Keep Your Cool

This week I am passing along a tip contributed by a reader, Mike Lilley. He keeps cool by wearing a cooling vest. After doing a little research I found three types of vests for sale: one that circulates air, some that use evaporation, and some that use phase change gel. For attic work I think we can rule out the air vest because it works by circulating ambient air through the vest. In dry heat the evaporative vests should work well, especially outside. However, in an attic in the southeast, I think their performance would not be enough to keep you cool. Mike said that the workers at his company use cooling vests with phase-change gel packs.

The gel packs are similar to the blue-ice packs you might use for your cooler, with one big difference. This gel freezes and melts at 58°F. Remember that the temperature of a substance stays the same as it changes state. This is an important concept in making air conditioning work. This gel stays at 58°F until all of it has melted, and 58° is comfortable, as opposed to keeping a 0°F gel pack next to your body. Further, you can freeze the removable gel packs in a refrigerator or in a cooler with ice. A couple of users commented that it is important to keep the packs flat during the freezing process. Otherwise, the hard, lumpy gel packs make the vest uncomfortable. Here is a link to learn more about these cooling vests. I must tell you that I have not personally used one – yet. But is certainly sounds like a cool idea.

Here are a few links to learn more about cooling vests.  
https://www.amazon.com/TECHKEWL-Phase-Change-Cooling-Vest/dp/B0002EWKTS
http://www.coolvest.com/
http://www.mycoolingstore.com/cooling-vest.html

Attic and Crawlspace Safety

In the last post I talked about a tech succumbing to the heat in an attic. Since the service business is about solving problems, not simply presenting them, I have been looking for solutions to tech safety. Bill Spohn of TruTechTools contacted me and offered a solution to prevent heat exhaustion and heat stroke. His company caries a line on skin patches called “HOTDOTS” that change color from black to yellow if a person starts to overheat. Each patch is a one-use patch good for one day. They come in pack of 6 for about $!6. So you can protect yourself from overheating for $16 a week – not bad. Here is a link http://www.trutechtools.com/HD6

His company also carries a full line of atmospheric gas safety monitors which can check for things such as oxygen and carbon monoxide. Here is a link to those
http://www.trutechtools.com/Atmospheric-Gas-Hazards_c_1907.html

If you are working on combustion equipment you really should have an atmospheric CO detector with you to insure the space you are working in does not have a dangerous buildup of CO. I would not trust the inexpensive detectors you buy in big box stores. They often have a long delay before alarming, even at levels that can be dangerous.  You need something that displays the CO level so you can test the space when you first enter without relying on an alarm.

A combustible gas detector is also advisable. You don’t want to enter a space that has a buildup of combustible gas. In the old days of halide torches I narrowly avoided being a statistic of an explosion caused by a gas leak. I was going to enter a crawl space to check for a refrigerant leak with a halide torch. I waited to light the torch until I actually got under the house, which probably saved my life. When I approached the crawl space door I smelled gas, so I did not light the torch. The odd thing was that there was no gas equipment under that part of the house. I followed my nose across the yard to a large LP tank with a bad leak where the line came out of the regulator. The LP being heavier than air had drifted downhill 50 feet across the yard and collected in the crawl space. I fixed the leaking flare and told the home owner what I had found. They said they had just received a delivery the previous day. Had I not paid attention to my combustible gas detector (my nose) there might not have been a “Fundamentals of HVACR” because one of the authors would have perished decades before. It is always a good idea to test the spaces you plan to enter. To be in a position to help anybody else you must first insure your own safety.

Heat Can Kill

When you think about the dangers of working on air conditioning equipment, you probably think about working with electricity, refrigerant, and torches. We often overlook a more obvious danger: the weather. The reason we have a job is because it is either hot or cold. A recent tragedy in Lubbock Texas highlights the dangers of working in attics in the summer. An HVAC worker was found unconscious in an attic and subsequently died. Here is a link to the local area news about the incident. Lubbock Tragedy

It is very important to be aware of the danger that hot and cold extremes can pose to workers. One of the most important aspects of safety when working in the heat is to keep hydrated – drink lots of water – and drink often. Evaporation of sweat is your body’s last available cooling mechanism. It is very effective provided that you keep the flow of water into your body. 

Air movement helps by accelerating the evaporation of the sweat. If possible, set up some type of fan to help move air in the attic space. I have known mechanics to disconnect a few duct runs and run the air conditioner to keep the attic cool. Of course this only works if the unit is working. 

Another way to avoid life threatening consequences of working in hot attics in the summer is to work early – preferably before noon. If someone really wants their AC working, they won’t mind letting you start work at 7:00 AM.

You must monitor your body’s reaction to the heat. If it is hot and you are NOT sweating, you should get out of the attic and hydrate. When you are hot, sweating is good. If you are experiencing a rapid pulse and muscle cramps and feel dizzy, you most likely are experiencing heat exhaustion. You should get out of the hot area, cool off and hydrate. If you have these symptoms and then develop a headache and have stopped sweating, you may be the victim of heat stroke – which is life threatening. You should get out of the heat, hydrate, and call 911.

The key is not to get to that point. When you work in the heat you must take breaks to hydrate and cool off. I recall a changeout where we worked all day – a lot of the day in the attic. We were swapping both the blower coil and condensing unit and repairing some ducts in the attic. It was 95 degrees outside and the house had a black roof with no shade. By the end of the day we were only working in 30 minute shifts and resting and drinking for 30 minutes. We would drink at least a quart of water every time we came out of the attic. Our clothes were as wet as if we had jumped in a pool. Honestly, I don’t think I could do that today. Don’t ignore what your body is telling you. If you start feeling bad while working in the heat – get to a cool place and hydrate.