Monday, February 20, 2012

Indoor Air Quality: A Global Perspective

As our month long “Breathe GREEN & Easy” educational campaign about indoor air quality progresses, we thought it might be interesting to put a global perspective on the issue.

According to the World Health Organization (WHO), nearly 2 million people (mostly women and children) die each year as a consequence of household air pollution levels that are typically 100 times greater than the WHO air quality guidelines. This stems from the fact that nearly half the world’s population cooks with solid fuels on poorly functioning stoves or open fires, primarily using wood or other biomass. (I don’t know about you, but I was pretty shocked to discover the number was still that high.)

Efforts to improve these conditions include creating and testing improved clean cookstoves, switching to higher-quality, lower emission fuels and improved household ventilation.

Most of us can count ourselves lucky that just by the chance of our birth country, we are not subject to such an extreme (and devastating) example of what poor indoor air quality can do. BUT, we are NOT immune from this issue.

If we look at the measures outlined to address this global issue – clean cookstoves, lower emission fuels, better ventilation – we find these measures are thematically similar and applicable to combating our ever day indoor air quality issues, even though they stem from different root causes. And, poor indoor air quality doesn’t care about geography – it equally has the potential to be fatal in our own homes, not just those in developing countries.

How do we see these similar issues in homes we perform energy audits on? First is overall poor ventilation. This is generally caused by the fact that homes are built or kept too ‘tight.’ We educate our clients to think of their home as a living thing, and it, too, needs good air (in and out) to ‘breathe’ properly. This is part of the ‘whole house’ approach advocated by the Department of Energy that all of our energy consultants are trained on. If your indoor air is just generally not great, you’re likely having headaches, allergy symptoms, prolonged coughs and colds, etc. While these have the potential to become serious over time, they usually initially manifest as annoyances.

The second major way we encounter these issues is by uncovering back drafting, where essentially the harmful byproducts of one system are being pulled back into the air flow of the home. This is the scenario where the threat to health and safety can be imminent. We’ve literally been brought into homes just in the knick of time to identify and recommend remedial action for such circumstances.

So why are “The Energy Experts” spending so much time on indoor air quality? Many people don’t initially draw the correlation between a home energy audit and indoor air quality – that’s why we’re out raising awareness. Because we examine all the systems, how those systems interact with each other and how all the systems interact with the building envelope, we are essentially testing air flow. We test air flow to see if too much, or too little, is moving in and out – and we can often identify problematic instances of indoor air exchange. You might also find our whitepaper on Space Heaters, the Stack Effect and Back Drafting very helpful in further illustrating this (especially for those in the colder regions right now).

We hope you participate in our month long Breathe GREEN & Easy campaign, in whatever way you see fit – make improvements at home for the safety and well-being of your family, pass the information along to a friend, or tell us a story on our Facebook page for a chance to win a $250 gift card. We hope to use the power of the internet to really bring this topic to the forefront, and potentially save a harmful situation from even happening.

Tuesday, February 14, 2012

Love Is In The Air! Along With Various Other Pollutants...

Ah, February 14th, Valentine's Day: Love is in the air! But that's not all: the indoor air of most homes is two to five times more polluted than the outdoor air! Here's a breakdown of typical pollutants found in a home: EPA: Learn About Indoor Air Pollutants. So how do you improve the air you breathe?

Obviously, removing the sources (or reducing them as much as possible) is your best bet. Several people buy products to help "clean" the air, like filters for your furnace and air purifiers. Filters will help, especially if they are replaced on a regular basis. However, a higher "MERV" rating is not always better! A MERV rating of around 8 seems sufficient for most homes, while a MERV 13 is appropriate for those suffering from asthma or allergies. The latter is also considered almost as effective as a HEPA filter, and those with a higher rating will significantly reduce air flow to your duct system without much difference in the particles they are able to filter out.

Air purifiers are not meant to completely rid your air of all particles or pollutants. However, they can be helpful if you've taken steps to reduce the pollution in your home's air and still aren't as comfortable as you like. Wikipedia has a great article about Air Purifiers that we would suggest reading if this is something you are considering.

Did you know plants can clean your air? Not only do they tend to remove some harmful pollutants that can frequently be found in homes, but they also add fresh oxygen! Be careful though- too many plants or watering them too frequently can increase the moisture and humidity in your home, which can have adverse affects on your home's air.

The biggest thing we recommend in improving your air quality (and what we know the most about!) is monitoring and/or improving building ventilation and air flow. It is actually important for your house to be a little leaky! It encourages a small but important exchange of indoor and outdoor air, which can disperse the pollutants that can otherwise concentrate within the walls of your home. I know- you're thinking "But what about energy efficiency?!" If you've ever had a professional energy audit done, the technician probably used a blower door. This tool measures the amount of air that is "exchanged" between the walls of your home (it is actually called the air exchange rate). This helps us make improvement recommendations to maximize your energy savings without making your home too tight and risking a higher concentration of indoor pollutants! Besides "infiltration," natural ventilation (open doors and windows) and mechanical ventilation (exhaust fans) are also important aspects to lowering the concentration of pollutants in your home.

Learn more about Indoor Air Quality.

Friday, February 3, 2012

Breathe GREEN & Easy: How Humidity Affects Your Indoor Air Quality

Many homes in the northern parts of the United States during the winter will have either too much humidity or too little.  A home should range between 30 -50% relative humidity, and if you're not sure where your home stands, a gauge can be purchased for as little as $5 or as expensive as $50.

Too much indoor humidity is typically caused by a lack of outside air: the home is very "tight," which tends to be an issue with newer homes.  Signs of this are:
  •     Condensation on glass
  •     Condensation on window frames, which could damage and lead to mold growth
  •     Mold growth on walls in closets and exterior walls (in severe cases)
To solve this issue, outside air must be introduced into the home to “dry” the home. There are various ways to do this, and as typical with any home improvement, they range greatly in price. Inexpensive ways of lowering humidity are to just open windows or utilize exhaust fans in your kitchen or bathroom more often. A more costly solution would be to install a whole house ventilation system, which will filter and temper the outside air prior to introducing it to the home. The key is to identify the ventilation rate of the home first to truly solve this problem, which is why blower doors are used in professional energy audits.

Conversely, many older homes suffer from too little humidity, causing static, dry skin, comfort issues and wood shrinkage.  Adding a central humidifier may or may not solve this, and is truly just addressing the symptom instead of the problem. The reason for low humidity is the leakage rate of the home; it is too leaky.  Air sealing these homes will reduce the leakage rate and the dry, cold air from entering the home, resulting in greater indoor air quality and overall comfort!

Are you experiencing symptoms of high or low humidity in your home? Share them with us on our Facebook Page, and you could win $250!!