As leaves change and summer temperatures begin to wane, you can get away with putting off unpacking your winter coat, but for building owners and operators, now is the time to start transitioning buildings from cooling to heating season. With new September leases settling in, it’s more important than ever to make this transition smooth and successful. But what exactly should your site staff be doing to prepare? To ease the transition, our engineers are here to help. Below is a checklist outlining the most important measures to take as we head into the next season.
Cooling System Shut Down
- If laying up equipment for the winter (summer boilers, chillers, etc.) decide on a dry or wet lay-up. For a wet lay-up, make sure the water is treated properly to prevent corrosion during the off-season.
- Drain cooling towers and check for water in low spots. If they run year-round, check operation of the basin heaters and tower bypass valve.
- If shutting down circulating pumps (such as chilled water) that have variable speed drives, consider running pumps at minimum speed. In some systems – particularly ones with old pipes, many terminal units, and clog-prone terminal unit control valves – this can prevent the strainer plugging and valve clogging that would have occurred when the pumps were restarted.
- Seasonal changeover – many systems require manual valve position changes as part of a seasonal switchover. Failing to make these changes properly can result in poor operation or even equipment damage. Does your staff have an up-to-date accurate valve chart? Is there a written procedure and checklist for switchover?
- For any equipment that operates with glycol, check the glycol concentration. Check that glycol feeder supplies are full and feeder equipment is functional.
Heating System Prep
- If boilers have been shut down, have your service contractor fill and start them. If they were running over the summer, they should be cleaned and re-tuned for winter operation at higher firing rates.
- If your boiler is dual-fuel, make sure the oil tank is full at the beginning of the season, so that you have enough oil for a few days of operation during a cold streak.
- Are controls operating in automatic mode at the beginning of the season? Are the setpoints correct? (Do you have documentation of what the correct setpoints are?)
- Check the operation of all heat-trace systems. These are often neglected and abandoned.
- After starting up systems, check that all indicating devices are working. Replace dirty sight-glasses, blown out pressure gauges, and the like.
- If hot water or steam pipes have not had flow during the summer, blow down suction strainers and boiler/s more frequently for the first week or two of operation.
- Check functionality of all outdoor air dampers and freezestats on air handler. Freezestats can be checked with cheap freeze spray. If the stat can’t shut the fan down and outdoor air dampers can’t close, you risk coil freezing and expensive coil damage, not to mention water damage when the iced-up coil thaws.
- Check all piping exposed to freezing temperatures for “dead legs” – sections of piping that have been isolated or bypassed and have no flow in them. These are a freezing risk.
- Check drain lines from any condensing combustion equipment, especially if it drains outside. Combustion condensate lines will stay open in moderately cold weather and then freeze and shut boilers down when temperatures are at their coldest. In freezing weather, building staff should be checking this every day.
These are just a few of the most crucial steps to take before it gets cold to ensure heating systems perform optimally when they’re needed most. We encourage building owners to talk with their site staff to ensure these steps are being taken and incorporate them into standard procedures and written documentation for seasonal changeover. Consistent and reliable operations and maintenance is the backbone of healthy buildings, happy staff and residents and minimal headaches.