Wednesday, June 18, 2008

Sure has been HOT in Austin!

Well, I think it is time for us to update our resumes. We are now Heating and Air conditioning Technicians and masons. After 25 years in the building business (off and on) it seems odd that we have never had occasion to do one of these relatively straight forward tasks. We have just always subbed them out.

Anyway, we needed to install a heat pump in our workshop this week and decided to do it ourselves. Of course, you can learn to do any task on the Internet, so it was no big deal. I had watched enough of our subcontractors lay brick to know how to do that. Only had six blocks to set to build a platform to raise the outdoor unit about 24 inches off the ground. It was easy to do but, a bit of a challenge to get everything perfectly level. Just requires a critical eye on the level. The only reason I set it so high off the ground was to keep it in the shade of the eaves during the summer. We designed the overhang to place the shade right at the base of the wall when the sun is at it's most northerly position. Since we had to set the heat pump out about 10 inches from the wall, it had to be raised to stay in the shade. I don't know if that makes any difference in efficiency but, it seemed like a good idea.

Installing the heat pump was a little more involved than laying the blocks but, still a pretty straight forward job. Probably took us 7-8 hours of work but, if we had another one to do, could do it in four. Had to run wiring to supply power to the outdoor unit and had to install a disconnect and put the unit on it's own circuit. Then comes the wiring and tubing between the outdoor unit and the indoor unit. Here is the outdoor unit installed:

This system we installed is called a ductless, mini-split, heat pump. I have never seen one before because we have always installed systems in houses with many rooms, and these are not made for that application. The indoor unit just mounts to the wall and supplies heated or cooled air from that one point, although, you can buy these systems with up to four indoor units. Since our shop is basically one large room, this system works perfectly.

These are easy to install and come from the factory pre-charged with enough freon for up to 25 feet of tubing (we only used 8 feet since the outdoor unit is directly outside the wall from the indoor unit). You do have to have a vacuum pump and gauges to hook up to the service port to evacuate the tubing and indoor unit prior to opening the freon valve. That, and a flare tool are the only special tools you need. By-the-way, I set a new personal lifetime record on this install. Made six flare connections in a row without forgetting to put the nut on before flaring. Didn't have to cut off a single flare. Here is what the indoor unit looks like:

This 12,000 Btu system is very quite and cools this shop nicely. I don't really try and cool my tool room or the upstairs area of the shop but, the main work area and office is about 1500 square feet, and this is doing just fine on that. Today it is 103 degrees outside so, it is a pretty good test.

If you have the right type of space to heat and cool (not chopped up into a lot of rooms) this is the way to go. Plus, it was fun doing the install.

No comments: