Thursday, July 29, 2010

SIPS for an R100 Roof

Well, the roof is not turning out to be easy.  the first option I've been working on is a 2x6 rafter system conventionally framed with sheathing and Grace Ice and Water Shield on the outside of it as an air and vapour barrier.  (PERSIST system).  Then 20" deep I-joists go on top of that assy, sitting on 2x4 purlins on the flat to minmimize thermal bridging.  Something is done at the top to form a 2.5" deep vent channel and then another layer of sheathing and then the roofing.  Long process, some big parts of it on scaffolding.  Costs are significant too.  Costing is complicated, but I have most of the numbers.  It is something like $19,000 of materials not including roofing.  Labour - who knows?


Then the SIPS solution.  the idea would be to frame the roof with the previously planned 2x6 rafters, then place the SIPS on top.  Air and vapour barriers are not needed, and neither is the vent channel.  It is solid insulation right through to the outside.  If code officials balk, then a conventional poly VB can be placed on the inside of hte inner frames.
Talked with Kent Truss in Barrie - they say the value of the SIPS materials for this application is about $30,000 delivered to site, (SIPS and their accessories only - no roofing).  The roof is a simple 8/12 pitch gable, total 2160SF on the outside.  Apparently this is about 2 truckloads of SIPS materials.
Installation is an additional $2/sf approx, but in our case, maybe double that.  Sips are max 12.25" thick - this is for manufacturing reasons, and also the 2x12 studs used to connect them.  since the thickest SIPs are R45.5, they would need to use 2 layers, the second being faced one-side only with OSB.  Special 14" long screws are used to secure the SIPS.  OSB facings are 7/16" standard thickness.

Also, largest SIPS panels available from Insulspan are 8'x24' (x previously mentioned 12.25"thk).


LT

Tuesday, July 27, 2010

Windows Again

Wow,
There are some fantastic window discussions out there.  Green Building Advisor has so much information in it. Fantastic!
Here is the link (Thanks to the Loading Dock Blog for the link  http://blog.loadingdock5.com/?p=192 )

http://www.greenbuildingadvisor.com/blogs/dept/musings/passivhaus-windows

Window Sourcing

Gualhofer, Optiwin, are two Euro window makers selling in NA. 
Here is the Gaulhofer NA site:  http://www.gaulhoferwindows.com/contact-us.php

Optiwin NA is easy to find.
Their Frostkorken door is approx $2000, I think, with VIP panels inside, rated R60 (!), this price with no frills.

Windows and really good Windows!

Conversation with Stephen at Thermotech was very enlightening.  Here is some info about their windows and windows in general.

Only 3 NA companies make the high-performance windows needed for Passive House.
  1. Serious Windows
  2. Thermotech
  3. Fibertec
The 2nd and 3rd are Canadian Companies.  you can also buy Optiwin, and Gaulhofer in North America.  Prices need to be determined.  This is a Blog http://blog.loadingdock5.com/?p=192 where they found windows from France for about $30,000 as opposed to the NA ones for about $10k.  That seems crazy, so I phoned up Thermotech to see if I can use theirs.  They apparently have performance data good enough to use in the PHPP software, so I'll be able to see if our house design can use their windows effectively.  Their frames are smaller and lower profile than the Optiwin and other Euro ones, so this makes some difference when choosing, as smaller windows may benefit substantially from the increased glass areas that low profile frames can provide, compared to the larger framed euro windows.  Thermotech windows use both Truth (operator) hardware and Roto (euro multipoint locking) hardware.  The Roto hardware operates multiple locks with a single lever.  The pultruded fibreglass frames are filled with insulation and joined using an injection-moulded grn corner piece, to which the frame stanchions are screwed (4 screws per corner).  The joints are then sealed with a marine-grade sealant (not silicone).  Thermotech windows all open outward.  There is no tilt and turn feature like the Optiwin and other euro styles. 
Here are some numbers on sizing:
  1. Tilt and turn windows work best at about 3 to 4ft wide.
  2. Triple pane casements should not be wider than 34" or the hinge hardware becomes inadequate
  3. Casement dimensions are max about 34"x72".
  4. Awning windows are good up to 4'x4' sizes.
  5. Pricing is by perimeter, except the customer base prefers 'united length'.  At a certain size, windows jump in price due to the need to thicken the glass, which is determined by wind pressures and CSA codes.  This size is 95 united inches (outside dim of windows, length plus width).  Above 95 Ui, glass must be 4mm thick, rather the 3.
  6. Thermotech recently began offering a triple pane glass with low -e, argon, and now low-iron glass called their 322 Gain Plus.  The low iron improves SHGC, though drops R value slightly.  Krypton fill adds about $20 to $30 per SF to window costs (!).
  7. Nice window hardware is by Roto, Segania, G. U. 
  8. Energy Rating (ER) rating is a Canadian rating system for windows that takes solar heat gains into account as well as R-value.  Thermotech windows perform very well in this rating system, in which solar gains over 200 days in the year are averaged.
  9. Here is a window discussion in GreenBuildingAdvisory.com:  http://www.greenbuildingadvisor.com/community/forum/energy-efficiency-and-durability/14850/serious-windows-vs-thermotech-fibertec-inline

Wednesday, July 21, 2010

Footing Insulations

Structural connections are the hardest parts to design for thermal bridge-free construction.  I've decided to install insulation under my strip footings.  There are high-strength insulation products such as Foamglas and Pur-knit and others.  They are expensive, and Foamglas is friable (brittle).  Therefore I plan to use HI-load 60.  An XPS 60-psi compressive strength rated insulation under the strip footings.  This stuff is R-5 per inch.  For nearly twice the price, you can buy HI-load 100, and Foamglass is beyond that price.  As an added benefit, the HI-60 comes in thickness up to 3".

The DOW building solutions rep said footings are insulated routinely by a large production builder in the Ottawa area - they have clay/silt soils that are highly prone to frost heave, and the builders insulate under the footings to protect their foundations during construction.  Railway tracks are also insulated using these HI-load insulations.
More on this later.

In Europe, they are making Foamglas gravel - all with recycled glass - I think this is fantastic, but no luck getting it here.

Kitchen Recirculating Range Hoods (Ductless)

Terrel Wong of Stone's Throw Design (see link to the Rosedale House) found the VentaHood Ductless range hood on the internet - It is a nice looking unit which has 3 grease and smoke removal stages, and it doesn't use a filter pad.  It employs centrifugal grease removal first, then a carbon pellet bed filter, then a large paper filter.  This is the best residential ductless range hood I've seen so far.  There are others by Kobe and Berbel, but this one seems the best to me, based on specs.  Canadian Appliances Inc. is to give me a price on these.

Note that a large capacity ducted range hood depressurizes the house, increasing the entry of soil gases into the home - such as radon.  If you are running the range hood with a fire going in the fireplace in the other room - bad situation - smoke all over the house.  Also, if you are running the ducted range hood and you have a gas furnace, gas water heater - also bad situation - CO gases may easily come into the house.  In these cases, you want to have a very leaky, energy hog of a house - then you might be okay.

Ductless is very much the way to go in an energy efficient, airtight house.
LT

Elevator

We've been working on getting an elevator on the plans for some time now - about a month or more.  The idea is that we want to be able to stay put in our old age, making full use of the house.  Moreover, we may be housing our aging parents in the near future, so there is need for connection from floor to floor for them.  The main floor especially is sort-of barrier free for this reason.  We looked at wheelchair sizes, and didn't follow barrier free requirements in the building code (it is not mandatory on this project), but worked to make as much of the building as barrier-free as possible.  We also may have visitors who are in wheelchairs, or have bad knees, etc.  They can enter through the at-grade side entrance, then use the elevator to access the ground floor at 3' above grade, or any other floor. 

We used hoistway specs for residential elevators from the web - there are many.  We intend to rough-in the shaft, and install the elevator when money allows or necessity dictates.  Bob Nowak from Cambridge elevator in Cambridge, Ontario was very helpful.  From him we learned that the costs of residential elevators is from $25,000 to $35,000 installed, depending on the door style.  Sliding doors are more costly.  The installation must be done by the manufacturer or licensed installers due to liability and warranty issues.  The track comes in sections, so they are not too long to get into the house.  The cab is built-up so it too is easy to install.  The hydraulic cylinder is the largest item, at 1/2 the length of the required travel.  In our case, the cylinder would be 15' long, 3.5" outside diameter in the body and 9" OD at the ends (for about 10") and would weigh about 400 lbs.  A crane is not normally used during installation, if needed, it would cost extra.  I reviewed our Revit model and figured this item can be brought in from our side entrance to the main floor, and then there is actually space to maneouver it into the shaft at the first floor area.  Cambridge feels the hydraulic elevator is the safest type (there are VFD AC motor/gear styles as well - no Hyd Cyl).

The hoistway can be made with 2x4 framing or with 2x6.  It needs drywall inside to achieve the fire ratings.  Noise is very low due to the submersed motor (like a dishwasher, on the up cycle only - no pumping is needed on the down).  I also asked what happens if the hoistway is built a little too large - Bob said Cambridge builds all the cabs custom anyway, so they grow the cab to fit the hoistway.

We also need a 90 degree type of elevator which has two doors - front and side.  One can buy elevators with doors on front and back, on the front only, or front and side.  We needed one of the hoistway doors to be a sliding barn door style.  While the two cheaper models use swinging doors on the hoistway (and accordian or slider on the cab), Bob said the hoistway door can be made to be a slider rather than a swinging - There are interlocks on these doors so they can't be opened unless the elevator cab is there.  This slider possibility allows us to access a narrow landing with the elevator where there is no space for a swinging door.  This means the cheaper elevator models without automatic doors are still OK in our plan.

We will be roughing in the shaft, so each floor will have a large closet-like space.  We will remove the floors in these closets when it is time to install the elevator.
LT