Sniffing out culprits for odour complaints

Seven causes of unintentional air movement in condo buildings

Tuesday, May 16, 2017

By Dylan Haber

“My apartment stinks of garlic and I haven’t cooked in days!”

“Why can I smell the garbage chute in my bedroom?”

“If I have to smell Jimmy’s cigarettes one more time…!”

These are among the most frequent odour complaints building managers hear from residents plagued by unwanted scents creeping into their units.

Along with the benefits of a condominium lifestyle — urban living, fun amenity spaces, a diverse community of neighbours — come the pitfalls of a living space intimately shared with dozens of strangers — loud noises, boisterous kids and pets, or unwanted smells. For many, the odour problem is the most egregious. When foreign, and in some cases offensive, odours waft their way into one’s home, it can feel like a particularly intimate invasion. The negative emotional response can be significant.

Odour migration between interior spaces requires an open path of air travel (a door, a duct, a hole in the wall, etc.) and a pressure difference between the two spaces. Although building systems are designed to prevent unwanted air movement, there are often leaky areas that lead to unintended air and odour transfer.

Here are seven common causes of unintentional air movement through condo buildings:

1. Low-pressure corridors

In most residential buildings, fresh outside air is supplied to the corridors via a central make-up air unit, pressurizing the corridors. This allows fresh corridor air to flow into suites through gaps around doors and through the doors themselves, when opened. If the make-up air unit is off, malfunctioning, or undersized, the corridors are not sufficiently pressurized. This can unintentionally allow air to move in the opposite direction (suite to corridor) and then find its way into adjacent suites or common areas.

2. Unbalanced corridor air supply

The fresh air supply from the make-up air unit flows to the corridors in a central duct. Dampers at each branch are adjusted at construction to ensure the correct air volume is delivered to every floor. Over time, the system gets out of balance — dampers can shift; in some cases, residents will manually close the dampers off to stop “the cold air flowing into my suite from this vent.” If a floor’s fresh air flow is diminished due to balancing issues, suite odours may migrate into corridors, then into neighbour’s suites.

3. Wind-driven air movement

Exterior wind pressures are typically higher than those generated by the building mechanical systems. When windows or balcony doors are poorly sealed, or if there is an improper construction in the exterior wall assembly, exterior wind pressures can drive air inwards. The outdoor air may be carrying the smells of the garbage bins, cigarette smoke from the neighbour’s balcony, or kitchen/bathroom/laundry exhaust from surrounding suites.

4. Improper or missing smoke seals

While fires are difficult to prevent, there are strict construction requirements aimed at limiting the spread of flames and smoke. This applies especially to walls and floors between units. Sealant is required to keep smoke contained. A secondary benefit is that smoke seals also help to contain suite-to-suite odours. Mistakes can and do get made, however, and smoke seals may be missing or incomplete, resulting in odour paths. Ducts and conduits within fire-rated floor and wall assemblies can be especially challenging.

Another common odour transfer area due to poor smoke sealing is the often tricky interface at the vertical joint between an interior fire-rated wall and an exterior wall. Concrete walls are relatively simple to seal, but when wall construction consists of steel studs or window walls, it is increasingly difficult to ensure an airtight seal.

5. Elevator shaft air movement

As elevator cars shuttle up and down their concrete shafts, their piston-like action pushes and pulls large volumes of air along with them. This can cause unintended floor-to-floor air flows. For example, air from the garbage room may be sucked into a nearby elevator shaft and distributed to other floors. As elevator door seals wear, unintended air leakage will become more pronounced.

6. Intake and exhaust air short circuiting

Part of maintaining good indoor air quality is exhausting noxious air from kitchens, bathrooms and garbage rooms through the walls or roof to the outside. If the building exhaust air outlets are near windows, doors, or the fresh air intakes to make-up air units, there is risk of short circuiting: odour-laden exhausted air is drawn back into the building and re-circulated as fresh air.

7. Missing backdraft dampers

Suite kitchens and bathrooms are typically exhausted by individual exhaust fans that discharge through vents in the exterior walls. Backdraft dampers are installed in the exhaust ductwork to prevent reverse airflow and ensure the air is traveling in a single direction. If the dampers malfunction, exterior air can be drawn into the building through the exhaust ducts.

Making a diagnosis

While there are many possible causes of odour migration, they are all related to unintended air flows. That said, locating the errant airflow and correcting odour problems is notoriously difficult to do. Add in the fact that they are often transient — “Well, it only happens on Wednesdays at 3 a.m.” — and that people have significantly varying olfactory acuities — “Can’t you smell that? It’s awful!” — and the problem can get downright immovable.

Even with a strong understanding of building systems, solutions are unlikely to be obvious and it may take several measures to determine the origin of the issue. Here are a few common diagnostic steps:

Interview the complainant to put brackets around the problem. In other words, ask: What is the smell? Where is it strongest? When it occurs, who else notices? How long has it been a problem?

Review the condition and performance of the mechanical system, paying particular attention to the makeup air unit in the corridor. Measure the mechanical system airflows both subjectively and quantitatively. Also review the architectural drawings to understand system vulnerabilities.

Use smoke pencils or theatrical fog to illuminate airflow paths. Make selective openings in the drywall to check concealed smoke seals in vulnerable locations. Do blower door testing, which involves installing a large fan on the door of a suite to pressurize or depressurize the space. The goal is to induce air to flow across the breach, making it easier to identify via smoke pencil.

With skill, time and maybe some luck, the problem should be correctable, or at least reducible to a tolerable level. Some odour issues are either intractable, slight or infrequent, in which case it may not be worth the effort and cost to eliminate them completely. Rarely can air-tight perfection be guaranteed. Besides, the benefits still outweigh the risks in living within shouting, and smelling, distance of one’s neighbours.

Dylan Haber is a project manager in the property condition assessments group at WSP Canada Inc. A mechanical engineer by training, his experience includes performance audits and reserve fund studies for condominiums as well as property condition assessments for various building types, including residential, industrial, commercial and retail. He can be reached at dylan.haber@wspgroup.com.

Environmentally-friendly business is profitable business

Many associate sustainability with expense, but companies that have embraced it are financially outperforming
 Sainsbury's Open New Energy Efficient Store In King's Lynn
Sainsbury's new Kings Lynn supermarket is one of the retailer's most energy-efficient stores. Photograph: Matthew Lloyd/Getty Images
The failure of policymakers to make binding commitments at the Rio+20 Summit resulted, at best, in a lowest common denominator agreement that delivers few real benefits. In 2010, the UK Sustainable Development Commission (SDC) was axed as part of the government's spending cuts. In the US, Republican efforts to defund the entire Environmental Protection Agency risk even deeper structural shifts.

International governments' inaction and lack of leadership is clearly worrying but, at the same time, the proactive approaches of a few leading-edge companies are encouraging. Toyota, Sainsbury's, WalMart, DuPont, Tesco, Unilever, Marks & Spencer and General Electric have made tackling environmental wastes a key economic driver. As Jonathon Porritt, director of Forum for the Future, observed, a "governance shift" is occurring in the field of sustainability, with governments stepping back and businesses stepping forward to lead the change.

DuPont, one of the early adopters, committed itself to a 65% reduction in greenhouse gas emissions in the 10 years prior to 2010. By 2007, DuPont was saving $2.2bn a year through energy efficiency, the same as its total declared profits that year. General Electric aims to reduce the energy intensity of its operations by 50% by 2015. They have invested heavily in the Eco-magination project.

Unilever plans to double its revenue over the next 10 years while halving the environmental impact of its products. In 2010, WalMart announced that it will cut total carbon emissions by 20m metric tons by 2015. Closer to home, Sainsbury's has announced its industry-leading "20x20 Sustainability Plan" which is the cornerstone of the company's business strategy. It seems to be on track. In April this year, Sainsbury's said it had achieved its target of a 50% relative reduction in water consumption.

Tesco has announced that it will reduce emissions from stores and distribution centres by half by 2020 and that it will become a zero-carbon enterprise altogether by 2050. Toyota, already in its fifth five-year Environmental Action Plan, announced that it will improve the average fuel efficiency of its vehicles by 25% in all regions by 2015 compared to that of 2005. In manufacturing, Toyota has already reduced emissions per vehicle by 47% between 2001 and 2012.

Companies such as Tesco and WalMart, are not committing to environmental goals out of the goodness of their hearts, and neither should they. The reason for their actions is a simple yet powerful realisation that the environmental and economic footprints are most often aligned. When M&S launched its "Plan A" sustainability programme in 2007, it was believed that it would cost more than £200m in the first five years. However, the initiative had generated £105m by 2011/12 according the company's report.

When we prevent physical waste, increase energy efficiency or improve resource productivity, we save money, improve profitability and enhance competitiveness. In fact, there are often huge "quick win" opportunities, thanks to years of neglect.

Environmental waste is the best proxy for identifying and eliminating economic waste. That's the secret of these companies.

However, there is a considerable gap between leading edge companies and the rest of the pack when it comes to the adoption of lean and green ideas. There are far too many companies still delaying creating a lean and green business system, arguing that it will cost money or require hefty capital investments. They remain stuck in the "environment is cost" mentality. Being environmentally friendly does not have to cost money. In fact going beyond compliance saves cost at the same time that it generates cash, provided that management adopts the new lean and green paradigm.

Lean means doing more with less. That's why lean management supports green thinking and vice versa. Nonetheless, in most companies, economic and environmental continuous improvement are separate organisational silos and sometimes even come into conflict with each other. This is one of the biggest opportunities missed across most industries. Some companies are using lean and green as simultaneous sources of improvement in various sectors of industry – from automotive and retail to textile and brewing.

The size of the opportunity is enormous. The 3% Report recently published by World Wildlife Fund and CDP shows that the economic prize for curbing carbon emissions in the US economy is $780bn between now and 2020, rising to $190bn a year by 2020. It suggests that one of the biggest levers for delivering this opportunity is "increased efficiency through management and behavioural change" – in other words, lean and green management.

The report puts the return on investment (ROI) for lean and green interventions at 233%. In my experience, this is conservative: most organisations can achieve a far higher ROI when adopting the right behavioural and managerial changes. Some 47 studies from the likes of the Economist Intelligence Unit, Goldman Sachs, AT Kearney, Deloitte, MIT Sloan, Harvard and others show that companies that commit to such aspirational goals as zero waste, zero harmful emissions, and zero use of non-renewable resources are financially outperforming their competitors. Conversely, the DARA Group found that climate disruption is already costing $1.2tn annually, cutting global GDP by 1.6%. Unaddressed, this will double by 2030.

Here is an example. A couple of months ago I worked with one of the largest sandwich factories in the world. A team of great men and women engaged in a programme to reduce physical waste using problem solving techniques. The results were staggering. No one expected to see nearly 1,000 tonnes of waste prevented in just a few weeks in a very mature industry. Add to that, they also saved 9m litres of water from going down the drain every year with interesting financial benefits.

Keivan Zokaei is principal consultant at SA Partners LLP. He is co-author of Creating a Lean and Green Business System: Techniques for Increasing Profits and Sustainability

This content is brought to you by Guardian Professional. Become GSB member to get more stories like this direct to your inbox