Greg In The Desert

Last year I received a Master Cool evaporative cooler for free. I purchased some duct work from a local home improvement store but never permanently attached it. I had used duct tape to hold the whole mess together last year. Duct tape does a poor job of sticking to concrete.

This year I came up with a method of attaching the duct work by installing concrete bolts and bolting down extruded aluminum L channel to the concrete. I considered gluing the aluminum directly to the concrete but I wanted to have the option to remove it in the future.

I learned a few things about drilling through concrete. First: it takes a lot of power and my cordless Dewalt drill had a tough time with the drilling. It was just really slow (perhaps a lithium ion nano battery would have helped). I was meaning to buy a corded hammer drill anyway and the corded drill was 10 times faster. Second: it was easier to drill the holes in the aluminum L channel then use that as a template for drilling the concrete, rather than marking the concrete. The drill bit tended to walk a little in the concrete. Third: drilling concrete is hard on the drill bits. It’s good to have extra on hand.

I attached double sided window and door weather stripping to the aluminum L channel but left the paper backing on the other side. I filled in any remaining gaps with some outdoor rated silicon sealant.

I am far from done with this project. I need to verify that water is not leaking into the duct. I need to have someone clean all the duct work so I have not completely sealed the duct to the aluminum L channel. I want to install some sort of concrete sealant to the duct once it’s cleaned out.

Finally, I want to build a better stand for the cooler. I envision a wheeled stand with a built-in jack so I can easily move the cooler around for maintenance and adjust its height without additional help.

I purchased a reconditioned cordless Dewalt combo tool set (hammer drill, Circular Saw, Reciprocating Saw, Flexible Floodlight) well over ten years ago. The tools have been one of the best tool investments I made and they have performed perfectly over the years.

Except for the batteries. They no longer hold a charge and it’s time to replace them. My options are:

• New OEM batteries, throw out (recycle) the old batteries. A two pack of official DEWALT DC9096-2 18-Volt XRP 2.4 Amp Hour NiCad Pod Style Batteries from Amazon are $119 (about $60 each) and they hold 2100MAH of power.
• Have them rebuilt by someone like voltman batteries. They offer a higher capacity rebuilt NICAD battery of 3300MAH for $79.99 each.
• In 2007 Dewalt came out with the DEWALT DC9180 18 Volt Nano Tech Battery Pack. This battery is a replacement Lithium Ion battery that work in older Dewalt tools like I have. At Amazon, one battery costs about $111 (and I will need to buy a new charger).

I do not buy things on price along. So what performance metrics can I look at?

Comparing the two NICAD options, the rebuilt NICAD batteries are a better deal since I would be getting considerable more amp-hours for a little more money. Plus, I already have the chargers so there are no additional expenses.

Comparing the NICAD vs the Lithium Ion, the Lithium Ion weighs less than the NICAD. I love my Dewalt tools but they are heavy and the NICAD batteries are about 2.5 lbs vs 1.5 for the Lithium Ion batteries. Eliminating a pound off the weight of the tool would be good my tennis elbow.

For other performance information on NICAD vs Lithium Ion, I found a helpful FAQ on the Digital Reality Crew forums which has some comments from an experienced user. A few things I’ve noted is that the Lithium Ion battery will not loose power while being unused where a NICAD will, the Lithium Ion has slightly less capacity than the NICAD and the NiCad battery will fade as it looses power but the Lithium Ion will just shut off.

Based on this information I am heavily weighted toward the Lithium Ion option (one with a battery charger). Is there anything else I should consider?