Can a Building’s Seal Be Too Tight? This is a good question we want to clarify.
A tight and well-insulated building correlates lower energy costs and improved indoor living space comfort. It is why air sealing is a necessity in modern building construction. But too much of a good thing can be bad, right?
A Tight Building’s Myth
There’s a misconception that homes and buildings, like humans, need to breathe. So, a building’s seal that’s too tight isn’t an ideal scenario. But is it really common for buildings to be too airtight, though?
Many people think of tight homes and buildings as having issues with moisture. They believe that when building materials are tightly bound together, they can’t allow water vapour to escape. But this isn’t necessarily an accurate explanation. High humidity levels inside the home or building envelope are due to trapped moisture.
The truth is that building materials expand and contract during heat and cold cycles. They’re designed to move with changing conditions while maintaining an airtight seal. So, when building materials are correctly joined together, it’s not like they don’t breathe at all.
Balance Between Air Tightness and Moisture Control
But if tight buildings don’t have a high risk of moisture infiltration, why do we need to worry about humidity levels during air sealing projects?
When an unconditioned home or building is undergoing air sealing work, there are usually more open areas to “envelope.” This causes the structure to adapt by losing conditioned air through the newly created infiltration pathways. That’s why it’s necessary to get air sealing work done during the colder months of the year. This way, there’ll be fewer open areas for conditioned air to escape.
If you’re considering new building construction or a major renovation project, then it’s important to weigh what type of heating and cooling systems you want in your home or business too, so you can assure that the building’s seal is what you actually need.
For example, suppose you’re building a new home or considering upgrading your current HVAC equipment. In that case, it’s best to select equipment that has a high Annual Fuel Utilization Efficiency (AFUE) rating. This means the heating and cooling system uses fuel as efficiently as possible without creating contaminants in the process.
The AFUE rating will indicate how efficient your system is, but it won’t measure the created contaminants. To protect yourself against pollutants like nitrogen dioxide (NO2) and carbon monoxide (CO), you should request a filter installation during equipment upgrades or new construction projects. Also, make sure to maintain your heating and cooling systems to keep them running as cleanly as possible.
No Such Thing as “Natural Ventilation”
Old buildings and homes were constructed with natural ventilation in mind. They were designed to allow air in and out of the structure. But the problem with this method is that it doesn’t control what comes and goes through those openings. This can rapidly lead to the building’s seal issue.
That’s why we use ventilation equipment that takes care of indoor air quality inside our homes and buildings, as well as keeping humidity low. When considering your building’s options for heating, cooling, and ventilation systems, make sure they’re properly designed to adjust to changing conditions.
Since old buildings and homes didn’t have proper insulation or air sealing, there’s a little propensity for structural failure caused by condensation. When it does happen, then many times, there’s enough air exchange that prevents major issues.
But with newer homes and buildings, the risk of structural problems due to condensation is higher. These structures are more airtight thanks to energy-efficient windows and doors, better wall insulation, and more. Together they make the problem of condensation even worse for those who don’t know how to deal with it.
Luckily, technology has given us ways to solve these problems. For some, the solution is better humidity control through ventilation equipment or air-to-air heat exchangers. But for others, it’s simple preventive measures like sealing their homes and buildings more tightly.
Issues Associated with Poorly Sealed Buildings
A poorly sealed building has plenty of cracks, gaps, and air leaks. These openings allow humidity to get inside, and when it does, all kinds of problems arise.
Here are some of the most common issues:
- Condensation on windows and walls – If air gets in through cracks or gaps along windowsills or at door jams, then moisture will gather there when it’s cold outside, which leads to condensation.
Condensation on pipes, causing them to rust – If condensation forms on piping when they’re in insulation, the pipes begin to rust through, bringing all kinds of problems with them.
- Mould growth – Condensation leads to serious mould growth in buildings because it provides the perfect environment for microorganisms like mould spores and bacteria to grow.
Health issues caused by poor indoor air quality – If there’s excess humidity in a building, bugs and dust mites will thrive. That leads to respiratory issues like asthma and bronchitis for susceptible people.
Energy Savings from Air Sealing
Air sealing doesn’t just make an indoor living space comfortable and healthy – it also helps save energy. It’s been estimated that air sealing alone can reduce energy costs by up to 30%. These steps must be taken to properly air seal a house or building:
- Identify areas where there are leaks in the structure.
- Seal all cracks and gaps around windows and doors with caulk or weatherstripping.
- Seal all gaps and openings in the foundation, like where it meets with the home or building.
- Ensure that insulation is installed correctly.
- Fix any faulty ductwork in HVAC systems before sealing them up any further to keep energy costs down.
So, yes, sealing’s buildings can be too tight. But it’s not necessarily an irreversible problem if you manage a new air ventilation system in the existent HVAC to control moisture.
There’s an abundance of property owners who’ve successfully made their homes and buildings more airtight, and they’re happy with the benefits that come with it.
If you have any questions about building sealant or aerobarrier, get in contact with Okanagan Aerobarrier and we will be happy to help.