Reviewed by Gary E. Wilson, President & Designated Broker · Managing Greater Seattle rentals since 1982
HVAC is the system office tenants experience continuously and the one they complain about most. It is also the largest controllable operating cost in most office buildings, which means the same attention serves the tenant relationship and the budget at once.
The complicating factor is that comfort is subjective and the system is objective. A floor held precisely at its setpoint will still generate complaints, because people sitting by a window in afternoon sun and people sitting in an interior zone are having genuinely different experiences of the same correctly functioning system. Distinguishing a real fault from a distribution problem from an expectation problem is most of the work.
Wilson Management manages HVAC and air quality for office property across Bellevue, Seattle and the Eastside. For the wider service see Office Property Management.
Preventive Service
Mechanical equipment fails gradually, and almost all of it fails earlier without service.
The recurring items are filters at appropriate intervals for the building and its filtration level, coil cleaning, belts and bearings, refrigerant charge and leak checks, condensate drains and pans, economiser operation, and the outside air dampers and linkages that ventilation depends on.
Economisers and outside air dampers deserve specific mention because they fail silently in both directions. A stuck-closed damper starves the building of outside air, which is an air quality problem nobody sees. A stuck-open one admits unconditioned air continuously, which is an energy cost nobody sees. Neither produces an alarm, and both persist until somebody physically checks — which is exactly why they belong on a schedule rather than in a complaint queue.
Filter intervals are worth setting to the building rather than to a default. A building near construction, heavy traffic or wildfire smoke exposure loads filters far faster than the interval on paper, and a loaded filter costs fan energy while delivering less air.
Controls That Have Drifted
The most common cause of poor HVAC performance in an older office building is not failed equipment. It is controls that no longer do what anyone intended.
Buildings accumulate adjustments. A tenant complains, a technician overrides a setpoint, and the override stays. Schedules are extended for a one-off event and never restored. Sensors drift out of calibration and report values that are simply wrong. Sequences written for the building's original configuration continue running after that configuration changed.
The result is a system that appears correct on the panel and performs poorly in the space, consuming energy to do it.
The remedy is verification rather than trust. Comparing controller readings against independent measurements, reviewing schedules against actual occupancy, and checking that sequences still match the building. This is unglamorous work with an unusually good return, and it frequently improves the energy performance that now carries a regulatory dimension. See Energy Compliance.
Ventilation and Indoor Air Quality
Tenant expectations around ventilation and filtration have risen substantially and are unlikely to return to where they were. It is now a question asked during leasing rather than after a complaint.
The elements that matter are outside air delivery, filtration level and whether the equipment can actually handle the pressure drop of a higher-rated filter, humidity, and localised issues such as odours, printer and equipment loads or an unbalanced zone.
Filtration upgrades are the most common request and the one most often done badly. Fitting a higher-rated filter to a system not designed for its pressure drop reduces airflow, which can make comfort and ventilation worse rather than better while consuming more fan energy. Whether a system can carry the upgrade is an engineering question with an actual answer, and it is worth asking before ordering filters.
Where a specific complaint suggests an air quality problem rather than a comfort one, professional assessment is appropriate rather than adjusting setpoints and hoping.
After-Hours HVAC
Most office leases provide conditioning during defined building hours, with service outside those hours available as a billable extra.
Handled as a defined service — with a stated rate, a request process and clear billing — it is simply a line on a statement. Handled informally it becomes a recurring argument and an unrecovered cost, because tenants working late run systems the landlord pays for and nobody bills.
The mechanics worth settling are what the building hours actually are, how a request is made and by whom, the minimum billing increment, and how the rate was derived. Tenants accept after-hours charges considerably better when the basis is explicable than when it appears to be a number someone chose.
Handling Complaints Properly
A complaint process that resolves problems looks different from one that manages them.
Recording each complaint with its location, time and nature is what turns individual grievances into a pattern. Three complaints from the same zone at the same time of day is a diagnosable problem; three complaints logged as "too cold" is noise.
Investigating before adjusting matters, because the reflex of changing a setpoint in response to a complaint frequently creates the next complaint from the neighbouring zone. And closing the loop with the tenant — telling them what was found and what was done — resolves a substantial share of dissatisfaction on its own. Tenants tolerate an imperfect building; they do not tolerate feeling ignored.
Some complaints are genuinely about expectations rather than performance, and those are best addressed honestly. A perimeter office with west-facing glass will be warm on a summer afternoon, and explaining why is more useful than pretending a setpoint change will fix it.
Equipment Age and the Replacement Decision
Every mechanical system reaches a point where continued repair costs more than replacement, and the useful management act is recognising it before the failure that forces the decision.
The indicators are cumulative rather than dramatic. Service calls to the same unit increasing season over season. Parts becoming harder to source, which for older equipment eventually becomes impossible. Refrigerant type, where an older refrigerant is being phased down and its cost rising accordingly. Efficiency well below what current equipment achieves, which shows up as an operating cost the building need not be carrying. And an inability to hold conditions on the hottest and coldest days, which is the point at which tenants notice.
Three service calls to one unit in a season is not three incidents. It is one asset telling you it is finished, and treating it as three separate repairs is how buildings end up replacing equipment in an emergency in August.
Replacement planned in advance can be specified for efficiency, sequenced with other work such as a roof replacement, scheduled in a shoulder season when the building can tolerate downtime, and competitively priced. Replacement at failure achieves none of those. It also intersects directly with the performance obligations now applying to larger buildings — see Energy Compliance and Asset Planning.
Frequently Asked Questions
Why does HVAC generate so many complaints?
Because tenants experience it continuously and because comfort is subjective while the system is objective. A correctly functioning system still produces different experiences at a sunlit window and an interior zone.
What fails most often without anyone noticing?
Economisers and outside air dampers. Stuck closed, they starve the building of outside air; stuck open, they waste energy continuously. Neither raises an alarm, so both need scheduled checking.
Our building looks fine on the control panel but performs badly. Why?
Almost always drifted controls — accumulated overrides, extended schedules never restored, and sensors out of calibration. The panel reports what it believes, not what the space is experiencing.
Can we just fit better filters?
Only if the system can carry the pressure drop. A higher-rated filter on equipment not designed for it reduces airflow, which can worsen comfort and ventilation while increasing fan energy. It is an engineering question with a real answer.
How should after-hours HVAC be handled?
As a defined billable service with a stated rate, a request process and clear billing. Handled informally it becomes an argument and an unrecovered cost.
How often should filters be changed?
On an interval set to the building and its exposure rather than a default. Construction, traffic or smoke exposure loads filters much faster than the schedule on paper.
What resolves complaints fastest?
Investigating before adjusting, and telling the tenant what was found. Adjusting a setpoint in reflex usually creates the next complaint from the adjacent zone, and tenants tolerate an imperfect building far better than being ignored.
Get Started
HVAC decides both the tenant experience and the largest controllable line in the budget, which makes it worth managing rather than reacting to. Wilson Management, Inc. has been doing that for Greater Seattle owners since 1982.
Request a free analysis or contact us. You can also reach our Bellevue office at (425) 453-0089, 1380 112th Ave NE #203, Bellevue, WA 98004.