What happens here?

What happens here?

Buildings, energy, energy policy, indoor air quality, problems, triumphs, successes, failures and the people and processes that affect them.

Feel free to draw any tangential connection you think appropriate.

I love spirited and enthusiastic exchanges, but please maintain the decorum.

Thursday, November 28, 2013

Happy holiday shopping season from Building Diagnostics

Thanksgiving morning and the local paper arrived at approximately 20 times its normal weight. The sales fliers will be recycled (in our house) or tossed in the trash. The next batch will arrive on Saturday and Sunday.

I was thinking about the cost and resources used to bring all this to my door and what I would like to see from stores this holiday season.  Using my awesomely nonexistent page design skills I made a display ad I'd like to see stores run in the papers instead of being inundated with glossy (and heavy!) inserts. If you happen to be the CEO of a store big or small and you'd like to use a version of this feel free. Consider it open source :-)

Store Name

A word with our customers in this holiday season

We would like to announce that this holiday season we are devoting the money we would have used on countless glossy sales fliers to feeding the hungry and providing shelter to the homeless.

We have also decided that we will keep reasonable hours, remain closed on holidays and encourage our employees to volunteer, with pay, for 2 - 4 hours a week, at local social service agencies. Our employees are all paid a wage that allows them to care for their families and not be a burden on the community.

Rest assured, dear customers, that we will still be offering excellent products at fair and very reasonable prices. We will work with our suppliers to offer the best prices we can; but we will not jeopardize our ability to serve the community as outlined above.

We hope that by making this commitment to our community we can earn your trust, your business and perhaps even your respect.

We wish you a wonderful holiday season. Please remember that this is a season for giving, but not to the point of financial stress. If finances do not allow you to give many material gifts we suggest a gift of hugs and caring. We have free hug gift cards available throughout our store.

Thank you for allowing us to be a part of your community.

Monday, August 19, 2013

Delight, a building science trait.

I spend most of my time thinking about the technical aspects of buildings. Water intrusion, air infiltration, insulation effectiveness, ventilation: these are the things that take up most of my time.

Geeking out on these is easy, working through the problems of moisture diffusion in an existing building and figuring out the best fix for a specific situation is so satisfying. Er, well, for me. But the truth is, most normal folks don’t walk into their house and think “I love this place because of the excellent building control layers.”

I once had the pleasure of working with a wonderful architect who said the most important thing he could put into a building was delight. If he didn’t get that, nothing else really mattered. He had all the technical chops you could ask for. He did great space utilization and circulation patterns. His designs were always appropriate to the surroundings. He did a great job keeping team members focused during job site meetings. And he was always thinking about how the occupants would experience the building. What would give them delight.

Creating delight is a tough job. What is delight? Does everyone experience it the same way? Can you really create it? Why is it so darn important?

Delight can come from lot of things. An unexpected trim detail, a view framed through a window, a lowered ceiling that makes a corner of a large room feel private. Some people are delighted by open spaces where many can congregate. Some like small, private rooms that they feel are theirs alone. Delight can be a very personal experience or it can be shared with everyone. Can delight be created? Yes, but you need to be open to experiencing it.

The importance? Delight can lead to love and when people love a building they care for it. If you really love your home you know that a roof leak is hurting something you love. Just as you notice little changes in your child's demeanor and suspect an illness you’re more likely to notice the small changes in a home that could be hinting at a problem. A well maintained (and loved) house will serve you better and cost you less, returning that love.

That sounds all warm and fuzzy, but how is delight a building science trait? Well, if the building doesn’t meet your basic expectations of comfort, safety and durability you’re not going to be experiencing much delight. And, if your not getting the delight it’s less likely your going to want to do the maintenance that might improve your experience. So it’s all part of the feedback loop.

A complete building, a great building, has it all; delight, comfort, security and durability. If you’ve got a home that has some of the delight qualities you want but somehow isn’t as comfortable as you would like maybe you should call a building science professional for a little counsel. It could get your relationship back on solid footing, saving the distress of calling a real estate agent to initiate a divorce.

What makes your home delightful? I’d love to hear, let me know in the comments below.

Tuesday, May 21, 2013

Clothes dryers, my least favorite appliance

No appliance annoys me like clothes dryers. They are not a necessity, they’re marginal in design and execution and they can burn your house down. At least the Chinese have decided that they’re a bad idea. Good for them.

OK, so we still have millions of these things in use every day, what will keep them running as efficiently as possible?

It all boils down to two basics, short and clean. Short, that's the exhaust pipe. The length matters because every foot of pipe increases the resistance to air flow. Elbows are worse, each elbow equals 3 – 5 feet of straight pipe. Longer, twistier pipe leads to lower airflow through the dryer. That leads to slower drying and potentially overheating of the clothes. Overheating leads to fabric shrinkage and reduces fabric life.

Too long. And there are screws.

Installation instructions usually are a bit vague on maximum length but 25 - 35 feet seems to be the consensus. Personally I think that's nuts, but there are a lot of loooong dryer vents out there. The pipe should (read MUST) be metal and be as smooth internally as possible. No plastic flex, metal flex only where absolutely necessary. Do NOT join sections of pipe with screws. Even the shortest projection will catch lint and quickly plug the pipe. Use tape designed for ducts, not duct tape, to join the sections.

At least this one isn't crushed. Yet.

 Clean, this is the tough one. I mean keeping the ducts free from lint which will reduce the diameter of the pipe and reduce airflow. All dryer have lint traps. Filter is a better word because none of them are particularly effective lint barriers. I guess they clean the lint before allowing it to go clog the exhaust vent. For years there have been two basic dryer chassis design. One has the lint trap at the bottom of the door opening, the other has the trap accessed from the top of the cabinet at the right rear.
The door location seems to be slightly more effective, but can still pass a lot of lint. The top mount design has a couple of weak points that allows slightly more lint to pass around the edges of the filter.
Both designs are compromises in terms of airflow and effective lint trapping. A finer mesh would stop more lint but would greatly restrict overall airflow. Most of the lint that ends up in the ducts passes through the trap itself. If you take a chunk of the built up lint in a dryer vent and rub it between your fingers you will see that it is actually very fine particles.

Actual lint, no kidding

As the lint trap clogs during the drying process the fine particles are actually trapped by the accumulated larger particles. Unfortunately by then the airflow is greatly restricted and the air is forcing its way around the edges of the filter. This is particularly bad on the top filter design.
For best operation the lint trap must be kept clean. This is the major choke point in the system. The trap should be washed periodically, especially if you use dryer sheets for fabric softening. The sheets cause a film build up on the mesh, reducing its size. Remember, never push the start button until the filter has been cleaned.

Despite the fact that you clean the lint trap you still need to clean the ducts on a regular basis. How often will depend on use, but at least once a year. The best way is to disassemble the pipe from the back of the dryer and where it goes through the wall. Frankly, because of the poorly conceived way dryers are designed this is a real pain and most people won't do it. Get a dryer brush that fits your duct system, most likely 4 inches, and clean it from the outside. Tape the exterior flap open and start cleaning at the end. Do a short length and withdraw the brush and clean it. Run the dryer on the air setting for a couple of minutes and repeat. When you have cleaned as much as you can reach (if it doesn't reach the dryer you need to disassemble the pipe) start the dryer on the air setting and carefully run the brush in again. You may get more lint, so don't put your face near the outlet.

An interesting fact, clothes will dry just fine on an outside line year round. It take longer in the winter but it will work. When it's cold try doing a couple of loads of wash at a time, dry what you need in the next two days in the dryer, the rest can go on the line. Jeans and heavy things may need a little indoor drying time to completely finish them. We bring a couple of pieces in at a time an hang them near the radiators, works like a charm.

So, keep the dryer properly vented and clean the lint trap frequently. Then go to the hardware store and buy a clothesline. Line dried clothes smell better and last longer and you get to go out more often. We have a winner.

Thursday, May 9, 2013

The most cost effective solar strategy, a garden.

One of 4 trays of seedlings.
It’s always good to broaden your horizons, especially when it comes to saving energy. While I focus on buildings it’s good to be aware of the other parts of life that impact energy consumption and the environment. I also like food fresh from the garden.

How can a backyard garden save energy? I lifted a paragraph from the Sustainable Table website which covers the basics.
Conventional food production and distribution requires a tremendous amount of energy—one study conducted in 2000 estimated that ten percent of the energy used annually in the United States was consumed by the food industry. Yet for all the energy we put into our food system, we don’t get very much out. A 2002 study from the John Hopkins Bloomberg School of Public Health estimated that, using our current system, three calories of energy were needed to create one calorie of edible food. And that was on average. Some foods take far more, for instance grain-fed beef, which requires thirty-five calories for every calorie of beef produced. What’s more, the John Hopkins study didn’t include the energy used in processing and transporting food. Studies that do estimate that it takes an average of seven to ten calories of input energy to produce one calorie of food.

(Note for the Nerd: 1 Btu equals 252 calories.)

If you bypass the supermarkets and food factories you can turn that formula around. Whether you plant a large scale garden or just grow a few herbs and vegetables in containers you can eliminate the bulk of the fossil fuel used and take advantage of one of the most efficient solar collectors available, leaves.

The net gain (food calories available/fossil fuel input) varies by crop, but using seeds you will save transportation energy (lighter, less bulky to transport) and if you use natural fertilizer and/or compost that you till in by hand you can easily get more calories of energy out than you put in. The sun supplies the balance.

The real bonus of course is the food, you get to select what you grow and the freshness makes the tastes sublime. You will never taste a better tomato than the one that you pull from the vine and eat still hot from the sun.

If you’re not inclined to garden there are other options to get fresh local foods. The USDA has a searchable database of farmers markets. You might be surprised at what’s just down the road.

You could by a share in a CSA (Community Supported Agriculture) organization and get a weekly supply of fresh veggies throughout the growing season. Here in NH, and I’m sure elsewhere, there are winter markets for locally produced bake goods and some greenhouse/cold frame grown crops. I’m not sure what the energy penalty is for greenhouse operation, but it could conceivably still be better than flying food in from South America.

One last point; there is a great deal of security in having a reliable supply of food in your area. So keeping local farmers in business and knowing how to raise your own crops (or chickens, pigs, cattle) should be as much of a priority as a secure energy supply. Keeping the lights on won’t make you feel better if you’re hungry

Tuesday, April 9, 2013

What does Infrared actually tell you about your home?

Infrared Imaging, commonly referred to as IR, is a very useful tool for anyone practicing building science. It provides visual images that offer clues to what is happening, temperature wise, in the wall (or floor, ceiling, roof...).

Wait, that last sentence is rather, well, limiting. Doesn't IR see through walls?

No, IR isn't magic. It's simply making a best guess about the temperatures on the surface of the walls based on a lot of assumptions. The operator of the equipment has supplied some of those assumptions as has the manufacturer of the imager. The manufacturer made his assumptions based on solid physics and years of testing. The operator is making his assumptions based on what he remembers from his training and how he is interpreting the conditions of the objects he's imaging. This can be a weak link, and it's where most bad IR interpretation starts to go wrong.

That's the other thing. IR doesn't tell you anything, it gives you information that you need to interpret. The operator needs to understand the workings of the system that's being imaged or the images make no sense. I work with buildings and I'm comfortable interpreting IR images of buildings. Ask me to evaluate an image of a horse and you might as well flip a coin, I'd be way in over my head on that.

Still, IR is a powerful tool to have. Because of the relative speed of acquiring information and because it can present that information graphically it makes diagnosing problems quicker and better. Homeowners get a better understanding as well. Seeing the effect of missing insulation really brings the point home quicker than the proverbial thousand words of explanation.

Let's take a look at a few images. The first one is simple. We're looking at a ceiling on the top floor of a building. The attic above is cooler than the room and the sun hasn't warmed it up yet. This attic had no access so I had to base my interpretation solely on this image. Fortunately when the contractor made an access to insulate the area properly I was proven correct.

The fiberglass insulation is in batt form. One end of a batt is being held up by the can light in the picture and the cold air in the attic is getting under it to the drywall ceiling. This is a classic situation and all too common. But this had been in place for 12 years and until I came in with a thermal imager no one knew about it. If you read my post on gaps in insulation you know how bad this can be.

One of the most useful things you can do with IR is find air leaks. With a reasonable temperature difference between inside and out I can use the blower door to create airflow. Once the door has run a few minutes you can get images like the one below. The cold air flowing from the attic creates the cold (blue) streaks on the warmer surfaces. Not only are these powerful for illustrating the effect, an air sealing contractor can use this as a guide to what needs to be done.

Important note: Ask anyone offering air sealing if they use a blower door and IR to find leaks and confirm results. Working without these tools is like tying your hands behind your back.

Once in a while you run into airflow strong enough that you can see it without a blower door. Every building science professional I have shown this image to assumes I had the blower door running on a cold day. The temperature difference was 20 - 25 degrees between in and out. My blower door was still in the van, so what happened?

I was in the lowest level of a former barn converted to child care. The building was a tall 4 stories and a really good example of the stack effect in a building that is leaky at both the top and the bottom. Think what the airflow would be like on a really cold day!

Sometimes unexpected patterns show up. Below is a small section of wall in a half basement. At the very top right is the edge of the board that caps the wall that is against the concrete wall. (BTW, this should not be done the way it was, that deserves a separate post.) The lower left is just a chair that intruded into the image. The orange-ish section on the right is mostly undisturbed fiberglass insulation under drywall. The center area, with those dark splotches are tunnels and nesting cavities created by mice. We confirmed this by removing the drywall (wearing protective masks and clothing) and cleaning out the mess and damaged insulation. Excluding vermin is really important in buildings both for health reasons and because they can cause damage to insulation and structure.

All of the above information was inferred from the temperature of the surfaces I looked at. With the IR and knowledge and experience with buildings I got the right answers. Ask your prospective energy auditor how much experience they have with buildings. If they were selling cars last month will they be able to adequately interpret the information they gather? Having the tools doesn't give you the skills and knowledge to use them.

Sometimes you can have a little fun with IR. I worked on several child care centers over the past few years. It was the most fun I've had on any project I've done. IR is not ideal for portraits but I got a lot of requests from the kids (Take my picture! Me too! You took her picture. Take mine). This little girl had just been playing outside and she was warming her cold hands on her forehead.

I'm told that IR is commonly being used in some countries as a medical diagnostic tool. The only interpretation I was able to make was that she had been having fun.

When you get an energy audit don't forget to have your picture taken as part of the process!

Thursday, March 28, 2013

Paying for advise can be cheaper than paying for the wrong product or service.

I cringe every time I hear it. "We replaced our (boiler/windows/insulation) and the house is still uncomfortable and the heating still costs too much."

Usually I'm on the phone. Someone has called, they've already spent a lot of money, have very little satisfaction and now find themselves calling someone who is probably going to charge them money to tell them they made a mistake. To be honest I probably feel just as bad as they do. I'm going to charge them money, tell them they need to spend money on something else to save energy and feel more comfortable and I have to do it without saying that they made a mistake. My job isn't to rub it in.

So make us both feel better, pay me first. Really.

Why call me (or perhaps some other building consultant) instead of just calling a contractor? So that when you spend money on your home you'll be comfortable that it was well spent, because you had a plan. I don't sell anything, I only work for you. My job is to make the process easier for you. I help you make the plan.

How do we start? Usually with an energy audit. The process gets me to see the important parts of the building. Plumbing, heating, electrical and structure in addition to the insulation, ventilation and windows. We might be done at this point. Depending on your goals you might feel that you have enough information to proceed on your own. A lot of people do and that's fine. Please drop me a note after you're done to tell me what you've accomplished. Send some pictures too.

Suppose you've got big plans for your house. An addition or major rehab, residing, new electrical work or maybe finishing the basement for that man cave. Do you want to use this as an opportunity to add insulation? Does the basement have water problems? Is there some mustiness in the laundry room that you'd like to get rid of too? How do you know where to start?

We can make a plan. Once the energy audit is complete we can talk about how you can integrate the information from that with your overall goals. If you need further guidance I can write specs for each step of the process. I can suggest the best order to do things so that work doesn't have to be undone and redone. That can get expensive. Do you need help evaluating bids from contractors? Perhaps you need someone to inspect the work as it progresses to see to it that your work is done according to the specs we laid out earlier.

The important thing is that each plan is designed for you. The combination of services will be what you need, no more or less. I like to think of myself as a mapmaker for my customers. I want to get you safely, efficiently and cheerfully through your projects.

It all starts with a call. If you call me first you can call the rest of the contracting team with more confidence. You'll have a plan.

Tuesday, March 26, 2013

Little gaps in insulation can let a lot of heat escape.

And I can prove it: q(Btuh) = U X A X ∆T! See, end of post. All done, fini.

OK, that's not fair let's look at some pictures.

This is a small gap in insulation. It is about 1 square foot out of an area of 75 square feet. The insulation is R19 and for the sake of argument we will say that it really is working as R19 The metal top of the fan box is close enough to zero that I will use that. So it would seem reasonable to say that the average R value is 18.75 [(19 X 74)/75].  That's hardly any difference, 18.75 Vs 19? Nothin!

Except that's wrong. Q(Btuh) = U X A X ∆T. "Q" is the total energy flow(measured in British Thermal Units per hour), "U" is the rate of heat transmission (in Btuh/square foot). "A" is the total area and "∆T" (Delta T) is the temperature difference across the surface in degrees Fahrenheit. "U" by the way is the the measure of the rate of heat flow. We just lost R though, where did that go?

Engineers and scientists measure the rate at which things happen. R value is how much that rate slows. Getting from "U" to "R" is easy, divide 1 by either and you get the other. R 2 = U 0.5. R 3 = U 0.33. R is handy as a marketing tool, the higher the number the better. That's pretty easy to understand. Also you can add R values, which you can't do with U.

So with our exposed fan above how do we figure the actual R value of the total area? Here's the formula: U(avg) = [(U1A1) + (U2A2) + (U3A3) .../ A(total). (BTW, does anybody know how to get proper math formulas with sub characters out of HTML?)

In the example above we have R 19 at U 0.0526316 and R 0 at OOPS, can't divide by 0, lets call the fan R 0.5 = U 2. We have 74 square ft times 0.053 = 3.922 plus 1 square foot times 2 = 2 which adds up to 5.922 which we divide by total area (75) and end up with an overall U value of 0.07896 which equals R 12.66. That is a big difference for missing one square foot of insulation.

Of course there are those joists in there, 16 inches on center, which have an R value of about 5.5, this is going to make things worse. I won't run the whole formula but in a simple framing system like this about 10% of the area is joists, so 7.4 square feet. Now we have 65.6 square feet at R 19, 7.4 at R 5.5 and 1 at 1/2. Result? R 10.9 at most.

See how fast it slips away? What if things were worse?

That's a big hole. I didn't calculate the effect because I knew it was coming out. The owners were afraid to run it so it just sat there as a hole in the insulation. It leaked a lot of air too.

Sometimes it just looks like a wall (or an electrical box) until you use the IR imager. Even if you can't see it the effect is still there. What can look like an innocent little gap is really robbing you blind.

Want another way to look at it? Let's start with an R 40 attic.  Lose one percent of your insulation, lose more than 25% of your R value. Lose eight percent and you only have 25% left. Makes you want to hurry into your attic and neaten your insulation doesn't it? Well, do a good job and don't forget about the attic hatch.

Thursday, March 21, 2013

Insulation is like a practical pair of shoes. Not sexy but oh so comforting.

The price of solar electric panels, or photovoltaics (PV), is really low. Depending on the source I've seen price guidelines that range from $1.75 to $3.75 per watt installed. That's actually a huge range and part of the reason is that most installers quote costs AFTER incentives (Rebates, tax credits, local tax allowances, etc.) which vary widely by location. But, PV is still a good deal. So why wouldn't it be the first thing you do?

Well, for one thing I work mostly with conservation measures, so it's less work for me. A better reason might be very simple. Conservation, air sealing and insulation, will make you more comfortable, PV panels won't.

Aha! I saw your head turn. You like to be comfortable, right? I can do it for you and save you money. Those PV panel can save money but they won't make you feel all warm and secure on a cold winters night. Let's have a little chat about the least sexy part of this, air sealing.

Air sealing involves some really dirty work, see least sexy above. You climb into attics, move insulation raising all sorts of dust (you are wearing a really good dust mask aren't you) and seal every large, medium and small hole you can find. The temperature in the attic is probably between very hot and hotter-than-people-are-able-to-survive-at. All the sweating you are doing will make the dust you are raising stick to your skin. The good part is that when you come out of the attic you will feel chilly. Even if it's 95F and humid.

After the attic you can do the crawl space and/or basement which will be cooler, but could be nasty in a different way. All in all this is pretty unglamorous. But if you have eliminated most of the big drafts in your house you will be more comfortable (no cold air blowing over your skin) and saving money. The more holes you fill the more you save.

Insulation comes after air sealing. Almost always. Sometimes insulation is air sealing, but only if it is rigid and not fluffy. Depending on your choice of insulation you will be dealing with materials that are either itchy, dusty, or both. Unless it is rigid, then it will cost a lot more. And you will be back in the attic and crawlspace. YIPPEE!

So how will insulation make you more comfy? It will warm up the surfaces near you. OK, that's not the same as warming up you, but really it's better. Just a bit of physics, that's all. Heat behaves very consistently, it goes to cold. That is, a warm thing will give up heat to a cold thing. Since you're typically warmer than the walls and ceilings, or you should be, you will be giving up heat to them. The warmer they are the less heat they will take from you. That make you more comfortable. Simple right? Just not very sexy.

That's OK. Now that you're nice and comfy you can sit around and plan how you're going to get that PV system installed.

Questions or comments, or if you want to complain that I really dumbed down the physics just use the comment box below.

Tuesday, March 19, 2013

The energy auditor has seen houses messier than yours. Let her look under the sink :-)

It's a common problem. I get to a house, we start going through the building and then I reach for the cabinet door. I always say "may I?" but usually the answer is a question; "Do you have to? It's such a mess."

Let's go to the pictures:

The first image is what I am interested in. This particular image was taken before I started the blower door. There is a lot of cold air coming in and that's a very, very important thing to find.

This is the visible image taken simultaneously with the IR above. Some people might see a slightly messy storage cabinet; I see a place where air is leaking and a place that needs to be checked for water leaks as well. This one is is probably slightly neater than average, but I don't know or care. Really.

When an energy auditor comes to your house take heart. We have all seen some really messy (and dirty) houses. As long as I can get to the places I need to and see what I need to see your house is fine. If you don't have time to make your house look like a magazine layout don't worry. I don't talk about my customers housekeeping and my conversations with other auditors have never been about messy houses.

That eliminates that as an excuse, but there are things you can and should do to prepare for an audit.
  • Make way to attic hatches. Often these are, inexplicably, in closets. Please at least remove enough stuff so I can get to it.
  • If you have a duct system I need to get to all the supply and return registers. If you feel warm or cool air on your feet when sitting on the couch there might be a register under it.
  •  I need to be able to close all windows, exterior doors and skylights.
  • If you have a wood, pellet or coal stove or boiler/furnace it need to be out and fully cooled when I arrive. Otherwise I will not be able to do the pressure testing that is so critical to evaluating your house. If these are your only source of heat we should reschedule to a warmer time of year.
  • Please be home at the time of the appointment. I will be on time because I want to have the opportunity to meet you and discuss what I'm seeing with you. If you want your contractor to be present too I'm comfortable with that. If you are using another auditor please check with them on this.
That's about it. When we are talking on the phone prior to your audit I will ask some questions to find out if any other preparation will be needed.

Your house doesn't need a complete spring cleaning to schedule an audit. I think I can do enough good for your house(and you) that a little embarrassment is a small price to pay. But don't be embarrassed. Just call, I'll like you and I promise the state of the house won't make a difference.

Comments or questions? put them in the box below.

Thursday, March 14, 2013

Old houses are like old people. You can learn a lot from them if you take the time and respect them.

One of my indulgences is taking time to look at a detail in an old house and trying to get into the head of the craftsman who made it. I can't say that every try is successful, but when I do figure it out there have been some great "Aha!" moments. More than a few times it's taken years and some other discoveries to see what was going on.

Sometimes it's a structural choice; how were two pieces of wood joined, why was that support here and not there. It could be material choice or why did that window go into THAT corner. Sometimes there's a really good, smart reason, other times it's tough to figure and there are some clear mistakes. These are lessons that are sitting right there waiting to be learned and many of them are still applicable today.

One important thing about successful (surviving) old buildings is that they could dry out if they got wet. Quickly too. And that's the important part, if wood stays wet it rots. If it dries quickly it's fairly forgiving of some periodic wetting. If you let it get too wet too often your building won't survive for future generations to see how stupid you were.

How did they dry and are there lessons about that for today? They dried because of lot's of air and energy flow and materials that don't trap moisture. No insulation and free air movement in wall cavities are a recipe for drying. Interior horsehair plaster dries very rapidly which also helped keep the walls dry. Of course in the 18th & 19th centuries showers and hot tubs were in short supply and indoor swimming pools were even rarer. So buildings had lower moisture loads to deal with and had good drying potential. That's a good way to make a building that will last.

We have become more regular in our hygiene and with high energy costs we want insulation in our walls and ceilings. This puts us in a bit of a bind because we just messed up our building longevity strategy. What to do? Let's go back to our original building and see what else we need to change. Well, if the walls won't dry, maybe we should keep them from getting wet! Some of those old details will still work for us and some won't. If we are expecting better thermal performance we need to give the walls (and other building parts) better water management so they can make it to the next generation and beyond.

With future posts I'll explore the details, but new construction will have different solutions than rehab, probably. With rehab or retrofit you have to think more carefully about what the strengths and weaknesses of the building are, what the extent of the planned work will be and what can realistically be done within those constraints. The reason I love working with older buildings is that I can use all those lessons I mentioned earlier and, with luck, get some more.

Oh, one more thing. When you do undertake a rehab on an old building remember to leave a penny with the year you completed the work where someone will find it when they get around to their own project in the future. They'll know that you were thinking about them and maybe take the time to learn a few lessons of their own.

Tuesday, March 12, 2013

Radiant barriers are seldom the cost effective option, especially in the north.

This is the current perversion of a bit of science into over enthusiastic marketing. Radiant barriers can, when properly installed, reduce radiant transfer of energy. The question is whether this is the best use of your home improvement budget. In my opinion the answer is almost always a resounding NO!

Before we go any further download this information from the Oak Ridge National Laboratory (ORNL) http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&ved=0CF0QFjAE&url=http%3A%2F%2Fwww.ornl.gov%2Fsci%2Fees%2Fetsd%2Fbtric%2FRadiantBarrier%2FRBFactSheet2010.pdf&ei=MIY3UdahKsSo0AGfnYAg&usg=AFQjCNHP3S7G_7P2KLEhesLTMuIOId31NA&bvm=bv.43287494,d.dmQ

This rather dull fact sheet lays out the case for and against the radiant barrier in different climates, with savings estimates for several starting points. In short it finds that even in warm climates radiant barriers are not always the cost effective solution. Cold weather climates really offer little opportunity for savings.

Have you ever been approached by a salesperson for this technology? What was your reaction to the pitch? Leave me a comment below.

Thursday, March 7, 2013

Architectural appeal IS an important part of building science.

Our buildings should please us. Sometimes they should inspire, sometimes calm; but if we don't care about them we won't care for them.
Have you ever lived in a building that you loved to arrive at? A place that made you proud to call home, that felt like it wanted you to be there?
I hope you live there now. If not, what do you think would get you to feel that way about the place you live now?
I need a good garden space, some wildlife in my yard and a good window to see the yard from while I'm having my morning cup (on days it's too chilly to have it outside). My inside list includes a workable kitchen space, a place to read and good daylight. My neighbors figure into the equation too, but that is getting a little away from the buildings aspect. Or is it?

What would your list look like? Is the focus inside or out? Leave a comment, I'd love to hear what you think.

Monday, June 13, 2011

Doug George remembered

I tested one of the tightest houses I have ever encountered the other day. I haven't run all the parameters such as CFM/surface area or the much less desirable ACH, but my raw numbers for a 2000 sq ft walk out basement ranch WITH a garage under (not part of the 2K) was 345 CFM/50.

Must be a SIP job or more likely spray foam right? Sorry, the framed walls are insulated with fiberglass batts, the below grade walls with rigid foam and the attic with cellulose. Oh, and it was built in 1995, at a price comparable to "standard" construction of the day.

The builder was the late Doug George. I didn't know him but those who did heap praise on him both as a builder and as a human being. I do know that the man knew how to detail a building enclosure.

Every framing junction is sealed with caulk or foam. The Tenoarm air barrier is taped at all seams and to all adjacent materials. I have seen a few pictures of the building in progress and I couldn't see any faults. Most of the air leakage seemed to be coming through the wood stove and the fresh air intakes. I am humbled and impressed.

This has reminded me that what really matters in creating quality buildings is a customer who understands that there is more available than the tract house standard and a builder who understands how and why to deliver it. I think that I'm coming back around to the education theme again, don't you?

The next newsletter will cover this in more detail along with some thoughts on why every builder will not be able to follow this path and what the alternatives are.

In the mean time I would suggest that you hoist your favorite beverage in honor of Mr. George whether you knew him or not. Those of us who didn't obviously are the poorer for it.

Friday, September 24, 2010

Woods and walls

One of the interesting aspects of the human mind is how it can draw parallels between seemingly unrelated subjects. It happened to me this morning while reading a blog post about biomass and its place in our energy future.
A concern raised by one poster, and a concern I share, is the potential over harvesting of our wood resources by companies more concerned about supplying their boilers than sustaining the resource. 
My short take on this is that the answer is to apply strict management to the resource or leave it alone.The leave it alone approach, no harvesting at all, is unrealistic. Wood is too useful a resource to suddenly decide that we can forgo its use altogether. If we are going to harvest wood we need to apply resource management techniques that maximize yield while preserving the forest and all the environmental benefits it supplies.
A little management, maximizing yield only, leaves us with the situation with large clear cuts and the associated problems of air, soil and water quality problems. Strong management using sustainable harvesting techniques and using plans that address the specific site can result in a forest that can sustain wildlife, soil, water and air. So if we are going to take and use the resource we need to invest our time and energy to gt the details right.
I can apply that same management logic to the exterior walls in a building. For years we got away with minimal management of air and water movement in our outside walls. All we had to do was keep most of the water out and the uninsulated un-air-sealed walls survived just fine. The water that got in, and it did, dried quickly enough because there was enough energy flowing through the walls to evaporate and disperse the water.
Then we started asking these walls to do more. To hide the wires and pipes our increasingly technology based lives demanded. And we added insulation to keep us warmer and we asked for fewer drafts so we could wear light clothing in the winter. But we didn't do much to improve our management of the water. It still got into the walls, but now the energy flows available were greatly reduced so it stayed there longer.
Water is the great giver of life. All life forms that we know about need it. Unfortunately the life forms that tend to grow in warm dark damp places like the inside of walls are know by names like mold and rot.
A quick aside if I may, there is no such thing as dry rot. You just didn't see it when it was wet.
Back to topic: If we are going to continue to extract all these services from our walls we need to more vigorously manage the water. Exterior drainage planes and properly installed windows and doors on the outside are a good start. Exterior insulation to control condensation on the inside of the wall is a great idea too.
Inside the walls we need to use materials that reduce air movement and are moisture tolerant. We need to make sure our interior wall surfaces minimize air movement yet still allow for drying (If we are going with the drainage plane/exterior insulation). Pay attention to ventilation to control humidity and be vigilant about controlling bulk water. If we do these things we can have walls that provide the services we want and that will last a long time.
So whether it's forests or walls, if we want them to serve us we need to be willing to devote the effort to manage and maintain them. It's only fair.

Wednesday, August 25, 2010

Dot Edie Ewe

I harp on this subject constantly so I thought it rated a blog post. The most important thing we deliver to our customers and clients is education.
We should be delivering the specific tasks we are asked for, whether analysis of building flaws, recommendations for new equipment or building shell improvements. That is what we were hired to do. But unless we leave them with a broader understanding of the hows and whys have we accomplished anything?
There are and always will be clients who want only specific answers to specific questions. I guess they are good for business because they will pay you over and over to answer the same questions on different projects. I have a hard time enjoying that kind of work, there is very little challenge.
Answering the same question for different clients can be interesting because it is an opportunity to teach the answer, not just supply it. The client may not need you to answer that same question anymore but when other questions need answering your name should come up.
That is an opportunity for you to learn something else to educate on. And to then create a more interesting client who will ask more interesting questions which will require you to learn something... It's almost like perpetual motion. Hmm, I wonder if I can attach a drive shaft to that.
Ultimately a client who you have educated is a client who will respect you. It is also a client who will advertise for you, which is not a bad thing either.

Monday, August 9, 2010

More on Infrared

In my latest newsletter (check my website for newsletter archives) I talked a bit about interpreting infrared images. It got me thinking about the state of the technology and where it fits into building science.
When I took my course for my level 1 thermographer certification  I was impressed by the technical knowledge and skill of the instructors on all things IR. But in the section where they talked about building investigations there were a few things they said that made me realize that they were a bit weak in some building science details.
The current state of IR usage in buildings is still on the cusp as to who is using it. For years it was like the early days of computers. The tasks were performed by computer people, not people who were the experts in the task. As desk top computers proliferated and became increasingly easy to use the focus shifted back to having task experts use computers to do the job. It became easier to teach the use of the computer than to teach the task to a computer expert.
My only concern is that there are people who are learning building science only through use of infrared technology. I hope that they will come to understand that all they are seeing with the IR are clues, not facts. They still need to have a good solid understanding of what can be happening to figure out what is happening.
As always, other voices are welcome.

Thursday, June 3, 2010

Avoiding the "savings" trap

The main reason people give for not pursuing building energy improvements is "poor payback". Unfortunately those of us who have been using cost savings as the sole or primary justification for recommending measures are directly to blame for this. We have set up the expectation that all energy saving improvements will "pay for themselves in just a couple of years".

When this payback period stretches beyond 2 - 3 years businesses tend to lose interest. Homeowners pass if paybacks exceed 5 years, or less if they anticipate moving. So what can we do? How about ignoring payback altogether?

Let's ask this, are buildings created with a specific payback period in mind? Usually that answer is no. Buildings are built to serve a function or set of functions that range from creating shelter from the elements to massaging the owners ego. Are there reasons within that range that we can bring in to the retrofit proposition that can trump payback? I think the answer is yes, the challenge is shifting the conversation.

Comfort is a reliable sales point. Most of my residential work is still focused on comfort issues. How do we bring in other issues such as indoor air quality and building durability? Obviously if there are glaring defects in those areas owners will be on board. But how do we bring those in proactively?

Anybody willing to chime in? I presume that since this is a new venture it will take a bit to get going, but be brave and jump in. I hope we can share thoughts. and solutions.

Wednesday, May 26, 2010

Let's get started

I am experimenting with a blog as a supplement to my newsletter. I expect that I will be posting a few times a month, give or take.

My hope is that this will be a little more interactive, allowing my readers to reply to me and to each other.

Let's have some fun and share a little knowledge. Knowledge is the one true all purpose tool.