When the sun doesn't cut it... the heat pump will

The "Passive house" concept relies on the sun as a heat source, as well as internal heat sources such as people and appliances.  The typical Minnesota home needs a furnace with a heating capacity of 80,000 Btu/h.  In contrast, our house could use one with a heating capacity of only  14,000 Btu/h.  The system that was installed is a Fujitsu variable speed multi-split heat pump.  It has almost twice the necessary heating capacity, but was the lowest available.  This system also provides air conditioning with a cooling capacity of 22,000 (Btu/h).  The split system heat pump means that the compressor and condensing coil are outdoors and the evaporator coil and blower are indoors.  Two indoor units were installed, concealed within the ceilings of the first and second floors.  These systems are often ductless, but our architect designed a ducted system to insure each room would be comfortable.  To heat the basement, two small electric baseboard heaters under the windows will suffice, and no active cooling will be needed down there.

Progress was also made on our alternative heating system- the gas fireplace.  The framing was completed and the unit was set in place.  Marketed as the "world's most efficient fireplace system", the vented Mantis fireplace exceeds 90% efficiency and humidifies as it heats.  We anticipate enjoying the ambiance and utilizing the thermostat-controlled fireplace as the main source of heat on most winter days.  With a heat output of 25,200 Btu/h, it alone exceeds the needs of the home.  In reality, the heat pump was installed to fulfill the code requirement, but the air conditioning it provides sure will be nice. 

Our fresh air ventilation system with efficient heat recovery is yet to be installed, and we'll describe that when the time comes.

Window container watch

The ship is traveling at 9.1 knots down the St. Lawrence River, heading southwest towards Montreal.  To plan, it is estimated to arrive at the port later today, container off-loaded and placed on rail transport to Chicago.  From Chicago, it will make its way via truck to Minneapolis.  The big unknown in timing is US Customs and Homeland Security.  A new update to come soon regarding the HVAC system, how it works and installation.

The making of the house doors

As we wait for the windows, we thought it would be great to take Ed Gullickson, owner of Doors of Distinction, up on his offer to walk us through his shop and see the process of making our doors.  Friday we took a scenic road trip to Amery, Wisconsin and spent some time learning about the process.  Their craftsmanship is desired by many across the country; at the time of our visit we saw a few doors destined for HI, MN, and CA, to name a few.  

We have a total of three doors, a front and two rear glass doors.  For the level of performance needed, we saw the high precision tools used to achieve the desired measurements and seal.

Let me start with the rear doors; the performance goals are to reach an R-12 insulation value.  This controls the energy moving in and out of the home, the second part of the design will control the air-tightness of the door and how it functions as part of the overall house coat we are in the process of putting together.  Each of the doors will have triple-pane windows, be 2 3/4 inches thick, and will weigh appropriately 200 pounds total.  The process of gluing all the parts together requires 40 hours and that is followed by a total of 9 coats of epoxy sealer (same sealer used for building wood boats).  Once that is completed, the primer and three coats of paint will be applied for the final finish.  As for the front door, it will follow the same steps listed above but since there is more wood and glue, it could reach 250+ pounds.  Despite the weight, the craftsmen assured us the doors will be easy for our kids to open, thanks to the ball bearings in the hinges.  There is approximately 70 hours of work put into a typical front door after the design is finalized.  We worked with Dan on ideas we had for what the front door should look like, and after a few days we saw the final CAD drawing that we moved forward with.

Over the next few weeks as the house gets prepared for the window and door arrival, Ed will come out and make final measurements for the sill, threshold and jamb design.  We are truly excited to see the final product make its way home!

Front porch footings and basement work

The house project has been moving along rapidly with the nice weather we have had.  Over the past week the porch footings were put in place and the basement slab (4 inches) has been poured (on top of 6 inch high density foam insulation) with an amazingly smooth surface finish thanks to the power-troweler Ryan used.

The basement has quickly had the addition of framing done and soon we will have the stairs completed down there.  All I-joists are up and in place on the facades of the house, which continues to bring on-lookers wondering what the additional 12 inches will be used for.

My window tracking addiction

Our windows are now in a shipping container and on the way from Germany.  We are able to track the location of the ship minute by minute, and now I track it as I would be tracking a package from Amazon.  This seems to have impressed our 8-year-old as he put it "this is EPIC", the container is scheduled to be delivered around the first week of June.  The windows and doors will play a big role in the blower door test we need to perform to validate how well the house is sealed; we can move to the next step of exterior insulation once that is completed.

We have scheduled some time this week to visit Doors of Distinction, and watch our front and back doors being made.  They are one of a hand full of places that make doors that meet the Passive House air-tightness goals, more on that after the trip to Wisconsin!!

Basement work complete

With a few days in the rain, we finally got a break to tap into the water and city sewer.  With that done we were able to finish the insulation of the basement flooring, first laying 2 inches of sand followed by 6 inches of firm foam insulation.

With all plumbing done in addition to the foam, the vapor barrier now set and taped sealing the basement.  Tomorrow the city inspection is done early in the morning and we then pour 4 inch basement slab.  While the cement truck is there we also have footings framed in place for the porch so that will also take shape.

Rain delay the past few days ...

Happy Earth Day!!

Today the exterior walls of our house are getting thicker and will ultimately be 18 inches thick with plenty of dense pack cellulose insulation.  The SIGA tape (high performance adhesive tape for the pre-installation of vapor control layers on hard surfaces such as wood and metal) has been placed around all windows, doors and wall seams.

On the west facade of the house the 12" I-Joists are up and the south side work has begun.  With the anticipation of rain tomorrow the roof membrane will go on in the morning and will allow for second floor interior wall framing to begin in dry conditions.

Two months down

Time flew by the past two months; progress has been great although snow, more snow, and mud has slowed down progress during the early spring season.  On Friday the I-Joists were delivered and will be installed next week; we have the window and door openings now framed and bucks in place.  Very excited to get the windows installed now that we have a tentative time of arrival.  In recent contact with the OptiWin (window manufacturer) I was provided with a neat link containing an over view of design and functionality.

We first saw the windows at TE Studio and then saw them in action at the MinnePHit home in South Minneapolis. Paul and Desirée have been more than generous in opening their home to us on a number of different occasions to get a feel for performance and environment in the house.  Check out their blog and Facebook page, Paul provides fantastic data on the performance of the house during the harsh winter months.

Second floor and roof trusses are up

What an exciting couple of days.  We have the second floor exterior walls framed and roof trusses were put up yesterday.  The big battle is all the mud that is causing all kinds of issues to get material up to the house.  

Trying a little something different to show the progress, we typically record the time laps and now that all walls are up can't get full shots of the action.  Here is a Photosynth of second floor and the roof trusses as of last night.  Also check out the pics of progress done to date in the gallery.

Taking names this week

The past week has been extremely busy.  Off the job site, our baby daughter was born on her due date and we couldn't be happier :)

As for on the job site activities, we have the sub-floor completed and all first floor walls up.  The RJ Stegora crew started early morning in 20 degree snowy weather.  In one way, I assume it helped with freezing all the mud and made the site a bit more building friendly (I really hope that was the case).  As the sun made its way out, our neighbor kid and our oldest found an interesting place to catch a view of the action!

Framing does go up relatively quickly, but with this house it is done twice to accommodate the extra insulation on the exterior of the house.  The second floor will need to be framed in addition to the roof before the vapor barrier can be placed on the external walls.   The I-joist is not structural, but since it is installed in full height sections of the house, it will provide great support in addition to housing the insulation.  The drawing to the left provides a comparative wall assembly diagram to help better understand the differences between Passive and standard construction.  Plumbing was also completed in the basement and with inspection scheduled for next week, we will finally see the 6" insulation boards placed in the basement and 4" concrete slab can then be poured on top. 

It might float at this point

The Basement walls are sealed and the dimple mat is in place.  The drain tile was also installed and for the rock delivery we witnessed a unique truck that is remote controlled and with a conveyor belt arm that can propel rocks into place as far as 100 feet away.

Just in time to beat the rain, the back-fill is also completed and that is captured in this week's time-lapse video.

Next up is removal of the extra back-fill; Monday is a big day as the first floor will take shape with framing beginning.