By Chad Edmondson
It’s only a matter of weeks before new commercial buildings codes must comply (or state’s must a request for extension) with ASHRAE 90.1 -2010, as we reported in an earlier blog. And it looks like federal buildings will also have to follow suit too – albeit a little later.
Just this month the US Department of Energy (DOE) published in the Federal Registrar (so it’s official!) that new federal commercial buildings and new federally built multi-familyhigh-rises must comply with the efficiency standards set forth in ASHRAE 90.1-2010. The compliance date is one year after publication of the rule or July 2014. The rule updates baseline federal commercial standards with measures that are projected to save 18.2 percent more energy than the 2007 version of ASHRAE 90.1. The change is also expected to cut energy costs by an estimated $1.74 billion over 30 years and reduce carbon dioxide emissions by nearly 90 million metric tons over 30 years.
You’re Ready – Right?
This shouldn’t come as a surprise (although it might). News that the DOE would require states to update their commercial building codes in accordance with ASHRAE 90.1 - 2010 by October of this year has been out for well over a year. Unless the state has asked for an extension, there are literally just a few weeks left for them to update these codes. The new requirements that directly impact the mechanical HVAC engineering community include:
- Performance tested heat exchangers. Plate type liquid-to-liquid heat exchangers must be certified under AHRI 400 – 2008
- Mandatory pressure-drop calculations. Engineers must calculate pressure drops through each device and pipe segment in the critical circuit at design conditions to size pumps.
- Mandatory economizers. With the exception of climate zones 1A (southern Florida) and 1B (southwest Arizona), air or water economizers will become mandatory on systems with a cooling capacity of greater than 54,000 Btu/h.
- Integrated economizer control. Economizer systems must be integrated with the mechanical cooling system and be capable of providing partial cooling even when additional mechanical cooling is required to meet the cooling load.
- No more constant speed pressure boosting. Pressure boosters systems may no longer be controlled based on setpoints that are based on pump discharge pressures. Rather, they must be controlled based on demand.
Busy mechanical engineers will have had nearly a full year of practice at complying with these new standards by the time the rule applies to federal buildings and multi-family high-rises. We have dedicated several blogs and webinars to the new standard and ways in which it will impact mechanical design. Click on any of the links above to learn more. You may also check out some of our webinars on the same topic here: