(6.4.2.2) Most engineers do this already but this eliminates the “rules of thumb” or estimating of pump head. You must calculate the pump head including the pressure drop through the worst terminal unit and the piping losses to it. HVAC Pumps and the 2015 Michigan Energy Code Today most boilers scheduled are high efficiency and have great turndown but the standard (6.5.4.1) indicates the turndown must be a minimum of 3:1, 4:1 or 5:1 based on size. Obviously this can be accomplished through dedicated pumps, but in systems where the pumps are on a common header, the use of isolation valves is required. In systems where the plant has more than one boiler or chiller, section 6.5.4.2 of the standard requires that we stop the flow through the boilers and chillers that are not operating.

Our experience is that most engineers have incorporated these change into today’s design. The ASHRAE 90.1-2013 Standard contains a couple of key changes affecting these systems. Deppmann Company is a leading manufacturer’s representative in boilers and water heaters.

Boilers and the 2015 Michigan Energy Code We still see some schedules defaulting to the old “rule of thumb” of 10 PSIG or 23 feet. Bell & Gossett GPX plate exchangers meet this requirement.Ħ.5.1.3 Although this is not a change, I should remind you that the maximum pressure drop of water side economizers was limited to 15 feet in prior standards. This is an important change that must be incorporated into your selections and specifications. Water Side Economizers and the 2015 Michigan Energy CodeĦ.4.1.4 Plate type heat exchangers such as those used in water side economizers or free cooling must meet the requirements of the AHRI 400 test procedures. Here is a quick summary of some of the key changes. Deppmann seminar series have captured these changes and alerted engineers and contractors to the design changes required in hydronic systems. There are many changes from the 2007 ASHRAE standard to the 2010 Standard, and even more from 2010 to the 2013 standard which the new code is based on. The prior Michigan Energy Code aligned around ASHRAE 90.1-2007 standards. The code follows ANSI/ASHRAE/IES Standard 90.1-2013 with some modification. The new code is available through the LARA website which links to ICC. Deppmann Monday Morning Minutes looks at a few highlights of the new code.

The long expected changes to the code were filed with the Secretary of State on with an effective date 120 days after filing. The 2015 Michigan Energy Code is changing with an expected effective date of September 20, 2017.

Ashrae 90.1 2015