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Why does a high quality ventilation system matter?


High air quality matters because we live here!


Did you know that EPA studies show indoor levels of pollutants may be 2 to 5 times –

and occasionally more than 100 times – higher than outdoor pollutant levels?  It’s true!  


The list of things that can spoil air quality in a home is long and diverse: 


Chemicals From cleaners, paint and finishes, hobbies, personal care products, solvents, pollution...many have high volatile organic compounds (VOC’s) that are highly reactive gases directly harmful to human and pet health


Radon Radon is a naturally occurring gas in some areas of the country.  Through diffusion, radon can enter a home and cause significant health problems.


Suspended particles Coarse, fine and ultrafine particles from outdoor pollution, burning of fuels for heating and cooking, and reactions between ozone and some volatile organic compounds can directly impact health and comfort.


Microbes Microorganisms like mold, bacteria and viruses can all have serious health affects


Pets Dander and hair are major sources of allergens


Pests Dust mites, cockroaches, mice are major sources of allergens   


Humidity levels People find 40-60% humidity comfortable.  Humidity lower than 40% can cause eye irritation, dry skin, and rashes.  Humidity above 60% can cause water damage and mould problems.


Improper ventilation Causes many health problems and is the most important factor determining indoor air quality.

The problem with older homes


Older homes were not designed to be air tight. Outdoor air comes in and goes out though gaps and cracks around windows, doors and pipe penetrations ventilating out pollutants and other air quality spoilers.  While fresh air does enter the building, it’s problematic because:


Leaks are energy losses Leaky homes lose energy and are high energy use homes.


Comfort problems  Unconditioned air may be bone dry, cold winter air or wringing wet hot summer air.  Either cause of uncomfortable drafts, hot rooms, cold basements and other temperature comfort problems.  


Unknown amounts of pollutant removal  It is unknown if it is enough ventilation in the right locations to remove pollutants.


Unknown amounts of moisture removal It is unknown if it is enough ventilation to remove humidity that can result in mold, and rotting walls and roofs.  


Unknown where the air comes in from  It is unknown if the air being brought in is actually clean and fresh.  Unclean or contaminated air could be entering from a moldy crawlspace or from gaps around pipes or from the exhaust air from the next door building.


No controls There are no controls to allow occupants to bring in more fresh air when they need to.




Air quality: the True Turtle quality difference


A high performance home is designed and built with a robust suite of air quality strategies including:


  • specialized equipment

  • intensive filtration

  • meticulous installation techniques

  • construction practices supporting high air quality

  • low toxicity finishes

  • 3rd party verification and testing


All of these components are verified and tested by independent 3rd parties so that buyers are assured these higher quality components have been installed...and most importantly, they are tested to work at 3 their design values.  This comprehensive approach delivers higher quality air from the start of construction to the end of the buildings life.

Quality installation remove impurities where they happen: bath and kitchen exhaust fans


Ever been in a bathroom that fogged up the moment you turn on the shower?  Ever wonder if your range hood is actually doing anything other than making noise??


You are not alone.


Code requires that bath fans draw a specified amount of air based on room size and that kitchen exhausts draw 100 cubic feet per minute (cfm).  However, it is not required that these important pieces of equipment are tested post installation.  No testing and verification means a very high percentage of bath fans and kitchen exhausts just plain don’t work.


Why don’t kitchen and bath fans work?  The reasons are many...


  • Kitchen exhausts are typically recirculating systems where the air is filtered through ineffective, low quality filters that rarely get cleaned and that do not remove humidity.  They dump the same air they removed back into the room!

  • Kitchen fan damper is improperly installed so that the flap only goes partway open

  • Too many turns...each bend causes 25% loss in air flow

  • Ducts get crushed or torn during construction

  • Bath fan damper is blocked at fan by a screw or nail

  • Dampers blocked at wall/roof exit


What are other issues with fans?


  • Energy hogs.  cfm/watt they just use a lot of energy due cheap, inefficient motors.

  • They’re loud.  Everyone’s been in a bath where it sounds like a jet taking off or when turning on a kitchen fan just isn’t worth it because it’s too loud.

  • No control except for off and on switch.  Ever left a bath fan on all day?  You’re not the only one. 

  • Exhausted to the attic, not the exterior of building.  Dumping damaging moisture to the attic space


What is a quality installation of an exhaust fan?  


A fan that:


  • draws the required air flow and exhausts it to the outside

  • is quiet

  • uses a low amount of energy

  • goes off when it should Seems simple, right? 


But so many contractors get this wrong, wrong, wrong!!

How we install bath and kitchen exhaust fans 


Quality equipment


  • high performance Energy Star bath fans have a high cfm/watt

  • high performance Energy Star bath fans low sone rating so they are very quiet

  • bath fans have timers so people can ventilate as needed, without having to remember to turn the fan off

  • kitchen exhausts are direct vented to the outside, not recirculating

  • kitchen exhaust fans are not oversized...more is not better, just wasteful!


Quality installation


  • Minimal turns in ducting: one bend is preferable, two bend maximum.

  • Straight, short duct runs 

  • Visual verification of no crushed or damaged ducting

  • Sealed ducting at the fan and sealed at the exterior penetration with the wall so all the air goes outside for air tightness

  • Insulated, if appropriate

  • Roof exits are goosenecks, avoiding flaps that can impede flow. Side wall flaps are tested and adjusted to assure they allow air flow


3rd party testing of installation quality and performance


  • After we do our quality control, 3rd party verification and testing then confirms that our ducting meets their high standards.  

  • Then they test the rated air flow to confirm that it makes the required amount of air flow.


Our bath and kitchen fans work.  We know that they do, and now you know too.

Specialized high performance equipment to provide fresh air to living spaces 24/7


Our houses have a mechanical system with a fresh air supply designed in to provide fresh, filtered outdoor air to living spaces 24 hours a day.


The heart of this system is an Energy Recovery Ventilator.  An ERV is a specialized piece of equipment that is far above what current building code requiresthat brings fresh air inside.  In actuality, an ERV does three things:


  1. It provides continual fresh air throughout the house 24/7

  2. It exhausts stale air to the outside 24/7

  3. It does the above two things with minimal energy use.




An ERV is a heat and moisture recovery device captures heating (or cooling) and transfers that to the incoming air to pre conditions the fresh air so that minimal energy is used by the home’s HVAC system to get the fresh air to the right temperature and humidity.


This equipment is tested as part of the LEED certification process to verify it draws and exhausts therated amount of air per ASHRAE standards.  


We want to know that it works...and this test verifies that.

Specialized high performance filtration


If you are sensitive to dusts, allergens, volatile chemicals?  If so, have you seen our air filters?  WOW!


We specially design high performance filters into our HVAC system to remove much higher percentages of particulates large (pet dander, dust) and small (flour dust and car emissions) from the air.


Our standard filter is either a MERV 11 or 12 removes 60% or greater of particles in the 1-3 micron range; for example flour dust and auto emissions.  See chart below for more comparisons and a better understanding of removal effectiveness.


In contrast, a typical 1” HVAC filter is a MERV 4-6 which removes less than 30% of 1-3 micron particles.


What’s a MERV??


Minimum Efficiency Reporting Value is a measurement scale designed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to rate the effectiveness of air filters.The scale is designed to represent the worst-case performance of a filter when dealing with particles in the range of 0.3 to 10 micrometers. The MERV rating is from 1 to 16. Higher MERV ratings correspond to a greater percentage of particles captured on each pass, with a MERV 16 filter capturing more than 95%of particles over the full range. (Thank you Wikipedia for the concise definition of MERV.)

Quality construction practices: Sealed HVAC and post-construction flush 


Sealed HVAC during constructionWe seal our HVAC duct and registers during construction to block construction debris and particles from being distributed into the air when the system runs. 


While we strive to use non-toxic components, we also prepare for the worst.  After all construction iscomplete for a minimum of 48 hours we “flush” the building.  Meaning all cabinet doors and drawers are opened, all doors are opened.  Exhaust fans are continually run and the HVAC fan is on.  Windows on every floor are opened and the building is flushed.  This removes much of the initial off gassing fromconstruction prior to occupancy.

Quality control via 3rd party testing and verification


Chances are very good that you’re not a home inspector or green building professional.  But you are probably someone who wants a high quality home.  


You don’t have to be an expert because we’ve already hired an independent 3rd party to assess the home’s quality so you don’t have to.  


This independent 3rd party performs: 


Bath fan testing

Our 3rd party verifier performs a hood test to verify that we meet the ASHRAE required 50 cfm per bath fan.  We always meet or exceed that requirement.


Kitchen exhaust fan testing

Our 3rd party verifier performs a hood test to verify that we meet the ASHRAE required 100 cfm per kitchen exhaust. We always meet or exceed that requirement.


ERV testing

ERV’s have rated performance intake and exhaust parameters.  We always meet or exceed those parameters to ensure proper performance.

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