RENTERS BEWARE: APARTMENT HVAC CLOSETS CAN BE SOURCES OF MOLD AND DEGRADED IAQ

Furnace on water damaged OSB platform.  The return plenum is located beneath the platform.

Furnace on water damaged OSB platform. The return plenum is located beneath the platform.

A common practice in multi-story apartment and condominium complexes is to house the furnaces in closets that are located on the patio or balcony for each unit. The closets are aligned vertically in each building. Although the orientation is convenient for plumbing access, numerous water damage issues are inherent to this type of HVAC set-up.
Water damage from plugged condensate drain tubes or malfunctioning condensate drain pans is common. Slimy biological growth in PVC tubing and drain pans pan causes overflows. Current or historical overflows from the pans will appear on the sheet metal plenum under the A-coil. Drips and mold growth from malfunctioning units above a closet are commonly apparent as drip stains or growth on the ceiling and walls of the closet.
Water damage caused by freezing and thawing of the AC coils is common in apartment HVAC systems. Filter changes are often left in the hands of uninformed tenants. Plugged filters prevent sufficient air flow to the coil, causing it to freeze. As the coil warms up, the ice thaws, releasing large amounts of water into the return plenum, floor system of the apartment, furnace platform, or furnace closet below the damaged unit.
Another issue associated with stacked HVAC closets is the installation of the furnace on a platform, which is commonly constructed from plywood, drywall, or oriented strand board. When wet, all of these materials support the growth of mold and bacteria, which can produce various toxins. Additionally, the glues and resins in these materials can be liberated when wet.

Ceiling of furnace closet showing water entered from HVAC  closet above.

Ceiling of furnace closet showing water entered from HVAC closet above.

The return plenum in furnace closet systems is located beneath the platform, with the underside of the platform being the top of the plenum, a concrete slab serving as the bottom, and the walls of the platform forming the sides of the plenum. In addition to being difficult to clean, a water damaged common plenum provides both a contaminant source and transport pathway.  Dust mites, insects and their fecal material, garbage, cigarette butts, contaminated chunks of paper, and rodent feces are just a few of the treasures that have been recovered from plenums under furnace platforms.
When damage does occur, the underlying cause of water must be corrected. This involves replacing plugged drain tubing, cleaning drip pans, cleaning coils, and changing filters. For consistency, preventive measures in the form of routine inspections and HVAC maintenance should be the responsibility of the management company or maintenance staff.
Addressing the consequences of the water damage, whether it manifests as biological growth or deteriorated building materials, is imperative to appropriate HVAC hygiene and good indoor air quality. Contaminants on water damaged plywood, OSB, and drywall in the furnace closet and on the furnace platform can cause adverse health effects, whether the growth is active or historical. Once dried, mold and bacteria engage in survival mechanisms that can include toxin production and increased sporulation. When dry, the contaminants are easily liberated into the airstream.  Mold remediation is required when building materials in furnace closets become contaminated. The remediation involves two components (1) removal of the mold or contaminated building material and (2) addressing spores that are released from areas of actual growth. Engineering controls, containment barriers, HEPA filtered air filtration devices, personal protective equipment, HEPA vacuuming, and damp-wiping are all essential for safe and effective remediation in water damaged furnace closets.

Return grille located inside of the apartment behind the furnace platform.  Stains show repeated wetting fo tack strip.

Return grille located inside of the apartment behind the furnace platform. Stains show repeated wetting fo tack strip.

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BASEMENT FLOODS: Primary Damage and Secondary Mold Growth

Flooding of basement, whether the water travels through foundation walls, is caused by a broken pipe, or backs up from a drain, requires immediate action to prevent exposure hazards from mold, bacteria, chemicals, pesticides, and other contaminants. Just as families should prepare and rehearse plans for addressing fires, pre-emergency preparedness is essential to safeguarding health and property values after flood events.
Flood Preparedness
I. Identify the source of water. This is important for several reasons:
• The severity and types of contaminants in flood situations are defined by the origin of the water. For example, if the flood water has fecal material, toilet paper, etc. that are indicative of a sewage back-up, the water has the potential to cause significant harm to exposed individuals. In addition to mold, bacteria, toxins, and human pathogens, sewage water can be contaminated with viruses, chemicals, and pesticides.
• The origin of the water can define whether or not insurance coverage is available. Many homeowner insurance policies include riders for sump pump failures and drain back-ups. Homeowners should be aware that the coverage is not always mentioned by the agent. The cost is typically less than $100 per year, but most consumers don’t know that it is not included in the general policy. Additionally, most insurance policies do not cover damages associated with ground water intrusion that enters through foundation walls or basement windows.
• The origin of the water could determine if liability is to a municipality for negligence, such as insufficient maintenance of storm drains or pumping stations, can be demonstrated.
• The origin of the water can assist in developing an appropriate remediation scope. If flooding is from ground water or sewage, high velocity fans should not be utilized for drying until decontamination is completed. The fans can blow contaminants from affected to non-affected areas. If the water originates from a clean water source, such as broken supply line for a washing machine, high velocity air movers and dehumidifiers should be employed as soon as possible. If surfaces are dried within 24 – 48 hours, mold will not likely grow.
II. When to call your insurance company
In most cases, the insurance company should be called sooner than later. Delaying notification could cause denial of claims or delays in appropriate structural drying, which could promote mold growth that might not be covered by an insurance policy.
Homeowners should know in advance what types of water losses are covered by their insurance carrier. Knowing what the deductible and other out of pocket expenses are for a claim , as well as understanding whether additional riders are needed for mold, drain back-ups, and sump pump failures, is imperative to making wise financial and risk assessment decisions. Also, knowledge of what is and is not covered will assist in decision making regarding whether making a claim is advisable, as making claims that are not covered might compromise the insurability of a home or could cause rate increases.
III. When to call in professionals
The answer to this question depends on the origin and severity of water damage, as well as the type of building materials that are affected by water. If sewage, ground water, or storm water affects large or inaccessible areas, gets into a furnace, reaches depths that require wading through raw sewage – call a professional.
If storm, sewage, or ground water does not recede within a few hours – call a professional.
If porous cellulose building materials such as drywall, plywood, insulation, and carpeting is affected – call in a professional. Scrutinize contractors in advance and call immediately.
Since insurance companies usually require that homeowners take action to mitigate losses, having on hand the phone numbers of pre-vetted restoration contractors can save time and money. After major storms, contractors get booked up quickly. If possible, do not rely on your insurance company to pick the contractor. Choose your own independent third party that has a good reputation and appropriate certifications in water damage restoration. Information on certification can be accessed at IICRC.org.
IV. Quick responses
If water recedes to the extent that electrical and biological hazards are not imminent, healthy homeowners can don protective clothing and take action to protect their belongings and the indoor environment. With appropriate precautions, drains should be verified to be open, pumps should be used to remove standing water, and dehumidifies are to be put into operation. Removal of non-restorable contents reduces indoor contamination and minimizes secondary damage from high relative humidity.
Items to be discarded include affected papers, cardboard, books, stuffed animals, stuffed furniture and other non-restorable items immediately. Disposal should be documented with photos and lists, or items should be placed in receptacles until they are documented.
Wet carpeting should be removed as soon as possible. All wet items should be bagged or wrapped in heavy gauge polyethylene. Transport items only after they are bagged or wrapped. If possible, discard through a basement window or door to minimize cross-contamination to living spaces. Be mindful that contaminants are present, and healthy individuals with no history of breathing disorders are the only candidates for self-remediation. Protective water resistant overalls, gloves, rubber boots, and P100 respirators should be worn.
V. Habitability
If occupants experience adverse health symptoms such as headaches, itchy eyes, sore throats, congestion, gastrointestinal disorders, dizziness, or other flu-like symptoms, the home should not be occupied until decontamination is complete and verified by an independent third party consultant. Infants, elderly people, diabetics, people on immune-suppressive drugs, respiratory illnesses, or heart conditions should be removed from the home until decontamination is complete and verified. A physician should be contacted if symptoms develop after exposure.
VI. Independent third party consultant
If a homeowner suspects litigation, confrontation with the insurance company, or serious health issues, it is strongly advised that an independent third party mold and water damage consultant be hired to assess damages and develop an appropriate remediation scope. It is a good idea to have names and numbers of vetted consultants available in advance.

DEAD MOLD CAN CAUSE ADVERSE HEALTH EFFECTS

Mold in Wall Cavity Can Enter Living Space

I was recently surprised in several situations where consumers were told that dead mold is okay because it does not cause adverse health symptoms.  The fact that dead mold, toxins, and mold by-products can cause adverse symptoms is not a new concept.  It was certainly included in all of the beginner mold training classes that I attended more than fifteen years ago.  Also, in 2001, EPA published information on the adverse health symptoms that can be caused by dead mold (Mold Remediation in Schools and Commercial Buildings).

Overhearing this kind of information relayed to a customer at “big box” store where the associate told a consumer that killing mold with a certain product was all that was needed to remediate a moldy attic caused me cringe.  Listening to a remediator argue this point with a homeowner who was sick after a botched remediation job made my blood boil.  Consumers look to professionals to guide them.  Mis-information is not only unethical, it can cause serious health problems.

Allergic type reactions from dead mold, mold spores, fragments of molds, and mold metabolites (toxins, volatile organic compounds) has been widely accepted in the medical field for decades.  Some of the health effects from mold, whether it is dead or alive, include:

  • Irritant reactions, such as itchy eyes, sore throats, and rashes
  • Suppression of the immune system
  • Inflammatory responses that affect the liver, kidneys, and other organs
  • Multiple chemical sensitivities
  • Chronic fatigue
  • Brain fog

The ability for dead mold, mold fragments, and mold metabolites to cause adverse health symptoms is one of the primary reasons that mold remediation standards of care from EPA, OSHA, the Institute of Inspection, Cleaning, and Restoration Certification require containment barriers, engineer controls, and HEPA vacuuming when moldy building materials are disturbed.

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