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Dealing with Earthquakes

Will a Radiant Barrier Help My Home’s Air Quality?

Radiant barriers have been a “hot” topic for the last few years: If to install them, where to install them, and how to install them.  Are they worth the work and cost?  It’s time well-spent to do some research before diving in with such a project.

Radiation is one of the three types of heat transfer, along with convection and conduction.  A radiant barrier is a material with a shiny surface that reflects radiant heat back outside the home.  If the barrier gets dusty or is installed incorrectly, however, it does not work well. 

According to Attainablehome.com (a builder’s website devoted to building of modern, sustainable, and high quality homes that is within reach of household incomes), properly installed radiant barriers can reduce heating costs in the hottest months in southern climates, if the home’s air conditioning system is located in the attic. It can also offer a degree of protection to that equipment when the barrier is installed over the equipment, “shielding” it. 

In colder climates, however, radiant barriers are not recommended for several reasons.

  • The savings in reflecting heat away from the home in summer is minimal.

  • Cold climates can allow moisture to condense behind the barrier, creating mold issues.  Perforated radiant barriers can reduce this problem, though.

What is “properly installed”?  Here is a good video showing installation of a radiant barrier over a garage.  Radiant barriers:

  • Need an air gap: don’t install the barrier sandwiched between existing insulation, as it can conduct heat into it.  For instance, do not install radiant barrier foam board (such as LP’s Techshield) and sprayfoam over it. (energyvanguard.com)

  • Need to be relatively clean: dust will reduce the effectiveness of the barrier, so installing on the attic floor is not recommended in most cases. 

  • Must be the right type for your home/climate. There are:

    • Perforated and non-perforated: Perforated barriers allow vapors to escape through the barrier, reducing the chance that moisture or mold will build up behind it.   If you live in a hot, humid climate and have a vented attic, a highly permeable barrier like “Super-Perf” from AtticFoil is recommended to allow moisture to pass through. 

    • Made with insulation or board attached to the radiant surface

  • Must not block air flow in the attic.  Most vented attics have soffit and ridge vents, so do not block the air flow between these two, or moisture issues may result.

In a 2010 article that still applies today, energy advisor Martin Holladay stated there are 5 factors that determine whether a radiant barrier is a good option for your home (discussed in this video):

  • Do you live in a hot climate?  Yes = consider radiant barrier.

  • Do you live in a humid climate?  Yes = the radiant barrier must be carefully and correctly installed so that moisture problems are not created.

  • Do you have a one-story home?  One story homes tend to have larger roofs to cover the livable square feet, so a radiant barrier in a one-story home will be more effective than a two-story home of comparable square feet.

  • Do you have air ducts in your attic?  Yes = consider radiant barrier to shield them.

  • Is the air barrier installed correctly?  This is imperative, so the barrier has to be compatible with the insulation in your attic.

In times of low-cost energy, installing a radiant barrier may not be worth it. (energyvanguard.com)  For example, in Houston in 2011 (a hot climate in a year with similar kilowatt-hour (kwh) energy cost to today), a homeowner could save about 180 kwh per year with a radiant barrier installed on their 2000 sf newbuild home, considering that it is installed under the roof decking and the only additional cost was the more expensive barrier under the decking ($200).  This is about $25 per year savings, which would be an 8 year payback if there is no mortgage, or only about 50 cents per month if there is a mortgage (check the article for the explanation!)  It’s not a whole lot, but if energy prices go up (they will at some point), the savings could be more.

According to this video, LP Techshield (an OSB board with aluminum coating on one side) produced an 18 degree reduction in temperature in a doghouse.  Another video using the same product achieved an 8-10 degree reduction in a real house. 

So, how does all of this affect your air quality?  At HypoAir, we are in favor of not adding things that harm you or your home, so adding a radiant barrier to an existing home must be carefully considered.  Here are some steps to check whether it is right for you: 

  • If you have an unvented attic, a radiant barrier is likely not to benefit you.  If you have a vented attic, make sure the vents are not blocked and there is sufficient insulation in the walls/floors of the attic facing the conditioned space. 

  • Consider the current state of your attic and take temperature and humidity measurements in the attic and in the home as a “baseline”.  

  • If possible, you could conduct a small “experiment” in a part of your attic that faces the sun by installing one roll only (best if it shields some ductwork) and seeing how it affects attic and home temperature and humidity.  

  • If this test is favorable, continue with installation of the rest of the south- or west-facing sides.  Although I could not find much information about it, radiant heat is not very applicable on the north-or east-facing walls in the northern hemisphere. 

  • If humidity increases with the test spot under similar atmospheric conditions, it’s best to terminate the experiment and remove the barrier. 

Radiant barrier material is not very expensive, so if you can install it yourself, it can provide energy savings going forward.   It’s best to take your time and research the pros and cons of installing it in your home and not succumb to pressure from a salesperson, however.  Overall, it should not increase your energy use or humidity levels, so make sure to hold the manufacturer and/or installer to their claims.  We’d love to hear from you on how radiant barrier affects your home’s atmosphere!

Photo by Greg Rosenke on Unsplash

Dealing with Earthquakes

Dealing with Earthquakes

Just like many other controversial topics, there is conflicting evidence on whether earthquakes are increasing.  Some news sites say that there is no increase in earthquakes; it just seems that there is an increase because reporting methods have gotten better (usgs.gov).  However, a journal for the insurance industry reports that earthquakes are increasing in US oil regions.  This 2021 article “reveals that tremors of above the magnitude of 2 on the Richter scale quadrupled in 2020…The oil and gas industry is contributing to the increased seismic activity through its practice (of) the saltwater disposal through underground injection.”  Oklahoma, Texas, Louisiana and New Mexico were the areas studied, and more frequent and larger events continue to occur.  

California has hundreds of “fault” lines (a fracture or zone of fractures between two blocks of rock, which allow the blocks to move relative to each other) (usgs.gov), two of the most infamous being the San Andreas fault in southern California and the Hayward fault in the San Francisco bay area in northern California.  Here is a picture of what frequent earthquakes look like (source: earthquaketrack.com):

If you live in a zone where earthquakes are frequent, you’ll know that the effects of earthquakes are manifold (source: getuhoo.com). 

Dust:  “A case study was done in New Zealand following the 2010 earthquake that hit Canterbury, along with its aftershocks. The data from the study shows that PM10 particulate matter levels hit 140µg/m3 over a 24 hour period, which is well over the National Environmental Standards for Air Quality (NESAQ) threshold of 50 µg/m3. The amount of PM2.5 concentration also hit 127µg/m3 at this time, about 90% of the level of PM10.”

 “The vibrations and tremors hitting buildings and homes loosens up dust and drives them into the air. Tectonic shifts can disrupt sediment and expose them to the air where they linger as particulates for days or even longer. Even in homes the jolt can release dust that is normally packed away and bring them out into the open, underscoring the importance of keeping a clean home.”  

We agree; it’s important to have dust control measures in place before a small or large earthquake shakes things up!  Here are our top ways of controlling it:

  • Minimize carpet and fabric furniture if possible

  • Frequent vacuuming with a HEPA vacuum 

  • Use of a MERV 13 filter (if possible) in your furnace/HVAC

  • Use of a standalone HEPA filter in areas where you spend a lot of time (living room, bedroom)

  • Brush and bathe pets weekly if possible

  • Keep several MERV and HEPA filter changes, as well as N95 masks, on hand for use during emergencies.

Fire and water damage:  According to earthquakeauthority.com, the primary damage in an earthquake is caused by surface rupture and ground displacement, when the ruptured fault produces vertical or horizontal movement on either side of it.  However, liquefaction is another odd consequence that damages pipelines too: solid soil will change into a “liquid” during violent shaking, causing support systems to fall away.  When this happens, pipelines break and fires can start, spewing all kinds of chemicals into the air, ground and water.  In this severe case, you should have an evacuation plan if this kind of disaster affects your immediate neighborhood.  If you are experiencing these pollutants from several or miles away, shelter in your home if possible, and keep windows and doors closed with the HVAC on “recirculation” mode with minimal fresh air.  Here are some ways to mimimize the pollutants you’re breathing inside:

  • Use of a MERV 13 filter (if possible) in your furnace/HVAC

  • Use of a standalone HEPA filter in areas where you spend a lot of time (living room, bedroom)

  • Keep several MERV and HEPA filter changes, as well as N95 masks, on hand for use during emergencies.

  • For fresh air, you can use a Window Ventilation Filter to keep smoke, dust and pollution out of your home. 

  • Units like the Germ Defenders and Air Angels will help to mitigate harmful contaminants by converting them to larger particles that will fall to the floor. 

Landslides and Tsunamis: Landslides are the movement of rock, earth, or debris down a sloped section of land, and are caused by rain, earthquakes, volcanoes, or other factors that make the slope unstable.  (nationalgeographic.org).  Obviously, this type of earth movement will trigger a lot of dust and pollution released into the air as earth and buildings and infrastructure are demolished in the path of the landslide.  Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea. (noaa.gov)  The wave can cause catastrophic flooding upon hitting land, which brings building devastation and mold to the buildings that are not destroyed.   

There are “early warning systems” in major quake zones, however they can only provide warning to those outside of the epicenter (10 miles or more), and they only provide warnings of larger, more violent earthquakes. (caltech.edu).  

Preparedness is key.  In addition to the measures listed above, you can also prepare an evacuation kit in case you have to leave your home, which of course is useful in disasters other than earthquakes.  Judy.co is a company devoted to emergency kits that include water, food, power and tools so that families can survive for short periods following a disaster.  With advice from this page at ready.gov, you can build your own kit.  We sincerely hope that no one is injured or affected by such a disaster in their lifetime, but sadly in areas like northern California, this is not what experts predict will happen.  Earthquake risks can be high in the beauty of the South Pacific islands, the mountains of Mexico, and the plains of Oklahoma, so wherever you live, be aware and be prepared!

Photo by Dave Goudreau on Unsplash