Bathroom Ventilation- It used to be that a bath with a window did not require a ventilation fan. That is no longer true. Today, any room with a toilet, shower or tub must have an exhaust fan and it must duct to the exterior of the home- not into the attic.
The primary purpose of the exhaust fan is to lower moisture levels- not odors.
The best fans use a squirrel cage blower rather than the propeller type fan. They move more air at quieter noise levels (sones). For most baths look for a fan rated at 80cfm at 1.2 or lower sones level.
Kitchen Ventilation- There is no code requirement for an exhaust fan in kitchens. Depending on your cooking habits a vent hood may or may not be necessary.
Recirculating hoods use a charcoal filter to remove odors but do nothing for moisture levels.
Like bath vents, the squirrel cage fan moves more air at less noise level. If you install a vented hood it is critical to install the appropriate ductwork and be certain it is ducted to the exterior of your home.
Determining appropriate cfm's of air movement depends on your cooking habits and position of the hood. An island hood will require greater air movement than one mounted against a wall.
Decorative fan-light in oil rubbed bronze finish, opal glass
Bath vent with single or double infrared heat bulbs. Does not require separate circuit.
Broan Heat-Vent-Light, 1500 wall heater, 4" duct, 2.0 sones. Requires 20amp circuit.
Broan Vent-Light available in 80 and 110 cfm. Extra quiet at 0.6 sones.
Decorative vent-light with brushed nickel trim, white opal glass
Broan Vent-Light with recessed can appearance. 1.5 sones, 4" duct. Add other recessed can lights.
Controls bath fan based on humidity of the room. Turns on and off automatically.
Typical range hood that can be ducted to the exterior or recirculated.
Commercial style range hoods have higher air flow and will require 7-10 inch diameter ducts.
Wall mount chimney hoods can be vented or recirculating. Available in 300-600 cfm.
Island range hoods require more air movement since they draw air from all directions. Hood needs to be turned on several minutes before it is needed to create air flow pattern.
Very popular is the combination microwave and hood. Available in vented or recirculating. Often have automatic temperature switch to avoid overheating the unit.
Telescoping range hoods rise out of the cabinet and duct down through the basement joists. Very effective approach for island vents.
Blower units for wood hoods are available ducted or recirculating but require a duct grill cover on the upper hood to recirculate.
A very inconspicuous hood that slides out from under the cabinet during operation. Blower unit consumes much of the cabinet above.
Higher quality fans feature squirrel cage blowers that move more air at less noise levels.