Category Archives for "Air Quality"

Which air purifier should I choose for my home?  Part 1: Airflow

We get this question a lot, and truly, we understand how daunting the choices can be.  At HypoAir, we will guide you with a personalized plan according to your home or living space.  The best thing you can do to find that optimal air purifier, then, is to know the space you’re trying to purify, which mainly depends on airflow. 

Maybe you’ve watched a video during science class that shows someone adding a drop of dye to a glass of water and watching it slowly change the color of the whole glass to blue or red.  There are some similarities, but unfortunately it’s not that easy!  The spaces in your home are divided by walls and doors.  You may be in your home office with the door closed while your partner is cooking dinner, and start to smell good things.  The aromas are making it through the ventilation and around the door, but does that mean that the whole home is experiencing the same air quality?  No, because as soon as you open the door and start to walk toward the kitchen, the good smell may intensify, and you may experience other smells along the way (like the cat litter box in the laundry room–ugh!).  Unless you live in well-ventilated (moving air) studio, our home’s IAQ is by no means homogenous. 

Airflow also varies by season and time of day.  Writing this post, I am seated in my home’s sunroom during the winter.   The sunroom is a beautiful but poorly insulated part of my home.  I live in the southeast US, which on this day in February had a low of 33 degF last night, and I high of 70 degF today.  To make this room more usable in the winter, I use a wood pellet stove to heat it on chilly mornings.  The stove blows hot air straight out, and I keep the two ceiling fans rotating at low clockwise to bring the heat down from the ceiling.  When the outside temperature gets above 65 (which was about 11am today) then I can shut the stove off and even open some outside windows to let fresh air in.  Sitting in the middle of this long room, I feel comfortable, but I know that the ends and corners are definitely not receiving the same heat and ventilation!

Optimizing your home’s ventilation does a lot for its IAQ.  The National Center for Healthy Housing identifies two types of ventilation that can be used to improve IAQ: spot ventilation and dilution ventilation.  Spot ventilation includes bathroom and cookstove exhaust fans, which pull odors and harmful combustion by-products out of your air during the use of those spaces.    Dilution ventilation conditions for your entire home through 1) air changes and 2) air cleaning.  Dilution ventilation is the workhorse that really makes or breaks IAQ.  Air changes are necessary; by adding fresh air (about 0.35% of the home’s volume per hour), harmful contaminants are diluted.  If your air feels “stale” then a good place to start can be by opening some windows on the opposite ends of the home  (provided the air quality outside is better), making sure your HVAC filter is in a clean state, and turning on the HVAC fan only, to circulate fresh air into all areas of your home. 

This leads into the next question: can I ventilate with open windows and purify at the same time?  The answer is for the most part: Yes, with common sense applied.  If you live in a high-traffic area, rush hour probably has worse air quality outside, so don’t let that polluted air in during rush hour.  If you live in the country as I do, you can open windows whenever the pollen, temperature and humidity outside are not overwhelming.  Fresh clean air is always needed to dilute polluted air inside, and actually helps your HypoAir purifier because the object is to take what’s good about outside air, and bring it in.  The important part is getting the mixing going!  Open bedroom and bathroom doors when possible, use room fans, or your AC fan set to “on” (not “auto”), to get good airflow going.  

This may seem like a lot of work just to achieve good dilution ventilation, and you’re right, it can be!  It shows that the evolution of home design actually went backwards in some respects.  While living in the New Orleans area for 10+ years, I took several plantation home tours when friends were visiting.  These magnificent homes were smartly designed in many ways.  High ceilings allowed the heat to rise and take in more cool air through doors and windows, creating a natural circulation within rooms.  Windows and doors on opposite ends of the house could be opened to induce cross-ventilation.  Transom windows over doors could be opened for ventilation even if the door was closed.  Porches shaded the home’s interior from the heat during the hottest part of the day.  Longwood, a unique antebellum home in Natchez Mississippi is octagonal; although it was never finished, there is a main rotunda that joins all the six floors to create a convective current to sweep summer heat up and out of the house.  Even the octagonal design has no corners of dead air in each room.  Our recent ancestors may not have had ways to deal with dustmites, pollen and particulates, but they certainly made the most of dilution ventilation, even without electricity.  I grew up in a home in Maryland (hot sticky summers) with one window AC unit and a whole-house attic ventilation fan.  What did we use the most?  For sure, it was that attic fan.  My sister and I would be summoned to open windows on the first and second floor and turn on the behemoth louvered fan, and the fresh air would start to flow in and cool the house in preparation for bedtime.

Enough of the olden days…! How can I accomplish good dilution ventilation with a minimum of effort?  

• You don’t need to have screens in all windows, but a select number of windows should have clean screens and be easily opened.  Consider installing allergen-filtering window screens in these windows at least.  
• You can add smart controls to your ceiling fans so that all can be turned on via an app on your phone.  This review gives the details on which smart products will work with the fans in your home. 
• Smart thermostats can also remotely switch the fan to “on” from “auto” 
• Place floor fans strategically where there seems to be no air movement. 
• Tackle the problem of closed doors.  Sometimes it’s not always possible to open every door–like at night, when privacy, sound or light issues warrant bedroom doors to be closed.  The AC fan creates positive pressure in the bedroom, while the air handler is trying to suck the air through a little ½” gap under the door (in most cases it’s just not enough of a gap).   The solution is to install these In-Door Return Pathways, which are easy to install and allow air to circulate more freely through your home.  Bathroom doors are perfect for these too.
• When it’s not possible to open windows due to rain, temperature or outside air pollution, visit our post “Fresh Air Intakes for HVAC” to see what’s available in letting your AC bring the fresh air in.

Next: check out our Part 2: Air Cleaning section to read the rest of Which purifier unit should I choose for my home?

Air Quality inside your car

Ahh, I remember my days of commuting to work in northern Virginia…with NPR and a cup of coffee for 45-50 minutes, the little cabin of my Ford Ranger hugged around me like a safety blanket against the traffic and elements.  For many commuters, their car is a sanctuary of control, from temperature to volume to speed.  What we don’t control, and don’t even know about, is the air pollution that infiltrates our little safety zone.  Without knowledge, we can be helpless against it. 

For those living in or traveling through high-traffic areas, air pollution can be significant.  According to research at University of California Riverside, your car is like a small box with holes in it.  What’s inside the box, eventually becomes the same as what’s outside the box.  The time this takes depends on fan speed, ventilation mode, and cabin air recirculation.  

According to UC Riverside, when encountering heavy pollution, it is best to close the windows, set the ventilation to “recirc” and set the fan on low.  This will allow the car’s cabin filter to take out some of the ultrafine smog particles.  However, this setting should only be used for a short time, because the concentration of carbon dioxide from passengers’ breathing starts to become high.  Surprisingly, increasing the fan speed will increase ventilation, even without changing from the “recirc” setting, because the car cabin is not tightly sealed.  

Research from Washington University in the St. Louis School of Engineering and Applied Science would add one more step: turn on your air conditioning.  Technically, the fan and recirc settings are the same whether you’re running the AC or not.  However, when the air hits the cool surface of the evaporator, the pollutant molecules are attracted to it and tend to stay there instead of continue into the cabin of your car.  Students’ research showed that the pollution level was reduced between 20 and 34 percent by turning the AC.  

Back at UC Riverside,  Professor Heejung Jung says the best ventilation setting would be a “fractional recirculation”, where the flap controlling recirculation is opened at specific angles to improve ventilation.  His team of researchers are assembling a database of specific car models and test data, to help the average car owner achieve better air quality using the controls they do have. 

Then, there are the pollutants you can control.  Dust and mold are two allergens that you can clean out of your car, to a large extent.  

• Keeping food wrappers and crumbs cleaned up and mopping up spills quickly will prevent mold and mildew from growing.  
• A regular quick vacuum and wipedown with a damp cloth (no cleaning chemicals needed) will reduce dust in the air.  
• Changing the cabin air filter regularly (at least every 15,000 miles) enables the car to filter the air too.  Definitely change the filter if you smell a musty smell when turning on the air conditioning, as that could be a sign of mold growing on it. 
• If you notice a foul smell when turning on the air conditioning, it may be that rodents have urinated on the cabin air filter or built a nest there.  Besides cleaning or changing the air filter, you can keep them out by using a safe rodent deterrent under the hood when you are not using the vehicle, and/or inside the vehicle when you are. 

Your car can benefit from a deep clean sometimes too (with the right non-toxic cleaners).  You don’t need a professional upholstery cleaner; even spritzing upholstery and carpets with hot water and soap and vacuuming with a wet/dry vacuum will remove deeper contaminants.  Make sure to do this on a warm day when you can leave the windows down for several hours to further dry and ventilate the inside so that mold growth doesn’t accelerate.

Some car companies have recognized the need for better air quality in the car and are building active monitoring and purification into their new models.  Volvo is one such company, which partners with CabinAir, a spinoff of Swedish air purifier company Blueair.  CabinAir electrically charges fresh air particles, then passes them through an optimized filter, in order to trap even ultrafine particles (pm2.5).  The system only allows 4% of harmful pollutants into the cabin (also filtering out 99.97% of airborne viruses and bacteria), compared with 50% using traditional cabin air filters.  This system can also be retrofitted into existing cars by installing the new CabinAir filter with charging system, and the NordZone Air Quality Monitor (which may be also synced with the NordZone App on your phone to provide the total view of interior and exterior conditions).  The NordZone Air Quality Monitor displays lights indicating when you have fresh air but not clean (too many pollutants), clean air but not fresh (too much CO2) or clean and fresh air, by sampling and measuring PM, VOCs and CO2.  Hyundai and Tesla are two other carmakers that have introduced air quality monitoring and cleaning in their new models. 

Bad outdoor air quality, just like slow traffic conditions, can be predicted and avoided.  The newest generation of cars will be equipped with proactive air quality guidance in order to allow the driver to take an alternative route before they even start driving, or guide them out of areas of worsening air quality.  Companies like BreezoMeter have constructed millions of “Virtual Sensors” which extrapolate air pollution based on data from real sensors and algorithms.  What a breath of fresh air for the commuter!

Hypoallergenic Hotel Suites?

During my peak travel days in the 1990’s and early 2000’s, there were only 2 options of hotel rooms: smoking and non-smoking.  If I walked into my room and detected smoke, of course I could go back to the desk and ask for a smoke-free room.  For those who suffer with allergies, however, even these "smoke-free" rooms can trigger allergy attacks because of pet dander, mold, dust mites and fragrant cleaning products.  Hotel chains are paying attention to their health-conscious customers now, and there are more options available. 

What you see in a “hypoallergenic” hotel room is what you would want in your own home:

• Ideally, a solid floor instead of wall-to-wall carpet
• Solid wood furniture with minimal upholstery
• Dust mite-preventing mattress, boxspring and pillow encasements
• Anti-microbial, mold-free shower curtain and mats, and ventilation in the bathroom
• Clean air conditioner/heater units 
• Additional air purification (such as a HEPA filter)

These are all designs/add-ons that hotels can offer to reduce allergens, but the major hotel brands have added additional cleaning processes and certification, such as those used by Pure Wellness. This company uses a seven-step process of ozone shock treatment, AC unit purification, Pure Clean Sanitation, Pure Shield Barrier, 24/7 air purification using Disinfecting Filtration System technology, Fresh Clean Air (Tea tree oil cartridge in the AC unit to sanitize the outflowing air), and allergy friendly bedding including mattress protector and pillow encasements.  Rooms are deep cleaned for initial certification, recertified every six months and deep cleaned again every two years.   Such rooms typically command $20 or more extra to the consumer.  

Hyatt debuted their class of hypoallergenic hotel rooms in 2010, named Respire Rooms.  The hotel says that “the air in Respire by Hyatt rooms on average is 10 times more pure than outside air due to lower particulate counts.”  To find similar rooms, visit pureroom.com/find-a-pure-room .  Although there are thousands of Pure Rooms in the US, I was pleasantly surprised to find two such hotels within 100 miles of my country home.  

Not everyone is a fan of Pure Rooms, however, and it seems to be mostly due to management of the room between certifications.  When hotel staff are not educated in the why’s of using only non-toxic, unscented cleaning products such as laundry detergent, toxins and smells can quickly build up.  Reviews from sufferers of MCS (Multiple Chemical Sensitivity) for Pure Rooms are not purely positive.  The tea tree oil cartridge in the ventilation filter, for example, may seem “fresh” to many people but is a disabling scent for those with MCS.  Also, Pure Wellness does not require that carpeting be removed from rooms when they are converted, which can harbor allergens between deep cleanings. 

How can I find a hypoallergenic room outside the US? A representative for Pure Wellness commented that as of February 2022, their company does not take responsibility for any rooms outside the US.  Room to Breathe is a UK company which provides similar services as Pure Wellness, but they do not have a comprehensive directory of rehabilitated rooms for booking purposes.  For the moment, I think it’s best to search “allergy-free hotel ______”, adding the name of your destination city.   Don’t forget to do the same for cruise lines!  

Sometimes peak seasons or emergency traveling preclude the ability to stay in one of these rooms.  If there are no such distinctions available, you can mitigate the conditions on your own.  It takes a little planning and perhaps a few more pounds in your suitcase, but you can do it!

• Skip online booking or the 1-800 number, and try to call the hotel directly and connect with someone who is familiar with allergies and how the rooms are cleaned.  Ask about the use of fragrance-free cleaning products, if the air conditioner or heater filter has been cleaned recently, and when the carpets have been deep cleaned.  If possible, ask for a room that has not had pets, and was cleaned some days before, to allow for the cleaning product VOCs to dissipate.  
• Bring your own towels, if possible.
• Bring your hypoallergenic sleep sack that protects against allergens in the sheets next to your skin.  It should have a pocket for the pillow.  Here are some options:
  • BraveEra 100% Silk Travel Sleep Sheet claims to be machine washable, drying in about an hour, costs about $100
  • Browint has a number of options in silk, silk/cotton and microfiber for less than $60
  • ASOOX makes a comfortable microfiber sleep sheet set that comes in 1 or 2 person sizes for less than $30. 
• Stay in a hotel that has laundry facilities to launder your sheets and towels if necessary.  
• Bring your own air purifier, if possible.  The Air Angel is extremely travel friendly and works on 110v/240v (you’ll just need a plug adapter if in a country outside the US).  Plug it in near your bed when you first arrive, and let it work while you go to dinner or entertainment. 

Plants as Air Purifiers?

IF you lived in a sealed environment like a spaceship or biodome, then plants could be extremely helpful in reducing harmful VOCs (check out NASA’s BioHome).  Since most of us live in a much more dynamic environment with many air leaks, entrances and exits, a new study calculates you would need a virtual forest (like between 1,000 and 10,000 plants per 10 ft2 of floor space) to reap the benefits of higher indoor air quality due to plants alone.  That said, we still want to advocate for plants. Why?

• According to the creator of NASA's BioHome, Bill Wolverton, the VOC absorption rate of a plant has direct ties to ventilation of the roots.  He worked with a Japanese company to create the EcoPlanter, a Plant Air Purifier, which supposedly allows one plant to do the work of 60 or more plants in terms of eliminating VOCs.  This concept is being updated radically to add newer technology such as a PCO filter and UV light, in startup company Koru, that combines the power of AI with the plant's natural air filtering qualities.  It will self-care for the plant, monitor air quality, never need filter changes and eliminate 99% of air pollutants. Plus, it looks better than an air purifier!  
• Some plants are great at removing nitrogen dioxide (NO2), which is a common air pollutant from vehicle emissions. In a study conducted by the University of Birmingham in the UK, a Peace lily (Spathiphyllum wallisii), Corn plant (Dracaena fragrans) and fern arum (Zamioculcas zamiifolia) were all tested in separate chambers, and each was able to remove about half of the NO2 in their chamber, within an hour.  The size of the chamber relative to the size of a normal office or apartment, would require about 5 plants to reduce NO2 pollution by about 20%. Way to go, plants!
• If you have limited floorspace for pots but still want the maximum number of plants, there are a number of companies who can help you install plant wall systems for a dramatic and multiplied air purifying effect.  
  • Respira.ca has easy installation videos for their free-standing or wall systems, and you can purchase their plants or your own (tips are provided for preparing your own plants).
  • Growupgreenwalls.com has pre-built walls and dividers for purchase
  • Livewall.com and Growup.green create custom walls for your home
• For many years I was fascinated by a friend’s pet fish and plant combo: The peace lily fed off the nutrients (waste) of the betta fish and the plant returned clean water to the fish: a win-win situation especially when you consider the much-reduced need to clean the fish tank!  However, there are disadvantages to the fish in a simple flowervase/tank: its diet, breathing, and temperature are not regulated well.  The ideal environment for these type fish incorporate an air bubbler, filter and heater, in all called an “aquaponics fish tank”.  AquaSprouts is a company that has a few setups that keep the fish in a much better environment than a vase.   It’s a science that kids will want to learn and participate in, too.   
• Then, there is the psychological effect of plants : they do good things for the ambiance of our environment and our overall well-being!  This one page cites dozens, if not hundreds of benefits of plants and interaction with plants, shown by studies.  Indoor plants and spending time amongst outdoor plants boosts memory retention, increases attention span, and has a calming effect on our brains, enabling us to focus on the task at hand.  Flowers and ornamental plants reduce stress levels, contributing to moods of  relaxation, security and happiness.  In the hospital, plants in patient recovery rooms accelerate healing, even more so with patients who participate in plant care.  Plants increase our empathy and compassion for others, improving relationships.  Increased energy and learning ability are also results of environments beautified by plants.  With all these benefits, who can say no to adding a few plants in their home or office?
• If your home is naturally on the more humid side (over 50%), then there are plants that can absorb water from the air through pores in their leaves (stomas), helping you to dehumidify.  Xerophytes and Epiphytes are examples of this (plants you would see growing in warm climates).  Air plants (tillandsia), boston ferns and peace lilies also make fine dehumidifying partners (see photos and more plants here)! 
• If you live in a dry climate, plants that require more water will naturally “humidify” a room.  Evapotranspiration is the method in which plants move water from their roots through the stems and leaves, into the air through their stomas.  This study indicates that “ 25 spider plants in 4-inch-diameter pots or fewer, larger plants, could increase the humidity of an interior bedroom from 20% RH to a more comfortable 30% RH under bright interior light conditions.”  If you don’t have a lot of bright light in your living area, you can switch to jade plants, which do more of their evapotranspiration during dark periods.  Here is a list of other plants with humidifying benefits.  Who knew?
• Plants are easy additions to decor: from classic ferns to eclectic cacti and orchids, you can use a plant to add style to any room.  There are also species of plant available for every skill level, from beginners to the serious green thumbs, and thankfully some of the best at eliminating indoor toxins are among the hardiest!     Here are some super-easy, common varieties to invite in (trust me these are really plants, not insects):
  • Spider plants 
  • Snake plants
  • Aloe Vera
  • Boston Fern