One month of occupancy in my Passive House, an update
December 5th, 2010 by Gary Konkol
1940 square feet seemed large, but when it comes to filling the spaces with furniture and possessions, it didn’t take long to realize I had more than I needed. Goodwill has been the beneficiary.
Having three house levels plus a roof terrace, leads to lots of steps, just like a built in stair master. I thought I was exercising prior to my move, but my legs tell me I wasn’t exercising enough by their aching, however, it didn’t take long for this to resolve.
The views are wonderful. The snow has really cleaned up the landscape while coating the trees. Star gazing is great from the roof terrace, as is the “living” in the tree tops during the day and watching the birds in trees as well as soaring overhead. So far the herd of 6 neighborhood deer have not been a frequent visitor of my yard, we’ll see how my deer fence fares when the plants start sprouting and looking more tasty for the deer.  One nervous 8 point buck, was walking on the outside of my fence a few weeks ago. He hasn’t returned; yet.
My biggest surprise has been the amount of heat the windows allow into the house. Sitting in the sun a few weekends ago, it was clear that this was not a typical indoor sun experience. The sun was warmer than what I had previously noted in my other houses. It was comfortably warm. Listening to Tim Eian during a house tour the next week, I finally heard the window stats in context. 64% of the sun’s heat is transmitted through the windows into the structure, more than twice as much heat as a standard window will allow. Earlier in the Fall, I needed to lower the exterior shades to prevent the house from overheating. After this experience, I thought I would see how long I could have my in floor heating mats unplugged before the house became too uncomfortable. On Sunday, 11/28/2010, after a mostly cloudy 8 days, I plugged in the heating mats with the house temperature at 60 degrees. It took about one day for the temperature to normalize at 67 degrees.
On sunny days the house temperature goes up 10-15 degrees using only solar heating through the windows along with the heat my two dogs and canary contribute, with an outdoor temperature of 10-30 degrees.
Similarly, the solar hot water and photovoltaic systems are very sensitive to the cloud cover. But even on the 10 degree days, the solar hot water tank gets up to 100 degrees.
This relationship of the house to the sun, outside and weather has heightened my awareness of the outdoors in my day to day living. The large windows and grand views only add to this awareness. It is a comfortable awareness and increased connectedness to the larger world; even if it is only outside my window.
The cold weather brought house contraction sounds; some quite loud. It took a me a while to determine this was the cause of my dogs being skittish and on a hunger strike last week. Fortunately, they and I have become accustomed to this “house talk”, as well as having less of this settling as time has passed.
As the weather turned cold, I noticed Box Elder bugs on the windows. Unlike my previous houses, this time the bugs were on the outside. Certainly, a nice change.
As I was shoveling this morning I saw little footprints of a mouse or vole had circled my garaged looking for a crevice to gain entry. No such luck for the little rascal, he’ll just have to stay in the woodpile this winter. Such a nice perk of a Passive House, it’s built very tight and by extension, so is my garage, at least for rodents!
Have an enjoyable Holiday Season, stay warm, but do get outside!
November has been extremely cloudy this year. It’s interesting to see the performance of the home without significant solar heat gain potential—especially on those days where we do get an hour or two of sun. It’s amazing to hear about the dramatic impact a couple of hours have on the temperature inside. In a way, this is the anticlimactic season for this home, as it’s performance is based on passive solar heat gains, which we’ve been mostly denied since you moved in. At the very least however, this is a great stress test for the backup heaters. I cannot wait to hear about the sunny days in sub-zero January and watch the balance of the incoming and outgoing electric meters start to shift.
Gary,
Thanks for sharing your experience in the house. This is valuable to us. How has the tankless water heater been working for you in terms of amount of time for hot water to arrive and if you notice temperature different between sunny and cloudy days/nights?
J,
The sun makes all the difference. On cloudy days, the solar thermal system does not even activate. Low flow water fixtures means that it takes a while for the hot water to arrive at the faucet, without a real difference between solar hot water and “boosted” hot water from the tankless heater in either the temperature or timing of hot water arrival at the faucet. The tankless electric hot water heater is working as promised, very well.
How will you cool the house in the summer? I noticed your stats about the windows; I’d sure hate to close the shades on all that beautiful sunlight in July just to keep heat out!
The house is “cooled” by tempering the incoming ventilation air. This is done with an earthloop, that connects to the airstream via a liquid-to-air heat exchanger. This system can also dehumidify the incoming air. The shades are mostly used for swing-season shading. In the summer, the sun is high enough in the sky that the window’s inset location in the walls provide most of the needed shading. Also, since the blinds act like regular venetian blinds, they can be set at an angle where they reject most of the sun’s heat yet still allow for views and natural daylighting. They are much more versatile than fixed shading elements and essentially become thermostats for the home.
Dr. Konkol,
I am the executive of a Twin Cities advocacy group that works on energy issues, and am writing to say I was wowed by your house story in the Strib.
I looked for an email address or a phone number on-line to contact you and congratulate you. Fresh Energy would love to have you as an ally and contact.
If you are interested in featuring your house in some of our advocacy work for energy efficiency and solar energy, just give me a shout at noble [at] fresh-energy [dot] org. I would welcome the chance to visit you, see the house, and tell you more about what we do, and see where there might be opportunities to combine efforts.
Here’s a mention I made of the StarTribune coverage in a blog posting I did last week on solar energy success stories of the week.
http://www.fresh-energy.org/index.php/blog/A-great-week-for-solar-energy.html
Michael Noble
Fresh Energy
[…] Konkol lives in a Passive House in the Woods in the American Mid-West. After a cold winter’s month of occupancy, he writes: My biggest […]
Hi Gary. Your house looks beautiful. We are currently building a PH in Connecticut and have learned so much about life in a PH from bloggers like you. I have a question about laundry. What type of clothes dryer do you have and how is your experience with it? Thanks for sharing.
Diane Honig
Diane,
I maintain the website and I forwarded your message to Gary.
Tim
We specified a condensing dryer from Bosch for the house: http://www.bosch-home.com/us/products/compact-washers-dryers/compact-dryers/WTE86300US.html
An exhaust-type dryer would not be able receive enough combustion air through the airtight building envelope.
As the designers, we also recommended outdoor drying with a rotary dryer and indoor line drying in a room with exhaust (e.g. the bath or laundry room). Dryers use a fair bit of energy; therefore, we encourage alternate methods for clothes drying.