This heat pump Goes Up to Eleven

EnergyGuide label on the mini-split heat pump installed to heat our new Super GreenHome.  It goes up to eleven!  Note that the efficiency scale bar on the bottom of the tag only goes up to 10.2.

This is a Fujitsu Extra Low-Temperature Heating mini-split air-to-air heat pump.  The manufacture claims it operates down to -26^oC.  We've had it installed for only a month now, but we did have a -25^oC morning.  I went out to check and it was purring away making heat.

More pictures to come...

Come see the Yukon's Second LEED Registered Home

Come see our little SuperGreen laneway home - it's nearly finished!  This is arguably* the most energy efficent home in the Yukon, scoring an EnerGuide rating of 89!  The home is registred as a LEED Canada for Homes project and really is a model of sustainable housing in Whitehorse.

So come for a visit and tour - Friday April 3rd - drop by between noon and 7pm.  Note that this is a laneway house, so access it from the alley between Wood and Jarvis Street, between 7th and 8th.  



* Why do I say "arguably", well so there is one other home in Whitehorse recently rated at 89, but it is a big home and they used a big heat pump to score so well--the current EnerGuide rating system is not kind to small homes.  ALSO, Habitat for Humanity's triplex built out at Champagne & Aishikik First Nation's Takhini River subdivision scored a 90, but again they cheated by putting whopping 14kW photovoltaic array on the building.  It's building envelope isn't as energy efficient as ours, but the big renewable energy generation raises their overall EnerGuide rating.  Either way, these are all great, high performance homes and the debated about who's most efficient really is becoming a fun academic game. 

Heating people, not air

One of my favorite online publications is called "Low-Tech Magazine".  I few weeks ago I thought they'd written an article just for me--it was called: Restoring the Old Way of Warming:  Heating People, not Places

This article, along with the follow-up called How to Keep Warm in a Cool House, cause us to re-think how we currently heat houses.  The focus of these articles is challenging the current practice of heating air to keep people warm.  The authors look at alteratives in "spot heating" or heating the occupants directly. Any wood-burner knows the best place to be is sit around the wood stove in the living room.  More old-tech in action!

It was a particularly timely article because we just installed radiant electric heaters in the garage we are building.  The idea being to heat the occupants and objects instead of the air because when you open the garage door, out goes all the warm air.  They seem to work just fine, but will it translate into any significant energy savings? Tough to tell. 

Wall mounted electric radiant heaters in the garage.

The other interesting application the authors point out is that radiant heating (where you heat objects, not the air) is a good in existing, lower performance leaky houses.  By using radiant or conductive you can keep the house's air temperature lower, but the occupants can stay comfortable.  This will reduce energy losses through leakage of hot air from the house. There are some interesting ways of doing this both old-tech and new ideas (heated office chairs!)

Anyway, a good read if you interested in re-thinking how we stay warm and comfortable in your houses in a time of rising energy costs, especially existing older housing:

Part 1: Restoring the Old Way of Warming:  Heating People, not Places
Part 2: Radiant & Conductive Heating Systems
Part 3: How to Keep Warm in a Cool House

Lots and lots of Sprayfoam

Yesterday they started sprayfoaming our little laneway house.  Although sprayfoam is often used in certain applications as part of house construction, the unusual thing about this house is we are using a whopping 7.5" of closed-cell sprayfoam, installed on the outside of the building.  This acts as a big blanket that completely envelops the house.  Green Building Advisor calls sprayfoam the "King of Insulation".

First layer of closed-cell sprayfoam being installed.  All finished trim and windows have been masked-off to protect from over-spray.

Closed-cell foam has an R-value of 6 of 6.5 per inch.  This means the sprayfoam provides at least R45 on the outside of the house, plus it acts as our air barrier and vapour barriers.  

The closed-cell foam has to be built up in layers.  I looks like they can put on about 2" to 3" of foam each pass, so it will take them a few days to completely fill the 8" cavity.

Today while I was watching the contractor work (the job is so big the they actually using TWO sprayfoam rigs at the same time to do the job), I was thinking it seems a bit crazy to put on this much insulation because it is a lot of work (and cost).  But then I realized it is like pre-buying all of my fuel / energy now.  By superinsulating the house, I've built in keeping the house warm now, at the outset.  I won't have to buy a bunch of energy for the remainder of the life of the building because all of the insulation reduces the heating needs of this home by 90% over a conventional home.

The sprayfoam contractor is Energy North Construction and so far they seem to be doing a good job.  They've been pleasant to deal with, accommodating and responsive.  This job is unusual, but they were keen to tackle it.  

As bonus content, here is a little video of dancing sprayfoam guy:

SuperGreen Laneway house construction progress pictures

As with most blogs, I had the best of intention to post a bit more regularly.  But June got really busy with work and other parts of "life" and so have fallen off the wagon.  To catch up a bit, I've just posted a series of construction progress pictures over this month, complete with captions describing things of interest.

Foundation with mudsill installed, ready for framing to go up.  Note 3" square cut washers on anchor bolts.  These are to provide better hold-down of the building during large earthquakes and is one of the earthquake resistant design elements of this home.

Another view of the foundation.  Garage area has been backfilled.  The sump is visible in the basement (foreground) which is to lift both the basement floor drain and under-drain up to the sewer line because the sewer is higher than the basement.  Also you can see a 4" ABS stub to the left of the sump - this is the vent pipe tied to the under slab radon venting system.  It is unlikely the radon vent will be required due to the tight construction, but the vent piping is added now because to add it later would be a real problem!

Floor and first wall put up.

This laneway house replaces an old garden suite.  It uses the same sewer and water connect as the original garden suite - which is plumbed through the house on the front of the property!  The original suite used a heat-trace on the water line to prevent freezing.  We've replaced it with two waterlines (insulated black pipes on the left) to allow for a re-circulation system to prevent freezing.  This is yet another energy conservation measure because re-circ uses significantly less electricity than heat traces. 

6" of perimeter insulation is installed over the shallow footing of the garage to frost-protect the footing.  At the corners this insulation extends 3-feet from the building.  We've re-used extruded polystyrene insulation that was salvaged from the roof of Porter Creek High School last year. 

Another view of the frost-protected footing insulation being installed.  Note the drainage gravel below which encapsulates the perimeter drainage pipe.  This is water management component of the building's comprehensive durability plan to help ensure a dry, long-lived home. 

First floor framing up.

2nd framing going on.  Building has continuous plywood sheathing again for durability and earthquake resistance.  I'm starting to see many builders switch from OSB back to plywood sheathing.  Continuous OSB sheathing is pretty good, but plywood is slightly better as it performs better if it gets wet.  

Interior of garage portion.  Note that tall I-joists are used for second floor.  These are larger than is needed for the short span, but it allows for large cut-outs in the I-joists to pass the ventilation duct work through.  This keeps the mechanical nice and neat, avoiding unnecessary boxed in duct chases.  The primary ventilation duct runs are preplanned and installed - visible in this photo. 

Guest room area on main floor.  Partition wall to garage is a staggered stud wall (right side of photo) for extra insulation and reduced sound transmission.

 

Another view of the garage.  Note 4.5" of closed-cell spray foam has been applied to the earth.  This provides both the vapor/capillary barrier and insulation for under the garage concrete slab.  It's also pretty nice to work on during construction.

The second floor has a small cantilevered box window in the bedroom.  This is a few of the framing used to support that cantilever.  I inspect all of these connections and hardware to ensure all required nailing is in place (again, nailing inspections is another durability plan element).  It is quite surprising how often nails are missed.  I shutter to think how much nailing is missing in conventional production-style homes!

Roof trusses going up.  Trusses had to be craned from the street, over heritage house at the front of the property!  Note the window and door extension boxes are installed (one with Bluskin for waterproofing).  These are to extend the windows and doors outward when the 8" of exterior closed-cell sprayfoam will be installed later.  

Roof trusses being installed.  Truss tails are pre-painted because they will be exposed when the home is finished.  A Craftsman-style home detail where the soffits are open and the rafter tails are visible.