Which Furnace Filter is right for you? Are washable filters the most environmentally consious choice?

You may ask yourself, do I have the technical know how to determine what is best for my HVAC system?  The answer is a definite yes, it is not difficult, but will take a little bit of reading to understand how the system works.

Why you should care

Forced air HVAC systems require a cartridge “media” style furnace filter for my furnace.  We know what they look like.  The packaging usually says “16x25x1 or 20x25x1.”  When you go to the big box store, there are so many furnace filter types and it is easy to get little overwhelmed from what seems should be a really simple choice.  To complicate matters, HVAC experts can’t agree on what is the best method of filtration as there is a wide difference of opinion.  I think this is attributed to the fact that a “one size fits all” solution does not really exist.  Who cares honestly? Well you should, the type of filter can affect the life of your furnace, your health, and the energy efficiency of your system as a whole.  It is possible that your 95% efficient furnace with a variable speed ECM motor can consume the same amount of natural gas as a 92% furnace because of poor airflow or using the wrong filter.  It’s a bold statement.   More often than not, the most expensive disposable filters are not necessarily the best choice for the average homeowner’s furnace.   The analogy I would use is filling your car with 92 octane gasoline, when the car manufacture specifies 87 in the owners manual.  Despite that many people feel 92 octane is cleaner and therefore better for their car is a misconception which is still debated to this day the same as furnace filter quality.

Who is going to cough first from poor air quality, you or your HVAC system components?

Indoor air quality needs for a person is not necessarily the same as the HVAC system component needs.  Those two different needs are far too often blurred as the same requirement.  Furnace components are expensive to replace.   They can and sometimes do fail prematurely by getting dust trapped in the blower, heat exchanger or air-conditioning coils.  This is especially the case with ECM variable speed motors in 95% efficient furnaces, as they are prone to failure if it is running at full speed for weeks at a time.  This is far longer than a variable speed is designed to run. You can be surely kicking yourself for not spending only a little bit of time once in your life to learn about filters and $5 t every three months on the proper filter for your system, so listen good.

At first, I found it hard to find good information because there are a lot of useless marketing out there about your HVAC systems requirements.  It is easy to get confused from what should be a simple choice to buy their product.  As mentioned before, the requirement for a furnace/air-conditioning  filter to function properly is not necessarily the same as the requirements that a human has to feel comfortable.  What I mean by this, is your filter can be doing it’s job properly, but you may be sneezing from pet dander.  Obviously in that scenario, you don’t have a good enough filter.  Or in a different scenario, possibly your furnace model can be sensitive to particulate matter and running too often with high static pressure, and you are a rough and tough human being affected by the extra particulate matter in the air, and you don’t feel the difference.  Just know that your requirements are not necessary the same as the furnace’s.

Pressure Treaded Decks. Repair or Replace?

Here is a hypothetical scenario (that I ran into last month)   Take a guess on which options are more environmentally friendly.  This is not as easy as you think.

You have an old patio deck that is 10-15 years old made of pressure treated wood.  The stain is almost completely gone, and the wood has splintered in many areas and in rough shape. You think the deck is at the end of life, but you are not sure.

 

Here are your options for the plan of action.

  1. Replace the deck with a more environmentally friendly product that uses 75% post-consumer waste as the main decking material.
  2. Stain the deck again, by pressure washing or sanding the old stain off, and make small repairs where needed to try and extend the life.

There are other options of course, but lets stick with these two for the time being.

The answer is…

It depends, but probably #1,

but most likely not for the reason you think!

The reason why #1 is probably a better choice is because prior to 2004, pressure treated wood was “treated” using chromium and arsenic.  The wood is called Chromated Copper Aresenate (CCA) pressure treated.  Yep, companies actually put carcinogens in our decks if you can believe it, until it was banned in residential use in Canada and the US.  Side note: it is still used in telephone/hydro poles today in new installations.  Today, the residential sector mostly uses Alkaline Copper Quaternary (ACQ) or less common  Copper Azole pressure treated, which is far less carciogenic, but also has it’s caveats which I will not discuss in this article.  Its also the stuff that’s now available at the big box stores.   You may have read about CCA  in the news about ten years ago about this stuff being used in playground equipment in public schools.  Ring a bell?  There is a website devoted to this stuff noccawood.ca though slightly out of date, it still has good articles.

My first gut feeling for this answer is to prolong the life of the deck, to reduce the amount of waste that ends up in the landfills by staining the deck.   Of course that deck will eventually be land-filled, but you are consuming less by protecting what you have now.  It’s like buying a new car ever three years when a lease expires.  Granted, someone else does use that car after three years, but no one will use your deck after you throw it out to the landfill.

The environmental issue here is, to properly stain a deck, you need to pressure wash it (or sand it).  If someone came in to pressure wash that deck, some of the chemicals are still encapsulated in the wood, but not nearly as much as when it was new.  The pressure washing could scatter some of those chemicals out of the wood.  The amount is not much, but I still would never recommend doing that.  Contained environmentally friendly items are always safer than uncontained.  Also, the soil directly under the deck is the area that will have the most chemicals in it.  When the deck is eventually removed, it must be done so with great caution, and the deck itself has no possible second use, and it’s life cycle ends.  It must go to the dump as the chromium and arsenic cannot be extracted from the wood, and cannot be buried or burned.

This is a similar concept as Green Houses Gases (GHG) in that carbon dioxide is trapped or stored in vegetation, and is released into the air when burned.  The pressure treated deck stores in the carcinogenic chromium and arsenic, it is safer to have it trapped in the wood, than all over your lawn.  Most likely you will have the highest rating in the soil within two feet beside of an installed CCA pressure treated deck (or under it).   If you had this done in the past don’t freak out, if you had a good installer, they may have been extra careful, and you are probably fine.  If you are skeptical, get the soil tested.  You could use an environmental testing company.

I guarantee you that not every decking company will take great caution when repairing or removing.  Make sure they don’t use their saws to remove the old wood spewing sawdust in the air with this stuff.  When you hire that deck company ask them what their removal procedures are, and keep in mind that the soil underneath the deck is probably contaminated.  Do your research.

Buildingology lessons learned

It doesn’t matter that scenario #1 has the recycled content, it is not nearly as important as the handling and disposal of the old deck from an environmental standpoint in this particular scenario.  This of course is a tad oversimplified, but it is important to know that performing the most environmentally friendly action in home renovations does not always carry labels or bragging rights with it (if that is important to you).

Here is a new question… If you get a new deck, is option #1 or new style ACQ pressure treated more environmentally friendly?  The answer is as always “it depends”.

Home Improvement Blog With A Taste Of Environmental Conscience. It Tastes Good.

Type of home improvement →  long term mindset

This blog is to educate homeowners on all matters regarding how their building works.

I also want to focus on methods of fixing your house that has an environmentally conscious element to it.    This is not exclusively the type of green where when you buy a product that advertises “green” or “eco” on the label, and where the homeowner gets satisfied that they did the right thing.  Don’t get me wrong, it’s good to have that satisfaction, but it is even better to know that the process of your home repair is well thought out, that you are trying to do the best you can.  It is far more important that you are taking into account the long term effects of you current home improvement choice, than just basing your design on picking that “green” product.