SBF #12 Heating system

The Margin Flame View cookstove is on site. With a thermostatic damper on the combustion air supply, that will be ducted in thru 3" pipe to the dedicated air intake port.
Small fans will be located in wall ports to move the hot air from the east side of the house to the west. 2nd floor vents will let the hot air up to the 2nd floor.

This constitutes the primary heat supply.

We looked at a heat pump to be backup, but with a price of 10K for primary capacity, it did not fit the budget. The basic idea here is to spend more on insulation and less on heating.

The owner decided he wanted a backup that would keep the house from freezing and protect from any damage. He figures the house will be maintained by a friend even if they are gone and to be able to drain all systems if there is a prolonged absence.
Looking at the heating system again, it made more sense to think about how we could take advantage of the heat dump for the hot water system and combine that with a backup for both hot water and heating. So I began to look into radiators that could bring extra heat from the hot water system and be supplied by an electric boiler if needed.
This preserves one of the primary goals of limiting any possible fossil fuel use, to the grid connection.

One draft heat loss analysis gave me a loss of 15,653 Btus/hr and then you might add 20% to account for coldest situation. The goal is to use less than 1 chord of wood for the heating season.

This can only be verified after a season of use. Stay tuned.

With heat loss we also have heat gain from windows/people/equipment as well as thermal storage capacity. I do not have numbers on this currently and the woodstove is probably oversized, but serves mutliple functions well. Having all the numbers would help more precisely size the heating system. As the owners were set on the wood cookstove, it was just a matter of the amount of wood to be used.
A more appropriately sized heater would have cost less.

By the way we removed a Peerless oil furnace, two 275gal oil tanks, a parlour wood stove and a bathroom electric heater.

SBF #11 - Ventilation/AQ

This post is likely to be controversial.
Against the recommendation of Andy Shapiro, who likes whole house ventilation. We will probably install 2 Panasonic FV-04VE1 Spot ERV's with low(66% @ 30 CFM ) efficiency and with max. 40 cfm each.

From panasonic:
WhisperComfort may also be suitable to meet whole house ventilations requirements under ASHRAE 62.2.

The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) set a standard for whole house ventilation, requiring that continuous mechanical ventilation be 7.5 CFM per bedroom (master bedroom x 2) plus 1 CFM per 100 square feet, with sone level not to exceed 1.0

Sunnybrook Farm: 2 beds + 1600 sq feet =38.5 cfm

We also are knocked out of Energy Star rating because we will not have kitchen exhaust(because there will be an electric stove, maybe with recirc. filter) and the ventilation is not above 50cfm. Again, the Panasonics are rated at 40cfm.

Reasoning-
1. The owner doesn't like the idea of installing all the ductwork for whole house system. He would prefer to open a window.
2. The house is small enough to get decent exchange with the two spot ERV's in the bathrooms.
3. The cost installed will be less than half of a whole house system.

We will also be supplying the woodstove with dedicated air supply with a thermostatically controlled damper on the intake.

The root cellar will also have thermostatic controls for ventilation.

It will be interesting to see how the blower door test turns out. If we are below 1ACH50, I think it could be useful to monitor the AQ. Check back for results.

I believe this design is only possible with a house that uses non-toxic finishes and materials that utilizes a free water vapor (or breathing) wall design. This means no vapor block in the walls/cieling. The air barrier must therefore be of a material that can allow water vapor to pass through but virtually no air to pass. We will be using 5/8" sheetrock. Clay and lime plasters also work and there are wood fiber boards that can do the same trick.

SBF#10 Windows are ordered

We decided on Serious fiberglass 725/525 series casement and awning windows with Pella wood clad "Natural Sun" windows on the south dining and den walls for the feel of wood.
Favored "H"(high solar gain) windows on the south/east and west and "L" to the north.

Specs:
Serious: double pane with heat mirror suspended film
Casement 7L : uframe-0.17 shgc-0.32 - North side
7H: uframe-0.19 shgc-0.56 - West/East side
Fixed 5H: uframe-0.18 shgc-0.57 - South side
Casement 5H: uframe-.22 shgc-0.57 - South side

Pella: double pane
fixed: uframe-0.30 shgc-0.56 "Natural sun" glass - south
casement: uframe-0.32 shgc-0.48 "Natural sun" glass - south
awning: uframe-0.29 shgc-0.27 "Advanced Low e" glass - 1 north window

29 windows for under $20K, spent a little more than budgeted(OK 27% over)
But not bad considering quality

Other considerations:
Fibertec -2nd(almost went with them- longer lead time did it, I think)
Thermotec - 3rd(too expensive for budget)
Optiwin-Energate-Linwood and more.

Now the doors....................
Linwood from Maine gave a decent quote for insulated wood entry door with 1/2 glass, multipoint latch and double gasket seal.
Looking at another local millwork shop in Barre, Vermont.
Hope to decide this next week.

SBF#9 What makes it a Deep energy retrofit.

In the last couple years this element has really become an interesting challenge for me. After a couple of years of immersing myself in energy geek world, I get to bring a lot of retrofit ideas together with a lot of freedom because of the depth to which we gutted the farmhouse. Interestingly, the old balloon framing style has helped with the fact that we are leaving the exterior skin on and insulating to the inside, which is typically the least favored option in terms of how to add insulation to the walls. I should say that this retrofit favors natural materials over petrol and chemical based ones.

So a deep energy retrofit for me means increasing energy efficiency by over 75%. To achieve this we are installing:
1. a continuous air barrier - ADA-sheetrock on the interior.
All electrical on exterior walls will be run on interior of sheetrock in wood chases.
2. 12" of cellulose in the walls(R42).
3. R20 on the foundation perimeter and floor.
4. A thermal envelop that minimizes thermal breaks.
5. R5 or better windows.
6. R80 ceiling with cellulose.

The energy analysis will be done under the mentorship of Andy Shapiro who will be bringing many years of experience in understanding the modeling of energy and moisture in the new design in order to make a predictable outcome.

The goal of the deep energy retrofit is basically to reduce the energy consumption of the house as much as possible with a modest budget through intelligent design to remove a dependence on fossil fuels, reduce carbon output and to conserve resources. We will track metrics such as the tightness of the house once we have completed the envelope as well as yearly use of fuel and power. The Passive House model is attractive, but not quite the right fit for this project. I believe the owners need to be 100% behind that kind of a focus. It will certainly inform much of the design. Passive and low impact design are a top priority for my design process in general. One of the things many people misunderstand about passive design is that it relies most on people's behavior more than the actual design. This means it will be much more difficult to design our way out of our current crises than to change our behavior.

We also see this project as a transition town model for sustainable design. This means there is no reliance on fossil fuels in the design other than through the electrical grid. It also means there is an integrated design that includes ecological processes such as food production and nutrient recycling with a composting toilet and greywater system.

Heat will be from passive solar and wood with an electrical heat pump for backup and hot water will be supplied by the cookstove and solar panels. PV panels will eventually supply electric power.

There is also provisions for food storage in the root cellar and a cold pantry. The greenhouse will extend the growing season to support a healthy homesteading operation for food production. Rainwater catchment will also passively support irrigation in the well drained soils rather than rely on the well pump.
The crew.

SBF #8 Sunnybrook farm design comes together

The design has evolved nicely as we have spent time disassembling the farmhouse. This time allows us to see all the perspectives and sit with ideas for several days.
Some of the conceptual overtones that we have been working with are traditional farmhouse (imagine that) with a touch of modernity. Another term that has come up is rustic elegance.
Some important ideas for me in this design is using what we have, and simplifying. Which means what ever we can recycle including sinks/toilets/copper/electrical fixtures and wood. It also means some really nice wood and granite from the barn. And it means other local materials from nearby.

In this view into the kitchen, you can see the reused barn beams and post.


This view looks into the Living/Dining room.
At the far end you can see the bedroom and Den which will have the hardwood floors that were retrofited some time ago. In simplifying we have removed the front porch and reduced the number of rooms by 2, removed a chimney, one vent stack and the kero boiler with all the baseboard.



The 2nd floor will be largely similar to the original layout. We will refinish the original wide pine floors throughout the second floor, except maybe in the bathroom where it looks like we might have tile.


Some of the more interesting details include a dumbwaiter rootcellar; the granite veneer chimney and interior stone window sills.
The greenhouse and outdoor kitchen are last to evolve. More to come.....

SBF #7 The Barn is Recycled

Here are two tie beam solutions to join to the wall.
The older half of the barn used a lap joint onto the rafter plate which is holding up great.
The newer half decided to tenon into the top of the post below the plate, this resulted in a major blowout on the two middle posts, as seen below.














The siding is coming off well as Aliza and Donnie deconstruct the skin first exposing the frame. The typical two layers of siding include the 1/2" inner layer and the 1" outer layer which is painted red and has gotten a beautiful patina over the years.

Still not sure where the siding will go, but the lower section looks promising as wainscote.
The frame will be used for structural beams in the Kitchen and Dining/Living Room. We will also use some pieces in the Kitchen floor and the outdoor kitchen.

SBF #6 What we found in the old farmhouse.

The gypsum plaster was put on after the window trim, adding over 200 ft of potential air and water leakage. The prodigous amount of air leakage is known for preserving the wood frame in old buildings that spent over 5 and 10 cords of wood heating. The current air barrier scheme is to use ADA. (Airtight Drywall Approach) Gasketing the planes to each other. Dense pack cellulose will also slow down the air and water, and effectively store some water as a heat sink during the winter.




The timber stud frame was balloon framed on the eave sides which are north and south. In the original house, the studs go two feet above the 2nd floor up to the rafter plate and on that sit 2x7 rafters on a 12/12 pitch. Floor joists are nailed to a floor ledger nailed to the inside face of studs with floor beams, square-hole joined to 4x10 stud-posts.
In the add-on kitchen here to the left, the rafter plate is closer to the 2nd floor. You can see the joinery here.


One of the issues with deep energy retrofits is that typically it is advatageous to add the insulation to the outside because of ease of creating a continuous insulative envelope and air barrier. This often makes sense where the exterior siding needs replacing.
In our case, the farmhouse exterior siding is in good condition. And knowing the cost of residing, I was thrilled to find the balloon framing from the interior that will allow us to build a continuous space for the cellulose to cover the outside edge of the floor ledgers.







And here is some of the wood lath that was spit from a board with a chisel. Seen sideways.