Tag Archives for " Air Quality "

What to do when you find yourself in an air quality emergency

What to do when you find yourself in an air quality emergency

We’ve all been on the other side of the highway when an accident snarls traffic for miles behind it, and our lanes of traffic slow down but continue to move.  Whew, glad I wasn’t on that side, we think…but sadly sometimes we may find ourselves stuck in an air quality emergency that requires calm, decisive action to quickly get to safe air.  

On Wednesday, November 8, 2023, a fire at a small chemical plant north of Houston sent plumes of black smoke into the air.   According to the Reuters report on November 9, Sound Resource Solutions blends, packages and distributes oilfield and other industrial chemicals including sulfuric acid, acetone and petrochemicals like xylene and toluene, according to the company's website.  These are chemicals that are acutely toxic with the potential to cause serious eye, skin and organ damage, as well as carcinogenic. 

A news article from a Houston news station released the list of chemicals that had been stored on the site during the last 2 years, which confirmed they are quite toxic.  

However, despite the smoke and shelter-in-place orders (which have been lifted), it seems that officials are downplaying the possible effects.

  • According to a Houston news channel video the day after the fire was extinguished (Nov. 9), the Texas Commision on Environmental Quality was monitoring the air and “did not detect any levels of concern from the samples”.  

  • In the same video, an official from the University of Houston said that rain would wash any chemicals out of the air, dilute them out and they eventually go into the ocean.  

Here are the problems we see with these assessments: black smoke was seen moving north toward Livingston, Texas.  Such smoke carries a lot of particulates, which will deposit on businesses and residents’ homes, vehicles and farms (food sources), as well as drinking water facilities.  Also, by our estimates, Shepherd, Texas is 50-60 miles from Trinity Bay, which is open to the Gulf of Mexico.  In order to get to the ocean (Gulf of Mexico), the particulates and chemicals will pass through many drinking water sources!  Once again, it’s probable that authorities are not releasing timely information about hazardous levels of chemicals in the air (and no water reports were discussed).

If you find yourself in an emergency area like Shepherd, Texas, it’s best to do one of two things: stay inside and implement air quality containment measures, or drive out of the area as soon as possible.  Here are our recommendations:

If you choose to stay inside:

  • Close all windows and turn off air conditioning and heating systems if possible.

  • Although most HVAC systems don’t have fresh air intakes, you should close these intakes if they do.  

  • Don’t use exhaust fans like the kitchen or bathroom exhaust fans.  Don’t use clothes dryers, either!  Each of these pull air out of the house, which consequently draws air into the home through cracks in windows and other penetrations.

  • If you have air purifiers, run them continuously.  If you have only one purifier, run it in one small room where you can shelter for most of your time.  If you don’t have an air purifier, here's how to make one using a box fan and a MERV-rated filter.

  • Don’t cook if possible; try eating canned food or food that doesn’t require cooking or heating.  The reason is that cooking and heating food releases even more VOCs into the air, and you shouldn’t vent these with the exhaust fan.

  • Monitor AirNow.gov for local air quality updates, because the air quality outside your home will eventually be the air quality in your home.  If air quality outside deteriorates, you may want to gather supplies and necessities and evacuate via car.

  • Use bottled (preferable) or home-filtered water until you are sure that tap water has not been contaminated (which may be weeks or months).

If you evacuate:

  • Make sure that the HVAC in your home is turned off and all windows/doors are closed before you leave.  You can leave air purifiers running in your home, however.

  • Make sure you use the best masks you have until you get out of the area.  Exchange your mask for a new one if you start to have trouble breathing. 

  • Spend as little time outside as possible. 

  • When driving, keep your air conditioner set to “recirculation” mode until you get out of the danger area.

  • Bring/buy bottled water. 

  • Monitor AirNow.gov for local air quality updates and check updates by local news authorities. 

  • Upon returning home, clean carefully and thoroughly!  We have recommendations in our article here.

Note that smoke particles, which can contain toxic chemicals, will deposit on the ground, making it easy for people and pets to bring them into the house, so you may want to be vigilant about removing shoes and cleaning pets’ paws when you can.

Many people live or drive within range of being affected by toxic spills, fires and environmental disasters, so your best bet is being prepared (and have a healthy skepticism of all-clear reports until you can research the situation).

Photo by irfan hakim on Unsplash

Why you need a moisture meter (and how to use it!)

Why you need a moisture meter (and how to use it!)

Moisture meters are like thermometers.  When you think, I feel warm…do I have a fever?  You might ask someone else to put their hand on your forehead for a reference check, but if they’re not sure, what you really need is a thermometer to verify your body temperature.  Likewise, sometimes in my own home I see a dark spot on a wall or windowsill that I hadn’t noticed before, and think, is that a water stain or actively leaking water?  I place my fingers or hand on the spot to see if I feel moisture, but if it’s not sopping wet, it’s sometimes hard to tell if there’s any difference with the surrounding material.  What I need is a moisture meter.

Moisture meters work to sense moisture by electrical conductivity.  Since water is more conductive than drywall, wood and many materials (other than metal),it uses this property of water to “detect” the relative moisture.  For this reason, some types of moisture meters are made for gardeners and farmers, to tell when the soil is too dry and plants need to be watered (this type doesn’t even need a battery).  Moisture meters for home inspections, however, come in “pin” and “pinless” varieties.  The “pin” type have sharp pins for actually sticking into the material, while pinless meters–you guessed it–don’t have pins.  This type detects moisture using conductance by either radio frequency or capacitance of a material.  (Evaluating Pinless Moisture Meters Vs. Pin Moisture Meters)  Both have their place in a professional home inspector’s toolbox for different reasons.

Here are some considerations to decide which moisture meter to use:

Accessibility and Damage: Obviously, you can’t insert a pin moisture meter into materials like concrete and tile without damage, so pinless would be the way to go.  Also, if the material is highly visible and/or valuable, you might not want to insert pins into it (even though the holes are small).

Speed: Pinless meters are much faster because you don’t have to stop and insert pins into the material.

Accuracy: Both types of meters can be accurate, but pin meters are preferred by home inspectors (when possible to use them) because pins have the ability to sense deeper into the material, and their readings are very repeatable when inserted into the same holes.  

Adaptability: Pin meters may come with a variety of accessories (types of pins) for different surfaces.  There are hammer electrodes (you guessed it-for hammering them in!), deep wall probes, extension probes and baseboard probes.  

Now that you know the difference, how do you use them?

For those that like videos, here’s a good short one by This Old House.  Here are the takeaways:

  • Thermal cameras can also be used to spot moisture in a wall because of temperature differences, but unless you’re an expert, you should confirm that’s it not simply missing insulation with a moisture meter.
  • When using a moisture meter, good dry material should show between 6-9% moisture.
  • 15% or more indicates a definite water intrusion problem.   You’ll need to consider replacing the material if it’s drywall, or if it’s wood, at least removing it to assess damage, expose the backside and dry it thoroughly.
  • Some meters are “combination” meters that have pins and pinless technologies.

It’s important to know some quirks about using moisture meters.  You can watch a very interesting video (up to about minute 5:50) from a reputable home inspector showing these points, or read them here: 

  • Metal also has low resistance to electricity (high conductivity), so if there’s metal in the surface, like a metal cornerbead in drywall or metal lath behind tile or nails or screws, you can get a reading that looks like moisture when in fact it’s dry; the metal gives a false positive.
  • Moisture meters are not very accurate on tile.  The minerals in the masonry/concrete can give a false positive.  Also, there can be metal flashing under tile, especially behind shower surrounds.  You must use intuition/other tools to find real water intrusion and remediate.
  • Dry dog and especially cat urine will give false positives because the minerals in the urine will permanently alter the composition of the material (drywall, carpet, etc.), causing it to be more conductive and appear "wet" to the meter.
  • Moisture meters only read water, not mold.  Although mold needs moisture to grow, it takes a few days to take root (typically 48 hours for very wet surfaces), so if you catch the moisture soon enough and dry it out quickly, you may not have a mold issue.
  • Moisture meters may give a normal reading (false negative) even though you have mold!  This can happen when the mold is caused by humidity.  A moisture meter will typically not pick up excessive moisture when the mold is caused by condensation.  The condensation occurs only on a very thin layer of the material.  While this is sufficient to cause mold growth, it typically will produce a normal reading on a moisture meter. (Humidity and Mold in Home)

Moisture meters can be used in other situations, too!  It’s nice to know:

  • Is the firewood dry enough to burn well:  It's important to burn only wood with moisture content below 20%. Burning wood with higher moisture content creates more smoke, which contains harmful chemicals and particulates and forms creosote on your chimney. It also gives you less heat, because it takes energy to boil off the excess water. (Storing and Drying Firewood)
  • How dry does a wood surface need to be in order to paint it?  According to an Amazon Technical Bulletin, most outdoor wood, concrete, stucco and plaster surfaces must be at or below 12%, otherwise the paint may not adhere properly, or risks failing early.  Indoor wood and cabinetry should be closer to 6%. 
  • Are your hard wood floors ready to install?  Wood flooring installers typically want the moisture content of hardwood floorboards to be between 6% and 9% (based on an indoor temperature of 60–80° F and 30–50% relative humidity).  (How to Measure Moisture in Hardwood Floors)

Finally, like many other products, the more functions a moisture meter has, the more expensive it’s going to be.  Here are some functions:

  • Ability to “calibrate”: although most cheaper meters do not have a “calibration” function, some have a button to return the device to a factory preset.
  • Ability to choose a very specific material (like concrete, drywall, softwood, hardwood, etc.) Here is a video showing the differences between using a cheap moisture meter and a more expensive one for woodworking.
  • Sensitivity: Instead of soft or hardwoods, some testers allow to select based on a table of listed woods, like this one (more specific for woodworking). 

Here are some devices to consider:

Pinless meters: 

  • Wood Moisture Meter (Pinless-colors), $37, has an LED display screen that looks like an analog meter, with green to red color codes that align with the moisture content.  The pinless moisture meter is penetrates up to 0.75inches deep.  Despite the warning that it’s not recommended for drywall, many customers report using it with success in finding leaks behind drywall before they became too serious.
  • Klein Tools ET140 Pinless Moisture Meter, $42: This rugged meter seems to be very easy to use in selecting the material and verifying the moisture content.

Pin meters:

“Combo” meters:

Reading the reviews on these devices, we’ve seen many homeowners and renters who are able to make quick, informed decisions to call in professional help and get repairs going before serious water damage and mold took root in their homes.  We think it’s an important tool to have in your toolbox whether or not you think you need it right now, because water damage can escalate quickly in hours and days, and the time spent looking or ordering one could be very precious!

Sealing your Attached Garage

Sealing your Attached Garage

For many people an “attached garage” is an asset in a home: the convenience of parking and walking inside under cover is very attractive when there’s extreme weather outside!  However, from an air quality perspective, attached garages are actually a liability, unless the garage has been air-sealed from your house!

In our articles about negative air pressure here and here, we talked about how contaminants can enter your home from the garage.  The garage not only has car exhaust fumes, it can also have paint or chemical fumes from your hobby, VOCs from pesticides and insecticides stored there, and possibly even exhaust gases from your gas water heater, furnace or clothes dryer.  Need we  mention the mold and mildew spores when humidity and cardboard boxes create the perfect environment for mold?  It’s almost like having an unsanitary neighbor in the apartment next to you…now, does an attached garage still seem like an “asset” to your clean, healthy home?

If you are coming around to a healthier way of thinking about your garage, it’s essential to consider installing some boundaries with this unsanitary neighbor!  “Air sealing” is more than just a tight-closing door.  It goes from the ground (foundation), through walls and insulation and even into the attic.  That’s right–if the attic over your garage is not sealed from the attic over your home, you got it–there is shared airspace and the possibility of contaminants crossing over from the air that circulates there due to changing temperatures. 

As with most air-sealing projects, creating this boundary is easiest if it’s done during the building phase.  The easiest way is to build your attached garage as a “separate” building…as in this article.  Jake Bruton of Airow Building in Missouri does it this way: do all the framing for the house, install your air barrier, and only then, frame the garage on the other side of the air barrier.  Finally, any penetrations like electrical and ventilation must be properly sealed. 

Another way to airseal during construction is to hang drywall on the shared wall inside the garage, foam the penetrations like light switches and outlets on that wall, and also run plywood sheathing above it to the roofdeck, using sprayfoam to seal the entire barrier in the attic as in this video.  Sprayfoam really is the only way to effectively seal around ceiling joists, which often run straight over the wall from the home into the garage.     

This is all great...for new construction.  What if you are buying an existing home, or just now want to upgrade your home?  First of all, examine that shared wall from the garage side, from floor to ceiling. 

  • If the drywall is finished, that’s good.  Finished drywall can be an air barrier.  However, you’ll want to remove any trim like baseboards or trim around doors, faceplates like electrical plates, and uncover any penetrations.  Get some spray foam in a can and seal all of these cracks with spray foam.   You’ll want to cover the space from the sill plate to the drywall, the spaces around electrical boxes, and around any pipes sticking through the wall like gas pipes or hot water pipes if you have a hot water heater in the garage.  Make sure to seal around the door frame if there’s dead space there. 

  • If the drywall is not finished (no tape and mud or just insulation), that’s even better!  Consider removing the existing drywall on the garage side (you can install it again later if screws were used), as well as any fiberglass or rolled insulation, and sprayfoaming the entire wall.  Spray foam can be an excellent air barrier if it’s done by a pro.  Before you schedule the job, however, go to the next point and prep the attic space so that they can foam there as well.

  • If the attic space between the garage and home are shared, you’ll need to build a partition wall between them.  Of course this is not a fun job, because attics are typically low, cramped and have extreme temperatures, but it’s critical if you’re going to do a thorough job.  Then, the wall can be sprayfoamed on the attic or house side, or at least foamed around the roof, rafters and joists and taped where plywood sheets come together.  

  • Ventilation (air conditioning and heating) is something that should never be shared between a house and garage, because that is a sure way to pull those contaminants right in and distribute them around your home!  If you do have a shared system, consult with an HVAC company about terminating the vents to the garage and installing a dedicated mini-split.  For small garages, a window air conditioner and portable heater will do the trick!  

  • If flexible ventilation ducts go over the garage with no vents, it’s really hard to get an air seal around flex ducts.  If you can’t/don’t want to switch to metal ductwork, install a collar in the attic wall that separates the garage and house (the one you build as in bullet #3 above), and attach the ends of the flex duct to it, so the wall can still be adequately airsealed.  

  • The door between the house and garage, of course, is an area that needs to seal tightly.  Adjust the door so that no daylight shows around the perimeter (I know, this is easier said than done!) and use weatherstripping around the sides so that it seals when closed.  If necessary, install a “sweep” on the bottom or replace the rubber seal in the threshold so the bottom seals as well. 

Here are some product recommendations for air sealing the garage:  

  • Air-sealing tapes can be expensive, but don’t scrimp: don’t use duct-tape, vapor-barrier tape or anything less than a product that is for air-sealing.  ZIP System is a great brand and be sure to buy more than you think you will need, because there always seems to be another seam to seal!  Use this tape to seal plywood edges together, seal the door frame to the drywall (if you can’t foam it), etc. 

  • Spray foam cans come in lots of formulations: small cracks (less than ¼”), larger gaps and cracks ( ), pest block formula (who knows what kind of chemicals are in there), but just be sure to buy a good number of the small and large gap formulations before you start the job.  Wear gloves, safety goggles and old clothing (long hair safely tucked away) because this stuff is super sticky!  Also, if you use a can quickly, you can reuse the same straw on the next can, and save the extra straw in case one gets plugged or lost.  Unless you buy the “smart dispenser” version, the straws and remainder in the can cannot be reused after about 30-40 minutes, so be sure to have several spray areas ready when you start spraying!  After it hardens, you can use a utility knife or hacksaw blade to cut away excess foam.  Consider these different products:

    • Great Stuff Window and Door gently expands so that frames will not warp under pressure.

    • Great Stuff Gap and Cracks (use in gaps up to 1”)

    • Loctite Tite Foam, pack of 2 for $19

    • Great Stuff Pro (large cans, $14 each–a great tool for a large job because it’s easier to dispense and can be reused for up to 30 days); however it requires a special gun.  Users report that a can goes a LONG way (3-6 cans on a large home) but if you have more air-sealing to do, it’s worth having several more on hand.

    • And more…

Not only will your house smell better and stay cleaner after these airsealing improvements, you’ll probably notice less cold drafts in winter and hot air in summer, since most attached garages are not conditioned.  Finally, complete your sealed garage upgrade with a funny sign reminding everyone to “close the door”...after all, airsealing can only go so far when the door is open!!

Photo by Kevin Wolf on Unsplash

What happens behind closed doors…

What happens behind closed doors…

What happens behind closed doors…is STAGNATION!  When you close the door to a room in your home, air is trapped in the room, resulting in the following:

  • If there is no fan operating, air will not circulate, and any humidity present in the air will saturate soft furnishings, increasing the likelihood that mold will grow (see our article on ventilation and one of our favorite tools, dpcalc.org).

  • If central air conditioning or heating is pushing air into the room, the closed door prevents proper cycling of air out of the room, causing the system to a create a negative pressure zone near the return grille and placing stress on the system’s mechanical parts like blower motors.

  • Again, central air conditioning or heating with closed doors causes imbalances in the temperature of the home, because conditioned air is prevented from mixing, which in turn affects the thermostat and causes the system to run longer to reach the temperature set point.

Keeping doors closed, in other words, is just not good for proper ventilation in your home!  This makes sense to us…until the question of privacy is brought up.  Of course, not everyone wants their door to be open at all times, even if it’s just cracked open.  Don’t worry, there are ways to get good ventilation even with closed doors!

The best solutions are brought in during the design phase of the home, before construction begins.  This is where our first idea is best incorporated.  Transfer grilles offset high/low in a wall cavity use the cavity to muffle sound, so that this design affords  the maximum privacy.  However, in order to avoid entraining dust and other building toxins from surrounding spaces, the cavity needs to be sealed by gluing the drywall to the studs and plates…meaning that this solution needs to be built in during construction.

Source: Building America Solution Center

If you’re realizing you need better air circulation after construction, then there are still more solutions to consider.  You can use a back-to-back grille over a door (or any high space on a shared wall), which have sheet metal baffles to block sound and light while still allowing the passage of air through the wall.  Here are some diagrams to show back-to-back grilles:

Source: Building America Solution Center

Thirdly, if wall space is an issue and you have attic space above the rooms, you could install a jump duct using flexible duct, two ceiling grilles, and foam sealant (to make sure air from the attic does not leak into your home).  Theoretically, a jump duct could also be placed through/under the floor to bridge two spaces, but in either place, take care to make sure the flexible duct is not crimped, and do not cut any structural beams like rafters or joists to install it.

Source: Building America Solution Center

Lastly, there’s a solution which I consider to be the easiest of all of these.  In-Door Return Air Pathways by Tamarack Technology are easily installed in the bottom of your hollow-core or solid wood interior doors (door must be 1-3/8” thick to fit).  Simply remove the door from the frame (I find that tapping the hinge pins out is easiest), lay it down, trace the provided template on the bottom of the door, cut it with a jigsaw, install the grille with two screws (provided) and re-install the door.  They do provide less privacy than the previous two options, but are quick to install (less than 30 minutes in my experience) and can be left white or spray painted to match any door color with paint suitable for plastic. 

In-Door Return Air Pathway installed in a solid wood door.

When you have the door closed with any of these three solutions, air is free to mix with the rest of the home, rooms do not become positively or negatively pressured, and you definitely have an advantage in keeping mold from forming in that room.  Additionally, the continuous use of the following in the closed room costs very little energy, but boosts your mold protection even more: 

Sure, we get it…everyone needs their privacy, but for health’s sake, make sure the air is flowing freely!  

Photo by Storiès on Unsplash

Excuse me but your fireplace is open!

Excuse me but your window fireplace is open!

Heading into the winter heating season, many of us are thinking of cozy nights snuggled inside our homes, not the cold drafts that spoil the atmosphere in more ways than one–ahem, even our heating bills!  Drafts are invisible sucks on our budget, like “phantom” power leeches that use electricity.  The drafts coming from the fireplace are comparable to leaving a window cracked open.  In our article about how to keep the fireplace from polluting the house, we noted that the average household can save 14% on their heating bill by weatherstripping the fireplace.   It’s time to prepare for maximum coziness!

Working fireplaces have dampers, and these should work well.   Dampers are like “valves” that should be closed when the fireplace is not in use, to prevent outside air (and smoke particles from the flue) from coming back into our homes when we’re not using the fireplace.  However, dampers are not air-tight; they just don’t have the ability to block drafts.  Here are several other places to really air-seal your fireplace:

1) At the chimney cap: this requires you to get up on the roof or hire someone to do that.

2) Inside the flue with a balloon: the balloon, however, can shrink as temperatures get colder, or get punctured on a rough surface and leak.

3) At the hearth (bottom): this is the most physically convenient place, and can be easily removable for those times you want to use your fireplace.

Although the first two can accomplish air sealing well with the right products, #3 is actually the healthiest because the chimney and firebox (with smoke particles on their surfaces) stays separated from your house air.  

Here are some ways we’ve found to seal out those drafts all year long: 

If your fireplace is a bare opening in the bricks, like mine, this is the most difficult to seal but worth the effort.  Here is are two ways to do it:

Method 1: You’ll need: 

  • 4 pieces of wood (at least 1” square, larger is better) or metal tubing cut to fit the length and width of the opening (see diagram below)
  • Foam insulation tape to go around the frame in the opening
  • Glue gun and glue if adhesive on insulation doesn’t work well
  • Magnetic tape or velcro tape
  • Optional: 1-2  tension rods will help stabilize the frame if the wood doesn’t fit snugly.
  • An insulated blanket or piece of plywood cut fit over the frame.

You’ll want to thoroughly plan out how the frame will fit together before cutting your wood or metal to length!  Here’s how I cut mine:

Then, add insulation to the perimeter of the pieces using the adhesive on them, or a glue gun, and fit the wood snugly back into the opening–you may need to re-cut the pieces to accommodate the increased thickness due to the insulation.  

You can add 1-2 adjustable tension rods across the opening or up and down for added stability.

Next, add magnetic tape or velcro to the front of the wood pieces in order to attach the insulation.  You can use all kinds of materials to cover the opening and get creative!  Just remember that there will be a temperature differential in winter or summer, so adding some insulation to the back of the material makes it even more energy efficient.

  • Foam board or cardboard (if cut to fit snugly, no tape is needed to secure it in the opening)

  • Bed blanket with extra insulation glued or stitched to back or inside

  • Old electric blanket with wire removed and extra insulation added inside (stitched in place)

  • Plywood

  • Drywall

Of course, if you decide to use the fireplace, remove ALL of these materials and store them away for re-installing later. 

Method 2 involves taking a baby or pet gate and setting it to firmly span the opening, then cutting a foam board or cardboard to fit exactly over it (you can cover the foam board with wallpaper or fabric).  While this method can be sturdier and quicker to do, it does involve finding an unused gate and cutting the foam very carefully so that it seals the opening. Alternatively, you could cut a used foam mattress topper slightly larger than the opening, and squeeze it into place to cover the gate (again, covering the foam with any decorative material). 

Here’s how my fireplace draft blocker turned out with a fleece blanket, 2 sheets of cardboard glued together, and a staple gun (admittedly I could have stretched the fleece a bit more or made a border for more visual interest):


Voila!  Just sticking my head into my fireplace one time during this project and smelling the lingering smoke smell made me think, why didn’t I do this sooner?  Drafts and smoke be gone all year long!

Summer Cooling: What are our options?

Summer Cooling: What are our options?

Many places in the US and around the world have broken temperature records this June.  Whether you’re in Minnesota or south Texas, it can be tough to keep your home cool during summer while maintaining a decent air quality.  We’ll go over some of the most popular ways of cooling your home and maybe some you haven’t thought of.  

If you’re not familiar with the different types of air conditioners and how they work, check out this article.  Note that newer air conditioners are also often “heat pumps” that can reverse the flow of refrigerant to provide heating in the winter.   

Central Air:  About 66% of homes in the US have central air conditioning, but this is not spread out evenly over the country.  As one would expect, central A/C is more prevalent in the south (37%), west (22%), and midwest (21%), versus the northeast (17%), and newer homes are more likely to have it.  (How Much Value Does Central Air Add to Your Home?) The best thing about central air conditioning is its distribution system, which allows multiple rooms to receive cooling and filtration from one unit.  With any air conditioning, it’s very important to do the following things:

  • Keep your home closed (a sealed system) so that warm, moist air is not introduced.  Letting in humid air from the outside will quickly increase humidity inside, because air at a lower temperature cannot hold as much moisture as warmer air, and humidity climbs.  This applies to windows, doors, and any significant leaks (like the door to an unconditioned attic or crawlspace).   

  • Change the filter on your unit regularly!   We can’t emphasize this enough: a dirty filter not only puts extra stress on the machinery like fans and compressors, but it increases cooling costs, and when the filter gets dirty enough, air will start to leak around the filter and get your evaporator coil dirty, providing food for mold.  Using the highest MERV possible for your unit will help keep the system clean and your air clean as well.  You can check out our article here to find out how to get more filtration out of your current AC system. 

  • For extra filtration, you can cut filter material to fit your vents, just don’t forget to clean or change these regularly, too. 

  • Get your unit serviced regularly.  Here are some things that the HVAC tech will do for you during a service visit:  inspect the inside coils, clean the outside coils and straighten fins if necessary, check the refrigerant levels and add refrigerant if necessary, and test the thermostat.  An HVAC system is a big investment (average $7000), so you’ll want to take care of it!  

  • Make sure your insulation is up-to-par: check air ducts to make sure they are not crimped and are fully insulated, and make sure there are no “bare spots” in the home’s conditioned-space envelope (ceiling or roof).  You’ve got to keep that cool air where it belongs!

Mini-Splits have most of the same parts as a central system, but they don’t have ducts to distribute cool air.  Instead, you could have one outdoor unit combined with up to eight indoor units, with the outdoor unit distributing refrigerant, not air.  In this way, you’ll have eight separate fans and filters inside, but these are smaller.  Mini-splits also have filters, so you’ll want to clean or change these on a regular basis.  One disadvantage with mini-splits is that the air filters tend to be similar to window air conditioners, which are cleanable, but they don’t provide high filtration, just large dust capture.  You will also want to get your units serviced regularly by an HVAC technician.  To get additional dust filtration, try adding standalone HEPA filters in the rooms that seem to get the most dust. 

Window Air Conditioners have come a long way in efficiency and looks!  They are one of the quickest installations, too: from buying one in your local home improvement store to having cool air in your space, could take as little as 1 hour.  Window air conditioners are a sort of “plug and play” cooling solution, but they also require regular maintenance of cleaning the filter.  Because the filter is equivalent to a very low MERV, like mini-splits, you’ll want to add a standalone HEPA filter to reduce pollen and dust.  In addition, if your window unit is more than several years old, it would benefit from a deep cleaning (see our article for tips on how to do that).   Some window air conditioners also have a feature that mini-splits and basic central systems don’t: a fresh air vent.  When this vent is open, you can get a small stream of fresh air from the outside, to dilute stale indoor air.  The only problem is that this air is usually not filtered or conditioned:  it’s the same as “cracking the window” without a screen.  To find this feature and operate it correctly, sometimes you’ll need to refer to the owner’s manual.   New window units with “inverter” type motors can be extremely efficient and this “saddle” style unit by Soleus even gives you your window view back, because it hangs below the window on each side.  It also has a dehumidifier setting to lower the humidity in your space. 

Portable Air Conditioners have become popular because like the name suggests, they are the most portable.  They can cool spaces without a window, as long as you have a place nearby to send the heat through the exhaust duct (through a sliding door with an adapter kit, for example).  You will also need a drain to collect condensate, or you will need to empty the reservoir every so often.  Portable air conditioners have the minimal filters similar to window air conditioners and mini-splits, so they are not able to filter smaller particulates.  It’s really important to clean these filters on a regular basis to keep your air conditioner working well!  Another downside to portable air conditioners is that they are less efficient than window air conditioners, and they have bulky hoses that aren’t the most attractive.  

Fans are the most common cooling systems we have, and many are cheap, at less than $50.  Fans cause evaporative cooling, where the circulated air carries heat away from our bodies in the form of water vapor.  Fans work well to cool us down if there is some humidity in the air.  (See our article about the detrimental effect of fans in extreme dry heat.)  You can use a combination of ceiling fans and portable fans to move air from cooler to warmer areas of your home.  Dreo Air Circulators are very powerful, efficient, and quiet because of the fan design, and because they use brushless DC motors that have a large range of speed with low energy consumption.  Since most fans don’t have filters, you can add standalone HEPA filters to cut down on dust, or add cloth filters to your tower fans. Filters for box fans (20x20”) are mainly the replaceable type, not cleanable, but $45 for a 4-pack of MERV-13 filters could help your space stay a lot less dusty.

Opening the windows is an option if you live outside of polluted urban areas, wildfire smoke, or excessive heat and humidity.  In these cases, it’s best to leave the windows closed and curtains drawn to preserve coolness as long as possible in the day.  If inside temperatures start to equalize with outdoors, however, you can use regular window screens in pristine areas, and Window Ventilation Filters in more polluted areas.  Although the filters restrict airflow slightly, they provide a good buffer against dust and pollen.  Here again, standalone HEPA filters will also help reduce dust in your home. 

Evaporative coolers, also known as Swamp Coolers, began to be popular in the 1920’s and 30’s when electricity was available, but residential air conditioning was not affordable/accessible. (Window air conditioners were invented in 1931 and central air conditioning was offered in 1931 but many Americans could not purchase them due to the Depression).   Swamp coolers use a fan to blow air over a wet membrane, which, if not cleaned regularly, begins to grow algae and smell like a swamp!  This older type of membrane is definitely not something we would recommend for air quality, but newer models like those made by Big Ass Fans uses a proprietary resin coating on the media that resists the growth of algae and mold to keep your airflow clean and people healthy.  Following the cleaning and maintenance guidelines are very important, too.  Another downside of this type of cooling is the massive airflow that could kick up a lot of dust.  However, if you have a large outdoor or unconditioned space and adding humidity into the air is not a problem, then an evaporative cooler could help you stay cool.  It would even help to cool a porch, from which you can open up air to your home to take in cooler air.

Heat Pump Water Heaters can actually cool your space.  It sounds counterintuitive–til you consider what this machine is actually doing.  Instead of creating heat by an electric coil or gas furnace, this type of water heater pulls heat from the surrounding air–in effect making the room in which it’s installed, cooler!  If you have the water heater installed in the garage or another unconditioned space, you can still reap the benefits by using ducts to bring warm air from your house to the heat pump, and cool air from the heat pump back to your house.  Heat pump water heaters do cost more than the basic electric or gas varieties, but according to the Department of Energy, they can be two to three times more efficient than a regular electric water heater.  However, when you consider you’re getting free cooling during the summer, you can deduct this cost from your cooling bill.  Another consideration is the size of room where it is installed.  It must be installed in a room at least 12’x12’, or have ducting to access larger areas, so it can pull the heat it needs from the ambient air.   If it’s time to replace your water heater, check with your plumber to see if a heat pump water heater would work for you!

There are many ways to move cool air from the basement into your home, but consider the quality of basement air before you make this move.  If it’s musty or moldy smelling, you’ll definitely want to get rid of that mold before trying to move that air upstairs.  For this reason, we can’t recommend circulating basement air in the rest of your home.

Whichever way you decide to cool your home, make sure that air quality doesn’t suffer.  Our Germ Defenders, Mobile Air Angels and Whole Home Ionizers sanitize air using bipolar ionization, killing microbes and agglomerating dust and pollen so it’s easy to filter or clean.   Extreme heat tends to lead to increased air pollution, so be conscious of air quality when you open the windows, or even when they are closed and outdoor air seeps in (as it always does except in the tightest of homes).   Check out our article to find out how to ride out a heat/air pollution wave safely!

Photo by Glen Carrie on Unsplash

What is Salutogenic Design? How can we use it in our homes?

What is Salutogenic Design?  How can we use it in our homes?

Salutogenic design comes from the two Latin words ‘salus’ meaning health and ‘genesis’ meaning origin.  It is the study of the origins of human health.  Aaron Antonovsky was an immigrant to the US in the 1920’s, eventually being drafted into the US Army in World War II and serving in the Pacific.  Much later after obtaining his doctorate in sociology, Aaron studied survivors of concentration camps and wondered, why aren’t more of them in very poor health?  It was his questioning of the means and causes of good health, rather than what causes disease, that set him apart. (The Handbook of Salutogenesis, Chapter 3, Aaron Antonovsky, the Scholar and the Man Behind Salutogenesis

Normally salutogenesis is focused on healthcare settings and providers.  However, we can take the same concepts and apply them to our workspaces and homes. In today’s news, we’re constantly being made aware of environmental and human threats like viruses and toxic spills that threaten our health.  The possible effects,  such as cancer, high blood pressure, and sickness, are always presented to admonish us, avoid this or suffer consequences!  It’s definitely hard to tune out these sources.  However, if we’re able to focus on what makes us feel good, the results could be much greater.  Whether you’re designing a home from the ground up or have some time and budget to make some changes, here are some concepts from salutogenesis to keep your perspective in the right place: your health.

Louisa Grey is a designer living in north London who has embraced salutogenic design.  She prioritizes space, light and air in her projects by identifying the direction of natural light and the optimum layout to encourage airflow.  She admires the design of southern Italy’s trulli (ancient homes made out of limestone with conical roofs) and often incorporates a similar building material–clay–in her modern works, because it is naturally abundant, has acoustic-controlling qualities, is dehumidifying, regulates temperature and can improve air quality.  Clay plaster on walls has a soothing texture and appearance that gives a rustic, hand-crafted look to rooms, which also saves on energy in manufacturing and reduces waste. (Interiors expert Louisa Grey on how to embrace salutogenic design)  

Well-placed windows should allow the right amount of sunlight into your home, such that it doesn’t cause a large cooling load but rather allow a range of filtered or dappled light.  There are a number of companies that also offer faux skylights (thus avoiding any leaks or roof problems!) when natural light is at a premium.  

Open-concept floor plans do have the advantage of seeming more spacious than the same size traditional floor plan, but there is also comfort and peace in having walls and doors define some spaces, like an office or home library.   

Porches, courtyards and the ability to open large windows or doors to the outdoors (in areas with good air quality) are very beneficial because they allow fresh air to fill your home and to warm or cool it.  Plus, they are an ideal place to keep plants that need a little shade or protection and surround your seating areas in green.  Even views of green–from inside the house–lower stress, lower blood pressure, improve cognitive functions (like your ability to learn or focus), increase productivity, reduce anxiety, improve mood … the list is extensive! (How Your Home’s Design Can Improve Your Health)

If you are not building from the ground up, however, there are still ways to apply this type of design in your home.  According to the previous source, one of the most popular methods of salutogenic design is to incorporate biophilic design, which is based on human’s innate connection to nature. To do this, you can incorporate plants into your home, a calming mural, or the actual “architecture” of nature such as a natural stone fireplace, spiral staircase, or live-edge shelving that protrudes at different widths and heights on a wall.  Honeycomb shelving or tiled floors also mimic natural shapes.

Texture and comfort inside the home are very important.  (Although rugs and upholstery can hold dust and dust-mites, the way they “warm up” a room to make it inviting and comforting is important enough to use them when you can.  Also according to Louisa Grey, scents are can also be a healing part of your home: try to use natural oils and purifying mists and flowers that are grown locally. (How to design a healing home – and the power of salutogenic design)

Salutogenic design can even encourage healthy behavior when features like stairs or a swimming pool are included, or workout areas are not tucked away into a back corner or basement (you pass by them on a regular basis).  A beautiful library space, whether it’s an entire room or several bookshelves and a comfortable chair with good light also encourages learning. (Salutogenic Approach to Design is at the Core of Wellbeing)

Salutogenic design follows the principle that “an ounce of prevention is worth a pound of cure”.  Many homeowners make this choice everyday: should we go for small pieces of quality workmanship in our decor, appliances and clothing, or larger but lower-quality items?  It’s true that good design, building and decor may cost more than “builder’s grade” plans and materials, but what you should reap is a lifetime (or at least as long as you can live there) of better air quality, ergonomic ease, increased productivity and creativity, lower stress and overall wellbeing.  Who can put a price on that?

Photo by Andrea Davis on Unsplash

Q: Do Air Handlers Belong in the Attic?

Q: Do Air Handlers Belong in the Attic?

A: It depends!

(Don’t you love that answer?!)  Every one’s home is different, as well as where their home is built (climate), so there aren’t hard and fast rules, but we can surely show you the pros and cons of putting your air handler in the attic.

First of all, an air handler is part of a split system central AC unit.  In these systems, there are two distinct parts: one contains the condenser that changes the refrigerant from a gas to a liquid to release the heat from inside the house (the condenser is usually located outside), and a second part that contains the evaporator (which absorbs heat from the house air) and a blower to move air through ductwork to different rooms.  This second part is called the air handler and because it’s not super quiet and can take up a good amount of space, many people install their air handler in the attic.

The attic may or may not be a good location for your air handler.  Here’s how to know: is your attic conditioned, or unconditioned?  Conditioned attics are considered part of the building envelope and they are insulated.  Conditioned attics don’t have to be “finished” per se with drywall and nice flooring, but they do need to be air-sealed from the outdoors.  Air handlers CAN belong in conditioned attics. 

Unconditioned attics (also called vented attics) are exposed to exterior temperatures through ridge vents, gable vents, soffit vents or powered vents.  There is no “air conditioning” so humidity, dust, insects and extremely high or low temperatures are all present in an unconditioned attic.  Air handlers DO NOT belong in unconditioned attics.  Why?  

  • For one, the air handler is responsible for moving the air you breathe, and even a small leak in it or the ductwork will pull humid, dusty, unconditioned air from the attic into your home.  
  • Extreme temperatures cause your air handler to work less efficiently, which translates to higher heater and cooling costs.  
  • The air handler is an expensive piece of equipment that can cost thousands of dollars; to minimize breakdowns and maximize its life, it’s best to place it in a clean, moderated environment!
  • Accessing and crawling around a dirty, dusty attic makes routine maintenance or needed repair work more difficult.
  • If the condensate drain plugs up and overflows the pan under the unit, guess where that water will go?  Onto and through your ceiling!

“Conditioned space” in your home costs money, because it is part of the square footage that realtors count when valuing your home.  For this reason, homeowners and many builders prefer to stick the air handler “out of sight and out of mind” in the attic or worse, in an unconditioned crawl space.  Now that you know better, if you have the opportunity, give your air handler an “upgraded” installation spot in your home.  Here are some tips for finding that spot:

  • The air handler should be centrally located in the home in order to minimize ductwork run lengths to all rooms.
  • Closets are better than the attic, but without enough room to do maintenance on your unit, small closets are not ideal.  Without room to walk or reach around the unit, HVAC technicians will have a hard time making good sealed connections with ductwork, and if anything needs repair, it takes longer to do it, possibly requiring removal of the whole unit.

It’s tough to understand how this air handler and ductwork were installed in such a small space.  (Source: energyvanguard.com)

  • A large utility space is ideal.  You will not want carpet or hardwood below the unit, so that any water leaks can be cleaned up easily.  Good lighting also makes it easier for you to check on the unit from time to time, and to change any filters.  

When replacing your air conditioning unit, we hope you will give serious thought on where to locate the new air handler.  Giving it preferential space inside your home will give you quality air for years to come.  It’s important, however, to make sure that:

  • This room or large closet has its own air supply and return, because when air gets sealed behind closed doors (and you will want to close the door to isolate the unit acoustically), mold can develop.  This can be accomplished by placing a grille in the return of the air handler, and placing a supply grill in the wall or through the ceiling with a “jump duct”. This article from renowned building scientist Joe Lstiburek shows the flaws of different locations and how to overcome ventilation issues.
  • Locating an air handler next to a gas appliance such as a gas hot water heater can be problematic, unless it is a “sealed combustion” unit.  The air handler will cause the room to be under slight negative pressure while the fan is on, which can affect combustion and venting of the water heater.  
  • If your furnace is a gas furnace, you’ll need to make sure it also gets adequate combustion air.

If you can’t bring it inside your building envelope, you may consider a unit that doesn’t require big air handlers–namely, mini-split units.  One external compressor/condenser can supply several indoor units (evaporators), which are typically hung on the wall, with only small refrigerant and drain lines running between the inside and outside.  Where there’s a will, there’s usually a way!


Insulating drafty windows makes a difference in air quality, not just energy savings!

Insulating drafty windows makes a difference in air quality, not just energy savings!

When you’re trying to make a whole house less drafty, you should go for the low-hanging fruit first.  That means big ol’ holes in the walls, floor or ceiling (like this disconnected register) come first.  If you don’t have any big holes, you can start on the smaller ones–and sometimes the smaller ones can add up.  That was the case in my sunroom. 

My sunroom is west-facing, which means in the summertime it gets brutally hot from sunlight, and in the wintertime it’s brutally cold from westerly winds.  On top of that, it’s fairly dusty and showed some of the highest counts of mold colonies in my home.  When I saw another cold front coming later in the week in December, I finally “made” the time to insulate the windows where I felt the drafts coming in.  I saw that the lower windows didn’t seal at the bottom when closed, AND the previous owner had cut the corners on the lift at the bottom for some reason (they rubbed on the trim?).  Due to these leaks, the room stayed quite “fresh”--meaning the CO2 didn’t really budge from outdoor levels unless I lit a fire in the fireplace on the other side of the room.  If you don’t have a CO2 monitor, I highly suggest getting one: here’s a portable version.

Therefore, the cons of my leaky windows easily outweighed this one “pro”: fixing them was a no-brainer!

Pros

Cons

Better ventilation (lower CO2)

More drafts of hot or cold air (higher energy cost)

More dust or pollution

More mold 

Excess humidity in house

Here are the tools I used: 

  • A spray bottle of TotalClean and several rags for cleaning the windowsills
  • Adhesive-backed weatherstripping in a suitable color to match your windows (low-profile like this one, ¼”, is good unless your windows are very misaligned) 
  • Scissors
  • Optional: A CO2 monitor is helpful–to see the effect on the room
  • Optional: Window locks in case the windows don’t lock afterwards (see below)

If you do have a CO2 monitor, leave the windows closed and take a CO2 measurement before doing the insulation work. You might want to do it while there are a number of people in the room, or you have a propane or natural gas stove burning (I know there are a lot of gas stoves out there!).  Extra people and gas appliances do two things–they consume oxygen and they give off CO2.  These should cause the CO2 to be higher than when the room is empty or no gas appliances are lit.

Next, just get down to it: use the TotalClean and rags to clean off the window sill where the lower half of the window seats.  If you have vertical sliding windows, find the best place to attach the insulation in the vertical track and clean that.  When the track is clean and dry, start peeling the adhesive backing off and apply the weatherstripping a little at a time, cutting it when you get to the end of the track. Close and lock the window to make sure it’s placed correctly.

If you find your windows don’t lock because of the extra height of the insulation (this was the case for my windows) there are a number of window locks available that can be easily removed if you have to open the window for ventilation.  I ended up getting a thumb-screw version that can be moved up a few inches if I decide to ventilate, while still keeping the window secure.  

That’s it!  When you have all of the insulation installed, close the window and repeat the CO2 reading, with or without activity (people or gas-burning appliances).  The CO2 levels should go and stay higher because there is less fresh air coming in.  Fresh air ventilation is needed in a home, but it’s best to do it in a controlled way, not just letting the air come in wherever there’s a small gap or crack.   For more ideas on how to air seal leaky windows, check out this video.

If you’ve completed an easy project that resulted in better air quality, let us know about it! 

Photo by Rob Wingate on Unsplash

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

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

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