Editor's note: On March 18, the authors will present “Rooftop Package Units and Indoor-Air Quality,” an hour-long Webinar produced and managed by HPAC Engineering and sponsored by Lennox. To register for this free event, go to http://bit.ly/93J8cJ.

Employees reporting to or remaining at work despite illness, a practice known as “presenteeism,” can have serious repercussions. Not only do sick employees tend to operate at less than their usual level of performance, they risk infecting others (see sidebar). The impact on a company's bottom line can be devastating; the total cost of presenteeism to U.S. employers is an estimated $150 billion to $250 billion a year and rising.³

In plans to curtail employer health costs, finding direct disease reduction or facilities improvement can be difficult. Often, health-cost containment is viewed as an administrative matter, with efforts focused postinfection. Managers assume ventilation standards fully cover indoor-health issues when, in fact, they specify the least amount of air required to keep buildings habitable and safe.

Facilities managers have at their disposal a proven and effective means of helping to contain employer health costs: increasing ventilation. This article will discuss how increased ventilation can prevent the spread of disease among workers in commercial and government office buildings.

Costs

The conditioning (cooling, dehumidifying, heating, and filtering) of fresh outside air is considered costly by most facility engineers. Compared with the conditioning of recirculated indoor air, it is. But when sick-leave costs are thrown into the mix, the conditioning of fresh outside air does not seem so expensive.

For instance, providing the ANSI/ASHRAE Standard 62.1, Ventilation for Acceptable Indoor Air Quality-required 20 cfm of fresh air for one office worker for one year in Jacksonville, Fla., costs $48 (Figure 1). That includes upsized-equipment costs of $2,000 per ton, spread over the equipment's 10-year life; electricity costs of 12.5 cents per kilowatt-hour; and fuel-gas costs of $1.25 per therm. Compare that with the annual sick-leave cost of $1,580 for one government employee or $478 for one private-sector employee. If doubling the ventilation rate could cut sick-leave costs in half — in a 1994 test, Polaroid Corp. doubled (from 25 cfm to 50 cfm) ventilation rates in 40 buildings (3,720 workers), achieving a 53-percent sick-leave decrease⁴ — the economic return would be at least fivefold. (Breaking even would require a reduction of sick-leave costs of just 10 percent.) Greater productivity attributed to reduced presenteeism and lower health-insurance costs attributed to fewer and/or less-costly claims makes increased ventilation even more compelling.

Increased ventilation is estimated to save the U.S. economy $6 billion to $14 billion in respiratory-illness costs, $1 billion to $4 billion in allergy and asthma costs, and $10 billion to $30 billion in sick-building-syndrome- (SBS-) symptom costs.⁵