Home Renovation Resources
Bathroom Ventilation
By Glenn Curtis
Bathroom exhaust fans are an important part of a home’s ventilation system. They eliminate odors, improve indoor air quality, and remove moisture and humidity that can lead to structural damage or mildew and mold growth. Unless a bathroom is properly ventilated, the moisture from a shower has no place to go and can penetrate into drywall, attic insulation and structural joists. If a mirror is steamed after a shower, or there is a build-up of condensation on bathroom walls, it may be time to service or upgrade the bathroom fan.
There are several factors to be considered when selecting a new or replacement bathroom fan: airflow rate, sound levels, energy efficiency, and aesthetics and fan control.
Airflow rate
Of the factors listed above, the airflow rate is the most important. The Home Ventilating Institute (HVI) has provided guidelines for the proper ventilation of a bathroom. For bathrooms under 100 square feet, the basic rule is to exhaust a minimum of one cfm (cubic foot per minute) for every square foot of bathroom area. So an 8’ x 10’ bathroom, 80 square feet, would have a minimum airflow requirement of 80 cfm. For bathrooms over 100 square feet, the calculations are based not on square footage, but on the number and type of fixtures in the bathroom. An allowance of 50 cfm should be made for each standard toilet, bathtub and shower. Allow 100 cfm for whirlpools and hot tubs. For example, a bathroom with a hot tub, shower stall and toilet would require a minimum of 200 cfm (100 + 50 + 50).
Once the required airflow in cfm has been determined, it is necessary to establish the amount of static pressure (SP), or resistance to airflow, in the exhaust duct system. This has a significant influence on the amount of airflow the fan will deliver. Many bathroom exhaust systems have a static pressure of 0.3” to 0.5”, which must be taken into consideration when selecting a bathroom fan. When static pressure increases in an exhaust system, the amount of airflow, or cfm, decreases.
Most bathroom fans sold today are marketed with cfm levels based on open-air conditions, or 0” SP. A fan rated for 100 cfm at 0” SP may not provide the necessary airflow for a bathroom when it is installed, because of high system resistance. It has been determined that some bathroom fans with an initial rating of 90 cfm at 0” SP provide no airflow at all when installed in a typical bathroom exhaust system having 0.5” of static pressure. To avoid this problem, it is important to know manufacturers’ published airflow rates at varying static pressures to allow for proper fan selection.
Air make up is an important factor to consider when sizing a bathroom fan. Fans will only remove air from an area at the rate that the air can be replenished, regardless of the correct sizing or rated air flow. In many cases, the space between the bottom of the door and the floor is adequate, but in some cases an additional air make-up source must be installed to allow the fan to operate at peak performance, such as an additional grille installed in the bathroom door.
Sound level
The second issue is the sound level of the bathroom fan. Various studies have shown that many people do not turn on their bathroom fans because they are too noisy. If the fans do not operate, they serve no useful purpose. When considering fan sound levels, it is important to check for the HVI rating. If a bathroom fan does not carry an HVI rating, there is a very good chance that the fan will be noisy. Recently there have been several proposed changes to local codes indicating that a bathroom fan installed should not have a sound rating higher than 1.5 sones (a sone is a scientific unit of perceived loudness).
A quiet alternative to traditional bathroom fans is the remote mounted in-line ventilation fan. These fans are mounted in the attic, thereby removing the motor and fan assembly from within the bathroom itself, and provide quiet and effective exhaust ventilation to deal with most airflow requirements. By removing the fan assembly from the bathroom space and mounting it remotely, the possibility of the ultimate in quiet operation, virtually 0 sones, can be achieved (depending on how far away the fan is mounted).
Energy efficiency
With energy savings being on everyone’s mind, choosing an Energy Star fan is, without question, the best choice. More than half of the fans operating in Canada today are not energy efficient models; in fact, some fans in operation today are using more than 180 watts of power. A retrofit of the bathroom fan can lead to savings in the electrical bill and increased performance of the bathroom fan.
Aesthetics
Once a fan has been found that is quiet, energy efficient and delivers the required airflow, it is important to look at the esthetics of the fan, or how the fan will fit into the décor of the bathroom. This is strictly a personal choice. Two different styles of bathroom fans are worth considering: traditional ceiling mounted fans and remote mounted in-line fans.
Traditional ceiling mounted fans are most commonly seen in bathrooms today. This type of fan has a fan and motor assembly mounted in the ceiling, housed in a box with a fixed air intake grille covering the mechanics of the fan. Although many of the newer designs have improved sound levels and airflow rates, they still have the motor and fan assembly mounted in the bathroom area, tend to be noisy, and are not designed to overcome the higher static pressures found in many exhaust systems.
Remote mounted in-line ventilation fans provide a much quieter operation, and are designed to overcome higher static pressures typically found in bathroom exhaust systems. In-line bathroom fans are normally mounted in the attic space, removing the mechanical aspects of the fan from the bathroom. The only visible portion of the exhaust system in the bathroom is an attractive exhaust grille. This provides a more esthetically pleasing look to the bathroom, with the ability to adjust airflow as required.
Another feature of remote mounted fans is that the air intake grille can be mounted directly over a shower or hot tub. In addition, the ability exists for one fan to exhaust air through multiple grilles. Remote mounted fans can provide up to 80% of initial fan rating, even with 0.5” of static pressure present in an exhaust system. This may result in the reduction in the size of fan required to meet airflow requirements.
Fan control
The last point to consider when upgrading a bathroom ventilation system is how to control the fan. This is an important aspect of the ventilation process, and is something that should be strongly considered. CMHC and HVI both suggest that a bathroom fan run for a minimum of 20 minutes after a shower, to allow for the removal of excess humidity and moisture. Many bathroom installations have the fan controlled by the same switch as the light, resulting in the fan being turned off as soon as the occupant leaves the room. It is recommended that a separate switch control the fan or, better yet, a timer that allows the fan to run for a pre-determined amount of time after showering.
There are many aspects to properly selecting the correct bathroom exhaust fan. Much of the information available today can be confusing. Whatever choice is made, it is important that the selection is based on fact, and not fiction.
Elements Home Design
Elements have a showroom of select healthy interior finishing products such as clay and hydraulic lime, coloured with natural pigments, wool carpets and oil finished wood flooring. On our visit, we felt warmly welcomed by Edward and really enjoyed his enthusiasm for his hand picked products. Check out their website or visit them on Salt Spring Island.
Budgeting
- Planning including: architectural design, interior design, engineering, surveys, permits, budgeting, scheduling - add 5 to 10% of project costs below.
- Kitchens: a total remodel, including flooring, cabinets, countertops, back-slash, lighting, appliances - Starting at $20K
- Removing a wall to create a great room including structural engineering, material, framing, drywall and flooring repairs - Starting at $15K
- Bathrooms: basic 4 piece bathroom, completely rebuilt - Starting at $15K
- En suite bathroom with a higher level of finish – Starting at $25K
- Additions to an existing home - Starting at $200 per square foot
- Basement Suites starting at $60K
Foundation for Deck on Steep Slope
See YouTube about replacing deck foundation.
BC Building Code
The BC Building Code 2006 currently applies to all Building and Plumbing Permits in Victoria Area municipalities. A new National Building code has been released, with a new release of BC Building Code expected spring 2012.
Web-based drafting programs
In case you are invigorated by the prospect of learning new software, there are several web based drafting programs available for your use.
Grants for Secondary Suites
The City of Victoria has made changes that will make installing a secondary suite even easier for homeowners. One of these changes is a grant program that will offer homeowners a grant equal to 25% of construction costs of new secondary suites, up to a maximum grant of $5000. Council approved this grant program on February 19, 2009 and the official launch date for the program was March 30, 2009.
Renovation Website by the Canadian Home Builders' Association
The Canadian Home Builders' Association has an informational website that is actually quite impressive.
Product Evaluation
The NRC Institute for Research in Construction (NRC-IRC) supports innovation in construction not only through research, but also through product evaluation by its Canadian Construction Materials Centre (CCMC). At http://irc.nrc-cnrc.gc.ca/ccmc you can review these evaluations. Most recently CCMC also provides the website links to the product manufacturers with the evaluation. Note: CCMC is not a consumer watchdog. The opinion rendered is limited to the question of the product's compliance to minimum code requirements. However, with the added link it is a valuable resource.
Sample Renovation Contract
The Canada Mortgage and Housing Corporation (CMHC) advises you to receive a detailed written proposal/contract from your renovation contractor for even the smallest of renovation and home repair projects. View their sample renovation contract.
The Canadian Construction Documents Committee
The Canadian Construction Documents Committee (CCDC) is a national joint committee responsible for the development, production and review of standard Canadian construction contracts, forms and guides. www.ccdc.org
Website Links
Pacific Solar Smart
Solar energy is a clean and abundant energy resource that can be used to supplement many of your energy needs. Solar energy can be utilized as a form of heat, such as solar water heating, and as electricity, such as solar photovoltaic. Pacific Solar Smart can provide you with a replacement energy source, not an alternative.
The Future of the Planet
Some links do not exactly fit into a readily defined category, such as Guy Dauncy's talk entitled ‘Spirituality, Hope and the Future of the Planet’, given at the First Unitarian Church of Victoria on Sunday, April 20/08 online, both audio and text, at http://www.earthfuture.com
Foam Insulation
You may have heard my story before about Steve Stitt the manager at Alpine insulation, insulating a second floor addition for our clients, a young family, into the night before Christmas. We had framed up a second storey addition while the family lived on in the main floor. The weather had been good, but turned dreadfully cold just days before Christmas and with their furnace just not keeping up, Steve came in and insulated the upstairs keeping enough heat in to make it work. So hearty recommendation for Alpine batt and blown insulation and also their Island Spray Foam branch.
Foam has the benefit of sealing up cracks in hard to get at places, plus maximizes head room in dormer and attic spaces increasing the likelihood of making use of your attic for heated storage or potentially additional living space. This works because it achieves required R rating in way less thickness and removes the requirement for air space above insulation - now accepted in Victoria when certified by an engineer.
Live Edge Design - Furniture and countertops from reclaimed wood, wind-falls and what is left behind after logging.
http://www.liveedgedesign.com/
Electrician and Electromagnetic Consultant
Walter McGinnis of McGinnis Electric, phone (250) 652-2554, does regular electrical work, plus can measure for electromagnetic fields and do wiring alterations to improve your situation if you ask. I have worked with Walter and can recommend his services. He is not at all pushy about electromagnetic issues, instead doing a thorough job by installing circuits, switches, lights and plugs strictly to code, which almost completely removes the possibility of magnetic fields. Walter's rates are reasonable and he and his crew clean up behind themselves leaving your home neat and tidy.
On Saltspring Island B.C. call Chris Anderson (250) 537-5102
or email at: emf@islandnet.com
Rainbow Consulting
Katharina Gustavs, of Rainbow Consulting, is an electromagnetic consultant who is referred to in the EM Radiation Task force Report to the David Suzuki Foundation http://emr.bc.ca/Articles/Suzuki-6.html There is also information in Wikipedia about electromagnetic fields and radiation. If you decide to make your renovation or new home to the safest electrical standards, Katharina is tops in her field.
Plan2Build
Plan2Build is a directory for all things related to building and home improvement.
VicStart Hotels & Directory
http://www.vicstart.com
Local Web Directory for the Greater Victoria
area. Links for cars, news, real estate, weddings....
All Images & Content Copyright © 2008 ConstructoGroup, All Rights Reserved
Privacy Policy
