Changeover Time is Coming

After one of the coldest winters in recent memory, the heating to cooling changeover is right around the corner. Here are some tips for making the changeover this year.

 

1)      During the shoulder season when heating may be required, Make Up Air units that are fed by Primary Boilers can be left in a heating mode while the fan-coils in the suites are switched over to cooling. With a cooler Spring appearing likely, this will allow you to provide some heat in the corridors while providing cooling insuite.

 

2)      Glycol – make sure that when draining coils of glycol to recover all of the glycol in clean storage containers. Do not let the glycol flow into the building mains.

 

3)      Basement Loops (Miscellaneous Heating Loops) that are fed from the Heating / Cooling Mains need to be manually shut down during the summer to prevent condensation in enclosed spaces.

 

4)      Do an inspection of the Cooling Tower well before your changeover date. With the ice storm, it is possible that parts of the Tower may have experienced some damage due to heavy ice.

 

5)      Make sure that outside, electrically heated areas are shut down for the summer or that the controlling thermostats are set to a minimum set-point a couple of degrees above freezing.

 

6)      Remember to call Provident Energy during your changeover. Unless the Energy Management System is commanded to the cooling mode, HVAC systems will not operate properly.

Tech Corner: Spring Change-Over

For many of us in the Greater Toronto Area, this was the winter that never came. With the recent warm weather during March Break, some clients are considering an early change-over.

Last year, we had several buildings that changed over to Cooling by the third week of April. For Heat Pump buildings, it is important that the Fluid Cooler be ready for the first warm days of the year. We advise getting Fluid Coolers ready by the end of April at the latest.

The vast majority of buildings switched over during the second and third weeks of May. It may be helpful to change over the in-suite cooling, while leaving the Make Up Air units in a Heating Mode until the end of May. This is possible with hydronic (water coil) and packaged air handlers. In this way, if there is a cold snap, there is still a source of heat in the building.

One of the most important things that must be done during the change-over is to check and isolate the basement loop heating systems. In some buildings these systems are fed from Primary Boilers, however, in some buildings these systems are fed from the Dual Systems. When fed from the Dual System, this can result in these loops having chilled water flowing through them resulting in condensation and the ensuing damage to locker contents, drywall ceilings and other areas.

After change-over it is also important to check to make sure that ramp heating and stair melting systems are shut off for the season.

For our clients - it is also important to contact Provident Energy when your change-over is occurring. When switching from a heating to cooling mode, the ‘action’ of valves must be reversed. For example, when in a heating mode, if you need more heat, the valve must open to allow more heat to flow. When a rise in the space temperature (the input signal) needs to result in an increase in an output signal, this is referred to as ‘direct acting’. When a rise in space temperature needs to result in a decrease in the output signal, this is referred to as ‘reverse acting’. An Energy Management System must be told when to work one way or the other.

A carefully planned change-over will ensure comfort through the spring and summer.