Air Quality

When I started building I knew nothing about venting or even that a house needs to “breathe” (fortunately, dad knew all about that).  I knew I needed an exhaust fan in my bathroom to remove moisture but that was the extent of my knowledge.  I have pretty severe allergies to grasses and molds and, thus, never open my windows, so I saved a lot of money by buying fixed windows.  I have one large slider window that is opposite my front door, which can create a cross breeze if needed.  The slider is also large enough to be a second form of egress.  My priority was insulation and making my house as air tight as possible.  While researching this I discovered new terms such as CFMs, ERVs, HRVs, passive house, etc.  Soon my head was swimming.  If I couldn’t crack a window, I needed to find another way to exchange the air.  This being Maine, I couldn’t have any old ventilator letting in icy air in the winter; yet, most heat recovery ventilators were too expensive or overkill for such a small space.  Plus, I needed to consider how the air would be filtered.

Luckily I came across a small energy recovery ventilator made by VENTS for rooms up to 343 sq. ft. and it had two MERV6 filters (not exactly HEPA quality but better than most units I researched).  It was expensive but a necessity that fit all my requirements – small with duct fitting within a 4″ wall, decent filtration, and capable of operating in colder weather (claims to be effective down to -4 degrees).   I don’t have any way of testing the actual airflow but I do know it’s doing something…  When mom was painting in the bathroom she turned the exhaust fan on to lessen the fumes, which created a new problem…  The drain pipe was hooked up but the P-traps were not installed, I had stuffed rags in all the plumbing openings, and the fan sucked fumes from the sewer out around/through the rags and into the house.  That smell will haunt me forever.  When we opened the window it broke the vacuum effect and all was right with the world again.  Once the ERV was hooked up it provided the same relief as the window, so I assume I am getting fresh air through it.  Below are the specs on my ERV and how it works:

Model:  TwinFresh Comfo RA1-50-2



  • Pending patent on ceramic ERV core:
    • Apparent Recovery Effectiveness is ≤90%
    • Recovers heat and moisture to reduce heating costs in winter and air conditioning costs in summer
    • Efficacy 5.7 CFM/W – Twice as high as the Energy Star requirement
    • Whisper quiet operation, as low as 0.2 SONES
  • Stainless steel outer hood:
    • Modern design that fits any interior and exterior
    • 100% corrosion proof
  • Plug-&-Play installation:
    • No special skills required
    • No balancing needed
    • Through the wall installation. Compact unit design
  • Multifunctional wireless remote control
  • Almost no maintenance required
  • Washable filter and core
  • MERV6 air purification
  • Antibacterial treatment of ERV core and filters



Control and operation modes:TF-Comfo-2-mode-3508


The ventilator is designed for both extract and supply ventilation with energy recovery function.

  • CYCLE I. While warm, stale air is extracted from a room, it passes through the ceramic energy core where the heat and moisture is being accumulated. After the ceramic core heats up, the ventilator automatically switches to supply mode.
  • CYCLE II. As the clean, fresh air from outside passes through the ceramic energy core, it absorbs moisture and it warms up to room temperature due to to the accumulated heat. As temperature of the accumulator drops down, the fan switches to extract mode and the cycle is renewed. The ventilator changes its operation mode for supply or extract ventilation every 70 seconds.

Ventilator hood and microwave exhaust fan vent.


Interior ventilation unit.

exh fan

Bathroom exhaust fan.

The bathroom fan is mounted above my dryer and the duct work runs through the loft floor to the front of my house.  I also have an over-the-range microwave that vents to the outside.  And my dryer also vents to the outside.

Toward the end of July, I started waking up in the middle of the night with sneezing, itchy eyes, and runny nose – full-on allergy attacks.  I’ve dealt with allergies all my life but I’ve never had them wake me up before.  Since this was a new phenomenon, I started worrying I was allergic to something in my house.  Then I reasoned that I had been living in my house for over 2 months with no problems, so that was unlikely (phew!).  Symptoms progressively worsened and it started to look like my old nemesis, aspergillus, was back.  CT scan showed multifocal advanced sinus disease.  I meet with a new surgeon tomorrow.  This will be my 6th sinus surgery, assuming that’s the plan, which it usually is.  Since surgery appears imminent and I don’t think I could get any worse in the meantime, I’ve been taking advantage of this time and doing some landscaping, planting bushes and pulling crabgrass.  All of the seed mom spread turned to crabgrass.  It’s hideous.  A while ago dad and I laid a path to the pool deck with 4 inches of gravel and built up the area around it with loam.  I plan to lay pavers next summer.  I think I might’ve enjoyed a career in landscaping if it wasn’t for my allergies.  I may even buy a good face mask and plant a raised vegetable garden next year.


I call the large shrub Gracie and the smaller one Dwight.

Anyway, back to air quality… sorry, I got distracted.  With all my sinus issues, I should be more concerned with what is in my air.  This was a good wake-up call.  I am considering investing in an air quality monitor such as the Birdi or Netatmo, or a basic CO2 and humidity meter, and see if I need to buy an air purifier.



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