Servel (the gas air-conditioning company) was there with a new, higher-efficiency product. The process, which uses a gas flame to produce cooling in a continuous absorption cycle, has always been plagued by the fact that the method isn''t very energy efficient. Servel didn''t change the process but just tightened it up, resulting in a 30% efficiency increase. Gas-fired air conditioners are available in sizes from 3 tons to 25 tons. A more efficient way of getting cooling from gas is to use the gas to drive a combustion engine, which drives a compressor. And while this isn''t new technology either, it is for my friends over at Goettl, a Phoenix-based hvac/swamp cooler manufacturer that has specialized in the residential/light-commercial market. The company''s gas-driven split-package air conditioners (the compressors/motors are remotely located) are available in 15-ton and 20-ton sizes.

I enlisted the services of my 10-year-old grandson, Dean, to help me in the preparation of the material for these articles. Figures 1-5 show Dean astride a progression of vehicles designed first for very young children up to vehicles, which require a great deal of skill to operate, for older children and young adults. Each of these vehicles provides unique opportunities to begin teaching children safe, competent, driving skills that are age-appropriate to the learner.When Dean was about 3 years old, he received his first battery-powered riding toy: a Power Wheels vehicle shown in Figure 1. By the time Dean was 5 years old, he had pretty well outgrown it. Although it only lasted him a short time, norton14metalchopsaw the Power Wheels is an excellent tool for pre-schoolers to begin learning initial driving skills.

Another popular recreational machine is the motorcycle. The one Dean is sitting on in Figure 5 (see page 20) is a smaller model, but motorcycles come in all sizes. These machines pose the most potential for serious injury and require both bike-riding and driving skills, but are not a training vehicle for someone just learning to drive.Children growing up on a ranch, farm or other rural property traditionally spend more time with family activities than children living in a city or town. They also assume more responsibility for helping with the work required to keep such a lifestyle running smoothly. Farmers are especially notorious for teaching their children to drive tractors, trucks and other equipment at an early age. Fun karts are an ideal way for these families to introduce their children to the skills and responsibilities of driving vehicles and machinery. Some models are powerful enough to pull a small trailer for hauling feed or doing chores around the homestead.

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