water heat and floor heat

This is our very fancy, highly efficient, heat pump water heater.  We are an all electric house and this  Airgenerate Airtap Hybrid meets the strict energy requirements required by the organization that will be monitoring our house.  It captures heat from the air to heat the water inside with a backup heating element for high use times.

Neil actually installed our boiler for the radiant floors.  The main heat in the accessory dwelling unit (ADU aka apartment) is from the in-slab radiant heat.

The manifold for the ADU is in the closet.  You can see the tubes sticking up in the above photo.  Actually if you look closely at the above photo you can see the in and the out tube going to the ADU manifold.  We have 2 zones for the lower level of the house.  The ADU and our main entry, office areas, and laundry.

insulation

One of the biggest steps we are taking to be more energy efficient in the future, is to add more insulation in the home now.  The Washington State Energy code is one of the most strict in the country, but we took it to the next level. 

In our 2x6 walls, we used Blown-In-Blanket-Insulation (BIBS) - basically dense packed fiberglass. Specifically JM Climate Pro, which gets us R-23 in 2x6 walls.  This fills in behind all the electrical and plumbing. You just can't get as good of a value with regular batts.  It is a better sound insulation, too. This coupled with our 1-1/2" rigid on the exterior gives us R-30.5 on our walls. In comparison, 2x4 walls with batt insulation only achieves at best R-15.  

In our ceilings we have R-60 or better.  Neil used 1.5" of unfaced rigid insulation as a baffle to create the 2" air channel above the insulation in our vented roof.  Then BIBS in the ceiling.  In the vaulted spaces we have R-62.4. 

The pink stuff at the top plate to ceiling intersection is sill sealer...typically used to air seal and separate the bottom mudsill to the concrete stemwall.  We are using it here to create another level of airsealing at this intersection.

Below is our downstairs entry looking towards the stairwell.  To the left you can see a muddy greenish insulation which is rockwool.  This is the wall that separates the apartment from the main house and it needed a certain sound rating as well as 1 hour fire rated construction. 

We also used the rockwool in bathroom walls for added sound insulation as seen in the wall separating the upstairs guest bathroom from the hallway below.

We had a couple of tricky locations to air seal.  Two roof to wall locations that we ended up spraying 3" of closed cell foam before blowing in the BIBS.  The spray foam is about R-7 per inch. In these roofs we do not have venting.  

The installers also sprayed 1" closed cell foam at the rim joists.

Next up...drywall!

lighting

One of the design challenges of a house, is creating an electrical layout.  Some things are obvious, like outlets for appliances and general outlets throughout.  Switch locations also are typically easy.  You place them in locations that you enter a room.  One of the things that is not so obvious is how best to light the space.  I designed all the spaces to maximize natural daylight and while there are places for special pendant lights, I wanted most of the lighting to not be so obvious.

Design Criteria
1. The majority of fixtures to utilize LED bulbs if not specifically LED fixtures.
2. Minimize cans.  We are paying extra special attention to our air sealing.  After doing extensive research online, we decided to forgo the use of cans in our ceilings where there is also insulation.  This means most of our upstairs.
3. Low cost.  It is very very easy to spend lots of money on electrical fixtures.  Not so easy to find aesthetically pleasing inexpensive fixtures.  I will do more posts on this later.
4. Providing enough light, but not over doing it.  In our current home, which is very similar space to our new main room space, we over did the lighting.  There are 4 cans in the kitchen we never use and a track light at the ceiling we never use and 2 cans over our sofa, that Neil dislikes when I use to read...so I now have a reading lamp.

Even after creating this lighting plan, it is important to do multiple walk throughs with the electrical contractor.  We made a few changes to lamp locations after seeing either conflicting framing or just rethinking what we want while in the space.  Ideally all the fixtures are chosen ahead of time so they can be placed in right spot, but the reality is, I know generally what the fixtures will be (sconce, pendant, light strip, track) just haven't selected and bought them yet.

plumbing and ventilation

We have been making steady progress and I need to catch up a bit on the blog, so I'm going to do a few posts this week.  Back in May, the plumber came and installed our rough-in plumbing...cutting lots of holes in Neil's framing.  We have since passed our plumbing inspection.

While the plumber was working, Neil installed our fancy Swiss ventilation system. (with a little of my help running the ducting) Because we are building a tighter house with more insulation than code requires, our heating loads are predicted to be low. It is also important that we bring in continuous fresh air.  Instead of losing the heat in the air we exhaust, we installed a Heat Recovery Ventilator (HRV) and specifically a Zehnder ComfoAir 200. This is the most efficient residential unit available to us.  It was also recommended by the energy consultants, Imagine Energy, that we worked with a year ago.  They did an energy analysis on the building and then made specific recommendations for our heating, water heating and ventilation.  I will do a more in-depth blog post on this at a later time.

Instead of having individual exhaust fans in the bathrooms and laundry, we have exhaust registers that are connected to the HRV.  We then have supply registers in the bedrooms and living spaces.  Before we inhabit the house, we will have the Zehnder rep come to the house to balance the system. 

There were a few reasons we ended up installing the system ourselves.

1. We had a hard time finding a mechanical subcontractor that had heard of it. Most tried to sell us on multiple spot Panasonic HRVs, which would have meant more holes in our building envelope, plus they are not nearly as efficient.  But we did end up installing one of them in the apartment portion of the house since we want a completely separate system there and it's a smaller space.
2. The subs that did quote us on installing the Zehnder wanted a ridiculous amount for it.
3. We both watched an install video and realized we could do it.  Especially since we were going to use the special Zehnder ducting shown above.  Our system was designed by Zehnder America and they were very helpful in answering our many questions.

Originally we were going to install the unit in the garage, but decided to keep it in conditioned space and put it in our conditioned attic above our bedroom and bathroom.  If you look closely you can see a grey box with 2 holes which will be connected to dampers that have the supply and exhausts ducts connected to it.