Question 1. My hourly rate is normally $10 / hour, however I'm willing to accept $8 given that this is the upper limit on the job advert.
Question 2. "HEPA" stands for "High-efficiency particulate absorption". (I have fitted a HEPA filter in a laboratory I used to work in!)
I am new to freelancer, however I hope you will see from my profile that I have a strong background in Environmental Engineering, primarily clean fossil fuels and clean cement production. I completed a PhD with the Energy Engineering Group in the Dept. of Chemical Engineering at Imperial College London last year, the no. 1 ranked chemical engineering department in the UK. This required me to handle large volumes of data for the publication of journal papers and ultimately for my thesis.
Other previous experience includes consultancy work for BP (a market review of oil spill remediation techniques), the UK Dept. of Energy and Climate Change - DECC - (a techno-economic assessment of "negative-CO2" technologies), the EU ClimateKIC (reviewing potential CO2-utilisation technologies) and for professors at Imperial College London (compiling a literature review on the interdependency of earth resources and meta-analyses on available global and land / water data). All of these projects required me to gather and organise data and to advise on the findings.
I am very familiar with Excel having used it for compiling mass and energy balances on cement plants.
Please contact me to discuss your project further.