|View From the Southeast, October 25, 2011|
A considerable amount of interior and exterior trim work and landscape and concrete work remained to be done when we moved into the house the end of May. At that time yellow Illinois clay (mud whenever it rained) surrounded the house on all sides, including the roof. Thankfully that expanse of yellow in the above photo is no longer exposed clay, but wheat straw spread over black topsoil seeded with Illinois number 2 roadside mix. Now we are in the midst of an extended drought (blessing or not?) The seeds are lying in dry soil and the straw is blowing away. Rain is again promised, as it has been so many times lately. We wait.
The house as seen above wasn't always that way. Between May and now involved a lot of grading and concrete work. How about a stroll around outside and enjoy some fall colors. October 24 was such a nice sunny day, I headed up to the roof for some pictures.
|View From the Southwest, October 24, 2011|
This photo shows the house in perspective with an expanse of open terrain (about two acres) awaiting landscaping work next year. Reinforced concrete retaining walls can be seen at the left end of the house, and our leveled yard lies along the south wall with all the windows. The A-frame house and shop building can be seen in the background.
|View of the Roof, From A Short Distance West of the House, October 24, 2011|
Finally the roof is finished! However, we still have to install the solar water heater. Hopefully that will be done later this week or next at the latest. Wheat straw has been spread on top of the grass seed on top of dry soil awaiting rain. Doesn't that look nice? Now as of today, November 1, some of that straw has blown over to Indiana or Ohio or somewhere, leaving many bare spots.
|Part of the Rooftop Looking East, October 24, 2011|
Here we are standing on the roof, looking out over the light tubes, vents, and the chimney for the masonry stove. A square concrete slab to support the solar water heater may be seen slightly to the right of and in front of the chimney. Somewhere deep (about five feet) below this surface lies a one-foot slab of reinforced concrete over the entire house and garage, and about two feet above that lies five inches of insulation sandwiched between layers of plastic. Oh, all of that seems so long ago. Hopefully I will say more about all that in the coming months as I find time to write.
|View From the North End of the Garage Looking East, October 24, 2011|
Here we are standing just north of the garage, which is at the north end of the house. The two protruding tubes in the foreground are air vents for the root cellar whose roof is some seven feet below this sloping surface. Five inches of insulation sandwiched between layers of plastic also cover this entire area. Here the buried insulation is used to keep the heat out of the root cellar as opposed to keeping the heat in over the house and garage. Some exposed yellow plastic may be seen along the top edge of a retaining wall in the middle of the photo. The north end of the garage retaining wall and its Mansard-type roof may be seen at the right edge of the photo. A berm may be seen at the left edge of the photo, used to divert runoff from the rooftop and surrounding hillside away from the A-frame house below. The blue 500 gallon propane tank serves both houses; we used about 350 gallons of propane last year and expect to use about 200 gallons this year.
By the way, we discovered some sandstone on our property, maybe enough build a small patio on the southeast corner of our rooftop. Let's wander back over there for a look around.
|View From Southeast Corner of Rooftop Looking Northeast, October 24, 2011|
This photo gives a nice perspective of some of the concrete work that has been ongoing for too many months. At the far left, we see part of the Mansard-type roof along the east wall at the north end of the house and the garage. Part of the paved driveway and parking area are visible in the lower part of the photo. A stairway composed of 22 concrete steps near the lower right corner of the photo leads down to the graveled loop next to the A-frame house. A sidewalk next to the propane tank and another set of steps lead down to a deck on the west side of the A-frame house. A reinforced concrete retaining wall runs from the north side of the A-frame house clear over to the lower right corner of the photo. A second reinforced concrete retaining wall runs along the edge of the driveway.
|View From Southeast Corner of Rooftop Looking East, October 24, 2011|
|View From Southeast Corner of Rooftop Looking Southeast, October 24, 2011|
These photos give an idea of the expected views from our future rooftop patio. The south and southwest views, which I neglected to photograph, cover about 1.5 acres of mildly sloping open terrain that hopefully will be developed into a sea of native grasses and wild flowers next year.
The two small concrete enclosures in the lower, right corner of the photo above are at the ends of the PAHS air system tube system that is not yet functional. I am constructing roofs and air filtration doors for these structures. So these past months we haven't had much fresh air circulation, and with such airtight construction it tends to make us a little cranky now and then. We compensate by cranking open a couple windows now and then; even so, the lowest temperature we've seen in the house since last June has been 70 °F. Not bad for no furnace.
Before heading inside, let's enjoy the fall colors with a few more views around the front side of the house.
|View of Southwest Corner of House and Retaining Walls, October 25, 2011|
|View of East Side of House, October 25, 2011|
|Area Northeast of the House, View Looking North-Northwest, October 25, 2011|
The first of the above three photos gives another perspective of the two concrete block enclosures for the air intake and exit tubes. It also gives another perspective of the southwest reinforced concrete retaining walls. In the lower, right corner of the photo may be seen the transition from rocked lane to concrete pavement. A grated drain runs across the paved driveway to divert water coming down the pavement from the rocked portion of the lane. The second photo shows the paved lane running along the east side of the house and the sidewalks leading to the front porch and sunroom. Patricia is cleaning leftover builder's crud off the windows. The third photo gives a nice view of the retaining walls at the north end of the house, the retaining wall along the base of the hill, and the steps leading up to the house.
So what about inside the house? We really enjoy all the sunlight that streams in, except when trying to read the screen on our laptop or when it's shaping up to be a 90+ °F summer day and the morning sun is poking in through the east-facing windows. We plan to install external rolldown shades on the east-facing windows before next summer. The highest temperature we recorded inside the house this summer was 84 °F with no air conditioning. But that extra heat was not wasted, as it slowly migrated into the thousands of tons of thermal mass above the ceilings, behind the walls, and under the floors. To see that this is working, we note that the temperature typically drops 4-6 °F overnight. In the past weeks, on cold, sunny October days the temperature reaches 74-76 °F and drops to 70-72 °F at night. On cold, cloudy October days the temperature reaches 72-74 °F and drops to 70-72 °F at night. This shows that we also get some solar heating through the clouds.
So what should we expect in the coming winter months? We have a number of factors that work for us and others against us. On the positive side, the house is very airtight and the walls are insulated to R40. The extra thermal mass of the house's exterior brick siding increases the walls' effective dynamic R values. For example, on sunny days the bricks absorb a lot of radiant energy from the sun. Much of that energy flows through the bricks toward the inner walls of the house. When the sun sets, the bricks' stored energy starts flowing back out toward the cold outside air, but that takes time. Even on a cold January night it might take hours for all of the stored energy to escape from the bricks, but in the meantime they have acted as a buffer to weaken the cold night air's grip on the interior walls. Thus brick siding reduces the total amount of heat lost overnight through the walls, which is equivalent to increasing the walls' effective R values. The process works in reverse in the summer, also to our advantage.
On the negative side, we have lots of windows, and they represent big holes in the walls. Not that air passes through them, but heat flows through glass with much less resistance. We purposely chose windows with high solar heat gain, because the sun's radiation is our primary source of heat. (Our windows didn't qualify for energy rebates!) We also chose windows with high resistance to infrared radiation flow, which prevents much of the radiated heat energy from external and internal objects, such as us, from passing through. This significantly increases the windows' R values and makes us feel more comfortable inside the house, because the windows actually feel less cold in the winter and less hot in the summer. But they also drag down the indoor temperatures during the winter and drag them up during the summer. To reduce heat gain and loss through the windows, we will be assembling and installing insulated drapes (materials made by Warm Company) on the main windows this winter as time allows. In the colder months we will close the insulated drapes (R7) as the sun sets and open them as it rises. On very cloudy winter days, we may keep them closed to conserve heat energy. In the summer we will close them on the east-facing windows in the morning to keep out the sun's rays, and we may close them on very hot days to reduce the flow of heat energy. The sun's rays do not hit the south-facing windows in the summer months.
How about a quick tour of the house as it stands today, November 1, 2011? It is around 9:30 A.M. and the sun is shining brightly (our free furnace is on.) The outdoor temperature is 47 °F and the indoor temperature is 73 °F, having risen 3 °F since this morning.
|Dining Room, Part of the Great Room, November 1, 2011|
The darkness of this sunlit photo is somewhat misleading. The room is definitely much brighter than that; I just don't know how to properly set the camera exposure. We are looking out the south-facing windows as the sun streams in to the back of the room. No need for electric lights on a day like this.
|Living Room, Part of the Great Room, November 1, 2011|
The camera seems to have done a better job on this photo. The early-morning sun feels good while sitting in the recliner closer to the camera and later while relaxing in the recliner next to the patio doors, when the sun has swung around to the south.
|Kitchen and Arts&Crafts, Part of the Great Room, November 1, 2011|
Here we see that the sun's warming rays reach to the back walls of the kitchen and arts and crafts rooms. The concrete floors are covered by medium brown tiles, which allows them to absorb more of the sun's energy. The kitchen certainly doesn't need lights on or the light tube at this time of day. Maybe it will when we've installed and closed some of the insulating drapes. We like the soffet transition between the lower suspended ceiling in the kitchen and the higher suspended ceiling in the rest of the great room. The lower suspended ceilings in the back rooms are required for ductwork running the full length of the house to convey heated air from the masonry stove or cooled air from a three-ton air conditioning unit if needed.
|The Away or Quiet Room, November 1, 2011|
|Bedroom, November 1, 2011|
Our two bedrooms also enjoy the sun's warming rays. But what takes some getting used to is when a full moon lies off to the south at night and shines across the bed. The absence of a few things we'd gotten used to in our previous homes is also weird. No wind whistling through the cracks and fluttering drapes. At night we can't tell if it's raining unless we step outside. Thunder claps and distant freight trains are muffled rumbles. And lots of birds knock themselves silly crashing into our reflective windows.
|Utility and Laundry Room, November 1, 2011|
Drat, I was interrupted again by the plumber coming to see how he would connect our solar collector to the 80 gallon electric water heater shown in the above photo. There is an old saying that a watched pot may never boil, but it usually does heat up somewhat. So while I was away chatting with the plumber outside in shirtsleeves, I found that the outdoor temperature had soared to a sweltering 71 °F and the indoor temperature to 77 °F. We haven't had a 77 °F indoor temperature since late September or early October.
|Masonry Stove, Part of Entry Room, November 1, 2011|
If the sun should happen to burn out, this trusty gadget with a black oven included will come to the rescue. Not only will it heat the whole house for a day on a single charge of wood, we can get a tasty pizza and some bread and rolls on the side. Here we see the floor and stove soaking up some rays from the sun, which they can return as heat later this evening.
|Part of the Entry and Sun Rooms, November 1, 2011|
The sunroom has lots of greenhouse glazing and receives an abundant amount of sunlight in the early morning hours. Unfortunately it faces 20° south of east, so most of the sun is lost by noon. However, even on this 71 °F day, it reached a balmy 85 °F, almost too hot for the salad greens we are starting to grow. The sunroom can get fairly cold at night, so the sliding glass doors can be closed to isolate it from the entry room. We can easily move plants into the entry room if freezing temperatures are expected.
|Part of the Garage, November 1, 2011|
The garage door also faces east and can benefit from a nice day like today. Normally we wouldn't leave the garage door open on cold days, because the floor, walls, and ceiling have enough stored energy to keep the temperature above 50 °F.
Before closing this blog, I would like to comment on one more important aspect of this earth sheltered house. We are very pleased with the quality construction of the structure by Davis Caves. Before the house had been fully closed in and the interior temperatures were in the 40-50 °F range, we would occasionally see dripping water coming from near one or more tubes that protruded through the reinforced concrete roof. But each time we were able to verify that the moisture was coming from condensation on cold surfaces. It has been over a year since we've seen any drips or moisture on the concrete roof; with the house now closed in, we use a dehumidifier to control humidity levels.
Another important factor for the future success of our PAHS system is that the house was placed into a pure clay hillside. The excavators didn't hit any gravel veins or wet spots, which could indicate potential locations for ground water to flow near the structure and rob heat from the PAHS energy storage area. To insure at least that the earth beneath the floors remained perfectly dry, we placed drain tiles four feet below the floor all the way around the back walls and down the full length of the center of the house. We also placed drain tiles directly above the footings along the back walls. Until early this spring, water ran almost continuously from these tiles, indicating that moisture was getting to them somewhere. Initially much of the moisture came from incomplete and unsettled backfill around and over the house and from improper grading that left pools of water to percolate into the ground. As the backfill settled and the grading progressed, the flow rates subsided. The last of the remaining problem areas were eliminated with proper graded this spring, which is about the time all flow from the tubes stopped. We now believe that the pure clay backfill around the house structure has sufficiently settled and sealed so that very little moisture can percolate through it. In addition, the entire terrain around the house has been adequately graded so that unwanted moisture can easily flow away from the structure and foundation. The ideal temperatures within the house this fall have led us to believe that the PAHS heat storage medium is working correctly.