Office thermostat rant

ASHREA (American Society of Heating, Refrigeration and Air-Cooling Engineers - the group the sets the standards for things like this) says the right temperature for an office is the temperature at which 80% of the people are comfortable, ASHREA 55-81

So, I'm and Energy Engineer.  My job is to go into buildings and make them use less energy.  The first rule is don't do anything that decreases productivity.  People doing things make money, people whining about the temperature waste money.  So make people comfortable.  In a large office it's impossible to make everyone comfortable, thus the 80%, but just making it hot or cold is almost always a fail.

If your office is uncomfortable it's broken and can be fixed, it's not the way it has to be.  Oh and it doesn't have to cost a fortune to fix either.

WARNING ENGINEERING FOLLOWS  (Feel free to skip to the next post)

For years commercial buildings were built around the HVAC design principal  called constant volume reheat.  What this means is that the building moves the same amount of air all the time and delivers this same volume of air to each space all the time.  To control temperature as the space gets used the temperature of the air is varied as a result of the number of people, computers, coffee pots, copiers, etc.   To do this the air handler that serves the space cools all the air enough to cool the whole building on the hottest day, typically to 55 degrees to help with dehumidification.  Then if an individual space is cold, then a heating coil in the duct that delivers air to that space reheats the air to that space as needed to maintain temperature.  Pros are its simple and it *can* deliver very good control.  The bad is its energy inefficient.  If the person with the stat tries to save energy buy raising the temperature in the summer, they will have exactly the opposite affect.  That is because when the warmer air leaves the space and is returned to the air handler it then must be cooled back down before it can be sent back into the building.

More modern buildings use a variable volume system most of the time.
This means that there is still the reheating of air, but the volume is adjusted from a minimum to a maximum position first trying to maintain temperatures, then if the space is still cold the reheat is turned on.

So why does it result in discomfort, sensor drift, reheat valves leak hot water into coils when they are supposed to be closed.  Fire dampers shut blocking air flow, the heating coils are dirty and block air flow, the air flow measuring stations in boxes that control airflow are broken or out of calibration and need attention, the discharge air temperature on the air handlers is set to cold and has resulted in low delta T syndrome and the chillers can't keep up, the heating system is off or reset too low, the heating water or cooling water is too dirty and there is inadequate heat transfer, the control system is poorly programmed and has lost control, and on and on.

There are people who can help; it's rarely the people who got the building that way in the first place.