Posts Tagged ‘rooftop unit’

Thoughts on Industry Trends

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Thoughts on Industry Trends

Back in late January, I attended the ASHRAE Winter conference and AHR show – right in the middle of when the polar vortex was unleashing its fury on the northeast! As I look back on the messages that our industry is pushing, a few topics really popped out.

The phrase “conservation is our best energy resource” – we see ways to conserve energy every day, yet still get stuck in the “I can’t do anything about that” mode. Mention to a client that window upgrades may be a more feasible alternative than upgrading the boiler installation.

In a session on ASHRAE 90.1, one of the speakers pointed out this: Why do we stick to the usual temperature rises on water systems? A chilled water system design temperature is 12oF, always has to be 12oF. But shooting for the higher temps of 16oF or even 20oF is achievable. I can take that idea one step further. An existing chilled water system is designed for 12oF, but you can add to that system with loads that are designed for a higher rise. We’ve all heard the horror stories of low delta T on a chiller, but it’s the opposite if the load comes back at higher than design! If you can change the loads so the peak temperature rise is 14 or 16 or more, the existing chiller can handle it more efficiently. Plus you get the benefits of lower pumping cost.

Another sector of our industry which has received little attention, the rooftop unit (RTU), is hitting the energy radar screen. Keep in mind that almost 40% of space in the USA is cooled by an RTU. Efficiencies are going up, and the manufacturers have made it easy to retrofit by providing roof curb adaptors to fit the 1980s RTU you are replacing. I don’t do a lot of RTU work, but realized that the energy bar is still pretty low in ASHRAE 90.1, (EER of 11). There is talk of setting minimum SEERs of 15, and that is coming from outside of ASHRAE (DOE, I think). In many cases across strip malls in this country, the energy use in an existing space can be cut by 40% with a new RTU coming out in the next year.

It’s an exciting time to be in the business of heating and cooling, with many opportunities to make a lasting difference in energy consumption. I try to not get stuck in the usual ruts of design philosophy, and challenge everyone out there to do the same.