Category Archives for "Air Quality"

The Hidden Danger of Gas Appliances

The Hidden Danger of Gas Appliances 

Ok, confession: I didn’t learn the meaning of the expression “You’re cooking with gas now!” until I was about 25 because I didn’t grow up in a home with a gas stove!  When I learned it, however, I knew I wanted a gas stove in my own home because I like to try new recipes and of course, restaurants had gas stoves.  Gas was supposedly the best.

Fast forward to today—I have had gas stoves in my other homes, and no doubt it is a different method of cooking!  My current home has an electric stove (because it came with the house) but that renovation priority is declining because of new information about the by-products of burning gas.

Burning natural gas or propane in indoor appliances causes particulate matter (PM), nitrogen dioxide (NO2), carbon monoxide (CO) and formaldehyde to be expelled into the air, which are not adequately vented by exhaust fans. Gas stoves are the largest polluter but gas heaters, water heaters, and clothes dryers all contribute.  A 2013 meta-analysis (analysis of 41 studies) concluded that NO2 indoor air pollution from gas cooking increases the risk of asthma in children by 42% and increased wheeze (breathing difficulty).  Cooking on a gas stove in a small apartment for one hour raises NO2 levels in the air to easily surpass air quality limits set by the EPA and California Air Resource Board, or CARB.  Venting does help lower these levels, but many lower income families use stoves in kitchens that are unvented, though they are illegal.  In another meta-analysis, exposure to NO2 and COPD were positively associated.  

For the benefit of the young to the older members of your household, we hope that you will re-think “cooking with gas”! (and heating with gas, and drying your clothes with gas…)  As for me, my grill outside is working just fine!

What are VOCs?

What are VOCs? (They can’t be seen, but they’re all around us…)

VOCs are Volatile Organic Compounds.  “Volatile” refers to the low boiling point of the compound that causes it to disperse easily into the air.  These are emitted as colorless, sometimes odorless gasses from things like furniture, paints, cleaning products, copy machines, etc.  When released in your home, these gasses can build up to 2 to 10 times higher than concentrations outdoors.  VOCs can irritate your eyes and nose, cause headaches and nausea, damage organs, and some can even cause cancer.  Blast from the past: anyone remember “dittoed” homework sheets with a fragrant purple ink?  VOCs to the max!

In the past we may have needed olfactory proof that the cleaning product was working, but today “VOC-free” has become the smarter way to buy and live.  Although the paint industry provided some of the most visible and better-smelling changes in product, it’s a bit more complicated when it comes to laundry and cleaning products, because “fragrance-free” does not always equal low VOCs.

Although at the top of this post I noted that VOCs are “sometimes odorless”, which means there are some VOCs you can’t detect by smell, most people associate their negative reactions to products with fragrances.  In this study, people in the US, UK, AU, and SE were polled for sensitivity across a wide range of products and situations (like being around others wearing fragrances, smelling dryer vent emissions, exposure to air fresheners, deodorizers, and cleaning products), which showed approximately 32% of the general population has sensitivity to various fragrances.  The study analyzed results of 5 other studies of 249 common consumer products like air fresheners, laundry products, cleaning supplies, personal care products, essential oils and car air fresheners, to identify the top hazardous VOCs.  Ethanol was most prevalent in fragrance-free compounds, while terpenes like limonene, alpha-pinene and beta-pinene were most prevalent in fragranced products.  There were no terpenes in fragrance-free products, so the study went on to focus on terpenes, which can react with other compounds indoors to produce formaldehyde and ultra-fine particles. The most surprising takeaways from this study, is that:

  • “...fewer than 4% of all VOCs, and fewer than 5% of potentially hazardous VOCs, were disclosed on any product label, safety data sheet, or elsewhere”.
  • “ significant difference was found in the emissions of the most prevalent potentially hazardous VOCs between green (organic, natural) fragranced products and regular fragranced products”.

What does this mean for us when we go shopping for cleaning products or personal-care products?  Fragrance-free is better, because it indicates a lack of terpenes, a major class of VOCs.  And we need to do the research… because the label won’t tell us about VOCs and we don’t own the scientific equipment (beyond our noses) to detect them.   

Fortunately, there is help out there!   GreenSeal is an organization that is dedicated to advocating, testing and certifying products that are non-toxic, low-VOC, carcinogen-free and phthalate-free.  They have a huge database of products that are certified to meet these standards, such as the “general purpose cleaners” page.   Also, the Environmental Working Group (EWG) is a non-profit which has tested thousands of products and grades them on their website, and has a healthy cleaning guide

There are also many great privately owned websites that review cleaning and personal-care products that have few or no VOCs.  Here are a few of them:

  • is run by a team of family-oriented professionals with a passion for research and healthy living.  Here is their guide on safe mattresses and it includes several discount codes!
  • is produced on Native American lands.  Here is their list of the 15 best non-toxic laundry detergents. 
  • is a great resource for those who like to make their own products.  Here is a page with links for making everything from baby wipes to carpet deodorizers to candles! 

Now you know that not everything labelled “green” is actually healthy.  Cookware is whole ‘nother topic I’m afraid, but you can check it out in our post “Is My Cookware Safe?”

The Science of Humidity and how it affects us

The Science of Humidity and how it affects us

Humidity is super-important to our health, and the health of the spaces in which we live (which in turn affect our health).  But do you know how humidity is measured and how it affects us?  

Humidity is the concentration of water vapor in the air.  Necessary to life, we need water in the air we breathe, as well as to drink.  Water vapor hydrates our respiratory pathways and secondarily, enables us to stay warm–or cool.  Humidity is measured in percentage–but a percentage of what?  

Sometimes it’s easier to imagine a liquid, instead of a gas.  If you’ve ever dissolved sugar into water and keep adding sugar, there comes a point where the water will no longer hold any more dissolved sugar–the sugar will lay at the bottom of the container–at that temperature.  In order to dissolve more sugar, you will need to increase the temperature of the water.  This is the saturation point of the water for sugar.  Air works in the same way.  There is a maximum amount of water vapor that the air can hold before–you guessed it–it starts raining.  To increase the amount of water vapor, air temperature must increase.  Warmer air can hold more water vapor than cooler air, the same as warmer water can hold more sugar than cooler water. 

So then, “relative humidity” is the percentage of maximum water vapor the air can hold at a specific temperature.  It’s all “relative” to the temperature.  If you had 2 rooms at the same temperature (say 78 deg F), but one had 60% percent humidity and the other had 40% humidity, the 60% humidity room is holding a lot more moisture in the air, at the same temperature.  It is a noticeable difference.

Humidity is usually higher during summer months.  In the US, we are accustomed to the Heat Index (HI), “a measure of how hot it feels when relative humidity is factored into the air temperature.” (MintLounge, 2020)  But a more accurate picture of the stress heat and humidity have on the body is given by “wet bulb temperature”.  Essentially, a wet "sock" is put over the bulb of a thermometer, and it measures “the lowest temperature to which air can be cooled by the evaporation of water into the air at a constant pressure.... (In contrast) The dry bulb temperature is the ambient temperature. The difference between these two temperatures is a measure of the humidity of the air. The higher the difference in these temperatures, the lower is the humidity.” (, 2007).  It is very important to human life because it governs how evaporation of sweat into the air cools our bodies.  Think of the thermometer in a wet sock as your body covered in sweat.  When wet bulb temperature = ambient temperature, the sweat is not evaporating, because humidity = 100%.  If we dial up the heat, no evaporation allows no heat loss, which causes rapid overheating.  Scientists have marked 95 degrees F (35 degrees Celsius) at the upper limit of survivability: at or above this temperature/humidity combination, the body will overheat, causing organ and brain damage and death.   During this research, I looked at a country that knows heat: India.  India has been suffering with extreme heat for several years now.  2015 saw the country’s fifth deadliest heat wave (2400 people died), and other records were set in 2016 and 2019.  

Compared to the heat index in summer, wind chill is that mystifying element that makes cold northern winter days (usually drier, lower humidity) seem bearable and damp southern winter days seem very chilling!  Higher humidity causes the clothes we wear to retain moisture, which being next to our skin, will wick heat from our bodies, chilling us. 

If then, “feels like” temperature is most important, we can focus on controlling the humidity in our homes along with temperature.  

Humidity is super-important in heating and cooling.  Air kept at lower humidity is less costly to heat and cool.  Why is that?  Going back to the liquid analogy, think of boiling water on a stove or microwave or kettle.  Which takes longer to boil at the same heat level: 1 cup of water, or 3 cups of water?  Three cups, of course!   When trying to cool a humid room, the same principal applies–most of the energy is spent actually changing the temperature of the water vapor in the air.  Therefore lower concentrations of water in the air (lower humidity) takes less energy to cool.  The same thing happens in the winter: overly humid air takes longer (more energy) to heat.  According to, “hot and humid areas use 21.1% of their energy on air conditioning each year, while hot and dry areas only use 9.6% of their energy to air condition.”

Most importantly, the effects of high and low humidity have direct impacts on our health.

Water vapor in the air (humidity) is essential to keeping our nasal passages hydrated.  When the humidity drops low, the air is dry, and nasal passages feel congested because they are dried out and inflamed.  Eyes become irritated because tear production cannot keep up.  Skin becomes dried out, feeling itchy and more susceptible to infection.  In the age of coronavirus, air with low humidity is more hospitable to the spread of the virus in aerosol form (fine droplets that occur when someone sneezes or coughs).  This is because the water entrained with the virus quickly evaporates in dry air, allowing the virus particles to float indefinitely.  Drier virus particles actually survive longer by floating in the air than those encapsulated in heavier water droplets, which fall quickly to the floor. (

On the high side, too much humidity is also bad.  Excess water vapor in the air contributes to mold growth, more pests (insects and mites), and structural damage due to mold and rot. 

For many years, the optimal humidity range of indoor environments was 30-50%.  Due to the current coronavirus pandemic, some doctors are petitioning for the World Health Organization to change the recommended range to 40-60% relative humidity (  What is the top factor on CNN’s list of ways to prevent flu in your home?  Control humidity!

Humidity is a huge factor for optimizing our home environment, then!  How do we measure and control it?

To measure humidity, sensors like these are cheap and easy to place around your home (this particular type have built-in batteries, but you should check the battery requirements of others before purchase). 

Now–what do I do if I’m below 30%?  Typically, low humidity (below 30%) occurs in winter months when we turn on indoor heat, making skin and nasal passages dry and irritated.  Humidifiers help by introducing moisture into the air.  You can place a portable humidifier in the most-used room during the day, and move it into your bedroom at night for more comfortable sleeping.   If you are not sensitive to fragrance, some humidifiers allow you to add a few drops of essential oils for a pleasant scent.  Whole-home humidifiers can also be installed in your HVAC system.  If you are looking to increase humidity in your home as well as clean the air, you may consider an “air washer”.  This type of unit uses a stack of thin discs to capture dust in the air, which is then “washed” off the disc in a water reservoir.  Clean air that is exhausted from the unit is more humid.  It is a low cost air purifier/humidifier combination that only requires regular addition of water and rinsing out the disc stack.

What do I do if my home is above 60%?  Now this is a more common and complex problem.  Sometimes it is the outside climate coming inside through air leaks, and sometimes it’s a source of water inside the home that can be corrected to bring indoor humidity down.  You can check out our Indoor Moisture Inventory which will walk you through the most common ways to reduce indoor humidity.   If it's still too high after mitigation, you can hire a professional to perform calculations and recommend dehumidifier units, or in this age of DIY, you can actually calculate and research (and install!) units on your own. 

Here is a simple table that takes into consideration the square footage of your home and it’s “tightness” (insulation level and leaks).  According to this, I need about an 8.0 gallon-per-day dehumidifier unit for my 2000 square foot “average” home.   Here are how the measurements are factored into the sizing.   However, since my AC system is older (more than 10 years old), it would most likely be most cost-efficient to replace the whole system with a new system that includes a dehumidifier!  

Humidity control should be a top priority in all of our homes and indoor spaces–why not take some steps today?

Finding and Attacking Mold in the HVAC System

Finding and Attacking Mold in the HVAC System

I turned on the AC in my home last spring and a musty smell gave me suspicion that there was mold growing somewhere in the ventilation system.  I determined that I would not stick my head in the sand, hoping it would go away after more use.  I didn’t want mold to be distributed through my house via the HVAC, so I planned a “search and destroy” mission!  

I have to say that I lack fear about a lot of things, but experience has made me a bit more cautious.   I used to reclaim wood and would pick up interesting pieces off the curb.  This resulted in making me violently ill one time when the scavenged wood had black mold on it. Mold is dangerous, so if you think your A/C system has mold, you will want to wear a protective mask (more than a thin cloth or paper mask; N95 is ideal) and wear old clothes: plan to shower, wash hair and launder your clothes afterwards.  If you are highly allergic to mold or just squeamish, this is best left to someone who isn’t.

Timing: You will need to shut down the AC for at least an hour, possibly several.  For this reason, and the fact that the air handler is often located in the attic, don’t plan this project in the heat of summer (at least in the daytime).


  • depending on the model of air handler, various screwdrivers and socket drivers
  • Small containers to hold the screws
  • A flashlight or headlamp
  • A spray bottle containing hydrogen peroxide (3% is the standard solution sold over the counter—works fine. ) OR
  • A spray bottle containing 50% white vinegar and 50% water.  However, DO NOT MIX VINEGAR WITH HYDROGEN PEROXIDE!  It creates poisonous fumes.
  • Paper towels or disposal rags
  • Plastic bag(s) to hold contaminated towels or rags
  • A cup of hydrogen peroxide in a small pouring cup OR A cup of vinegar . (DO NOT MIX VINEGAR WITH HYDROGEN PEROXIDE!)
  • A roll of foil HVAC tape.
  • A can of wasp spray on hand if your attic has any access to insects (ie. through a ridge or gable vent)

First, switch the AC off at the thermostat and place a piece of masking or blue tape over the switch.  Then identify the circuit breaker that controls the AC in the breaker box, switch it off and tape over that breaker.  Although we won’t be messing with electricity, you don’t want the fan to come on while you have the air handler open, blowing mold spores everywhere!

Set yourself up next to the air handler in the most comfortable way (usually these spaces are tight, I know!).  Identify the drain from the coil unit, which is usually white PVC pipe.  This pipe drains condensation that drips off the coil while it is cooling the air passing through.  The condensation is a major source of moisture for mold, so if the condensation is not draining properly, it can 1) harbor mold and 2) back up and flood the drip pan, causing water damage to insulation and sheetrock and more mold.  If you’re already experiencing problem #2, it’s probably due to algae growing in the pipe and blocking it.  You can go outside and use a wet-dry vacuum on the end of the pipe to clear the blockage, then keep going with the next step here.

The white plastic pipe coming from the air handler should have a small bend in it.  This acts like a P-trap in the drains of your house, keeping vapors in the unit with a liquid “trap” .  Ideally there is a capped “vent” on the pipe.  You’ll need to unscrew or pull the cap off, pour the liquid hydrogen peroxide OR vinegar in, and replace the cap.  This will prevent algae from growing in the pipe and blocking it.  HVAC professionals recommended to do this about once a month during peak cooling season.

Next, put on your mask and find the access door on the air handler that is closest to this pipe.  We’re going to check for mold in the drain pan.  Remove the door and shine the light inside.  If you find mold,  don’t touch it directly.  First, saturate the area with the hydrogen peroxide in the spray bottle.  Let it sit on the mold ten minutes.  Then, use the rags or paper towels to clean the surface thoroughly and dispose of them in plastic bags as you go.

While you are waiting for the hydrogen peroxide to take effect, you can remove other doors around the coil to see if the mold spread to other areas.  I found that the compressor motor body was covered in it (this is another reason you need to turn off the electricity before starting) and some other places inside the duct. 

Try to determine the source of the mold.  If the drain pan was draining correctly, but there is still mold, it may be that the unit needs more insulation internally or externally.  Insulation prevents condensation where there should be no condensation, which is everywhere except the evaporator coils!

If you can, apply a Mold Preventer spray to the problem areas.  Some are effective up to 3 months, so even if you are not successful at stopping the moisture problem right away, this will prevent the mold from recurring for a time (buys time). Here are some non-toxic options:

While you are in the attic, check for screws or joints that are loose, that can cause an air leak.  Warm air leaking into the system will cause condensation, so if you find one, try to seal it up with the appropriate fastener or at least, the HVAC tape.  Also check for missing insulation on ducts.  If your attic routinely gets into the 90 degF or hotter range, then the white condensation drain pipe (that drains cool water through a hot space) should also be insulated to avoid dripping into the attic.

Now that the mold is removed and prevented, you can seal everything back up and get clean!  Here are the follow-ups you need to look at to mitigate mold:

  • The other source of mold food is dust.  Less dust = less mold!  Use the best HVAC filters you can afford and be sure they fit well and you change them on schedule.  HEPA filters really do help.
  • Consider installing a dehumidifier to help with the efficiency and lower mold growth.
  • Consider installing a BP-2400 to continually prevent mold not only in the system, but throughout your home.
  • If your system is over ten years old, many HVAC professionals suggest replacement of the complete system for efficiency and cleanliness.  Get quotes and consider other types of heating/cooling systems, which may be less susceptible to mold issues.
  • Some HVAC companies apply a polyurethane coating coat to their heat exchangers, which keeps the coils cleaner (saving energy), discourages mold growth (better air), and extends coil life by 3-4x.  Madd Air in Texas is one of them. 

Mold in the HVAC system is worth looking into. as you and your family's health depend on it! 

How to Improve Indoor Air Quality with Pets

How to Improve Indoor Air Quality with Pets

Pets are part of the family, so we just need to work smarter to keep everyone healthy even when one family member releases more allergens than all the others combined (ahem…)!   Here are the allergens we need to be aware of with pets:

  • Fur…not!  Actually, pet hair is not an allergen according to the AAFA, the Asthma and Allergy Foundation of America.  Pet hair can carry allergens like dander, urine and saliva.  Another myth:  there is no such thing as a “hypoallergenic” pet!
  • Dander, tiny bits of skin and associated microorganisms that live on it
  • Saliva
  • Urine and feces

The AAFA have a number of suggestions to cut down on allergies associated with pets, such as removing the pet from the bedroom, and asking someone without an allergy to brush the pet outdoors and change litter boxes (some of these are more feasible than others!!)  We think that the following suggestions are the most helpful:

  • Even if you have a non-shedding pet, their dander can still be an allergen.  Invest in a vacuum cleaner with a HEPA filter and use it often, and use an N95 mask while doing so and afterwards.  Anyone else in the home at the time should also wear a mask during and after vacuuming, because it stirs up dander and dust from surfaces into the air.   Here are some vacuum cleaners we recommend: 
  • Brushing your furry pets definitely helps them to shed hair and dander in a controlled way (preferably outside or during bath-time!)  You can check with your vet for their recommendations, and here are some pet brushes that are above average:
    • Furminator brushes have been reviewed by many to drastically reduce loose fur flying around the house.  The website helps you choose the right brush for your dog or cat, but the products are found on many sites.
    • Hartz Groomer’s Best Combo Brush is two-sided to allow you to detangle and remove longer hair, and slick down shorter hair. 
    • Chris Christensen has a full range of dog products which allow you to shop by breed (Azawakh, anyone?)
  • Bathing dogs and cats on a regular basis helps to keep their skin and coats healthy–check with your vet for bathing frequency and products, and check out this lineup of natural dog shampoos.  After all, if you are concerned about VOCs and toxins in your personal care items, your pets deserve the same care!
  • Pet Urine and feces…happen in the house sometimes.  Apart from training them to use your toilet (yes it’s possible), cleanup is a fact of pet owner life.  Fortunately sanitizing and deodorizing cleaners have evolved and do not have to over-scent your home to neutralize the odor.  Consider moving an Air Angel unit closer to the site of the accident (or where the litter box is stationed) to eliminate any residual odors.  Here are some other options that definitely help!
    • Colorfil manufactures HVAC filters that are especially helpful to pet owners, who deal with ammonia smells and related chemicals in urine.  The filter material turns from a magenta pink when clean, to a dull yellow when dirty, due to citric acid compounds that react with contaminants.  The company began to create innovative filter systems for NASA spacesuits in 2016 and moved on cabin air filters for vehicles and HVAC filters.
    • For natural, non-toxic cleaners that remove stains and odors, check out this extensive list.
    • Cat litters are quite varied but you should consider some major toxins in this product category.  Sodium bentonite, for example, is the clumping agent used in many litters, yet it is toxic when ingested by cats.  Dust created by some clay or silica-based litter is harmful for people and cats. Here is a list of natural litters with less chemicals.    
    • Another solution to the cat litter odor problem can be used with any type of litter because of a genius invention: a litter box with air filtration!  This one by BioStrike is very sturdy and the filters require changing every 3 months. 

I think you’ll find that the “positive reinforcement” of a cleaner home and easier breathing is worth the effort when it comes to fighting pet allergens!

OH (BLANK), it’s allergy season again

OH (BLANK), it's allergy season again

To my great surprise and disgust, one can develop allergies later in life, and not only in springtime.  This was the case despite living in the same city (New Orleans) for over 12 years.  I used to be amazed at the green coating on my vehicle and washed it off weekly without any respiratory reactions, but then suddenly one March, I was aware of SPRING.  Only in hindsight (when it’s nearly impossible to counteract the raging histamines and inflammation), I realized, am I allergic to pollen?  A couple years later, the onset was in the winter after a particularly rainy period and I was overwhelmed again. 

Even staying inside during “high pollen count days” is of little comfort if your home is not armed against pollen.  Here’s what we’re talking about: neutralization and filtration.

Neutralization breaks apart contaminants, makes them less harmful, or changes them for easier removal from the air.  Neutralization with HypoAir products looks like this: the polar ions cluster around contaminants such as pollen grains and mold spores (both are allergens, as the pollen grain comes with actively pollinating plants and the mold may come during/after a wet season), causing these contaminants to become heavier and drop out of the air, or more easily filtered out of the air (next step).  

Filtration is the next key.  Fortunately, pollen grains are relatively large in diameter, 10-17 microns in size.  That means you don’t need a HEPA filter (which target particles about 2.5 microns and larger) in the HVAC system to get most of the pollen out of the air.  What we recommend is changing the HVAC filter slightly early during high pollen season, even if you don’t see a visible change in the filter.  We do continue to recommend HEPA filter vacuums (or their equivalent like the Sirena) because the pollen on the floor will be entrained with smaller particles and they all need to GO!

You also need to consider the air you let into your home.  Just because it’s allergy season, it's not necessary to padlock your windows!  This is especially true in milder climates that don’t even require air conditioning or heat for much of the year, like southern California or Hawaii.  There are several products on the market that let you leave the windows open, but keep the pollen out.  Here is an allergen-filtering window screen material that is easy to wash down and maintain.  You can replace the material in some or all of your windows with this material (many local hardware stores have services to help with this).  

Circulation/movement of air through your home is a good thing; it enables air conditioning, heat, humidification or dehumidification to work more efficiently.  If you use ceiling fans to help circulate air in your home, you can check out these filters by BioStrike.  They are applied to the top of ceiling fan blades, and customers do see a difference in their cleanliness of their fan blades and surrounding area. 

Allergens are everywhere outside, so remember when entering the house, taking off outer layers can prevent spreading the allergens around inside.  This is especially true before going to bed.  Taking a shower before bed, washing or rinsing your hair, and changing your pillowcase more frequently can prevent you from breathing in allergens at night.   Contact us at HypoAir for customized recommendations on making allergy season(s) less painful for you and your family!

Humidity and an Indoor Moisture Inventory

Humidity and an Indoor Moisture Inventory

It is our core purpose at HypoAir to help you bring what’s best about outdoor air, indoors.  Replicating outdoor air indoors, though, isn’t always easy.  Sometimes outdoor air can be overwhelmingly humid, supporting all kinds of mold and bacterial growth on surfaces.  There are differing opinions on optimal indoor humidity: some sources say 30-50% while newer research indicates 40-60%.  Whichever advice you adopt, if your home humidity floats in the 40-50% range, you are doing well! 

Here’s what’s good about this particular range:

  • Better health: this encompasses so much:
    • better respiratory health due to proper humidity levels
    • less mold growth affects all areas of the body
    • bacterial and viral transmissions are suppressed
    • healthier skin and hair
  • Lower cooling costs
  • Fresher food

To measure humidity, sensors like these are cheap and easy to place around your home (this particular type have built-in batteries, but you should check the battery requirements of others before purchase). 

Now–what do I do if I’m below 30%?  Typically, low humidity (below 30%) occurs in winter months when we turn on indoor heat, making skin and nasal passages dry and irritated.  Humidifiers help by introducing moisture into the air.  You can place a portable humidifier in the most-used room during the day, and move it into your bedroom at night for more comfortable sleeping.   If you are not sensitive to fragrance, some humidifiers allow you to add a few drops of essential oils for a pleasant scent.  Whole-home humidifiers can also be installed in your HVAC system.  

It’s more common to be over 60% humidity.  Sometimes it is the outside climate coming inside through air leaks, and sometimes it’s a source of water inside the home that can be corrected to bring indoor humidity down.  Here is our Indoor Moisture Inventory which will walk you through the most common ways to reduce indoor humidity. 

Indoor Moisture Inventory

Air leaks:  Insulation and weatherstripping are boring but vital!!  I live in a home that was originally built in 1982.  Since the original build, the outdoor “porch” was closed in with no ducts for air conditioning and heating, a laundry room was added on, and a second story office was added over the porch with –yup–no air conditioning or heating.  Now, the porch-turned-“sunroom” is everyone’s favorite room because it has a long wall of windows showcasing the lake below.  Unfortunately, though, it’s one of the biggest sources of my moisture problems!   Some of the windows were drafty (you can do this candle or smoke test to find air leaks) and during storms, you could literally feel the wind coming around the windows into the wall.  All of the air leaks also cause humidity to come into my home.  What to do?  I had to ruthlessly find the air leaks and seal them. 

Windows: Now, I had recently (3 years ago) renovated the outside siding on the sunroom and made sure to seal it as much as possible with a vapor barrier, window sealing tape and caulk.  But, some of the drafts persisted.  I wanted to find a good indoor caulk that had low VOCs, because I would be doing the caulking during the winter when opening the windows to ventilate was not an option!  I found that a few caulks offer “Greenguard Gold” certification, which warrants that a product “has been tested and scientifically proven to have low chemical emissions”.  

Doors: Checking for drafts around my front and back doors revealed, indeed, they needed work.  Anywhere you can see daylight is number one priority, and even without daylight views, weatherstripping is a must.  

Other air leaks: Outlets and lightswitches on exterior walls are very likely to have air leaks.  You can seal these off with a pack of inexpensive gaskets like this.   Also check attic doors and can lights under attic space. 

Cookstove ventilation:  It’s so important to have a properly-sized, working vent hood for your cooktop and microwave, for several reasons.  Cooking releases a lot of moisture into the air, which increases humidity in your home.  Also, the other gasses released, such as cooking odors and VOCs from burning gas fuel, should be vented outdoors too.  Now, when you are venting from the house, you are actually pulling conditioned air from your home and exhausting it outside, creating a negative pressure (causing unconditioned air to leak into the house).   When it’s super-humid outside, guess what–even more humidity comes in.  With new-build construction and renovation, vent hoods with fresh-air intake can be installed that pull fresh air from the outside and are drawn right back out through the exhaust, mixing the cooking gasses with the fresh air. (Check out this smoke test on a new vent hood!)  No negative pressure inside the house and no increased air leaks around doors and windows.  If you have an existing vent, it’s usually easy to see if vapors are being pulled through the vent, or going right past it onto your cabinets and ceiling.   When I moved into my house, the microwave/hood combo above the stovetop was not being vented outdoors, so I changed that (microwaves typically have 2 vent options: to vent back into the room through the front, or to vent outdoors through the top or back).  Sadly, venting outdoors still did not pull the gasses from the cooktop below because the fan was not powerful enough.  Here is a great article on how to calculate the CFM (cubic feet per minute) needed to properly vent the stove.  For my electric stove with a wall-mount hood, which was 2.5 feet wide, I multiplied that by 100 to get the recommended cfm of 250.  I had to add 25 cfm for every turn of the duct in the exhaust path (plus 50 for mine, for a total of 300), and then compare it to the cfm needed for the size of my kitchen (704 ft3 divided by 4 = 176 cfm minimum ).  Turns out the microwave/hood combo unit I have is only 220 cfm, which confirmed my suspicions (too small for the stovetop!).  Time to upgrade to a dedicated wall vent hood…

Dryer ventilation: Do this test: bring your humidity monitor (yes, you really need one!) into the laundry room before drying a load of laundry, note the humidity, and then note the humidity again towards the end of the cycle or immediately after drying the load.  Did it increase more than 5%?  If so, check the vent hose for excessive lint, kinks or holes in it (sometimes they become disconnected completely!)  Rising humidity in the laundry room eventually equals rising humidity in the house.  If your vent and lint screen are clean and connected, and you still have higher humidity in your laundry room, you can at least mitigate mold growth by plugging in a Mold Guard in the room to run full-time. 

Bathroom ventilation: Do you have a mold problem in your bathroom?  This is an ideal place to find mold–especially in the shower or bathtub, which can stay perpetually wet depending on the humidity and ventilation.  Full bathrooms (with showers or bathtubs) need adequate ventilation.  You can use your humidity monitor again to check humidity levels before and then 30 minutes after showering and using the exhaust fan.  They should be nearly the same: if not, let’s check some common issues: 

  • It turns out that we should use the bathroom fan way longer than most of us do: not only during bathing, but also for 20-30 minutes afterwards!  On a cold day, I really don’t want to use the bathroom fan during a shower.  It sucks out all that wonderful moist heat….but, it really should be switched on if you want to mitigate mold in your home.  You can make a compromise–just don’t let that moist air into the rest of your house.  After bathing and drying off, keep the door closed, turn the fan on and open the bathroom window for 30 minutes.  The fan will have fresh air to draw in and also exhaust all the moist air. 
  • Sizing: the general rule is that bathroom vents should be minimum 50 cfm (cubic feet per minute), and at least 1 cfm per square foot of bathroom space.  An 8x10’ bathroom, for example, should have an 80 cfm exhaust fan.
  • Where to vent:  Bathroom vents must terminate on the outside of the house.  They may pass through ceiling or attic space, but you don’t want all that moist air ending up in the attic!  Do check that each vent goes outside and is actually working (lifting the vent flap with air expelled) (and for more tips on where to vent when installing a new fan, check this page). 

Basements: Ahh, that extra storage and living space seems to come at a high cost sometimes.  If your basement is not adequately moisture-proofed from the surrounding soil, or drained, the humidity can rise into the rest of the house and cause mold issues everywhere.  It’s best to leave a humidity sensor in this space and monitor it frequently.  Above 60% definitely needs dehumidification.  This permanent system reverses the "stack effect" in your house and forces air to exhaust from your basement, which is a great way to keep the humidity down.  The built-in humidistat causes the fan to come on automatically whenever humidity goes over a certain level.  The next option is to place a dehumidifier in the space with a moveable drain (such as into a shower or laundry drain) or ask a plumber for permanent drain options.  Use a HypoAir unit like the Air Angel in the area, and a separate HEPA filter will also help to remove mold spores.  Once you smell mustiness in the air, the mold has already started, so don’t delay on this one!  Check furnishings, walls, carpets and ceilings for signs of mold or mildew and try to determine the source of the moisture, whether it’s a specific “hole in the wall” or maybe something like lack of gutters on an upper story that causes water to pour off the roof and build up behind the wall.  If your foundation has an inadequate moisture barrier, it allows water from the soil to permeate the concrete.  There are companies that specialize in moisture-proofing your foundation or crawlspace, but be sure to get several quotes to assess a reasonable cost. 

Drain Vents:  I wasn’t aware of this problem until several years ago, when a friend who is a professional carpenter started to tell me about his problem with mold around sink drains.   For some reason I always thought that black mold under a sink stopper was normal, but no—it shouldn’t be!  Sink, shower and toilet drains must be properly vented for several reasons.  First of all, it helps the drain operate properly because the incoming water does not have to “push” the air bubble on the other side of the p-trap to drain; it simply drains by gravity and air pressure is equalized through the vent.  This venting is accomplished naturally if building codes and/or good design are followed…but sometimes older and new construction homes have neither!  The second reason that drains need proper venting, is to allow the outside vent to relieve nasty sewer gasses in an unobstructive fashion, instead of allowing these gasses to push on the p-trap and go back into the room, causing smells and mold.  If you have sluggish drain(s) that do not resolve despite cleaning, sewer smells and/or mold buildup in the drain, find a good plumber who knows about proper venting, so that he can evaluate your home’s vents and suggest cost-effective improvements.  

Miscellaneous leaks:  If you don’t have humidity sensors in each space, here is where you can do a walkabout with a single humidity sensor to find more hidden sources of moisture.  Take a reading in your main living space, then leave the sensor in each room outside of it for a few minutes, to acclimate.  Then take a reading in the outside rooms, and do closer inspections if the humidity is appreciably higher in a certain room.  Open cabinets, check under sink drains, pull back curtains, open closet doors, check walls and carpeting behind furniture…so many drains run through the walls of our homes, and are never seen or considered til they leak!   This is where your nose, and the sensor, can tell you to look until you find the source.  Then enlist help to get the problem fixed (check out these tips on replacement and repainting of damaged walls here).  If possible, avoid living in that space until the leak is stopped and any mold is cleaned up.  If it’s necessary to use the room, you can add a portable dehumidifier, HypoAir product like an Air Angel, and a separate HEPA filter to make the air cleaner until the mold source is eliminated.

Ewww! How can I get rid of that smell?

Ewww! How can I get rid of that smell?

Hopefully you’ve read our first post about smell, “Why does that smell make me happy? Or sad”  because it gives some background about how our sense of smell affects the rest of our body.  I mentioned some good smells like peppermint and eucalyptus oil, but of course there are smells that really turn us off, and that’s what I want to discuss here.  Maybe they are not even coming from your space, but from a neighbor!  In that case you can also reference our post “How do I improve air quality in my home when the people around me don’t care?”

It’s okay to admit that our spaces just sometimes stink.  Our cars, our homes, our office… it happens.  I still kick myself for forgetting that grocery bag of raw chicken in the car for three days!  Sometimes I visit friends with babies and there is the lingering smell of sour milk. And then there are pets, teen’s rooms, and stinky habits of others we can’t control. 

Of course, you can buy an aerosol can of deodorizer or Febreeze to mask or “neutralize” the scent.  Spray and voila!, your space smells like vanilla or fresh linen or coconuts.  Although actually has a page listing the ingredients and claiming the safety of their products, it does not list all of the ingredients, especially the potentially hazardous ones like phthalates (hormone interruption especially for children), 1,4- Dichlorobenzene (deadens sense of smell).  The Environmental Working Group (EWG), a non-profit organization dedicated to testing consumer products and educating consumers to make more informed choices about healthy living, tested the “Linen and Sky” version of this freshener two times, once in 2012 and once in 2017, for its two different versions.  The first version rated a grade of “D” on a scale of A-F; the second version in 2012 rated a score of “C”.  The same scent (second version) in the Fabric Refresher product also rated a “C”, however within that rating several ingredients are rated “D”, causing skin allergies, respiratory and endocrine effects, among others.  Now, the reason Febreze Air Effects could have an overall rating of “C” yet have more dangerous “D” chemicals in it, is due to the fact that it does have a few good, harmless ingredients like water, nitrogen, ethanol, sodium citrate and citric acid.  That’s what we need more of.

The EWG recognizes that this type of air freshener only covers up the odors…they are still there, we are still breathing them but they are cocooned in chemicals that don’t benefit us.  Their recommendation on both the Air Effects and Fabric Refresher products: search for a better air freshener/fabric refresher!  And this group delivers: check out their Air Freshener pages for a slew of A and B rated products (Febreze’s Pet Odor Eliminator, surprisingly, was rated a B, as was many Mrs. Meyer’s products). But at the top of the list?  Good old baking soda!  Here is where you can get great effects from a cheaper product (generic baking soda sold at less than $1 per box, is the same as brand name baking soda and still way less expensive than a can of air freshener). 

Many cleaning experts agree–natural products do work!  Remove the source of stink if you can (take out the trash, clean the litter box, ventilate the bathroom, etc.) and then place one of these in your space (with a fan and/or fresh air ventilation from an open window if possible to accelerate the process). All of the following remove the bad scents while adding little to no scent of their own (even vinegar in a corner of the room does not have a lot of smell):

  • Vinegar: placing an open bowl of apple cider or distilled white vinegar in a corner will help trap cooking and cigarette smoke odors.
  • Activated charcoal: Charcoal will not add a scent to the air but it will absorb malodors.
  • Baking soda: Just as baking soda works to absorb odors in your refrigerator, a bowl placed in a room will also absorb odors.  Adding some baking soda to your vacuum bag will also overcome the musty scents that linger there, too.
  • Lemon water: Water absorbs odors and adding slices of fresh lemon will provide a clean citrus scent.
  • Coffee grounds: Fresh coffee grounds add a scent to the air but also absorb odors when placed in an open bowl.

(Source: The Spruce)

We have one more recommendation for a natural deodorizer: HypoAir's new cleaner TotalClean.  Formulated with iodine, this non-toxic product not only cleans many surfaces around the house, you can spray it into the air around stinky places--trashcans, litter boxes and the like--to effectively deodorize!  

If you want to have a more permanent deodorizer with fan, HypoAir has recently introduced charcoal filters for the Germ Defender.  This little plug-in is powerful!  While it is sending out positive and negative ions to kill the source of the stink (moldy surfaces, bacteria, etc.), the charcoal filters are actively filtering and deodorizing the air.  This is a low-maintenance deodorizing and sanitizing unit you can place strategically in the stinkiest areas of your home (bathroom, laundry room, pet areas, teenager’s room, etc.)  

Now that the bad scents are removed, if you want to add good fragrance back in, here are some safe options for those who prefer their home to be lightly scented.  This list is sourced from

  • Beeswax candles: unlike regular scented candles, most of which are made from paraffin wax and give off hydrocarbon byproducts, beeswax candles do not pollute the air.   For a light scent, use beeswax candles scented with essential oils.
  • Diffusers: Did you know that you can get a scent similar to your favorite Yankee Candle (made from paraffin and harmful fragrances), by mixing essential oils in diffuser?  You can hack a “pumpkin spice” scent!  There are seven types of diffusers, some of which add more humidity to your space than others. 
  • Simmer pots will allow you to replicate more of those comfy scents, but with more humidity, since the medium for simmering is water.  If you have a high humidity problem in your home, it’s best to limit simmer pots for dry seasons like winter, and never leave them unattended. 
  • Vodka air fresheners:  Many commercial fresheners use various types of alcohols as “carriers” which emulsify fragrances and dry quickly, leaving only the scent behind.  Vodka is a very pure type of alcohol, and witch hazel is another safe “carrier” (but it does not evaporate as quickly as vodka). Higher proof vodkas mean higher alcohol content, but you’ll want a non-flavored one and cheap brands work just as well as more expensive ones.  Here are some recipes for popular holiday scents. 
  • Vanilla or peppermint extract: Saturate a few cotton balls with cooking extracts and place them on small saucers around the room. They also work great when placed in a vacuum bag or dust cup to add a bit of scent as you clean. (Source: The Spruce
  • This list of brand-name air fresheners from the EWG contains many safe options (grade A or B).  Aura-Cacia and Eco-Me brands have appeared on other expert lists as well.

The downside to essential oils is that they do contain VOCs; it’s what makes them so wonderfully fragrant.  Knowing this, it's smart to increase ventilation and limit the time of use.  However, by adding your own essential oils to any of these appliances, you know what is going into the air and you can control the intensity so that it does not overpower like some commercial air fresheners. Smells naturally delicious to me!

Air Quality Myths–debunked!

Air Quality Myths–debunked!

Don’t worry, at HypoAir we’re learning everyday too.  Whether the myth comes from the media, or your family, or just what you assume happens, many of the things we believe about air quality–are not true!  Let’s dive in and get to the bottom of these myths…

  • My old, leaky house has better air quality than new tighter ones because it “breathes”.  Well, yes and no!  Ventilation is good, but if it’s allowing polluted or humid air in, that’s not good!  We like to opt for controlled ventilation, when you can open a window on clear days but on polluted or humid days, close it and still get fresh, conditioned air through special intakes to your HVAC.
  • Air conditioners provide fresh air ventilation.  Actually, most air conditioners don’t provide any fresh air!  Standard central and window units are closed systems, which mean they are simply recirculating (and recirculating…) air within your home.  In order to get fresh air, you’ll need to have a special intake installed on your central unit, which may or may not filter and “condition” the air it pulls from outside.  Check out our post on Adding fresh air through the HVAC system for more info.
  • It’s best to clean your AC ducts every 3-5 years.  This is a myth perpetuated by some duct cleaning companies.  Actually, we (and the EPA) don’t recommend duct cleaning unless you have mold in the AC system, have a pest infestation (rodents, bats or birds usually), or excessive amounts of debris.  Normal dust in ducts doesn’t pose a risk to indoor air quality and it’s best left undisturbed, because there are risks that ducts can be punctured or damaged during cleaning, or cleaning chemicals can leave behind VOCs.  For more info, check out our post “Should I clean my HVAC ducts?”
  • My thermostat takes care of the humidity.  Are you sure?  Standard thermostats only regulate temperature, and when the system meets the temperature goal, it shuts off.  It’s best to have a second monitor, like our humidity sensors, to make sure you are meeting your humidity (40-60%) goal as well as temperature. 
  • When it comes to AC units, the bigger the system, the better.  Actually, installing too big of a system (central or window unit) will cause a problem called short-cycling, where the unit turns on, quickly brings the temperature down, but does not have time to reduce the humidity.   This is definitely not good for your home or the machinery, because damp air can cause mold and mechanical issues.  Lesson: the correct size is better!  Contact an HVAC tech to perform a load calculation to size the unit correctly. 
  • It’s normal for the upstairs of the house to be warmer.  Well, to some degree, but it doesn’t have to be a completely different climate than the lower story.  The two areas are called “zones” and even if you only have one AC unit, you can get the system “balanced” so it works less to keep both zones at comfortable temperatures.  Check out our post “Why selecting and sizing your AC system is critical for healthy air”.
  • I don’t always need to use the stovetop ventilation when cooking.  Yes, you do need it a lot more than you thought–roasting meat, baking, and even stovetop cooking that only creates fumes for a few minutes all exude a lot of VOCs and particulates from the pans, oils and food.  Cooking with gas emits much more fine particulates (PM2.5) into the air than electric. 
  • If a cleaning product has a natural smell, it’s not toxic.   Sorry!  This myth is why detergent companies market their products to smell “natural”, but load them with many toxic ingredients.  Also, some of the VOCs found in nature (like limonene, a citrusy smell) can react with other chemicals to form harmful pollutants.  Our recommendation would be to use products like TotalClean, which have no fragrance but do the cleaning job, then use your favorite essential oils to add a safe level of fragrance to your home.  Check out our post “Ewww!  How can I get rid of that smell?”  (hint–TotalClean works great as a deodorizer also!)
  • My personal products have nothing to do with my allergies/sinusitus/congestion.  Actually, they definitely could. Since the chemicals in our shampoos, soaps, lotions and deodorants are among those that form ozone in summer smogs, they can hang around in your house and on your body long after showering (Guardian article), causing respiratory irritation.  Some of the ways that we can reduce their effects on us is rinsing for longer, using  the bathroom vent (ideally continual use for 30 minutes after showering to reduce moisture in the bathroom too) and switching to non-aerosol products. 
  • Bleach is the best way to kill mold. Bleach certainly kills mold, but it also dangerous to your respiratory system and skin, and can react with limonene, a common citrusy-smelling VOC found in other cleaning products, to form secondary organic aerosols (SOAs), which are minute particles that compose smog.  There are a number of less toxic products that can kill mold, such as TotalClean (which contains iodine), hydrogen peroxide, vinegar, baking soda, grapefruit seed extract, etc. (be careful about what you mix together though!)  Check out this article for some natural solutions to clean up mold. 
  • If the EPA allows the sale of a household product, then it’s not toxic.  Unfortunately, the EPA does not know all of the ingredients that household products contain, because they are not required to be disclosed.  Organizations like the Environmental Working Group (EWG) and Women’s Voices for Earth (WVE) have tested many household products to reveal the toxic ingredients they contain.  Check out our post “Reasons not to use your mama’s (or grandma’s) cleaning products”, to be better informed for healthy purchasing!

Do you have an “Air Quality Myth” you would like for us to address?  Let us know!  

Reasons not to use your Mama’s (or Grandma’s) cleaning products

Reasons not to use your Mama’s (or Grandma’s) cleaning products

They say that family traits tend to skip a generation.  In my case, the cleaning habits did skip a generation, because my grandma would rather be outside or repairing a bicycle (her hobby), and I would definitely rather be doing anything outdoors than cleaning inside!  In any case, her old cleaning products like Pine-Sol and Simple Green are still around, but I found out that whenever I do get the urge to clean, I should not be using them.  What triggered my concern?  Several things, first being I knew from previous research that heavily-fragranced products contain a lot of toxic chemicals (see the post on Ewww! how can I get rid of that smell?).  Secondly, a recent study showed that simply mopping a floor with a normal terpene-based cleaner released as many nanoparticles into the air as are on a heavily-trafficked city street (yikes!).  I definitely am glad I do not have to clean as a profession.

Here are some common products (most of them overly-fragranced) that need a makeover.  

Pine-Sol: For some reason (probably because we lived in the woods) my mom favored Pine-Sol for cleaning our linoleum floors and the toilets and cleaning-wise, it seemed to do a decent job.  I even used it to clean my first apartment in the 1990’s.  However, it was recently discovered by Women’s Voices for the Earth (WVE) that many brand-name cleaners have hidden toxic ingredients, because manufacturers are not required by law to disclose all ingredients.  Their study and test-results give the details.  Pine-Sol contains toluene, which can cause pregnancy complications, limonene, which can cause allergies, and carbon tetrachloride, which is at least an irritant and at worst shown to cause kidney and liver damage.  According to the EPA it has already been discontinued from consumer use, but obviously manufacturers who are not required to disclose all ingredients to the consumer are also not purposefully disclosing to the EPA. 

Simple Green: Sounds pretty good, right?  I never like the smell of Simple Green, and maybe now I know why, because it was on the aforementioned study by WVE.  The formulation “Simple Green All-Purpose Cleaner Non-Toxic Biodegradable” contains toluene, and “Simple Green Naturals Multi-Surface Care Lemon Verbena” contains phthalates, which cause hormone disruption and neurodevelopment disruption, and 1,4-dioxane, a cancer-causing ingredient.  The manufacturer was already ordered to pay $4 million in a class action settlement (2021) for making misleading claims about being a “non-toxic” cleaner.

Fabuloso: I was not familiar with Fabuloso until I started visiting family homes of a Latina friend.  It is quite popular in the Latin community, as it was created in Venezuela.  Full-strength Fabuloso, though formulated to emulate botanical fragrances like lavender and “spring in bloom” is very strong on the nose and eyes and every part of your respiratory system.  This smart Latina dug into  disclosed list of ingredients to find it contains Sulfuric Acid, 2 Phenoxyethanol, Sodium Hydroxide, Propylene Glycol Propyl Ether, and Alklbenzenesolfonic Acid, all of which are mild to severe respiratory irritants.  The EWG gives the Fabuloso Lavender Multipurpose Liquid Cleaner, one of the most popular fragrances, an “F” grade for toxicity.  It is certainly not “Fabulous”, and the not-uncommon habit of boiling it on the stove to perpetuate the fragrance can damage lungs and cause asthma in children.   However, it is a brand leader globally and a cultural icon, which means it will probably not die slowly.  

Do you want to be sure that you’re not breathing toxic nanoparticles or chemicals when you clean and afterward?  Our new product TotalClean is the one to replace floor cleaners, countertop cleaners, toilet cleaners and even spray deodorizers, because it performs well in all of these categories without toxic chemicals or fragrance.  If you want to add in fragrance, try adding a few drops of your favorite essential oils, which can be changed for your mood or the season.  This product has already replaced my Windex and Febreeze (also on the WVE list), and another countertop cleaner.  Maybe cleaning will move up the priority list–you never know!