May 2, 2007 by Jeff.

Welcome back.  It’s time to discuss energy-efficient foundations, and why this one works.

Our design called for storing heat within an insulated, 14″ thick basement floor.  Heat exchange would be accomplished by blowing air though a 1 by 3 foot main plenum running down the middle of the slab.  This plenum fed 24 equally-spaced 6” round ducts buried in the slab and emerging around the perimeter of the room.  My calculations showed that with 4 inches of Thermax foam beneath and around the slab, this 3000 cubic foot concrete block would bank enough heat to keep the house from freezing even with 90 days of no sun.  Under typical winter sun conditions, calculations said the slab would keep the house at a constant 65 degrees.  Concrete is cheap, dense, and a good way to store heat for active solar hot air systems.

Building inspectors want footings, not slabs.  It took some time and persuasion to convince our town building department that a 14 inch thick slab was better than a 12 inch footing.  We kept ductwork away from the outer 16 inches of the slab and the inspector reluctantly signed off.

Like many building sites, we were constrained by the locations of well, septic and existing drainage patterns, not to mention views and road access.  The excavation wound up on top of a hill.  Soil consisted of 3 feet of heavy clay loam on top of a loose shale and clay mix.  Some small seasonal springs surfaced as we dug the excavation, adding to the mess.  Luckily, we had planned for the worst.

The bottom of the hole received 6 inches of gravel, carefully leveled and compacted.  Into this we set perimeter PVC drainage tile leading to daylight down the hill.  This kept the springs at bay while we continued working. 

I wanted the basement to be living space - dry and warm - and all the more important since the floor was our heat storage.   Although the performance of Thermax should not be degraded by water (it is closed-cell foam), I wanted to keep everything as dry as possible.  I found a 45 mil reinforced geotextile fabric which was waterproof and able to stand up to being sandwiched between gravel and foam.  Even better was its availability in large, custom-seamed sheets.  I bought a 60 by 80 foot piece, more than enough to wrap our 40 by 60 foundation, and laid it on the gravel base.

On top of this went 2 layers of 2-inch Thermax, its seams offset and sealed with aluminum foil tape.  Thermax is hard to crush and is rated for slab and footing underlayment.  Around the edges went an 18 inch vertical Thermax wall (again, 2 layers offset and taped) to act as a perimeter form and insulation for the slab.  We backed this with 2×4 reinforcement and stakes to withstand the pressure of the wet concrete.  We completed the foam formwork on the hottest day in July, baked from above by the sun and from below by the foil surface.  Then we called the concrete company.

Since I needed the 6-inch ducts centered in the slab, we first poured a 4-inch slab, leveled it and waited overnight until it to set up.  On top of that went the main air plenum and the branch ducts.  We strapped the ductwork to the slab with metal banding and power-driven nails to keep it from floating up when the main slab was poured.  The end of each duct was turned 90 degrees upward, carefully leveled and propped, and sealed with scrap foam.  Once the 8-inch basement walls were poured, these ducts would see daylight just inside the solid perimeter required by the building inspector.

Pouring the main slab was one long, hot and exhausting day.  The Thermax walls held the pour, and we embedded 2×4’s along the edge to create eventual keyways for the wall pour.  We gave it 2 days to set up and then used a masonry blade to saw relief cuts into it on a 4-foot grid.  With the combination of foam underlayment, embedded ductwork and relief cuts, the slab has never cracked and remains dry and warm 12 years later.

Once the slab was completed, we had a foundation contractor pour 8-foot high perimeter walls.  These were again wrapped on the outside with 2 layers of 2-inch Thermax.  Then we unrolled the border of the geotextile fabric, cleaned it and brought it up and over the walls.  18 inches of gravel backfill completed the excavation.

I’ve been questioned about the attention we gave to insulating the slab.  Many builders feel that the ground provides sufficient insulation, and it’s true that below the frost line we could count on a constant 50 degree ground temperature.  On the other hand, that’s a 50 degree heatsink, damp and infinitely large.  Then there is the 4 feet of frozen ground above the frost line, not to mention exposed wall above the ground.  Our Thermax wrap prevents heat loss to the ground, keeps the slab and walls dry and warm, and definitely contributes to the overall success of the house.  Using it as formwork for the slab clinched the deal, and I would do it again the same way.  It’s worth it – the house is proof of that.

This photo shows the basement in 2007.  Just to the right of the vacuum canister is an air duct coming out of the slab and heading to the first floor.  Air ducts were arranged to route warmed air from the slab to the basement, first and second floors and run inside finished walls upstairs.  The exposed poured concrete walls are warm and dry, thanks to their insulated and waterproof exterior wrap. Most of the basement has been finished into guest quarters and a recreation room.

Next time: the shell.

Posted in Tools and Techniques, New construction | 1 Comment »

April 19, 2007 by Jeff.

The Saratoga Environmental Expo this past weekend was a pleasant surprise.  Boosted by the celebrity power of Daryl Hannah and Ed Begley, turnout was impressive despite atrocious weather on Sunday.  I manned the Saratoga Farmer’s Market booth Saturday morning and met many fine people who expressed true concerns about global warming, sustainable agriculture and what they could do to help.

Ninety exhibitors covered the gamut from organic food and toiletries to wind power and fuel cells.  There was the usual big name sponsor – in this case GE, touting their environmental sensitivity.  GE is moving into wind and solar as they continue their work in coal and nuclear generation, so I will give them the benefit of the doubt for now.  Their main concern is making money, and at least they are doing some good to balance the bad.

Touring the exhibits, I found some interesting products but nothing especially noteworthy.  More energy-conscious design-build firms are sprouting up, which is encouraging.  One of the designs I saw was somewhat impractical for our cold, damp climate.  It featured passive solar and low R-value cotton fiber insulation, a combination that just won’t cut it here in the northeast.  Smart builders with potential included the Phinney Design Group (www.phinneydesign.com) and Rob Blanchard (www.thearchitectureteam.com).  I give them both an A for enthusiasm and a B- for practicality.

It was nice to see the spray-foam insulation guys out in force.  I’m a big fan of sprayed-in foam – it provides the best combination of insulation, air and vapor barrier and sound reduction.  Newer formulations are nontoxic when cured and don’t continue to emit harmful gasses.  Now that we have a local Icynene installer (Northeast Spray Foam – www.northeastsprayfoam.com) I can finally recommend someone local (my old favorite – Standard Insulation – traveled from Utica which made them a bit pricey).  Another foam – Sealection 500 (www.correcte2.com) is soy based and may offer similiar benefits as Icynene, but I remain unconvinced.  Spray foam is a must-have for new construction and one of the keys to successful low-input houses in the northeast.  I’ll be talking more about Icynene in the Westerlo house series.

Energy generation was also highlighted by the usual cast of characters: windmills, photovoltaics and solar hot water.  I can make a strong case for windmills and especially solar hot water, but the economics of PV continue to disappoint me unless you are planning to own it for more than 20 years.  PV is coming down in price, but even with subsidies and tax credits, it offers more good feeling (your compact fluorescent lights reduce CO2 emissions) than financial return.  NYSERDA would probably disagree with me, but it’s their job to promote PV.  It’s my job to promote practical, economically-viable solutions.  Are you listening NYSERDA?

The last interesting tidbit is Green Roof Systems (www.agreenroof.com).  These guys sell plastic grids and filter mats that sit on your (reinforced) low-slope roof to maintain a nice lawn up there.  It’s purported to save energy, although I suspect only on the cooling side – mud and turf don’t offer much in the way of winter protection.  From an esthetic point of view I like the idea – a grass roof – and would consider putting one on my next shopping mall just for the PR value.

Here are some pictures – enjoy.

Posted in Events, Grass Roots | No Comments »

April 15, 2007 by Jeff.

Let’s continue prying into this big old house.  We’re trying to reduce that $500/month gas bill and discuss what’s causing it.  Could it be those big drafty holes called windows?

As with many older houses, these windows are double-hung single pane.  Double-hung means there are two sliding sashes (the moveable parts) – an upper and a lower.  Casement windows are different – they are single sashes hinged on the top, side or bottom and typically operate with a crank.  We’ll leave those for another day.  Single pane means just that – no insulating double panes here.

There are many things we can do to make these windows more energy-efficient.  We start by making sure the putty is in good condition, replace missing sections and seal the glass to the putty with a good coat of exterior paint.

Older windows often use sash cords and weights to counterbalance them and make them easier to open.  The pulley openings let in outside air, and the weight pockets on either side of the window don’t help.  Pullman Manufacturing makes replacements featuring spring-loaded bands instead of ropes and weights.  These units seal the pulley hole and allow stuffing the weight pockets with insulation.  Highly recommended.  Tom Silva on This Old House swears by them, and so do I.  www.pullmanbalances.com 

There are fixed sash picture windows here and there.  Since these don’t operate, we make sure all seams are well caulked and painted, inside and out.  Then we buy some shrink-wrap storm window kits, the kind that mount with tape to the interior window frame.  It shrinks tight when heated with a blow drier and doesn’t look too ugly.  This extra air space adds an insulating cushion to the window, reduces condensation (condensation = rot!) and helps keep out some noise.

I’d like to shrink-wrap all the windows in the house, but we only do picture windows and operable windows in unused rooms.  We trade energy efficiency for the safety of easy exit in the occupied rooms.  Those sashes get sealed around the edges with Mortite – long claylike strips which offer a good temporary seal and won’t get in the way in an emergency.  If you can’t find it locally, these guys have it and lots of other usefull stuff:  www.energyfederation.org  

You may remember that his house has old triple-track storm windows too.  These never seal very well, but reduce wind pressure and protect the inner windows.  We make a quick check to verify that all the storm sashes are clicked in to their tracks and locked tightly where they should be.  You’d be amazed how many are down an inch or two, making them next to useless.

Barring complete replacement, these windows are now as energy efficiency as we can make them.  Next time we’ll move to the attic.  It has zero insulation, which is probably why the house structure is in such good shape.  Confused?  Stay tuned.   

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April 11, 2007 by Jeff.

This house heats and cools itself with no furnace and no air conditioning.  Looks pretty normal, doesn’t it?  That was the idea – I designed it to look like the typical American farmhouse – and spent about ten years building it in my head before breaking ground.  It employs active solar hot-air and superinsulation to maintain a comfortable living environment in upstate New York.

Completed in 1996, the house looks out over the Catskills and Helderbergs from a high and windy hilltop in Westerlo NY.  Westerlo lies 15 minutes southwest of Albany but is 1500 feet higher in elevation.  When it rains in Albany, it snows in Westerlo.  It’s a great place to prove how well theory translates to fact.

In the next few posts I’ll explain my goals in designing the house, the features that make it self-sustaining for heating and cooling, and some thoughts on what I would do differently next time.

Design mantras

From the start I wanted to evoke the typical American farmhouse: two story, steep roof, ells and porches everywhere.  Too many energy-efficient houses have given up style and visual comfort for performance.  It turns out you can have both as long as you’re willing to build in energy conservation, not just energy generation.

I wanted a house that was easy to live in, eliminating any need to fuss with cranky technology typical of solar heat.

I wanted a house that was fun to live in.  There are balconies, lofts, public and private areas where people can be together or find time alone when they want to.

I wanted a house that feels comfortable within the larger environment, in this case an organic farm.  I was the farmer, and the house needed to do its part to keep the farm efficient and successful.

I wanted a house that would stand for several lifetimes.  Too many houses today rot away long before their mortgages are paid off.  This is a house to spend a lifetime in and I built it to last.

This side faces north.  I’ve been teased that the windows look like gunports.  North-facing windows are for ventilation only – egress windows go elsewhere.  (Note: bathrooms do not need egress windows)  The view from this side is just hillside, so I went with the smallest windows possible.  They are there for summer ventilation.  The two propane tanks are for domestic hot water (yes, there should be solar hot water but I never got around to it) and a tiny gas-fired woodstove in the corner of the living room.

Here’s the east side.  It’s the “service” area of the house: driveway, back door, garage and herb garden.  To keep dirty shoes out of the kitchen, there is a mudroom and half bath just inside.  The long bumpout houses the kitchen and a small breakfast nook.

And finally the west side – facing the prevailing winds.  These windows satisfy egress rules and provide wide, sweeping views of the mountains from the living room and den.  The increased summer heat load was worth it.  I realize the appearance of this side is a little stark, but the wooded hillside it faces doesn’t care.

In a later post I’ll discuss the foundation and shell and we’ll get more into the philosophy and engineering of superinsulated houses.

Posted in Tools and Techniques, Energy Generation, New construction | 4 Comments »

April 6, 2007 by Jeff.

A little background on my father-in-law’s house: It’s a typical 1880’s wood frame, 3 story city house – narrow and deep, wood sided, slate and tin roofed. With 6 bedrooms, 3 bathrooms, parlor, living room, dining room, back wing and various closed-in porches, it’s a prime example of too much house for modern times. Be that as it may, we need to keep it comfortable without breaking the bank. Oh – and did I mention the complete lack of insulation?

Last time I talked about managing heat production. We’re adding a setback thermostat. We turned off the radiators and closed the doors of unused upstairs rooms. I would normally recommend adding zoned heat. He currently has one heating zone – one long loop of pipe servicing all the radiators. If he could put up with the mess and disruption, I would advise him to add 2 more zones – splitting the downstairs living and sleeping areas into daytime and nighttime zones and adding a separate zone for the 2^nd floor. Each zone would have its own thermostat. Figure 15% less on that monthly $500 heating bill.

The mantra for heat is “if you don’t lose it you don’t need to buy it”. Air changes (outside air coming in) account for most of the heat loss in older houses – some are so badly sealed that their air exchange rate (how many times the inside air volume is replaced by outside, unheated air) can exceed 20 per hour. So step-2 of the long-term plan is to do a thorough job sealing up the house.

Remember the air conditioner in the window? That’s one big hole to the outside. We need to take it out. Then it’s time to close and latch all the storm windows. Although double hung aluminum storms are not great, they are better than nothing and at least keep wind pressure away from the windows.  There are quite a few hanging open a bit, or just not closed at all.

Old double-hung windows suffer from a multitude of ills. We’ll discuss them in a future post. For now, let’s just say that we use weatherseal tape (plastic tape that doesn’t harm paint) to seal all the windows on the second floor and the tops of the first floor windows. Why don’t we seal the bottoms? We want them to open easily in case of fire. No one is living upstairs, so we can seal those windows completely.

It’s an old house. Lots of doors, none of them well sealed. My preference is to install insulated fiberglass doors, but that’s a job for warmer weather. So for now we add foam weatherstrip to the outside doors and make sure the storm doors latch properly.

Let’s move outside. Hose faucets and other wall perforations get caulked or filled with expanding foam, depending on their size and location. Keep in mind that sunlight destroys the foam, so don’t use it in exposed areas – it will get brittle and fall apart. Window casing gets caulked both at the wall and where the storm window frame hits it. We never, ever caulk the bottom of the storm window frame – it needs to be left open to let rain seep out. While we’re at it, we clean the seep holes to make sure water doesn’t build up and rot the wood.

Next time: What do to about old windows…

Posted in Tools and Techniques, Retrofit | No Comments »

April 3, 2007 by Jeff.

I’m pleased that the Supreme Court ruled in favor of the states on the CO2 case. In a nutshell, they determined that tailpipe emissions of CO2 are a pollutant and that the Federal Government - doing business as the EPA - has to do something about it. At a minimum, they have to allow individual states to legislate new standards.  States will now have more freedom to set their own emissions standards and force car makers to build what they should have started building long ago - fuel-efficient cars. I for one will not be sorry to see the demise of Chevy Suburbans and Lincoln Navigators.

Here is a snippet from the AP describing the situation:

Supreme Court to Hear Arguments on Tailpipe Emissions
By LISA FRIEDMAN\ Washington Bureau

WASHINGTON — U.S. Supreme Court justices on Wednesday began weighing whether to force the federal EPA to regulate tailpipe emissions in a high-stakes case that could test California’s new greenhouse gas laws and set the stage for congressional action on global warming.

Led by Massachusetts and California, a dozen states argued that they face an imminent environmental threat unless the Environmental Protection Agency acts, and attorney James Milkey likened the harm from emissions to “lighting a fuse on a bomb.”

But Deputy Solicitor General Gregory Garre argued that the EPA lacks the power to regulate carbon dioxide as a pollutant under the Clean Air Act. And even if it had the authority, Garre said, it would not act because of “the substantial scientific uncertainty surrounding global climate change.”

For California, the outcome of the case could determine whether it can proceed with sweeping regulations requiring new vehicles sold in the state to cut tailpipe emissions by 30 percent by 2016.

Automakers have sued to block the rules, which are set to start in 2009.

If the justices rule that the federal government must regulate tailpipe emissions, it could free the state and others with similar laws from legal threats.

But if justices rule that the Clean Air Act does not cover climate change, emissions-reduction laws could be stopped in their tracks.

Posted in National | No Comments »

April 1, 2007 by Jeff.

My father in law asked me to look at his utility bills today. It seems National Grid (our local utility - well sort of - they are British) just realized they were only billing him for natural gas delivery charges. His third-party gas supplier’s cut dropped through the cracks the past 4 months and just figured out they weren’t getting paid. The result? A $1700 surprise.

Their $500 gas charge for the month of February would pay for a year’s worth of heat at our house. He’s asked for advice, and there are some immediate things I suggested he can do.

The first is to lower the thermostat - he keeps it at 72 degrees day and night. So we’re installing a setback thermostat to lower the heat at night when he’s asleep. He’s older and likes it warm when he’s awake; the heat stays up during the day. Many people like it cooler, but I’m not willing to make that argument just yet.

The second thing we can do is close off unused rooms upstairs and turn off their radiators. It’s a really, really big house and large parts are only occupied during family gatherings. We can shut off the entire upstairs for most of the winter. I’m not too worried about freezing pipes. His heating pipes are all within the rooms (remember, it’s an old house - it predates central heat so the pipes were added later) and enough heat escapes the first floor to warm them. Ditto the bathroom pipes and toilets.

I noticed he still has an air conditioner in the dining room window. That’s a big, drafty hole in the wall. It’s way past time to take it out!

Remember that setback thermostat? It’s going to replace the current thermostat, a 1960’s round Honeywell unit in the back hallway. Not only is it money-wasting technology, but it’s placed on an outside wall between 2 windows. I bet the heat runs 4 or 5 degrees warmer than the thermostat setting, given its chilly location.

I won’t go on about the old double hung windows and 1950’s storm windows, or the complete lack of attic insulation. Spring is almost here, and those are projects for next fall.

Posted in Tools and Techniques, Retrofit | No Comments »

April 1, 2007 by Jeff.

The word from a large environmental law firm in Albany confirms there’s a new sheriff in town. Clients who have seen 12 years of little to no enforcement pressure from DEC are getting concerned and calling their attorneys for advice. Good news for lawyers and even bettter news for the environent. Stay tuned.

Posted in Northeast | No Comments »

March 29, 2007 by Jeff.

Neat blog from Fine Homebuilding magazine on building Green in Omaha. I was a charter subscriber to FHB, one of two magazines (the other being Journal of Light Construction) that bridges the gap between “fine architecture” and “getting it built”. FHB was one of the first to look at double and trombe walls, insulated foundation forms, air exchangers and many of the other advancements that have gone mainstream. FHB and JLC point out common problems and how to work around them.

Anyway, the PATH guys build Green and encounter all the problems of trying to avoid compromises. Nebraska is cold - definitely colder than California. This gotcha is often missed by pundits. In-line water heaters don’t have a large tank of hot water to prevent freeze-ups. This is good and bad - there are no standby losses going up the exhaust stack or out into the room. Unfortunately, in-line heaters freeze unless you install them in heated spaces. Take a look over Fernando Ruiz’s shoulder as he wrestles with going Green in Omaha.

http://forums.taunton.com/n/blogs/blog.aspx?webtag=fh-pathproject

Posted in External posts & links | No Comments »