Lets Keep Airborne Contaminants from Entering Our Homes

[under review] We are specifically dealing with contaminants carried into the house by wind or on our persons. These are dust particles, pollen, or particulates from combustion or environmental pollution in the neighborhood or from where we work.

We are going to cover most entry points- feel free if you feel we miss one- and offer suggestions. The steps towards solutions here will range from structural and mechanical issues to personal practices. Our behaviors impact how allergens affect us. There is a continuum of action steps we can take from the relatively easy to quite involved.  Your own journey along this continuum will be chosen by you as you determine the level of pollution you feel is in your community and your family members’ sensitivity and vulnerability to these pollutants.

Lets look at the how airborne pollutants enter our homes

First off how big an issue do you have with pollution and contaminants in your community? Are you in an area  of dust generation? We know we have a big issue with pollen in North Texas. Each pollen has it season and we as individuals are at the mercy of the severity of the pollen season.

[stextbox id=”info” caption=”Dealing with pollen has wider aspects than our narrow approach in this page.” bwidth=”2″]Pollen can be lumped in as a contaminant that blows in but pollen issues are much broader and can be much more intense that our fight here which is protecting the inside air from airborne contaminants like pollen. We talk about pollen issues specifically here-[/stextbox]

Do you live by a busy expressway or major thoroughfare with lots of diesel trucks going by? Do you live by a fracking well in North Texas. Lots of dust and detritus coming up from those. These are forms of particulate pollution. Particulates from diesel combustion are a serious source of childhood asthma. And then you also have a personal idea of how clean you want your air.

OK, Lets proceed with the issues that impact how contaminants get into your home from the outside.

Contaminants sneak in through the walls and roof and attic

Actually, attics are a big contributor.

Lets define, for our convenience here- particulates, pollen, dust and all airborne things we do not want in the house as stuff.

Wind blows stuff into attics. Wind swirling around attic vents deposits stuff. Chimney flashings are not airtight to the outdoors- in fact, gaps are covered by flashing metal which sheds water onto base flashing materials of your roof type. Stuff can swirl around chimneys and float into the attic. Sloped roofing ,materials shed water but are neither water tight or air tight. Roof flashings, roof vents, ventilation ports all provide stuff entry points.  Wood decks have gaps in Plywood and OSB boards. Structural wood joints have cracks.

Air goes in and out and stuff just goes in. The stuff stays because the energetic air currents outside keep stuff suspended in flight while the much calmer air currents in the attic allow stuff to relax and sit.

Stuff collects in attics over the years. And then some insulations add dust too.
So we have all this dust in the attic- how does it get inside and on the coffee table?

First suspect to deal with is your cooling and heating system.

Chances are that you have an air handler in your attic and ducts in the attic. Your cold air return ducts are likely leaking- letting attic stuff get sucked up into the sucking side of the air handler- the return ducting in the attic. And your filtration system is missing the dust.

We need to look at the filtration side. Lots of problems are found here by HERS raters and HVAC technicians who are looking. Are the filters bent or ill fitting or damaged? If the filters do not fit, air can bypass the filter. The filtration system must be airlight except for the air passing through the filtration media. -PHOTOS –

Air is bypassing the filter. This is not only a dust generator but a serious defect in your cooling system causing you big problems with heating costs and humidity. Stuff bypassing the filtration system can damage your mechanical equipment and deteriorate efficiency.

Supply ducts leak too. This creates a negative pressure inside the living space for make up air. This negative pressure draws air currents from the attic and these air currents drip duct from the ceiling into the living space below. We go into greater detail later on these transport systems, but the first line of defence against stuff coming in from the attic, is a better understanding how well your mechanical system is working. We discuss all kinds of issues with ducts and HVAC systems here.

There is an accomplice in the attic that helps with distributing stuff into the living space. Air leaks in the ceiling. If the ceiling does not leak air, then no stuff can cross this boundary. Most homes have all kinds of leaks, but the attic is the biggest player here again- because of the natural pressure inside and outside homes, and the large surface between attic and home interior.

Pressure differences between air in the attic and the interior drive air through these air leaks. Pressure changes with the wind and weather and also seasonally. Conditioned air, in the cooling system tends to leak out of the lower reaches of the house and enabling hot attic air to settle into the living space. In the heating season, warm air floats up and out of the ceiling leaks creating a lower pressure in the lower reaches of the house, and cold air spills in the lower reaches to balance the pressure. Differential pressures and air leaks in the house are described in detail here.

Then there are other mechanical issues going on. Ceiling Fans create air movement in the house, and air movement acts on the air leaks in the ceiling. This air movement allows dust from the attic to settle out into the living space.

Supply air duct boots and ceiling grills are interfaces for air flow from the air handler into the living space. There are often gaps here between sheetrock and duct boots and duct grill. The air movement here can create air vortexes in the gap- create differential pressures that agitate and bring dust from the attic into the living space.

There is one reliable way to stop all these leaking paths from the attic into the interior. You need to instigate a plan to systematically eliminate the air leak passages from the attic into the living space. This will not only cut your heating and cooling costs and make a big difference in your sources of humidity but also eliminate the pathways for dust to settle into the living space, because these pathways have been eliminated by solving the air leaks. We talk about air leaks here.  By solving ducting issues and eliminating air leaks in the attic we have eliminated stuff coming in from the attic.

[stextbox id=”info” caption=”Ah, your air handler is in the crawlspace or the garage? ” bwidth=”2″]The stuff coming in might not be dust but it can be much more dangerous. Garages are a terrible place for Air handlers. Garages contain idling cars putting off carbon monoxide and the aroma of VOCs stored there until you paint or refinish or derust… We talk about air handlers in garages here -LINK and crawlspaces are a whole other issue… we talk about crawlspaces here. -LINK[/stextbox]

This carries us right into a discussion as to where your indoor air comes from?

It should not be a shock to you, that the fresh air in your home, comes in from the cracks in the walls and floors that exchange air with the outside. It comes in from the attached  garage or the crawl space. This means that our indoor air contains all the stuff in the outside air plus any other molecules it picks up from mold or car exhaust or critter carcasses in the crawlspace. or sill or attic…

And then there are humidity and moisture issues with air leaks here in North Texas – air leaks are not healthy as we already mentioned, but there is another aspect to this issue in relation to keeping airborne contaminants  out of the house.

That is when we open the window and the screen doors for some fresh air.

Where are we getting our fresh air? Lets visit the stuff we invite in through open windows and screen doors.

We have great weather in North Texas. We have a brief heating season where we run the furnace- if we have one- for a few days, and we have a slightly longer cooling season where we run the air conditioner for a few more days.

During the rest of the year and during that portion of the year when fresh air cooling co-exists alongside conditioned air for parts of the day, we love to open windows and patio doors and let the fresh air in. Well, the flamboyant fresh air also brings in stuff.

Air currents carry in stuff. Stuff enters through screen doors as individual little particles almost invisible unless you see dust particles in the sunlight beams. We notice the dust that settles out  after the doors close, the pollen  and particulates are either still floating around, sticking to some fluffy object, or flowing up your nose as you laugh and talk and breathe. When the sustaining air currents stop, the dust settles into layers on the coffee table, of the couch and pollen and particulate are mixed in too.

We go into more details about where our indoor air  comes from here.

How do we get fresh air in the house, without letting in the stuff?

We need to keep the windows closed…. the patio door closed… but we have to keep the house cool also- what can we do?

We are going to introduce a concept here of active ventilation. New homes have these systems now, because homes are getting tight and so we can no longer rely on natural air leaks to furnish clean air to breathe.

Is this an option for you? It depends. Large houses have extensive surfaces shared with the outside world. You are not going to have an issue with indoor air- unless you want cleaner  air- have people in your home sensitive to pollution and pollen  and particulates and you really want your air filtered and clean…  It is a matter of choice.

In a smaller home, that is well air sealed, with many fewer points of air exchange with the outdoors, you might decide that active ventilation makes sense for you.

So instead of opening your windows and screen doors to get fresh cool air, you bring in outside air through an active ventilation system where filtered outdoor air is brought in and stale interior air is exhausted. You can even make the system a bit positive, so that any air leaks are to the outside, rather than creating a negative pressure where outside air is leaking in.

You can even have a heat exchanger that cools the incoming air with the cooled conditioned aire you are exhausting from the house. That is for the cooling season. In the heating season your heat exchanger preheats the incoming filtered air with your warm interior air being exhausted.

That is just an example… there are many options with active ventilation to fit your needs and to make active ventilation a best fit for your situation. These issues are complex. They need to be well designed We discuss active ventilation in detail here.

Understanding the structural and mechanical systems which deliver our indoor air and our own part in opening up the house to the outdoors is critical to understanding where our air comes from- and how contaminants get in. You then can decide from your own perspective with a basic understanding of the underlying fundamentals- what you want to do. We discuss options of moving forward here.  -LINK-

Our daily activities-  going out into the world and touching stuff and working with stuff and playing in stuff and stuff just wafting down on us- means that we bring this this stuff back into the house when we return home.  This aspect of airborne contaminant transportatoin requires personal choices and new patterns of behavior and can entail forethought and new habits… They involve our pets too.

We are porters-  our pets are porters- tooting in joy-riding stuff.

We carry in stuff . Our pets carry in stuff. When we are outdoors walking, running, playing at the park- hiking in the wild, fishing- out to enjoy the wild flowers: we walk in clingy stuff, brush up against clingy stuff and it comes home with you. In your hair, on your clothes, on your shoes.
We play in dirt in the garden, we work in the yard, we pick stuff up in the yard and organize, and we carry the clinging remnants back into the abode and then proceed to shed this dirt and dust andpollen into the carpet, onto the furniture…

We need to have forethought and a plan in hand to deal with these clingy things.

We need a space where we can remove contaminated clothes and rinse off our faces and hands, and change into something where we can transition to take a shower and wash our hair… this is all complex- needs to fit into the environment we find ourselves. So this is a bit academic and abstract here- it becomes a carefully planned activity for you and for family members. You have your personal level of sensitivity, your personal level of concern and will find the steady state effort you are comfortable with.

No outdoor shoes in the house. Have some house slippers around to keep  from walking in the stuff stuck to the shoes…

Taking a shower helps wash the pollen out of your hair- off your skin- and can make that critical safety zone to keep the dust down and the contaminant level below inundation.

We  are working the safety margins here. We know the first piece of allergen does not make us sneezy, not the first grain of pollen nor the second grain, but at some point we are inundated and we react. We are taking action to stay below the level of inundation. We might have issues at times, but we are systematically limiting exposure by process not letting things go and then reacting later.
[stextbox id=”info” caption=”Do you garden?” bwidth=”2″]You have a special set of pants and shoes and gloves and hair nets and … you keep these separate and out of the main part of the house, and you will succeed in keeping a variety of pollens and pollutants- what kind of stuff are you digging in spraying, forking… out of the house.[/stextbox] [stextbox id=”info” caption=”Has everyone discovered saline spray? ” bwidth=”2″]A saline spray can also help keep the pollen rinsed out of your nasal passages. These can make quit e difference. Nasel irrigation works really well. Skip the neti pot and go right for the big spray bottle. The mixing is easy, and no tipping. You just squeeze. I use one. It works great for me. I use it on occasion and a saline spray several times a day.[/stextbox]

Dogs and Cats are like animated mops-

Pets outside are like little dustmops sliding over the most tantalizing aural sensations…
Animals can be brushed and their paws cleaned to remove pollen and dust and particles. This is easier said than done, and you get to figure out how to coopt the kitties and doggies and make them happy to cooperate. You get to dress appropriately,too. You are in the mix of stuff with your pet, so plan accordingly.

There is a great continuum over determining the world of dogs and cats and where they have fun, where they live and how much the cozy into the human spaces. This is left up to you. I will say that putting them into a soundproof booth overnight helps you sleep and they are happy to see you in the morning….

House cats and house dogs  are easier. All the contaminants they get into are self generated, or just stirring around in the stuff already in the house.

You can also have a designated cat and dog groomer in the house, and also a cat and dog bather… Pet bathing on a regular basis helps remove pollen plus all the other stuff cats and dogs generate with dander and salival out of the house,  too. No advice here for getting kitties into the bath.
[textbox] Rules for visitors <> no outdoor shoes in the house… dust the guests off, dust their hair, give them an appropriate garmet to wear over their clothes like a lab coat… I am joking. You are on your own when it comes to dealing with houseguests.

Keeping Dust and pollen and particulate repositories to a minimum.

I am an expert on clutter. Avoid clutter. Clutter is all that valuable stuff that is not quite worth reading right now, or with dealing with right now, but you don’t want to put away because you will deal with it tomorrow… we. Just stop it. Do what I say, not what I do.

Clutter has all these little fuzzy parts- all these facets for collecting dust and pollen and contaminant particles on the way to the return air duct until they are intercepted by your clutter where they are parked until you move the pile, or brush up against the pile, or add to the pile and that trapped contaminant swirls around and goes up your nose.

All those paper notes you are saving? They are important. Start a Google docs account and keep all your notes there. In a digital world where you can search with a search box rather than with your fingers through a pile of random and assorted notes. Yes, I know that writing on paper is often a great kenetic way to think and remember. So put the draft on paper and then  organize into a digital file. Through the note away or put it into a box with a lid.

Minimize the amount of stuff in your house. Not clutter really, but all the stuff you think gives the room character. Make the room more taciturn. Sentimental surfaces of cloth and frill need to be kept in a special place- in a chest to come out for special occastions. Hard smooth surfaces make poor hiding places for stuff.

Boxes with lids and cabinets with doors are great. You are reducing the surface area of your dust and pollen collectors. Keep stuff in collections out of sight and in covered containers.
What  are the essentials to keep? Well we want chairs around, and beds and tables…

You don’t have to get rid of down bedding… We are moving around to talking about the stuff that is essential. Bedding and quilts and covers and pillows.

[stextbox id=”info” caption=”Feather bedding as a dust collector and specially sweet hostel for dust mites is a myth.” bwidth=”2″]

It is a myth to believe that feather pillows and down comforters cause allergic reactions. This has led to a boom in sales of down alternatives and “anti-allergen” pillows. However, if you test the two types of pillows side by side, this myth is quickly put to rest. As it turns out, you don’t need to get rid of your feather bedding. It’s more likely that you’re allergic to the dust mites in the bedding rather than the feathers themselves.

Studies show down alternatives can make things worse because loosely woven casings allow dust mites, dander and mold spores to collect inside. Whether it’s down or synthetic, look for high-quality, tightly-woven casings and wash bedding regularly in hot water.[/stextbox]

With the essentials only, with all the near essentials close at hand in covered boxes, in drawers behind closet doors, in all those special places that warm or hearts but keep our precious stuff out of the pervue of dust and particles. We are making it harder for dust to squat arounf the house, and make it more likely that that dust will be capture by you or by the cold air return where it will be sucked up and trapped in a filter.

All these smooth clean surfaces makes it much easier when you wet dust everyday and vacuum with a HEPA filter equipped vacuum. Make sure you know how to vacuum properly. We all hate vacuuming so we hurry, do not track properly go back in forth and stir up more as much dust as we catch. I am sure there are youtube videos on how to vacuum properly. Do it often. Carpet is a big stuff collector. The  carpet industry sells this as a virtue, but is it really? You can only vacuum stuff off the top surface of the carpet. When it settles down into the fibers, it does not vacuum out. Keeping carpet clean is a toil.

[stextbox id=”info” caption=” Is it time to get rid of the carpet? ” bwidth=”2″]Carpet has all kinds of issues… new carpet can be full of volatile organic chemicals that drive us nuts… carpet can camouflage issues with moisture and mold. Dust mites like to get cozy in the fuzzy fibers of carpet… plus it needs to be vacuumed. We have to steer the roaring noisy machines around the house like an automaton. What if we just get rid of the carpet?. We talk the happy talk of a carpetless existance here. [/stextbox]

A final thought on the toxic materials that we do not see, that our bodies do not react too.

This page has completely mixed the concept of allergens- which are basically harmless stuff that some people are sensitive too when their auto immune systems create antibodies….  and the particulates and pollution that come in the same way as the pollens.

Many toxic substances are invisible and our bodies do not react to them.We have no reaction mechanisms to some of the most destructive contaminants that can come into our home, or be in our home. These are lead and asbestos. They relate here because quite often these toxic materials are transported into our homes, by family members on their work clothes. We address these quiet killers in the main article on healthy homes.

So I got a little out of hand here with exposed opinions on pets and house decorating… but these are the general principles for keeping airborne contaminants out of the house. If you have questions, or comments, or suggestions, please add them below.

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