How Should You Insulate Your Attic?

One of the hottest topics in energy efficiency and building science is “how should you insulate your attic?” Why? Simply put, the attic has more impact on your efficiency and comfort than any other single part of your home!

Let’s summarize why the attic is so important:

  1. The attic is the hottest part of the house in the summer and is cold in the winter
  2. Hot air rises up to the attic / cold falls drops into the living space
  3. Moisture rises and accumulates in the attic
  4. Central heating/AC systems and ductwork are often in the attic

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Heating Systems 101 – Learning the Lingo

She Blinded Me With Science!

One of the toughest things about researching a new heating system is learning the tech talk. Your HVAC company will throw out all sorts of terminology assuming that you understand what they’re talking about. Some might even be happy that you *don’t* understand so they can confuse you and sound like experts. Well, no more!

This post covers the most common terms that you’re likely to run across. I’m sure I’ll miss some or confuse you, so please post questions if there’s anything you’d like clarified.

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How to Install House Wrap around a Window

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Proper flashing detail around a window

Proper flashing detail around a window

When I head out around the countryside, I am frequently dismayed by all the examples of improper construction techniques. “There’s another house that’s going to rot out in a few years” I think to myself.

So, when I saw this new construction, I did a double-take. Did the contractor actually properly install the house-wrap (Typar or Tyvek) around the window? Amazing!

Let’s look at what they did right:

  1. They used Typar house wrap which is generally a better product than Tyvek. But installed correctly, each can do a fine job
  2. They installed the house wrap horizontally in long, continuous segments. This reduces the number of seams, which are potential failure points.
  3. They used the Typar tape for the seams. This is a little detail that is often missed. The house wrap is slippery material and using the wrong tape on the seams can lead to failure. Only the factory approved brand should be used whether it be Tyvek or Typar.
  4. *IMPORTANT* They sliced the wrap above the window and installed the top piece over the window’s nailing flange. This directs water properly. 90% of the installations are done without this detail which leads to water getting under the nailing flange!
  5. *IMPORTANT* They taped the wrap under the nailing flange and over the bottom sill. Again, this is critical for proper drainage. If water gets behind the window, it drips onto water-impervious Grace Vycor then drains out at the bottom flange. Most installers tape the bottom flange to the house wrap which traps water inside the wall.

So kudos to the builder. This home is much less likely to rot out than 90% of the other new constructions!

Generators

While it’s too late for this storm (we’re currently awaiting the full force of hurricane Sandy), I thought the current conditions were appropriate for a post on generators while waiting for trees to fall on the power lines and send our house into darkness…

If you’re thinking about getting a generator, you’ve got some big decisions to make. Let’s start by keeping this simple, then later I’ll review the technical details.

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Insulating Basement Crawl Spaces

Spray foam on crawlspace walls

Crawlspaces – those nasty, damp, moldy spaces under your home that you dread entering. They’re one of the least understood parts of a home and the source of countless problems. In this post, I’ll review some of the worst problems and how to avoid them.

Crawlspaces often have two big issues:

  1. Water / moisture – leading to mold and wood rot
  2. Cold / drafty – leading to uncomfortable conditions and wasted energy

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How NOT to insulate your house

Sometimes insulation hides bigger problems.

The other day, I was talking with a friend of mine – an energy auditor who was a builder for decades. The topic came around to bad advice that “experts” give about insulating. It’s something that we both feel passionate about because homes get ruined and people get sick when innocent people follow this bad advice. We both adhere to a similar do no harm philosophy of  “if it’s worked for decades as-is, don’t mess it up!”

There’s a science to building and the tighter and more energy efficient you make a home, the more important it is that you do things “right.” It’s like the difference between making a log raft and a submarine. A log raft is leaky, but it’s forgiving because it floats by virtue of the logs. It doesn’t have to be water-tight. A submarine had better be water tight and structurally sound or you’re going to drown and get crushed by the intense pressures of the ocean.

Unfortunately, unlike boats and submarines, homes today are often built in the cheapest way possible, with little regard to physics. Renovations are even worse because people often hire unqualified “low-bid” contractors to do the work without realizing that the few thousand dollars that they save on construction may cost them tens of thousands to fix or even send them to the hospital due to mold or poor indoor air quality.

The problem is, people familiar with building science are extremely rare, as are the chances of finding a builder who knows how to make a healthy, energy efficient home. That’s why you’re here reading this now – you want to learn what not to do when insulating and how to do it right.

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Do you wonder why your house gets dusty so fast?

Do you have something like this in your attic?

Do you feel like your house is always dusty, in spite of how much you vacuum and clean? Have you tried all the tricks – HEPA vacuum cleaners, air cleaners, taking your shoes off before coming in the house, washing the dog…. all to no avail?

Chances are good that you’re being plagued by a leaky duct and air handling system.

When you have leaks in your ducts (virtually all duct are leaky) dust from the attic gets sucked into the ducts and distributed throughout the house. Even if you have an excellent filtration system on your air handler, the dust can be sucked in from places that don’t get filtered, and blown into your home, usually leaving fine gray dust everywhere.

Before you call in a heating/cooling (HVAC) contractor, there are a few steps that you can take yourself.

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