The Front Lines of Residential Indoor Air Quality Dan Ventura
Learning Objectives What are the most common issues related to indoor air quality in single-family and multi-family residential buildings?
Learning Objectives What are the most common issues related to indoor air quality in single-family and multi-family residential buildings? How occupant compliance and occupant lifestyle affect indoor air quality, and how can systems can be designed to account for these factors?
Learning Objectives What are the most common issues related to indoor air quality in single-family and multi-family residential buildings? How occupant compliance and occupant lifestyle affect indoor air quality, and how can systems can be designed to account for these factors? What are the options for air filtration within residential environments and how necessary are advanced HVAC filtration systems for good indoor air quality?
Learning Objectives What are the most common issues related to indoor air quality in single-family and multi-family residential buildings? How occupant compliance and occupant lifestyle affect indoor air quality, and how can systems can be designed to account for these factors? What are the options for air filtration within residential environments and how necessary are advanced HVAC filtration systems for good indoor air quality? What are the main sources of VOC's in a residential environment and how can homes be designed to cope effectively with the chemicals in the air?
Most Common IAQ Problems Ventilation deficiencies Over-use of cleaners, fragrances, and products Mold and moisture Carbon Monoxide Sewer Gases Lead/Asbestos
Visual Evidence of Lack of Ventilation Ghosting- Visible stains following framing
Mold on cold surfaces
Mold and water damage on ceilings
Ventilation controls deactivated
Over-use of cleaners, fragrances, and products
Less Obvious Products
Poorly Installed Appliances
Lead and Asbestos in Remodeling
Occupants, Lifestyle, and Design
Make ventilation easy and automatic Don't wire fans to light switches Use the quietest fans available Noisy fans will be run less frequently Use fans that run on a motion-sensor to detect occupancy Fan will be shut whenever they leave the room Panasonic Whisper Green Select can run for 60 minutes after a shower Use HRV's in place of Fresh-air intakes whenever possible Cold air from fresh-air intakes may make clients deactivate the system
Educate your clients What is this thing and why do I need to use it? How should I heat/cool this home? Can I use the fireplace only? Can I just use space heaters? Can I block the crawlspace/attic vents? What are my maintenance schedules? Timers, trickle vents, HRV's, Fresh-air intakes Furnace, HWT, HRV, Mini-splits, Filter changes?????? Where are the manuals and manufacturer's information?
Measure your fan/ventilation flows
Choose your target ventilation CFM wisely
Common Ventilation Options Recommended ventilation improvements: The client may choose from one of the methods below. These methods will bring the home to the highest typically recognized standards (2013 ASHRAE 62.2) and should significantly decrease humidity, CO2, and tvoc levels. Install 24-hour timers on each of the 4 bath exhaust fans, and set them all to run for no fewer than 17.25 hours per day. Replace the 4 bathroom exhaust fans with Panasonic Whisper Green Select units each set to run at 40 CFM constant-flow and to run for 60 minutes at 80 CFM once the motion-sensor has been installed Hire a licensed contractor to install a fresh-air intake system or heat-recovery ventilation system on the existing forced-air furnace. These systems must be tested, balanced, and set to achieve the desired ventilation rate of 158 CFM as listed above. *This will be very difficult and/or impractical due to the central location of the furnace and lack of a clear pathway for a duct to the exterior.
CO2 Levels What are the guidelines and standards for ventilation? Ventilation rates for schools and office spaces are defined by various codes and standards. The most widely accepted standard is the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) Standard 62. Some state and local codes have adopted the ASHRAE Standard 62 ventilation requirements. According to ASHRAE Standard 62, classrooms should be provided with 15 cubic feet per minute(cfm) outside air per person, and offices with 20 cfm outside air per person. Ventilation rates for other indoor spaces are also specified. Standard 62 is currently being revised, so these rates may change. Using CO2as an indicator of ventilation, ASHRAE has recommended indoor CO2concentrations be maintained at or below 1,000 ppm in schools and 800 ppm in offices.
VOC Levels
Mold Spores
A well ventilated home
A poorly ventilated home
Haz-Mat Don't be afraid of pre-testing for lead-based paint and asbestos: It's required by law! It's the right thing to do for the client and the environment! It's a way to prove your professionalism Really? John's Remodeling service didn't even mention asbestos in their bid???
Filtration Options Media-filters are your friend If it removes things from the air and traps them in a filter it can do no harm Beware jargon and promises, they may not deliver and/or release harmful materials: Ionic Electrostatic UV Photo-catalytic
Types of Media Filters Furnace Filters Thickness MERV rating Activated Carbon (charcoal) Thin sheets Cartridges HEPA High Efficiency Particulate Air Filtration
MERV rating system
Activated Carbon/Charcoal
HEPA Filtration HEPA filters remove 99.97+% of particles 0.3 microns or larger
HEPA filter mounted to HRV and furnace
EPA warns against ozone generators If used at concentrations that do not exceed public health standards, ozone applied to indoor air does not effectively remove viruses, bacteria, mold, or other biological pollutants. Some data suggest that low levels of ozone may reduce airborne concentrations and inhibit the growth of some biological organisms while ozone is present, but ozone concentrations would have to be 5-10 times higher than public health standards allow before the ozone could decontaminate the air sufficiently to prevent survival and regeneration of the organisms once the ozone is removed (Dyas, et al.,1983; Foarde et al., 1997). Even at high concentrations, ozone may have no effect on biological contaminants embedded in porous material such as duct lining or ceiling tiles (Foarde et al, 1997). In other words, ozone produced by ozone generators may inhibit the growth of some biological agents while it is present, but it is unlikely to fully decontaminate the air unless concentrations are high enough to be a health concern if people are present. Even with high levels of ozone, contaminants embedded in porous material may not be affected at all.
Electrostatic Air Filters
UV Filters
Common sources of VOC's
Volatile Organic Compounds Cleaners Fragrances Cosmetics Paints Plastics Packaging Other Building Materials
Fragrances Read the warning labels They are not actually made from vanilla, cinnamon, pumpkin spice, fresh linen...etc. Most are bound to or made from petrochemicals It may smell like pine but it's chemically closer to diesel fuel If you wouldn't eat it, DON'T DIFFUSE IT INTO THE AIR!!!
Formaldehyde
If you learned one thing! The Solution to Indoor Pollution is Dilution! Stale and stagnant air out, fresh and clean air in
Recap of the Lecture What are the most common issues related to indoor air quality in single-family and multi-family residential buildings? How occupant compliance and occupant lifestyle affect indoor air quality, and how can systems can be designed to account for these factors? What are the options for air filtration within residential environments and how necessary are advanced HVAC filtration systems for good indoor air quality? What are the main sources of VOC's in a residential environment and how can homes be designed to cope effectively with the chemicals in the air?
Dan Ventura