LEED (Leadership in Energy and Environmental Design) has a lot to say about the materials used in building construction, bike racks, landscaping and what cleaning supplies to use. It simply does not have much to say about mechanical design – the stuff that actually consumes energy. Good engineering does not lend itself to being reduced to a LEED checklist. Almost every salesperson I see has a LEED AP designation – but what does it mean? It means nothing! It’s like judging the environmental impact of a car without looking at the engine!

Atmospheric boilers are crude, simple boilers built like barbeques with an open flame under a heat exchanger, which is usually copper fin tube.  They are grossly inefficient. They are not even legal in Europe and parts of the States. They are not even legal in China for God’s sake. Here we are about to ban incandescent light bulbs but allow these smog belching monsters to be installed in brand new condo buildings!

It’s inevitable that some pumps produce more flow than is needed. Triple duty valves (TDV) allow you to throttle the excess flow – but it costs in energy consumption. VFD (variable speed drives or variable frequency drives – they are called both) allow you to slow down the motor to reduce the flow and save energy at the same time. Not long ago, I saw both triple duty valves and VFDs used in the same pumps – and the TDV was throttled down to 60%. That’s about the stupidest thing I have ever seen!

I have just come from another high-rise building with a grossly oversized chiller. It’s about double the capacity required. The thing cycles on and off, and when it’s not doing that, its surging (which results when the gas runs backwards through the compressor) making a racket loud enough to disturb the residents of the apartments below. I cannot understand why designers cannot properly size equipment. The software for doing a cooling load analysis is straightforward, although tedious. They may save a few grand on engineering fees but pay far more in increased equipment cost, electrical consumption and increased maintenance!