Radon Mitigation using Ventilation Assessment Tool

Group 9William Allred

Joshua ChastainDaniel DiazRyan Nester

02/24/09 Group 9 – Department of Health

Introduction

Naturally occurring radioactive gas

Colorless, tasteless, odorless

Found all over the World

Kills over 20,000 people each year (EPA)

02/24/09 Group 9 – Department of Health

Introduction – What is the Problem?

High rise residential buildings also have Radon problems

Limited on mitigation techniques

Ventilation applicable to dilute Radon

Need methods to estimate airflow for dilution

02/24/09 Group 9 – Department of Health

Project Scope

Develop a spreadsheet tool to evaluate the parameters necessary for successful mitigation of a single unit within a multi-family structure using ventilation techniques.

Current radon level Target radon level Natural leakage to outside Ventilation rate required to reach target Evaluation of increased load on A.C. system

02/24/09 Group 9 – Department of Health1/27/09 Group 9 – Department of Health01/27/09 Group 9 – Department of Health

The Design Concept

Microsoft Excel Data Validation & Formulas Determining What is Needed

02/24/09 Group 9 – Department of Health

Design Concept – How it Works

Equations / Theories

Where: Aeq = Estimated Leakage Area P = Pressure ρ = Density of Air Q = Natural Ventilation Rate V = Volume ACH = Air Changes per Hour C = Concentration of Radon G = Generation rate of Radon

Q Aeq2P

ACH

Q

VG C V ACH

02/24/09 Group 9 – Department of Health1/27/09 Group 9 – Department of Health

Contaminant Equations

- Mass of Radon in zone i after a given time

- Initial mass of Radon in zone i

- Mass flow rate of Radon into zone i

- Generation rate of Radon in zone i

- Mass flow rate of Radon out of zone i

Dilution Equation

02/24/09 Group 9 – Department of Health

On-site Testing

Blower Door Fan Tests

Leakages found from Pressurization and De-Pressurization tests

02/24/09 Group 9 – Department of Health

On-Site Testing

Smoke sticks Pressure direction

Pressurization De-Pressurization

02/24/09 Group 9 – Department of Health

Results from On-site Testing

Documented leakage characteristics

Compared spreadsheet and actual values

Values are within 10% Unexpected leakage

sources

02/24/09 Group 9 – Department of Health

Results for Blower Door Test

02/24/09 Group 9 – Department of Health

Results of Blower Door Test

02/24/09 Group 9 – Department of Health

Spreadsheet Demonstration

02/24/09 Group 9 – Department of Health

The Future

Fine tuning Compare results to

efficiency regulations Make more

aesthetically pleasing

Write user manual

02/24/09 Group 9 – Department of Health

Acknowledgment

Special thanks to Florida Department of Health

Clark Eldredge Jorge Laguna

FAMU Director of Building Sciences Thomas Pugh

Faculty Advisor Juan Ordoñez

Homeowners Garmin Ranck Daniel Montesinos Nicholas Landera

02/24/09 Group 9 – Department of Health

References

Design of Fluid Thermal SystemsWilliam S. Janna

NIST Multizone Modeling Website (CONTAM)http://www.bfrl.nist.gov/IAQanalysis/index.htm

Minneapolis Blower Door Operations ManualThe Energy Conservatory

Walton, George. “CONTAM 2.4 User Guide and Program Documentation.” http://www.bfrl.nist.gov/IAQanalysis/docs/NISTIR_7251c.pdf