full of "stuff". We have decided on the drainage now -- they cast 'weep' drains into the frost wall and will have a perimeter system carrying away any accumlating water. The excavator said today that it is actually possible the water will find another way over the years and become completly dry. Dave is also putting a back-up sump pump system in just in case. Those years of waking up to floating shoes and socks when he was a teen ager in Bowling Green, Ohio certainly taught him to be careful.
I will try to get a few pictures of the inside of the walls tomorrow night - although I have an appointment with the cabinet maker to finalize the kitchen (much more fun that pipes and drains).
And there is more good news -- we finally have a working phone. We had a two phone system in our previous house and it works here. The base unit is in the garage and the extension sitting in the trailer -- I just talked to my mother and it worked great. I'm excited. Internet and phone - what's next? The dogs are having a great time watching the construction project. Milos is quite impressed with the speed of earth moving going on.