The November 2013 dinner meeting featured a presentation on energy efficiency of fan systems. The presenter was Tim Mathson, Principal Engineer at Greenheck Fan Corporation.

The energy efficiency of the Fan System is the measure of how well electrical energy is converted into useful energy of the airstream.
The energy efficiency of the Fan system is affected by:
*    the internal aerodynamic losses of the impeller and friction losses of the fan bearings
*    the frictional losses of the V-belt drive
*    the internal electrical losses of the motor
*    the internal electrical losses of the inverted drive or VFD

The overall efficiency is the product of the individual component efficiencies. Since efficiency is defined as the Power Output divided by the Power Input, it can be shown that the overall energy efficiency of the fan system is the Fan Power Output divided by the Electrical Power Input into the VFD.

Since an overall fan efficiency of 55% could be considered typical, it is important to make wise component selection. It is also very important to properly install the fan. System Effects, like undersized outlet ducts or elbows near the fan inlet would further reduce this efficiency.
AMCA Standard 205 provides a means of classifying fans based on their energy efficiency potential. AMCA uses the peak total efficiency of the fan alone based on its total pressure. Fan Efficiency Grades (FEG) are a series of curves that were designed to represent existing fan types. The higher the FEG rating, the higher the potential efficiency of the fan.

ASHRAE 90.1 - 2013, Energy Standard for Buildings, requires a fan to have a minimum FEG of 67, and the fan design point is to be within 15 percentage points of the maximum total efficiency of the fan. Major exceptions to this requirement include fans with motors 5 hp and smaller and powered wall and roof ventilators.

Specifying a minimum FEG alone would yield minimal energy savings compared to selecting the fan to operate within 15 points of its maximum total efficiency. FEGs should only be used to narrow down the types of fans being considered for the project. After that, the selection should be based on Brake Horse Power (BHP) required by the fan.

For a given fan cfm and static pressure, larger fan sizes typically have lower BHP requirements yielding lower energy costs. Selecting the larger fan would save energy but would typically increase first costs. A good balanced approach would be to consider the total 5 year ownership cost. This approach would take into account both the energy savings and first costs.

Alessandro Cupillari
Website & Gazette Committee Member

With any type of membership it is important that members feel that they are getting their "money's worth" for their membership.  An ASHRAE membership is no different in this regard.  This month the membership committee would like to remind you of some of the opportunities and benefits your ASHRAE membership brings you.
 
Before there was Linked-In and Facebook there was ASHRAE!  An ASHRAE membership connects you with over 53,000 professionals directly related our industry.  There are two society meetings held each year and multiple conferences that can be accessed by members.  There is also the ability to participate in the "YEA Leadership Weekend" held twice a year.  Not to mention all the activities and educational seminars hosted both at the local chapter level and online.

A new forum which allows you to participate in active discussions has been added to the ASHRAE society website and is known as "ASHRAExCHANGE", (https://www.ashraexchange.org/forum.php).  It has a lot of information on topics relevant to our industry and it is great venue to voice your opinions and gain knowledge from your colleagues.  

One of the biggest components of ASHRAE is the ability to have endless resources to develop your career and HVAC knowledge.  Within the "ASHRAE Learning Institute" ASHRAE eLearning courses are available and are ideal for training or earning PDH's/CEUs.  If eLearning is not for you then there also exists live instructor lead courses that you can add to your weekday agenda.  

With an ASHRAE membership you will have access to discounts on all ASHRAE publications, the annual ASHRAE Handbook, standards, new research and technology, the ASHRAE Journal, High Performance Buildings Magazine and E-Newsletters.  

Although you get a lot from an ASHRAE membership the most rewarding thing in ASHRAE is the ability to give back and help one another grow.  By volunteering at the Local Chapter level, getting involved in technical committees and contributing to the ASHRAE Foundation we insure that members both current and future will have lots to look forward to.  

Remember that there are two levels of ASHRAE to become involved with, Society membership and your Local Chapter membership.  Get the most out of ASHRAE by joining both and head out to the local chapter meetings to interact with other local members.  

These are just a few tidbits for you.  You will be surprised how much can be gained from your ASHRAE membership once you start looking!

Imtee Baksh, P.Eng
ASHRAE Membership Committee