NAFA Guide to Air Filtration Chapter 13 Owning

NAFA Guide to Air Filtration. Chapter 13 Owning and Operating Cost Another Approach…. Air Filter Comparison By Dirk ter Horst April 19 th, 2012

§ § § Objective Energy Cost Calculation: 2 approaches Calculation Example & Methodology Comparison Total Filtration Cost Tool’s presentation Conclusions OUTLINE

Present a practical and easy approach to air filter evaluations + operation based on: § End user/customer experience (Pressure drop and filter life) § Standardized filter life indicator (ASHRAE 52. 2 DHC) § All air filtration associated costs § Use of software Objective

NAFA Customer experience (Pressure drop and Time) § Constant environmental conditions § Average pressure drop § Straight Line § New approach § § § Customer experience (Pressure drop and time) Constant environmental conditions Time vs. Pressure Drop Time vs. ASHRAE DHC Air filter Pressure Drop vs. DHC Signature Assumptions and considerations

§ Considering the pressure drop changes linearly with time the energy consumption is expressed by: Where: ΔP 0 = Initial Filter pressure drop [Pa] ΔPf = Final Filter pressure drop [Pa] tf = operating time[hrs] = average pressure drop Linear Pressure Drop Approach

§ Considering the pressure drop of the filter versus time, the energy consumption is expressed by: Filter Pressure Drop vs. Time Approach

§ The energy cost is calculated by: § Linear pressure drop vs. time: § Filter pressure drop vs. time: Energy Cost Where: E = energy consumption [k. Wh] Q = airflow [m 3/s] ΔP = pressure Drop across the filter [Pa] t = the time is operating the fan [hrs. ] η = system efficiency (fan, motor & drive) [%]

$273/360 X 365=$277 $301. 2/360 X 365=$305. 4 Same results…

This example: Difference/year: $5, 863. 59 (22. 5%) Linear vs DHC curve. . For 100 filters

+ = Assumption: Air filters of the same efficiency and media type have captured the same amount of dust if they are exposed to identical environmental conditions over the same period of time Transposition…

Filter A: § § § MERV 14. 24 x 4 Box type. Initial pressure drop: 0. 35 inch H 2 O DHC at 1. 5” H 2 O: 67 grams. ASHARE Dust 2000 cfm $70. 0/unit Filter B § § § MERV 14. 24 x 4 Box type Initial pressure drop: 0. 3 inch H 2 O DHC at 1. 5” H 2 O: 143 grams. ASHRAE Dust 2000 cfm $70. 0/unit Two filters to work with… Example

Two different filters without DHC consideration Linear approach: US$ 701. 74/year Two different filters with DHC consideration Linear approach… US$ 9, 682, 90/year Linear approach… for 100 filters

Two different filters With DHC consideration Curve approach US$ 9, 173. 82/year Curve approach… for 100 filters

Pressure Drop of filters at change-out time for financial optimization: 0. 85 inch w. g. Cost reduction: $9, 712. 03/year (for 100 filters) Optimization Linear approach. .

Pressure Drop of filters at change-out time for financial optimization: 0. 60 inch w. g. Cost reduction: $10, 134. 13/year (for 100 filters) Optimization… DHC curves.

Filter Type Filter depth Frame type Frame material Filter media material Face screen Incinerable Filter brand/make Test standard Air flow Maximum final pressure drop § Efficiency § Test dust § § § § Test Laboratory Test filter procurement/source Age of test report UL 900 compliance § Fan type § Reasons for change out time § Other considerations Compare Apples to Apples…

Easy calculation…. Let’s see a software tool: http: //filtrationcost. lpdtechnologies. com Practical approach to TFC

LC 67 vs LC 143 Base

LC 67 vs LC 143 - High Energy Cost

LC 67 vs LC 143 -Low Energy cost

LC 67 vs 143 Base- Money Maker

LC 67 vs LC 143 - Production loss

§ Use the ASHRAE 52. 2 DHC curve information when evaluating the financial impact of air filters. § Calculate the recommended filter change out pressure drop (optimization). § The cheapest filter nor the filter with the lowest initial pressure drop are necessarily the best solution. § There is a WIN-WIN opportunity for the customers and the industry! Conclusions