November 6, 2018
To the unaided eye, the only air openings to a building are its doors and windows. Look a little closer and you will notice deliberate vent openings in a variety of places, including the roof walls, and basement.
Here are some vents you might see around the roof:
You can also find vents in siding, windows, and foundations. The vents allow buildings to emit indoor air and/or draw fresh air in from the outside.
Vents in your basement keep condensation from forming around your walls, floors, and beams. Small vents can be installed in the siding to keep moisture from accumulating behind the wall sheathing, which can damage wood and paint.
Attic ventilation is probably the most important. In the winter, condensation can form alongside the walls and ceiling, which can lead to rot and mold, damaging insulation, paint, wood, and plaster. In the summer, attic temperatures can reach upwards of 140 degrees Fahrenheit.
A steady exchange of air is necessary to solve temperature and humidity problems year-round. Balanced humidification systems are able to remove hot, humid air in the summer and water vapor in the winter.
| Ventilation System | Pros | Cons |
| Exhaust | · Relatively inexpensive and simple to install
· Work well in cold climates. | · Can draw pollutants into living space
· Not appropriate for hot humid climates · Rely in part on random air leakage · Can increase heating and cooling costs · May require mixing of outdoor and indoor air to avoid drafts in cold weather · Can cause backdrafting in combustion appliances. |
| Supply | · Relatively inexpensive and simple to install
· Allow better control than exhaust systems · Minimize pollutants from outside living space · Prevent backdrafting of combustion gases from fireplaces and appliances · Allow filtering of pollen and dust in outdoor air · Allow dehumidification of outdoor air · Work well in hot or mixed climates. | · Can cause moisture problems in cold climates
· Will not temper or remove moisture from incoming air · Can increase heating and cooling costs · May require mixing of outdoor and indoor air to avoid drafts in cold weather. |
| Balanced | · Appropriate for all climates | · Can cost more to install and operate than exhaust or supply systems
· Will not temper or remove moisture from incoming air · Can increase heating and cooling costs. |
| Energy Recovery & Heat Recovery Ventilators | · Reduce heating and cooling costs
· Available as both small wall- or window-mounted models or central ventilation systems · Cost-effective in climates with extreme winters or summers and high fuel costs. | · Can cost more to install than other ventilation systems
· May not be cost-effective in mild climates · May be difficult to find contractors with experience and expertise to install these systems · Require freeze and frost protection in cold climates · Require more maintenance than other ventilation systems. |
Source: U.S. Department of Energy
With today’s well-sealed and insulated homes, ventilation is more important than ever. The problem is you don’t want to bring in cold air in the winter or hot air in the summer. Sometimes, the outdoor air quality is worse as well.
This is why we highly recommend a whole-house balanced ventilation system. This makes sure there is an equal amount of air leaving and entering the home, getting rid of any problems such as negative house pressure.
Even with balanced ventilation, you still have a problem with the energy loss. That’s where a heat recovery ventilator (HRV) or energy recovery ventilator (ERV) comes in. HRVs exchange heat while ERVs exchange heat and moisture. Go with an ERV if you live in a humid climate.
Stale indoor air gets exhausted out while fresh outdoor air is brought indoors. The two air streams pass each other through a heat exchanger. Heat and sometimes moisture are exchanged through the two air streams.
Learn more about HRVs, ERVs, and balanced ventilation.
Fall and winter are popular times to increase insulation around the home. Regardless of the insulation you use, you will help increase the energy efficiency of the home. But, be careful because well-insulated homes need proper ventilation.
That’s why after every major insulation improvement or change, you should call your local HVAC contractor to inspect the building for proper insulation and ventilation levels.
Service Champions is known for trustworthy, on-time heating and air conditioning service throughout the East Bay, South Bay, and Sacramento areas.
Contact us today to schedule your custom indoor air quality solution.