The heat wave that rolled across the U.S. last week reminded us that summers can be both uncomfortable and costly if we don’t know the smart way of staying cool when the temperature rises up. Facility managers go to great lengths to keep facilities comfortable for workers, as this comfort is directly tied to worker productivity, while keeping energy cost and consumption low.
Here are some simple tactics in approaching the summer heat to stay sustainable and make workers comfortable so that they can concentrate on their jobs:
1.Set your thermostat at 78°F or higher. Each degree setting below 78°F will increase your energy consumption by approximately 5-8%.
2. If your system doesn’t allow each work station to control the temperature and/or air flow, think about providing ‘chill out’ zones, i.e. areas in the building that are kept cooler, with water available.
3. Provide and action list for the building users of the best ways to keep the building cool – e.g., to open blinds again in the evening before leaving for home, or open secure ventilators etc.
4. “pre-cool” your building (i.e. operate outdoor air fans at night to bring in outdoor cooler air, reducing load on chiller plant).
5. Inspect and clean both the indoor and outdoor coils. The indoor coil in your air conditioner acts as a magnet for dust because it is constantly wetted during the cooling season. Dirt build-up on the indoor coil is the single most common cause of poor efficiency. The outdoor coil must also be checked periodically for dirt.
6. Reduce the cooling load by using cost-effective conservation measures. For example, effectively shade east and west windows. When possible, delay heat-generating activities.
7. Relax dress-code in the summer (no ties, no jackets, short sleeves) during periods of hot weather can help improve comfort, productivity and staff morale. Make sure you lead by example.
8. Additional short breaks for staff during hot weather can help them tolerate the conditions and remain productive.
9. Keep the humidity low. A target range of 40 to 45 percent relative humidity is good,but there is no ideal setting. Most people are comfortable with a relative humidity ranging from 30 to 50 percent, but can tolerate 20 to 60 percent. With lower humidity levels(such as 30 percent), thermostat temperatures can be set slightly higher.
10. Try not to use a dehumidifier at the same time your air conditioner is operating. The dehumidifier will increase the cooling load and force the A/C to work harder.
Temperature Wars – Savings vs. Comfort” survey conducted by IFMA suggests the following additional initiatives that can be implemented to increase the efficiency of your HVAC
77% Updated or replaced HVAC components or system
73% Verified the building automation system (BAS) is working as designed
52% Installed more efficient light fixtures that reflect less heat
27% Modified ductwork
24% Installed new window shades
24% Added window film to improve thermal properties
18% Retro-commissioned the building
15% Provided more local control to occupants
10% Green initiatives such as green roofs, heat recovery and solar water heating
12% Other (see below)
Added energy management system to chillers
Added new control systems
Installed additional mini blinds in consistently problematic areas
Because the system is so new, we have not done any of the above
Called in an air balancer
Central monitoring of HVAC system
Communication/education campaign with the occupants
Continually tweak direct digital control (DDC) system and BAS for better control
Tied digital variable air volume (VAV) systems into building management system; implemented
demand control ventilation
Implemented an energy conservation policy. Among other things, it sets temperature standards of 70 degrees
Fahrenheit (heating) and 73 degrees Fahrenheit (cooling). As long as the space temperature is in this range,
no action is taken.
Initiated more central control of thermostats versus local control
Installed new, more efficient windows
Managing to American Society of Heating, Refrigerating and Air-Conditioning Engineers standards
Moved thermostats to more open locations to better sample area temperatures
Reduced air handler output by zoning off at night
Repaired ductwork in ceiling space, reviewed the BAS and made many minor adjustments
Installed sun screens on outside perimeter
Trimmed the building management control system for best energy maximization and occupant comfort
Upgraded controls and installed new energy management system
Applied night time set back in winter and summer. Turned off the electric base board heat in the winter during
unoccupied times, unless it was 20 degrees Fahrenheit below zero or colder.
Installed shades, tinted windows and overhangs, and a VAV system