Wind, water and wood

The last few weeks in western Montana have been some of the wettest in history. If you have ever had a roof leak, mold problem, or flooded basement, then you probably already know that wood and water don’t always mix. Often in the process of making buildings more energy efficient, we have the opportunity to address issues related to water. This post is about how our integrated package of insulation, air sealing, and mechanical services often includes preventing liquid water and airborne moisture vapor from damaging your building.

No soffit vents, no gable vents, and a nice icicle collection- prime for issues.

No soffit vents, no gable vents, and a nice icicle collection- read on to learn more about potential issues.

(Re)Move the Moisture

Looking at an attic bid this afternoon, I immediately noticed there wasn’t any attic ventilation at all. The roof is the primary water management system for the house. As such, they are exposed to brutal temperature extremes, high winds, rain, snow, hail, and UV. To put it simply, the life of a roof is hard. Attic ventilation is designed to allow outdoor air to remove moisture from the attic space, as well as reduce the temperature difference across the roof sheathing (remember, they contribute to ice dams). Removing this moisture is important not just to protect the sheathing but also to prevent condensation in the insulation.

Attic insulation prevents conductive heat loss from the house to the air in the attic. The more insulation you add, the colder the attic air gets- great, unless there is moisture in that air. If there is, the warm air carries the moisture up and into contact with the cold roof sheathing where is condenses. Good ventilation will carry that moisture and condensation away before it turns into liquid water and before it causes problems. Generally, warm air leaks from the house up into the attic because hot air rises and traditionally attics aren’t air sealed. Even having a properly sealed attic won’t always prevent moisture from getting into the attic air so having good ventilation is essential for preventing long term problems. In general, you never want to have unconditioned, un-vented space. Attics can be vented with soffit vents, gable vents, ridge vents, or dedicated surface mount vents. We can coordinate with a roofer to ensure that any upgrade properly addresses both heat loss and proper ventilation.

attic ventilation moisture management

That’s NOT frost, that’s mold- thanks to an improperly vented attic.

Down and Dirty

Does your floor ever feel cold or damp in the winter? This is the problem:

dirt floor crawlspace, moisture problems

Dirt floors are notorious for letting moisture into a building.

Your crawlspace or basement is a common area for moisture to penetrate your home often bringing other pollutants like dust and radon. Similar to an attic, conventional construction lets outside air into the crawlspace to prevent moisture buildup. Unfortunately, that lets heat out in the winter and if you have air conditioning, it can promote moisture damage in the summer. We’ve done several crawlspace upgrades recently, and our clients have been pleased to find how low impact the improvement process is. For existing buildings, it’s usually easiest to add insulation and a vapor barrier; making the crawlspace just like another part of the living space. This also has the bonus of providing storage space for the occupants. Unlike an attic, it’s not always possible to determine where the moisture is coming from so the products and systems we use have to be more specialized.

crawlspace, insulation, vapor barrier

This is the solution. Call Energetechs for your crawlspace upgrade.

Dam Ice on the Roof?

One of the most common issues behind a roof leak is an ice dam. Ice dams can also be a good indicator of energy loss through your attic. Ice dams form when the roof sheathing is heated by the building below, melting any snow that has accumulated. The liquid water then drips to the edge of the roof which is cold so the water re-freezes. Through the winter, ice and water shrink and swell with repeated freezing and melting. This can buckle shingles and/or damage the roof sheathing underneath, causing water leakage that looks like a roof problem. Other factors like low slope roofs or roof valley intersections can also amplify these problems, but most of the time the key issue is in temperature differences in the roof sheathing and heat loss through the attic. Learn more about how we air-seal and insulate attics here. You can also check out a great article about ice damming, here.


Hybrid solar electric oven cooks whether there is sun or not
View Post



Hybrid solar electric oven cooks whether there is sun or not

View Post

Ice Inside?

by Skander Spies

Serious cold temperatures, like the ones hitting most of the country right now, have a habit of making buildings “speak up” to their owners about a range of insulation, air sealing, and heating issues. Every winter we get a number of calls from owners with two particular issues: they have ice building up on the inside of their windows, ice on their walls, and/or they have water dripping out of their recessed can lights (or damaging the drywall around the light fixture). This post talks about why you get window condensation and ice can form on the inside of your windows. Our next post will talk about why recessed can lights can cause moisture damage or start to drip water inside your building.

ice on interior of window, winter house problems, condensation damage, window condensationAll too common, ice on the inside of windows in the winter.

Window Condensation

Many people have seen condensation and ice form on the inside panes of their windows. While it is most common on single pane windows, it is still a common problem for double pane windows in cold climates. This problem is related to something called dew point which describes the temperature at which window condensation occurs due to the moisture content of the interior air. There are several factors that affect the dew point temperature, and when you will get condensation.

Low thermal performance - most windows, even double panes, simply let lots of heat out. My mother refuses to sit near the windows at restaurants in the winter, because they make her feel cold. In the winter, the temperature on the interior surface of the window drops, because the window doesn’t insulate against the cold outside air. How far does it drop? With a modern double pane window (usually about R-3, learn more about R-value here), if the outside temperature is 0F and the inside temperature is 70F, the inside of the window pane will usually be about 44F. Yes, that’s 44F inside your house, and is the dew point if your house is at 40% humidity (which is a typical “comfortable” level). The interior surface temperature will continue to drop with the outside temperature, making condensation more likely, even at lower humidity levels. To keep your windows condensation free in almost any climate, you’ll need a window with a thermal performance of R-5 or better.

Humidity - if you have a larger family, pets, or cook a lot, then you are generating quite a bit of moisture inside your house. As you add moisture to the interior environment, it becomes easier for moisture to condense on the cold surfaces we described above. The colder the surface, the more condensation you get. If the surface is cold enough, the condensing moisture will freeze and turn to ice. Keeping your interior humidity below 30% is a good target to start with, but is not guaranteed to stop all window condensation.  A heat recovery ventilator is one way to control this humidity level by removing excess indoor humidity (it also removes pollutants like pet hair and dirt, learn more here).

Air leakage - windows are a critical part of the “air barrier” of your building, meaning that they seal outside air away from the inside air (that you want to keep warm). If your windows are not installed properly, they will leak air, even if they do not open. Operable windows (like a crank open or slide open model), tend to leak even more air, especially as they age. Cold air leaking through the window opening or around the sash (the part of the window that moves) will further reduce the interior surface temperature, making it more likely to get condensation and ice on the inside of the window. Casement and awning (or hopper) style windows tend to provide better airsealing performance, while horizontal sliders, single hung, and double hung windows can leak severely.

This site has a quick calculator that shows the relationship between air temperature, humidity, and dew point temperature (the surface temperature that the interior glass needs to be above to avoid condensation).

This site has several charts that outline what conditions are likely to create condensation on windows.

window air leakage, window condensation
The blue streak, and greenish blob in this infrared camera image indicate air leakage around this window.

Potential Impacts

Getting ice on the interior of your window means that the interior surface temperature on the inside of the window is below 32F- bad news for your energy bill, but really bad news for being comfortable in your home. Window condensation or ice inside your windows can cause several problems:

  • Long term damage to the window unit: Moisture (either as ice or water) will cause wood windows to swell and shrink, warping the frames and occasionally calling glass to crack. This also increases air leakage problems.
  • Health issues: moisture from window condensation and ice can become a petri dish for mold and other lung & sinus irritants.
  • Comfort: condensation and cold surface temperatures are unpleasant to be around. What good is having a beautiful picture window if its it too uncomfortable to sit around? Your quality of life goes down when you cannot enjoy your home or office completely.
  • Energy costs: if your windows are cold and leaky, chances are you’ll be raising the thermostat to try to compensate for the problem, which is expensive and frustrating. Most heat distribution systems do target delivering heat near windows, but extreme temperatures will usually win out, leaving you with a big energy bill AND an uncomfortable home.

Contact Energetechs to learn more about how window replacement, heating improvements, and ventilation systems might be able to alleviate your window woes. Until then, stay tuned for our next installment on recessed can lights!

Happy Thanksgiving!

At Energetechs, our mission is to create buildings that enrich our environment, our community, and our quality of life. This season, we are exceedingly thankful to prove this mission on every working day.

We are thankful for our clients that share this mission.

We are thankful to be part of a community of people and organizations that also pursue this mission.

We are thankful for the people on our staff and make Energetechs a great place to work.

Thank you for reading this blog, and we wish you an abundant holiday season.

New Zola Slim Aluminum Windows

A few weeks ago we had a very important arrival in our office- two beautiful samples of the newest Zola window. Architects have long loved the elegance of a slim aluminum frame windows, and these windows have traditionally had terrible energy, air sealing, and sound performance. Called ThermoMulti3x and ThermoMultiAero, these new units bring a new level of comfort and energy performance to aluminum windows in residential and small commercial construction. This post explains why these aluminum windows are unique in the marketplace.


Clean looks are in and thicker European window frame styles have long struggled to gain market share in the United States. The ThermoMulti units are designed to fit a more modern architectural style. A few features:

  • 2-15/16” overall jamb thickness
  • Frames designed to allow exterior cladding to cover the frame
  • Sash frames are recessed into the exterior frame
  • Optional seamless welded aluminum corners
  • Optional fully concealed tilt and turn hinge hardware
  • Available in 16 standard exterior colors and up to 300 custom colors

The clean lines on the ThermoMulti aluminum windows are simple for designers to match and maximize the feeling of connection to the outdoors.


Energy savings is one of several aspects in which the Panoramic line offers exceptional performance. All aluminum framed and curtain wall windows typically offer a thermal performance of R-2 or R-3. They are prone to condensation (also called fogging), sound transmission, and air leakage from thermal stress. The Panoramic View windows offer superior performance in each of these categories:

  • Optional soundproofing to 47dB (this reduces outside sound transmission by up to 93%)
  • Three layers of airsealing gasket in every operable unit
  • R-11 glazing package is standard on all units
  • Whole window thermal performance of R-7.1 (ThermoMulti3x) and 8.1 (ThermoMultiAero)
  • Tunable solar heat gain coefficients from 0.28 to 0.63 (0.54 is standard)

This level of performance means that designers can pursue a clean modern look without worrying about condensation, comfort issues, or sacrificing design goals like Passive House.

Form Factor

To complement their clean profiles, the ThermoMulti line come in a wide variety of form factors. The ThermoMulti line are available in tilt & turn and fixed windows, as well as in lift & slide, tilt & slide, French style  and entry doors. They can also be mulled into multiple units to offer a high performance curtainwall style system for high performance commercial buildings. Zola has long offered expansive size options to provide maximum design flexibility, and the ThermoMulti line is no different. Fixed panes up to 8’x10’ and tilt & turn units up to 5’x5’ are common on the standard production line. Even larger sizes are available with custom engineering.

We are proud to offer a truly energy efficient all aluminum window. Schedule an appointment or email us to learn more about this unique product.

Once billed as the world’s first zero carbon, zero waste city in the desert environs of Abu Dhabi, Masdar hasn’t quite lived up to its original ambitions. But it has come fairly close. Initially launched in 2006, the government-backed project has gone through several phases. Two years ago we visited the first Masdar Institute buildings with their iconic terra-cotta facades and rooftop photovoltaic panels. Now new buildings are sprouting, including Siemens’ regional headquarters expected to achieved LEED Platinum and three pearls from the Estidama rating system.

Once billed as the world’s first zero carbon, zero waste city in the desert environs of Abu Dhabi, Masdar hasn’t quite lived up to its original ambitions. But it has come fairly close. Initially launched in 2006, the government-backed project has gone through several phases. Two years ago we visited the first Masdar Institute buildings with their iconic terra-cotta facades and rooftop photovoltaic panels. Now new buildings are sprouting, including Siemens’ regional headquarters expected to achieved LEED Platinum and three pearls from the Estidama rating system.

Way to go OIT!

November 5, 2013

Sustainability at Oregon Institute of Technology

In addition to having one of the top engineering programs in the country, the Oregon Institute of Technology is a shining example of eco-friendly sustainability and renewable energy use. OIT introduced the very first Bachelor of Science program in Renewable Energy Systems. Their renowned Geo-Heat Center also serves as a national hub for geothermal information and development. Oregon’s elected leaders also chose OIT to be home to the Oregon Renewable Energy Center.

OIT is located within the city of Klamath Falls, Oregon. The city itself is known for its proximity to natural geothermal springs which it currently uses to provide geothermal heat to homes, schools, commercial buildings, municipal government buildings, process heat for the wastewater treatment plant, and for snowmelt systems for sidewalks and roads. Nestled in the Klamath Basin on the eastern slopes of the Cascade Mountains, Klamath Falls is surrounded by stunning natural beauty; certainly an inspiring setting for creating an environmentally-conscientious culture.    

 Sustainability at Oregon Institute of Technology

Solar Photovoltaic Panel Array

Klamath Falls calls itself, “Oregon’s City of Sunshine.” Generally, the sun shines there 300 days out of the year. OIT wants to power itself entirely using clean renewable energy. To help achieve this goal, OIT is installing a 2.0 MW solar array. The 7,800 solar panels optimally placed on nine acres of hillside will generate enough electricity to power approximately 35% of the campus. The solar array at OIT will be equivalent to 225,150 gallons of gasoline saved.

OIT claims that when used in conjunction with the soon-to-be completed 1.75 MW geothermal power plant, the campus should be able to generate most, if not all, of the electrical power it needs.

Sustainability at Oregon Institute of Technology

Furnace Replacement Season

by Skander Spies

Here at Energetechs we’ve pulled up our gardens and found our hats and gloves for biking to work. Autumn sends all kinds of signals, and chances are that one of them is coming from your furnace. Thinking about winter, many of our clients start asking questions about insulation or air sealing to keep their homes warm and comfortable. While these are great questions to ask, a furnace replacement is often the most effective first step to reduce utility bills, while increasing comfort and air quality. This post is about 3 reasons why replacing your furnace is one of the most important home investments you can make.

Reason #1: Safety

We’ve all heard that heat rises. Most furnaces built and installed before the mid 1990’s relied on this fact to operate properly. These furnaces use some of the heat from burning natural gas to lift exhaust fumes up the furnace flue and out of the living space. This type of furnace is called “atmospherically combusted” and it means that your furnace is open to your living space. This also means that your furnace sucks warm air out of your house, increasing your heating bill and causing uncomfortable drafts. They also usually require “make up air”- which is a fancy name for a big duct in your house that dumps cold air from the outside directly into the furnace room. When your furnace is open to your living space, you can run the risk of “back drafting” meaning that not all the exhaust leaves the house, putting you and your family at risk of carbon monoxide poisoning and other issues. You can read more about back drafting here, and from the US Department of Energy.

Starting in the late 1990’s “sealed combustion” furnaces started becoming popular and affordable. These units have sealed pipes that keep the exhaust gas away from your living space. This single difference means your gas bill gets about 15% smaller, your house will feel less drafty, and you don’t run the risk of exhaust gas poisoning.

Reason #2: Comfort

As we discussed above, older furnace suck warm air out of buildings. This can cause uncomfortable drafts throughout your home as the furnace sucks in cold air from the outside. There are several other advantages associated with newer furnaces:

  • A new furnace can be sized properly. Most older furnaces are too big for the houses they serve, meaning they turn on and off again, making noise and blowing air around. A furnace that has been sized for your home will turn on and off fewer times per day, which reduces noise and increases the lifespan of the furnace. When you talk with a contractor about replacing your furnace, insist that they perform a “load calculation” which will determine how big your furnace needs to be in order to heat your home.
  • A new sealed combustion furance will have a quieter fan and (probably) multiple stages of operation- meaning your house won’t sound like a jet engine when the furnace kicks on.
  • Older furnaces can be harder to maintain, and in our experience that usually means that they are maintained poorly, if at all. Having your furnace fail in the middle of January is no fun, yet many older furnaces do. If you have an older furnace, make a plan to replace it, so you aren’t grasping at straws when the snow starts to fly.

Reason #3: Air Quality

Your furnace is one of the most important parts of maintaining healthy air quality in your home. When your furnace pulls in air from your living space to heat it, it draws in airborne dirt, pet hair, and other pollutants which can be filtered out. Older furnaces tend to have 1” filters that offer limited air filtration. We insist on using premium quality MERV13 filters on every project because we insist on healthy air quality for you and your family. It’s easy to upgrade your filter as part of a furnace replacement, and your lungs will thank you when you do.

Your family deserves a better filter!

Tags: net zero