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Low-E Coatings for HET Data & Conclusions 2 October 2002 John Good. Ambient 9ft. Ambient 86ft. Ambient 9ft. Foil. Passing through Louvers?. LO/MIT. TiO 2. Ambient 9ft. Ambient 86ft. Foil. Ambient 9ft. Foil. LO/MIT. Ambient 86ft. TiO 2. Ambient 9ft. Ambient 9ft. Ambient 86ft.
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Low-E Coatings for HETData & Conclusions2 October 2002John Good
Ambient 9ft. Ambient 86ft. Ambient 9ft. Foil Passing through Louvers? LO/MIT TiO2
Ambient 9ft. Ambient 86ft. Foil Ambient 9ft. Foil LO/MIT Ambient 86ft. TiO2
Ambient 9ft. Ambient 9ft. Ambient 86ft. Ambient 86ft. Foil Passing through Louvers? LO/MIT TiO2
Ambient 9ft. Ambient 86ft. Ambient 9ft. Passing through Louvers? Foil Passing through Louvers? LO/MIT TiO2
LO/MIT Durability Tests Shoe Scuff Finger Nail Scratch
LO/MIT Durability Tests Shoe Scuff
Conclusions ALUMINUM FOIL IS RECOMMENDED COATING: • Performance - Foil • Al Foil stays 2-5 times closer to ambient temperature in 3 out of 4 measurements. • Installation – LO/MIT • Both coatings are easily prepped and applied. • Long Term - Foil • Foil will probably stay cleaner than the soft & rougher surface of LO/MIT. • Adhesion of foil is very good with no de-lamination problems reported by other Observatories. • Assuming the foil ever becomes “heavily oxidized”, it will perform as well as a fresh, clean coating of LO/MIT. • Maintenance - Foil • Recoating of LO/MIT will be a given every 5-7 years. • Multiple layers of gummy coatings. • LO/MIT is a permanent decision. • No other coating can be applied on top of LO/MIT. • Removable only with solvents – power wash won’t do the trick. • Al foil can be be re-laminated. • Much easier if the adhesive lasts since removal of old layer would be difficult. • No problems reported so far. • Aesthetics – Foil • Cost – LO/MIT (both costs are reasonable) • Aluminum Tape: $35-37k • $22k (tape & primer) + Labor (~6-8 man-weeks) + $7k (125ft. Man-lift) + $1.5k (Misc. Supplies). • LO/MIT: $19-21k • $5.5k (paint) + Labor (~6-8 man-weeks) + $7k (125ft. Man-lift) + $1,500 (Misc. Supplies).
DIMM Tower Foundation • Poured last Friday. • 15 tons of concrete. • Good work McDonald Physical Plant!