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.

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!

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.

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.

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.

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.

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.