We have become much more familiar with the steps we can take to improve our home’s energy efficiency. However, one element tends to get less attention than the rest: ventilation and systems to maintain good air quality in our homes. Even in an A-rated home, you can have problems with condensation when the ventilation isn’t good.
Ventilation systems expert Stephen Walsh of AerHaus Ventilation offers the following tips.
What can cause problems with mold and condensation?
“It’s common to see mold or condensation on the north side of a home or in rooms with two or more exterior walls,” says Walsh. This is because these rooms tend to be colder than other rooms in the house.
Other reasons for these problems are excessive moisture buildup and poor ventilation. You generate moisture by breathing, cooking, washing and drying clothes. Two people sleeping in one room at night can generate 40-50g of water per hour. That’s nearly a pint of vapor generated by each person overnight.
Rooms with private bathrooms are more at risk of developing condensation or mold problems, especially when the bathroom has no natural ventilation and relies on a fan to extract humidity. If ventilation is insufficient, you will get condensation buildup on cold surfaces.
The fans installed in most homes are axial fans. These fans are designed to be installed on a wall through a straight duct leg. However, they are often equipped with several meters of ductwork, which means that they do not work as efficiently as they should.
What are the options for improving the air quality at home?
One option to help improve ventilation in a bathroom or bathroom is to replace the axial fan with a centrifugal fan. These are the least disruptive metrics to consider as this is a straight trade but should yield a good result.
A standard axial fan works like a propeller in an airplane. It is not designed for high resistance or high pressure scenarios. On the other hand, a centrifugal fan works like a hamster wheel or turbine. It’s designed to take a lot more pressure so you can adapt it to a few yards of conduit and get the result you need.
The alternative would be to install a mechanical ventilation system, of which there are two main systems – centralized and ducted, or decentralized and ductless.
A centralized or channeled takes care of the whole house. This is the best system to install if you are looking for total control of their flow in your home. Unfortunately, these systems are the most difficult and disruptive to install or upgrade. They require three or four inch ducts running from a heat recovery unit to each of the rooms in the house.
Heat recovery ventilation will do three main things: supply filtered fresh air to living areas and bedrooms; extract stale and humid air from damp rooms; and, during the winter months, recover 80-85% of the energy you would have traditionally lost.
Ductless systems are also known as demand ventilation or central exhaust systems and consist of a fan connected to each of the wet rooms. These fans measure the humidity level in the rooms using sensors. Depending on the humidity level, the fans automatically adjust the airflow in each room to compensate for the condition. When these fans extract, they encourage the fans mounted on the living space windows to draw cool air into the room.
Ductless systems are the most popular solutions when people don’t want to disturb their homes too much.
How can you maintain good air quality at home?
“It is important to insulate and ventilate correctly. If you go for a high level of insulation but skimp on ventilation – or vice versa – you will end up with problems,” says Walsh.
If you have a problem with poor air quality, always try to establish the reason first. For example, if you have a patch of mold on a ceiling, look for gaps in your attic insulation. “Venting systems won’t fix damaged window seals or lack of insulation,” says Walsh, so it’s critical to address these issues first.
Dry clothes outside whenever you can and open windows when cooking to prevent moisture buildup.
We all use our homes differently, so everyone’s home will require a slightly different solution. “The good news is that there are simple solutions to most problems,” says Walsh.