An Air Conditioning Failure Plan

by John Bisset

At a recent broadcast conference a group of us were talking about experiences that gave us more respect for the dangers of broadcast engineering.

For me it was an incident that took place while I was working inside a transmitter during a thunderstorm. Lightning had blown up parts in an FM cavity. Eager to get the station back on, we replaced and rebuilt the damaged parts.

Fig. 1: Keep nitrogen tank caps secured to tanks that are not in use.

My partner and I left to get sodas, hanging the trouble lamp inside the cavity while we were gone. When we returned we saw that, in our absence, lightning had struck the antenna, traveled down and into the cavity and roasted the trouble lamp.

My associate and I looked at one another and decided the station could stay off the air until the storms passed.

Danger comes in many forms in our profession. Some situations might seem harmless.

Ray Tadry follows up our discussion on the necessity of securing nitrogen tanks so they won't fall over. He adds an equally important consideration: Ensure that there is adequate ventilation during bottle changes/purges. Nitrogen will displace oxygen in a confined space and will become an asphyxiant.

Thanks for the reminder, Ray. The process of oxygen depletion is unnoticeable, as nitrogen is an odorless, colorless gas. Adequate ventilation is a must whenever you change a tank, especially in winter months when doors and windows are kept closed to retain heat.

Ray can be reached at ray.tadry@verizon.net.

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As spring rolls along, pollen can become a nightmare at transmitter sites.

Even in closed-air systems, any pressure differential will give pollen an open door into the building, primarily through cracks and under the door.

Fig. 2: Avoid a flood. Blow out air handler condensate drains and pressure-clean the coils in the condenser.

Spring-cleaning tip: Check the transmitter door threshold. Make sure the rubber isn't worn away and that the door offers a good seal.

Now's the time to spray the threshold with a good bug killer. Spray under the top of the doorframe with a bee and hornet killer; this will deter wasps from nesting at your front door. An intact threshold also will deter water during those brief, sometimes violent spring storms.

If your transmitter site is air conditioned, contract with an air-conditioning mechanic to pressure-clean the condenser coils. Spring is a good time to perform this routine maintenance. Clean coils will improve air-conditioning efficiency and your system won't work so hard.

If you question the need for this service, note the bugs, pollen and dirt that a pressure cleaning removes.

While the mechanic is at the site, have him check the belts on air handlers and clean the condensate drains. Algae build-up will clog drains, resulting in a flood.

The cost of such maintenance is minimal compared to a compressor replacement. Most HVAC contractors will offer a package deal to do your multiple sites. Before the really hot weather hits, schedule the work.

Do you have an "air conditioning failure" plan? A couple of box fans, an exhaust fan, a backup air conditioner qualify. Remember, if your air conditioning fails, closed systems will heat rapidly, even with a solid-state transmitter. Plan so you'll know how to keep things cool.

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Fig. 3: A homemade 'log rest' offers a space for the log without compromising console operation.

There never seems to be enough space in a control room for logs.

Fig. 3 shows how Lamar Smith and his staff at the Entercom Scranton properties gave the jocks a little more space. The "log rest" straddles modules that are used less frequently on this Harris-Pacific console. The studio is a stand-up operation, so the Plexiglas panel allows jocks to see what's underneath, if necessary.

This is the kind of control-room feature that will be appreciated by the air staff and won't kill your budget.

John Bisset has worked as a chief engineer and contract engineer for more than 30 years. He is the northeast regional sales manager for Dielectric Communications. Reach him at (571) 217-9386 or john.bisset@dielectric.spx.com.

Submissions for this column are encouraged and qualify for SBE recertification credit.