Venting- on-demand Minimizing Energy Loss through the Exhaust Ventilation Systems in order to meet Sustainable Design Standards
Approach Controlled Venting Versus Natural Venting Controlled Air Supply Versus Natural Air Supply Combined Venting Versus Individual Venting = Sustainable Designs
Design Objectives Aesthetical Environmentally Friendly Design Space Saving Economical Reliable
Applications Sports Arenas Apartments / Condominiums Hotels / Resorts Offices Hospitals Schools Colleges Museums
Boiler Exhaust What? Central Plants / mechanical rooms Multistory heating appliance systems How? Mechanical Draft Systems Modulating Over-draft Damper Systems Modulating Combustion Air Supply
Clothes Dryer Exhaust What? Central Laundry Facility Coin-Laundry Facilities How? Modulating Dryer Venting Systems Modulating Combustion Air Supply
Clothes Dryer Exhaust What? Multistory dryer systems How? Modulating Dryer Vent Systems
Kitchen & Bathroom Exhaust What? Multistory kitchen ventilation systems Multistory bathroom ventilation systems How? Modulating Building Exhaust Systems
Fireplace Exhaust What? Multistory gas-fireplace venting systems How? Mechanical Draft Systems
Boiler Efficiency versus Draft
Invisible Exhaust US Capitol Washington, DC Aesthetical A natural draft chimney must terminate at least 3 feet above anything within 10 feet. The Hemisphere, Ft. Lauderdale, FL Rigel, South San Francisco, CA
Minimal Design Restrictions Design A chimney must be designed with as few changes of directions as possible and the shortest possible distance to the outside
Minimize Stack Shaft The Getty Museum Los Angeles, CA Soldier Field Chicago, IL Space Saving A chimney must be designed for the maximum input of all the heating appliances it serves. A naturally vented heating appliances should be vented by its own chimney. Spurs Arena San Antonio, TX
Mechanical Draft System
Mechanical Draft System
Modulating Over-draft Control MDF
Green Building Design Modular venting design reduces the overall venting material cost per boiler. Down-sized chimney often pays for the Mechanical Draft System A boiler s actual operating efficiency can increase by 5-20% when an On- Demand Mechanical Draft System is used. Economical
Green Building Design Economical Boiler Capacity Efficiency Rating Efficiency Loss % Efficiency Loss 3,000 MBtu/Hrs 85% 35% 3.5% 15Therm/Hrs 1.5 $ 9,000 Efficiency Loss per Year In $ (*) 6,000 MBtu/Hrs 85% 6.0% 2.9 Therm/Hrs $ 17,400 10,000 Mbtu/Hrs 85% 8.0% 9.5 Therm/Hrs $ 57,000 Unit Price: $ 1.20 per Therm Running Time: 5,000 Hours per Year
First Cost Analysis Ordinary Stack Material Cost Economical EXHAUSTO System Material Cost Item Qty List Price Item Qty List Price 20" pressure stack 35' $ 5,775 12" pressure stack 50' $ 4,600 16" pressure stack 5' $ 630 12" Tee 1 $ 345 14" pressure stack 5' $ 535 12" end cap 2 $ 260 10" pressure stack 5' $ 405 12" x 8" reducing Tee 4 $ 1,240 20" Tee 1 $ 610 20 " end cap 1 $ 205 20" x 8" reducing Tee 1 $ 410 20" x 16" tapered reducer 1 $ 360 16" x 8" reducing Tee 1 $ 355 16" x 14" tapered reducer 1 $ 280 14" x 8" reducing Tee 1 $ 335 14" x 10" tapered reducer 1 $ 245 10" x 8" reducing Tee 1 $ 295 10" end cap 1 $ 130 20" stack cap 1 $ 640 Total $ 11,210 Total $ 6,445
Quality Components Reliable Source: NEMA
Typical Building Exhaust System Individually vented or power-vented Common Power Vented
Building Exhaust Requirements IBC 716.5.3 Penetration of Shafts 22 subduct Exhaust fan at upper Exhaust fan at upper terminus, powered continuously to maintain upward airflow to the outside Must run 24/7
Building Exhaust Requirement Eliminates the need for fire and smoke dampers
Powered Dryer Vent Systems Multiple Termination DEDPV (Dryer Exhaust Duct Power Ventilator) venting multiple Type 1 or 2 clothes dryers
Dryer Exhaust Fan ETL Listed to UL705 :"The product (BESB/MDVS) covered by this report is a modulating air exhaust system. The product consists of a box ventilator and a modulating control for permanent installation. ti Its intended d use is exhausting of lint-laden air from single or multiple type I and type II residential and commercial clothes dryers.
Powered Multi-Story Exhaust Systems Make-up Air #2 Corridor Pressurization + Bottom Make-Up + Direct-Ducted Make-Up. Recommended method for apartment buildings. You can get 60 CFM under a smoke-rated corridor door per NFPA 105 and 50 CFM via a louver. Disadvantages: Larger Rooftop unit and more energy cost Larger corridor supply shafts, the cost of duct running in the corridor of every floor. Large, bulky make-up ducts on the lower floor that connect to the bottom of each stack Source: ASHRAE report
Powered Multi-Story Exhaust Systems Exhaust and Make-up Air #4 Corridor Pressurization + Variable Speed Exhaust. This method uses no bottom make-up, no top make-up, and no direct-ducted supply through the corridor. It uses a variable speed motor to vary the fan speed to match a pressure sensor in the stack. The sensor is very sensitive and can slow the fan down to 3% flow. Disadvantages: The system is $2,500-3,000 000 more per fan system than a 'regular' exhaust fan. This system is always less expensive in operation than system stem #2. Source: ASHRAE report
Green Building Design The goal is energy savings LEED points Economical
Green Building Design Test result from 2-year test by Enbridge Gas, Toronto, and NGTC, National Gas Technology Centre, Montreal Economical Conditioned Air Savings (cuft/day) Laundry Utilization Profile Conditioned Air Loss to the Outside (cuft/day/dryer % Dryers in Laundry Profile Laundry Profile Operation (%/day) (min/day) MDVS Fixed Speed Savings 100 1.5 22 1,318 1,422 104 75 3.9 56 2,550 4,356 1,806 50 86 8.6 124 3,739 10,793 7,054 25 16.7 240 5,308 21,656 16,348 0 69.3 998 7,062 105,830 98,768 TOTAL 100 1,440 19,977 144,057 124,080 1 Therm = 100 cuft of gas Cost per unit - $ Annual savings when using variable speed Annual savings per dryer Lost Heating: m3 gas/year 3,795 0 0 cuft/year 134,020 0.012 1,608 402 Lost Cooling: kwh/year 2,957 0.1 296 74 TOTAL ANNUAL SAVINGS - $ 1,904 476 Savings per bathroom Bathroom exhaust savings should equal 50% of dryer savings. Each bathroom fan exhausts 100 cfm compared to a dryer's 200 cfm. 238
Example Garlands of Barrington Units Savings per unit Annual Savings Dryers 70 $476 $33,320320 Bathrooms 225 $238 $53,550 Estimated Annual Savings - Total $86,870 Fan Savings 74 350 $25,900 The Bottom Line Savings of $112,000 per year Additional installation ti cost of approx. $100,000000 Payback: 1 year.
Americana Glendale, CA 140+ MDVS and MBES systems serving dryers 140 MDVS and MBES systems serving dryers, kitchens and bathrooms.
On-Demand Control The key to optimal performance is an efficient control design EXHAUSTO Other
On-Demand Control Effects of inefficient control design System start-up can be delayed. Boiler operation can be effected by control interference The appliance sees varying draft or pressure Small operating variances create large control variances Safety functions are delayed to eliminate nuisance shutdowns. Inefficient dyer operation Noise problem due to hunting fan in kitchen and bathroom exhaust systems
Responsibility Reduce Emissions Environmentally friendly Low Energy Recyclable Materials Demand-Controlled = LEED Points
Next Step.. What is Your Strategy for Minimizing Energy Loss through Exhaust Ventilation Systems in Order to Meet Sustainable Design Standards?