1. Purpose Reduce energy usage within the home by recovering heat from attic. and using it to supplement the house heating system Problem Statement Design and develop a control system that will enable a whole house. fan to recover heat from a hot attic and return it to living space Predict attic temperatures and determine fan operating conditions Estimate a yearly cost savings associated with recovered heat Develop market and advertising strategies for product release 20” Plastic duct added to fan Decreases chance of debris pickup Increases fan access to warm air layer at top of attic Metal strip for strength Ducting before and after metal strip was added Attic temperature distribution from Florida study Ducting Heat Transfer Analysis: Model predictions based on Florida Temperature Study Operating Range Completed an energy balance to check temperature predictions with new temperature study data Whole House Fan With Latent Heat Recovery ME 481 Multi-College Program Engineering Andrew Gillett Chad Kleinow Andrew Kruk Kevin McKay Marketing / Advertising Chrystal Kozsey Melissa Poirier Alyse Solomon Academic Advisors Dr. Brian S. Thompson David Regan Michael F. Lobbestael Project Sponsor Bob LaZebnik Airmaster Fan Company Special Thanks to: Dr. Gregory Wierzba - ECE Brian Wright - ECE Dr. Neil T. Wright - ME Todd Burghgraef – DornerWorks Specification Supplement current HVAC System Solid State Controls Regulate operation of fan based on seasonal setting and. temperature data Minimal input from user after initial setup System should be cost effective and provide energy savings to. customer Fluid Dynamics: Computational Fluid Dynamics (CFD) in Fluent Models examined flow patterns in attic for a variety. of conditions Used to validate the need for ducting on fan Energy equation used to predict temperature layers and fan run time in addition to heat transfer analysis Comparison of velocity vectors and temperature for fans with and without ducting 1. Opto22 G4OAC5 Solid State Relays (SSR) 2. Opto22 120D10 SSR(High Speed) 3. DS1620 Digital Thermometers 4. BS2 Basic Stamp Microcontroller 5. ULN2803A Line Driver 6. AO Smith 1/3hp Motor Capabilities: Based on: 68 o F thermostat setting Above 75 o F in attic Below 64 o F ambient air Map Key $2 - $ 4 $4 - $6 $6 - $9 Modeling Control System Components: Economic Analysis Annual Cost Savings by State Number of sunny days within temperature range Energy pulled into house per sunny day Furnace cost for energy – motor electricity cost $ Annual Cost Savings 90 days15,000 kJ / day$10.53 - $0.82$9.71 per year Finance Parameters Net Present Value Profitability Index Payback Period Current Energy Prices -$7.200.84 9.3 Years Rising Energy Prices $7.871.63 4.82 Years Average Ambient Temp (°F) Average Attic Temperatu re Operation Time Points 5257.81 hours 5358.92 hours 5460.03 hours 5561.14 hours 5662.24 hours 5763.32 hours 5864.53 hours 5965.61 hours 6066.71 hours Shingle Temp (K) Measured Temp (K)Error Average310.25310.972.41% Model is valid! Summer Mode Evaluates actual room temperature and. desired temperature set by user If the room is too hot, the fan turns on high. speed exhaust If the room is too cool, fan does nothing Winter Mode Evaluates actual room temperature and. desired temperature set by user and. compares them to the attic temperature Attic must be more than 5 degrees hotter. than the desired room temperature Room temperature must be less than desired. temperature 1 1 2 3 5 4 Asphalt Shingles Roof Plywood q solar q in q o (reflected) 2” x 6” Roof Joist House Information Size = 1700 sq. feet Dark Shingle Roof Location = Cocoa, Florida q o + q in = q solar