Sweater Weather and Long Johns

Fall is in the air, which--as my mother taught me--means it's sweater weather. Last week, President Lee Myung-bak of South Korea recommended wearing thermal underwear as an energy conservation measure in his country. Hearkens back to one of my earliest presidential memories--Jimmy Carter advocating energy conservation by putting on a sweater and turning down the thermostat.

Will Lee's long johns be a laughingstock in his country, just as Carter's sweater remains an object of ridicule for many people here? Only time can tell. Yet I remain baffled by the fact that most conservative politicians are not more 'conservative' when it comes to energy consumption. I'm disgusted when the likes of Ann Coulter and Rush Limbaugh ridicule energy conservation measures and pump the use of gas-guzzlers.

Sure I understand they are out to 'defend individual liberty' and 'property rights' and to fight 'tree worship', and I know they often speak tongue-in-cheek with lots of irony and satire. But while they may not literally mean everything they say, they certainly don't do enough to promote the enhancement of national security through energy independence. Sure they promote "drill here, drill now," but the most immediate way that American citizens can contribute to national energy independence is reduce! Conserve!

And we can have an immediate impact on our own personal finances and thus the national economy as well. The less money we send overseas for oil (to people who don't like us), the more we have to invest in our economy at home. And whenever we waste energy resources, we are not merely wasting our own pocket money right now: that which we waste we borrow from our children. We are creating an energy deficit for our heirs that is every bit as much of an albatross as the national debt we are hanging around their necks. For while the proven oil reserves keep growing, the actual oil reserves--what God has put in the ground for our collective use here on our planet--keep dwindling. They are finite, and there will come a time when they are truly scarce.

I can think of a couple of reasons Carter was mocked for wearing a sweater: on the one hand, it seemed unpresidential for him to stoop to talking details of sweaters and thermostats. It seems a bit like the president telling us to eat oatmeal for breakfast. Then too, it's just not concrete and easy to pin down just how much of a difference a little thermostat change really makes. In any event, Carter didn't adequately connect the dots between national security or other national interests and such small details as a change in thermostat setting. Yes we were going through hard economic times, but thermostat settings seem personal, like none-of-big-government's-business. It never became a patriotic cause--like victory gardens in WW2.

And maybe there's another reason--perhaps he asked too much 'sacrifice'--along with too small a justification. He called for setting daytime temps at 65° with a setback to 55° at night. Most people have a hard time with that, even with a boat load of sweaters and long johns. More recent suggestions have been along the lines of 68° for daytime (DOE) or 70° (EnergyStar). Last year, I was bent on setting our house thermostat at 68° (and I thought that was high) and my family wanted it at 72° (or above). Eventually we negotiated 69° as a compromise. And I agreed to let the kids use space heaters in their rooms. I tell my kids (with a wink) that God gave us sweaters for a purpose and they are learning to dress appropriately for the season.

I was proud of them at that point. Progress is a matter of degrees! It was something they grew into. Our bodies adjust, and often it's a matter of comparison. I've seen night guards in Nairobi shivering in 55° air wrapped in several layers of coats, while I was reveling in the beauty of a July night that was below 80°! They shiver because it's one of the coldest temperatures they ever have to deal with.

So how much difference can a few degrees make? Estimates come in wide ranges because because it depends greatly on the house, the weather, etc. DOE claims a 1° reduction for 8 hours a day can save 1% of heating costs (see their page for further discussion); equivalently, a 1° reduction 24 hours a day might save around 3%, speaking in ballpark terms.

But here's what it did for our house. This is a graph of our home gas usage for the past 7 years:

While there's an overall downward trend, it's a bit jumbled to read because of wide fluctuations in weather especially during January and February. Also, 2009 was a better year than 2010, adding to the spaghetti tangle. In all, however, the following table summarizes the gas usage for winter months versus summer months for 2011 versus prior years, with a resulting 20% reduction in heating consumption. However, when adjusted for the added electric consumption of the space heaters, the actual energy reduction was just 10%. Still, that's progress.

Average Gas Use (mcf/day)
Years*	Winter* (Dec-Mar)	Summer (June-Sept)	Heating Load (=Winter - Summer)	Heating Load Reduction
2005-2010	0.68	0.06	0.62
2011 gas only	0.55	0.05	0.50	19.7% **
2011 with space heaters***	0.62	0.05	0.57	9.9% ***
* The winter months are December through March and are listed by season according to the calendar year in which winter ends. For example, December 2010 is grouped with January through March 2011 to comprise the 2011 winter season.
** Based on thermostat set to 69°, down from low to mid-70's in prior years.
*** The mcf per day has been adjusted upwards to recognize increased electric usage due to space heaters. Adjustment made based on relative energy content using the conversion factor: 1 mcf = 302 kWh.

Bottom line: claims of 5% to 30% savings on heating costs based on modest thermostat adjustments are definitely within reach, both by turning the thermostat down all day and/or by using a setback at night or when no one's home. Here's a good article on the setback theory and practice, including a 3-year testimonial of a 28% reduction in heating costs, plus references to studies that consistently show significant savings are possible.

What about my office? I share once again a graph of my electric usage over the past 7 years. As can be seen by the dark green line at the bottom, this past January and February I managed to beat or tie both of the prior 2 years, which in turn greatly undercut the previous 4 years.

The following table isolates the average daily heating usage for winter months (December through February) by subtracting out the average April bill (minimal heating or cooling use):

Average Electric Use (kWh/day)
Years*	Winter*	April	Heating Load (=Winter - April)	Heating Load Reduction
2005-2008	68.6	48.7	19.9
2009-2010	39.0	31.0	8.0	60% **
2011	28.3	21.3	7.0	65% ***
* The winter months are December through February and are listed by season according to the calendar year in which winter ends. For example, December 2010 is grouped with January and February 2011 to comprise the 2011 winter season.
** Based on thermostat set in 50's (as cold as marginally-bearable with heavy clothing).
*** Based on thermostat set to 50° during the day and 45° at night, and using a personal 300W space heater.

Yes, this past winter I managed to cut my heating load by almost 2/3's! And that in spite of a bitter cold spell in February. Of course, I admit my thermostat settings were insanely cold at 50° daytimes and 45° nights. But that was for the overall building (house). Sitting at my desk was made almost-bearable by a little radiant space heater (300W). In reality the temp in my actual office was well north of 50°, maybe close to 60°. And yes, I wear long johns and sweaters both!

So does it matter that someone else has their thermostat cranked up to 80°? That is, does it matter to you and me, to society? In truth it does. Not just in the big picture, long-term impact. But it hits one's neighbors right now. Remember those rolling blackouts here in Texas last February during that bitter cold snap? And everyone's electric cost is impacted sooner or later by the maxing-out of the power grid. I'm sure there were people last February who thought they had a right to a toasty home or office. Maybe they think they've earned the right as an American citizen.

They forget it is supremely a gift from God that they were born in this land of opportunity and can earn a living and provide for their family here. Every blessing from God is given so we in turn can be a blessing to others. Let's see now, am I my brother's keeper? Or let me ask, who is my neighbor?? It is disgusting that some conservatives choose to mock the wise actions of responsible people, and to scoff at voices that advocate reason in the matter of stewarding God's resources.

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The LORD mocks those who mock,
but gives grace to the humble. (Proverbs 3.34)

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Biomass Energy??

Aesthetically, fireplaces are always nice. They even feel warm when you're up close. But I've always known they're terribly inefficient. After all, most of the heat goes straight up the chimney--around 80%. The real score could be even worse, because the rising hot air has to be replaced by cold air pulled in somewhere through the building envelope, which can make other rooms colder (per MythBusters test - but see discussion).

Last year while talking to a friend, he told me of seeing a fireplace insert that could easily heat the whole house. I started investigating and found that modern fireplace inserts are not just a little more efficient than open fireplaces--they can in fact be quite efficient and generate large amounts of heat.

In the current climate of energy-consciousness, along with the modern efficiencies of wood stoves and fireplace inserts comes a fancy newfangled term: biomass heating--which simply means the recovery of energy recently captured in biological material. It's what people have been doing for millennia, but now made chic. Biomass stoves can either burn traditional sticks of wood or wood pellets made of compressed sawdust. Pellet stoves can potentially be more efficient because the burn rate can be micromanaged: they have a hopper and conveyor belt that maintains the rate of new fuel added to the fire. The downside of pellet stoves is that the conveyor belt stops when the electricity goes off; also, you can't grow your own fuel.

The EPA (Environmental Protection Agency) serves a useful role when it comes to biomass stoves by providing standards and a certification of how clean the stoves burn. As opposed to regulation, this is information that permits you and me as consumers to compare complex and difficult-to-evaluate competing products. A fireplace insert is really just a wood stove that fits into the fireplace opening, so the list of certified "stoves" includes inserts as well.

So last spring we ordered two fireplace inserts--one for our home and one for the office. We went with a mid-range model from Napoleon (1402) that runs around $2,000 installed by Eric Harton (see his website). If you are out at the State Fair of Texas in the next few weeks, drop by his booth at the Embarcadero building booth #27. A nice guy who does good work.

Objections overcome

The smoke-filled air in Congo
obscures the world's largest volcano
--just 10 km away.

When I first started looking into biomass heating, I had no idea biomass could be a serious 21st century fuel. After all, I've seen mountain air painted gray by the smoke of cooking fires in Congo. It seemed so quaint--but especially dirty. So, there are several intellectual hurdles to overcome:

1. "Doesn't biomass energy pollute the air with dirty smoke?"
   If you see and smell smoke from your neighbor's chimney, you can be sure they don't have an efficient wood-burning insert. Even older wood stoves or inserts produce 15 to 30 grams  per hour (gph) of particulate matter. An efficient stove produces a little smoke only in the first 15 minutes while it is warming up--then the visible smoke disappears. EPA certification requires less than 7.5 gph, with most new stoves scoring under 4. Our Napoleon model is rated at 3.5 gph.
2. "Aren't we supposed to be planting trees? Cutting down trees can't be green."
   Except that it can be done sustainably. Replant trees and they will grow. Grow your own fuel. I planted many trees at my office (our old house) 10 to 15 years ago. Just from trimming them they provide a lot of wood. Look at how many tree trimmings go to the landfill each year. That's wasted biomass fuel. It's better to burn it instead. Some of our own trees need to be cut down soon because of overcrowding or because they're starting to shade our solar array. I plan to replant trees in the back of the yard just for fuel.
3. "Burning wood is inefficient."
   It's true that an open fireplace radiates at best 25% of it's heat into the room and sends the rest up the chimney. A wood stove reverses the heat loss, giving off as much as 85% or more of it's heat into the house. It does this by slowly burning the wood at a high temperature of around 550°. The oven bricks heat up and slowly cook the wood. In addition, super-heated jets of air provide fresh oxygen to re-burn rising smoke before it actually leaves the oven. (There are also catalytic models that achieve slightly higher efficiencies. But these also add a couple hundred dollars of cost every few years to replace the catalyst, which is fragile and also subject to premature breakage.) In addition, electric blowers in most models circulate air around the stove and disperse the heat into the house. This is one point at which I think the stove makers could improve--why not use an external combustion engine (a Stirling engine) and just use the heat of the stove to power the blowers?
4. "Doesn't burning wood release carbon into the atmosphere?"
   Tree's capture carbon and the sun's energy, and burning them releases the energy for use and the carbon back to the air to be recaptured by new trees. If dead trees rot instead, the same carbon is released back into the atmosphere. Either way, there is a closed carbon cycle. The issue raised with fossil fuels is the release of carbon back into the air that has been sequestered for millennia--potentially upsetting the current balance of components in the atmosphere.
5. "Can you really heat a modern house with wood?"
   Look at the BTU/hour rating of a stove. Compare your furnace rating. A small gas furnace may put out 50,000 BTU/hour. Our Napoleon stove is rated at 11,400 to 70,000 BTU/hour--it depends greatly on the type of wood burned and how much you stoke the fire. Hard woods contain more heat content and will burn longer. Of course, a home's architecture affects how much of the home one heating "appliance" will warm. In general, biomass fuel will be considered a secondary and emergency source of heat by most users. But it could be quite a substantial source.

Payback period 'guestimate'
Currently I have no hard data to go on for our houses. I can only speculate. What if 50% of our heat this next winter could come from wood? For our home that would amount to $320 saved in our gas bills; for work that would be closer to $200. Subtract out the $100 each I spent to deliver 1/2 a cord (4' tall by 8' long stack) of wood at each location, and the savings is relatively small. The payback could be 10 to 20 years. However, I expect to be much more comfortable at the office because I will relax the extreme austerity measures I've implemented the last few years! And there is the ambiance to enjoy. I'll report back in the spring after we have actual data about savings at home and at the office.

The Hearth, Patio and Barbecue Association provides a calculator to give some sense of the relative potential cost savings of adding a new biomass stove. It's interesting and based on some 'typical' situation, but clearly there are more variables than just the cost of the new fuel vs. the cost of the old fuel. Especially critical is the question of how much the family actually makes use of the new 'appliance' (stove or insert).

After all, there's work involved in stoking the fire. But if you enjoy your fireplace anyway, it's a matter of enjoying more fruit from your labor. A good stove will burn the same amount of wood much longer because it burns the wood more slowly and thoroughly. Many stoves have a stated burn-time of 9 hours or so.

And what about splitting wood? Does that count as chores or exercise? Maybe both. For a city dweller, buying a new maul (the proper tool for splitting wood) and learning the technique for the first time brings a feeling of accomplishment. Even my younger son found it a challenge to see if he could split wood with one blow. It certainly gets one out-of-doors for a bit and builds a connection with God's creation--kind of like a campfire experience. You can't get that from a cold--or hot--furnace.

Tax Credit
Finally, biomass stoves are a beneficiary of recent green initiatives at the federal level. They are eligible for a 2011 Consumer Energy Efficiency tax credit of $300 if their thermal efficiency rating is at least 75%. While the emissions level of an insert is easy to identify on the listing of EPA-certified stoves, the thermal efficiency rating is harder to nail down. The EPA listing appears to show a set efficiency rating for all stoves by class: 63% for non-catalytic wood stoves, 72% for catalytic, 78% for pellet stoves. Manufacturers, however, often list efficiencies well above 80%. Apparently the tax credit efficiency rating must be certified by and obtained directly from the maker. Our Napoleon inserts are certified at 78.83% efficiency.

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Peter followed Him at a distance, right into the high priest's courtyard. He was sitting with the temple police, warming himself by the fire. (Mark 14.54, cf. Luke 22.55-57)

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Open Window "Policy"

The record-breaking summer of 2011 (hottest average in the nation) is seemingly over for DFW. Everyone knows this year holds second place to 1980 for the longest continuous streak of 100° days. But it now holds record for the greatest number of 100° days (70 days as of September 13). And, just as important for electric load, 2011 holds title to the most days with daily lows above 80° (40 days as of August 17).

Free Cooling
But now with the lows falling into the 60's, it's time to take advantage of some cool natural ventilation. Until this year, I've generally kept my office closed up tight and depended solely on the central a/c to do it's job. But this spring I thought I'd try taking advantage of some of the cooler days and nights in order to run the a/c less. Each morning I would throw open my office window and open the sliding door in back and let the cool breeze blow through. No fan needed, and the a/c could wait till later in the season--or the day.

The result? A clear savings in electric consumption as compared with the past two years. The graph below shows a 36% reduction in electric usage for March and April. The brown line is 2009, the light blue is 2010, and the dark green is 2011.

Opening the windows was the only major difference between these years, so this simple zero-cost action accounts for the total reduction in electric usage shown. The daily average fell from 33 kWh per day to 21 kWh. That's a monthly savings of about 360 kWh (= 12 kWh/day x 30 days), or a savings of roughly $36 a month (based on 10¢ per kWh). That's $1.20 a day I'm being paid just to open the windows(!) Or $144 per year if the savings can be replicated for two months this fall. We'll have to wait and see--it's time to start saving.

By the Numbers
Though our electronic gadgets cost plenty of electricity, we can also put them to good use to save energy. I never trust myself to judge the temperature outside accurately--I always use a thermometer. I keep a wireless thermometer in a shady place out back with the inside read-out in a convenient place near my thermostat. It makes for an easy and accurate way to determine when to open the windows and when to close them.

The weather forecast is also useful. If the projected high is in the low 80's (depending on your personal comfort zone), you can plan to leave the house open all day. Remember that fans can make the afternoon comfortable as needed.

My own rules of thumb:

Forecast High	Action Plan
above 83°	5° difference needed to open windows close at 75° to 77° *
83° or below	open all day
* Based on a/c thermostat set at 82°

In a home setting, of course, the windows can open up all night, giving an even better temperature differential and additional time to cool the house down.

The Downside
Humidity. To maximize comfort and minimize energy consumption, indoor humidity levels need to be 30% to 50%. The a/c dehumidifies the air when it first comes on, but it has to work harder to do so. This is why I've built a 5° minimum temperature difference into the rules above. On any given morning the outside humidity may be well above 50%. One could pay close attention to this detail and refine the rules further--but then they would cease to be rules of thumb! The 5° differential has served me well.

The Tremendous Added Upside
There's a joy in the journey, and a lot of enjoyment to be had from God's creation! The call of birds, the rustling of leaves, the refreshment of a gentle breeze. I remember back to college when I lived in unairconditioned dorms built back in the 30's (1930's that is, and I lived there in the 80's). Some of the best times I've had with the Lord were spent reading God's Word at my desk before an open window, with a cool breeze on my face and the dawn gently breaking outside. It was in those quiet times during my first semester at UT that I truly felt the Lord calling me to missions in the future.

Why have I kept these gifts securely locked outside my windows all these umpteen past years since? Convenience. Just a minute or so of saved time. Ugh! I'm glad for the change back to a lost joy.

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So change your minds and turn back, that your sins may be wiped out so that seasons of refreshing may come from the presence of the Lord. (Acts 3.19)

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