Tag Archives: Air Quality

How do I keep dust, smoke and other particulates out of the house?

A house should manage indoor air quality by regularly exchanging stale “used” indoor air with fresh outdoor air. You also can improve indoor air quality by avoiding unnecessary sources of contamination, such as restricting smoking to outdoors, storing fuels outside, and selecting low-VOC paints and furnishings. During the year, the air in the Interior can contain particulates from wildfires, wood smoke, dust, pollen, car exhaust and other sources that cause you to shut the windows. That’s where filtration systems can help.

Air filtration options

When it comes to indoor air filtration, the best choice for you depends on many factors, including the size and tightness of your house, your existing ventilation system, your sensitivity, and the amount of particulates and other contaminants in the air.  Be aware that irritating and harmful particulates don’t just come from outside but also inside — sources like tobacco smoke, animal dander and mold spores. Other contaminants include gases in paints, carpets, cleaners and other household products. The most common filtration systems are mechanical and target particulate matter. Prices range from about $200-$300 for a one-room portable filter to $6,000-$8,000 for a heat recovery ventilator installation with filtration.

Standalone filtration

The simplest system is a standalone air purifier, which contains a fan and filter elements all in one unit and can be plugged into the wall. These systems are designed to be portable and recirculate air in a single space, and will reduce pollutants like allergens, pet dander and dust from that space. These work well in homes where air quality problems are isolated to one or two areas.

Multiple room air cleaners

Air filtration systems that can serve multiple rooms or even the whole house typically cost more and will require an in-line fan and ductwork, but tend to be more effective.

Keep in mind that whether large or small, filtration systems by themselves don’t introduce fresh outdoor air, but they can provide air cleaning and heat distribution. Whole house systems may be a good option for those with bad allergies or respiratory problems.

Many homeowners who heat primarily with wood install small circulation systems, with an in-line fan and ductwork in just a few rooms to move heat around the house, said Richard Musick, of Ventilation Solutions LLC. The size of the fan is based on how much air you want to circulate.

“If it’s only a couple of rooms, you can get away with a 200 cfm (cubic feet per minute) fan. Big houses can require up to 900-1,500 cfm,” Musick said.

Heat recovery ventilator filtration

While new HRV systems often have high levels of built-in filtration, older models are generally only equipped with coarse debris filters whose primary purpose is to keep the core and motors clean. To help ensure good air quality, a simple filtration system can be attached separately in line with the warm-side supply port on the HRV. All the HRVs at CCHRC have a prefilter to catch the big particles, a main particle filter to catch small particles, and a carbon filter to remove odors, aerosols and VOCs. These filters can be found at HVAC and hardware stores, and are inexpensive and easy to replace. Note that the carbon filters typically need to be replaced more frequently than other air filters.


Filtration systems are measured by a MERV rating — or minimum efficiency reporting value — which goes from 1 (traps bigger particles) to 20 (traps the smallest particles). You pick a MERV rating based on what you’re trying to filter. For example, MERV 1-4 will take care of pollen, dust mites, and most animal dander, while you’ll need at least MERV 13-16 to filter out smoke particles. HEPA (high efficiency particulate arresting) is in the 17-20 range, removing more than 99 percent of tiny particulates such as carbon dust from the air.

Typically MERV 15 represents the upper limit for residential HRV systems as anything finer may restrict too much airflow. The EPA Office of Radiation and Indoor Air notes that filters with MERV ratings between 7 and 13 are capable of reducing unhealthy particulate matter almost as well as HEPA filters. Additionally, activated carbon filters can be used to neutralize smoke and VOCs.

House tightness

Homes built today are more energy efficient with better insulation and higher levels of air tightness than many of the homes built in previous decades. Building codes now require mechanical ventilation systems for all new residential construction in most if not all northern states. This is simply because uncontrolled air leakage can no longer be counted on to provide the fresh air needed to keep a home healthy. Generally speaking, the highest performing ventilation systems available today will include balanced and regulated fresh air exchanges, in combination with air filtration.

No matter what system you get, check to see what type of replacement filters are required.  Some models may use proprietary filters that are more expensive to replace or have more limited filtration capacity.

What you need to know about correct ventilation and installing duct work

Q: My home has condensate on the windows. I want to put in a new bathroom fan, but I need to know the correct way to vent a bathroom exhaust fan and the correct size of motor the fan should have.

The airflow through a bathroom fan is measured in cubic feet per minute (CFM).

A bathroom needs a minimum of 50 CFM intermittently or 20 CFM continuously. Fans are labeled with a CFM rating, but the duct work you attach to the fan will affect its flow rate.

If you run ducting in long, 30-foot runs and/or lots of 90 degree turns, you will need to double the fan capacity to 100 CFM. Ducts for a bath fan exhaust can be run with plastic, such as ABS or PVC, or metal, such as 29gauge warm air snap seam.

Ducting made of smooth materials will let more air flow than the flexible slinky-style duct materials, which are only appropriate for very short lengths, approximately 5 feet.

Another use is for the connection between the fan and the ducting, in order to reduce vibration.

If the ductwork passes through the attic, or any unconditioned space, it will need to be sealed and insulated to prevent heat loss.

There are several local companies that can assess your situation and install the right system or sell the appropriate hardware if you want to do the job yourself.

If, after installing and using your fan, you continue to see condensation on your windows, you may want to consider a more substantial ventilation system for your home. Today, most building codes require some form of mechanical ventilation.

This can range from an appropriately sized exhaust fan operating with fresh air inlets installed in the living spaces to a Heat Recovery Ventilation System (HRV).

Regardless of which type of system is used, it must be sized and installed to meet the needs of the home it will be serving.

Few show up to address upcoming borough air quality changes

From The Fairbanks Daily News-Miner, Friday, January 14, 2011:

Only a few residents addressed the upcoming air quality ordinance during public comments preceding the sparsely attended Borough Assembly meeting Thursday evening.

The air quality ordinance (2011-03) was reframed after voters in October’s municipal election approved a proposition eliminating limits on the types of wood stoves that can be used and prohibiting the fining of borough residents for smoke emissions or burning certain items.

The revised ordinance will be up before the assembly for public comment at its Jan. 27 meeting.

At issue is the borough’s attempt to meet federal clean air standards by 2014 without turning air quality regulation over to the state.

Heat ventilators and snow on the roof: How to handle both of them

Q: I have an HRV (heat recovery ventilator). I have been told it needs to be balanced.

What does that mean and how do I do it?


This is the darkest, coldest period of the year when people spend the most time indoors, so having a properly functioning ventilation system is particularly important. A heat recovery ventilator (HRV) must be balanced and tuned so that it delivers as much air as it exhausts. Because the resistance to air flow varies with different lengths and types of ductwork used in the system, an unbalanced system may deliver too much or too little air, and operate inefficiently. Balancing an HRV involves measuring and adjusting the airflows through the unit, and it should be done by a professional with the proper metering equipment. A sticker should be placed on the HRV noting when it has been serviced.

A homeowner can still perform a basic inspection.

This includes cleaning the filters in the unit, and making sure that the intake and exhaust grilles on the outside of the home are clear of snow and debris. In the rooms, the supply and exhaust grills should also be examined to be sure they are open, clean and moving air without obstruction.

Q: I have a roof with a very steep pitch. I’m worried about snow sliding off my roof and damaging my gutters. What can be done about this?

Because of November’s icy rains, unprotected gutters may be more vulnerable than usual this year, particularly those made of plastic which may not be able to handle the additional weight.

Unfortunately, it may be neither safe nor even physically possible to deal with the problem now. Next summer, when the roof is clear of snow, there are several things you can do to prevent snow from damaging gutters. If the roof is metal, then snow stops are often cheap insurance and will not only protect the gutters, but any people or property that could be struck by melting snow in the spring. Vulnerable areas such as chimneys and entryways can also be protected by a cricket, which creates a berm that will divert sliding snow to either side.

If you plan to buy new gutters, then professionally installed seamless gutter systems are worth a look.

Metal gutters are typically made on-site in long sections using a forming machine. They are attached through the fascia with long fasteners and are, in general, much stronger than standard gutters.

Since the snow will likely stick to the roofs in Fairbanks with greater tenacity this year, keep an eye on those areas that could be vulnerable to falling snow when things start to thaw — it may be wise to put up some temporary signs to warn passersby.

Vehicles needed for exhaust emissions research project

From The University of Alaska Fairbanks, Tuesday, January 4, 2011:

The Alaska Department of Environmental Conservation, with help from the Fairbanks North Star Borough, is conducting a study to measure wintertime fine particulate (PM2.5) emissions from gasoline-powered light duty trucks and cars in Fairbanks. Vehicles of all ages will be considered, but 1986 models are needed most. Vehicle owners will be paid $50/day if their vehicles are selected and used for emission testing, which is planned for two to four days in early January and two to four days in late January or February. Testing will be conducted at the FNSB Transportation Department at 3175 Peger Rd.

If your vehicle is selected, you will be contacted in approximately one week for additional vehicle and usage information, and to arrange a physical checkout of your vehicle at the borough’s transportation department. Testers won’t be able to test vehicles with exhaust leaks, liquid leaks, or other testing safety issues. All test vehicles will be fully insured against damage. Participant transportation to home or office will be provided once the vehicle has been dropped off and for vehicle pickup following the testing.

If you are interested in volunteering your vehicle, please call or e-mail Nadine Winters at nadine@acsalaska.net or 457-6258 with the following information: Vehicle make, model, model year and your daytime phone number or e-mail address.

UAF is proud to work with the borough on this program as well as other research efforts related to air quality in Fairbanks. This work is in line with UAF’s commitment to making our campus and our community a more sustainable one for those who work, live and learn here.

Fairbanks borough pollution plan goes before assembly for final touches

From The Fairbanks Daily News-Miner, Wednesday, December 29, 2010:

An air pollution plan that has so far taken more than a year to push through for the Fairbanks North Star Borough will no longer carry any fines or enforcement power if a revised version is approved next month.

Borough Mayor Luke Hopkins revised the air quality ordinance to comply with a ballot measure passed in October banning the borough from regulating home heating devices. The proposed ordinance will go before the Borough Assembly for first reading Jan. 13.

“We had an air quality plan passed. We barely entered winter, to see if it would have an effect on the large emissions we have in our airshed, when voters said ‘No thanks’ in October,” Hopkins said.

Now enforcement falls to the state and could end up being tougher than local control would have been, Hopkins said.

An advisory panel unanimously approved the updated plan Monday, but only because it had no choice, said Charles Machetta, chairman of the Air Pollution Control Commission. The updated version reduces a mandatory program based on hard limits and penalties to a voluntary program based on education and expert assistance.

“It’s a pretty toothless document,” Machetta said. “The sentiment of the commission is, we hated the document, we hated what happened with Proposition A (the ballot measure) and our hands are completely tied.”

The revised plan also transfers enforcement power to the state, which abides by similar air quality regulations and could enforce compliance through civil action rather than fines.

Continue reading: Fairbanks borough pollution plan goes before assembly for final touches

Experts recommend chimney upkeep, furnace inspection

From The Fairbanks Daily News-Miner, Saturday, December 25, 2010:

Charlie Whitaker has cleaned chimneys of boilers, furnaces, fireplaces and wood stoves through his company, A Chimney Sweep, for 27 years.

“Boilers and furnaces can malfunction at a moment’s notice,” he said.

While he did not inspect the chimney of Alyson and Mike Padilla, which leaked carbon monoxide into their home last week, he offered some common advice for maintaining and detecting problems in oil-fired boilers and furnaces. He also explained the common causes of soot in these systems.

The National Fire Protection Association recommends you have your chimneys inspected and tuned (if they require it) annually.

State takes lead in limiting Fairbanks pollution

From The Associated Press, Saturday, December 25, 2010:

Since North Star Borough voters eliminated fines for pollution-causing heating devices, the state’s Department of Environmental Conservation has taken up the responsibility.

But, KUAC-FM reports, the DEC must work through several steps before actual enforcement can take place.

The EPA has put Fairbanks on notice to reduce particulate levels by 2014.

DEC acting Air Quality Division Director Alice Edwards said the state’s regulations allow it to issue an advisory that limits the wood-fired heating devices when air quality is low.

“The DEC advisories provide another way for people to find out the status of the local air quality,” Edwards said. “It also allows DEC the ability to follow up on certain compliance concerns that are related to opacity from wood-fired heating devices.”

Violations of the advisory could begin with notices of violations and issuance of nuisance abatements, and could eventually result in civil penalties and civil suits.

Continue reading: State takes lead in limiting Fairbanks pollution

Fairbanks borough administrators rewriting air pollution plan

From The Fairbanks Daily News-Miner, Thursday, December 23, 2010:

Administrators for the borough are rewriting an air pollution prevention plan following October passage of a voter initiative. The borough’s public pollution control commission will review the changes Monday.

The changes follow commissioners’ request that borough officials try, “as much as possible,” to retain oversight of pollution’s impact on visibility and trans-property boundary effects, Mayor Luke Hopkins said.

The commission meets Monday at 6:30 p.m. at a special venue, Pioneer Park’s Civic Center and Alaska Centennial Center for the Arts.

EPA forms group to increase tribal role in pollution prevention

From The Tundra Drums, Tuesday, December 21, 2010:

The U.S. Environmental Protection Agency is forming a new tribal committee to provide tribes with an opportunity for greater input on issues related to toxic chemicals and pollution prevention, the agency said in a press release.

The move is part of Administrator Lisa P. Jackson’s priority to build strong tribal partnerships and expand the conversation on environmental justice.

EPA is establishing a National Tribal Toxics Committee (NTTC) that will give tribes a forum for providing advice on the development of EPA’s chemical management and pollution prevention programs that affect tribes. Given the uniqueness of tribal cultures, communities and environmental problems, the forum will help EPA better tailor and more efficiently address a variety of issues, including preventing poisoning from lead paint, expanding pollution prevention and safer chemical initiatives in Indian country, and better evaluating unique chemical exposures on tribal lands.

“This new committee will help increase our already close collaboration and communication with federally recognized tribes and intertribal organizations on critical issues relating to chemical safety and pollution prevention that affect Native peoples,” said Steve Owens, assistant administrator for EPA’s Office of Chemical Safety and Pollution Prevention. “We are committed to reducing toxic exposures and increasing pollution prevention among tribal communities, and to respecting tribal sovereignty, culture and heritage.”

Continue reading: EPA forms group to increase tribal role in pollution prevention