Here’s a preliminary list of things that could be done to reduce energy usage in the Villas. It is based solely on observations made in Villa 1A. Other units may be different. Not all items may apply or necessarily be feasible for every unit…
- Replace all incandescent lamps with CFL or LED. (This will not only reduce electric demand, but reduce cooling load as well (the inefficiency of the lamp all ends up as waste heat which adds to the AC load. Inefficiency hurts you twice. Read More…
- Replace electric ranges with gas. (Or at least pipe the units to allow buyers the option.) This option will also require a ducted range hood (which is highly recommended anyway, for a variety of reasons…)
- Replace refrigerators with high-efficiency models. Read More…) (How to Choose an Energy Efficient Refrigerator)
Note: Another advantage of a well-insulated refrigerator — besides lower energy use — is that it will keep your food cold longer during an extended power outage. And you can reduce the size of the battery backup system required to run it.
- Replace ceiling fans with something more efficient, durable and effective, rated for exterior or high humidity environments. Read more…
- Incorporate natural ventilation in roof. (Something that allows warmer air under the ceiling to be vented out, create chimney effect, drawing in fresh air through doors & windows, without expending energy.)
- Install air transfer grilles between rooms for free flow of air from each to the roof vent. (Or just leave doors open, and/or undercut them.
- Install light pipes for natural daylight in selected rooms. (e.g. Solatube).
- Install low wattage task lighting over work surfaces (e.g. LED or CFL strips under kitchen wall cabinets). Right now (at least in Villa 1A) the only way to get good light is to turn on 4 halogen lights recessed in the high ceiling, plus light on ceiling fan plus light in range hood. And it’s still poor lighting over work surfaces. Read more…
- Improve hot water system design, variety of options that would improve on existing. Solar, gas, instant shower head (no, not the cheap plastic Costa Rican ones, but a high quality german made one). Install at point of use instead of across the room so you don’t have to run a bunch of water before it starts to get warm, which then is left in the pipes to dissipate its heat into the space after you turn it off.
- Ultra-low flow shower head. (reduces not only water use, but energy use).
- Coat roof with reflective paint (reduces “heat island” effect). The temperature of a dark colored sheet metal roof is a lot higher than surrounding greenery.
- Install one dedicated emergency backup electric circuit back to panel with a transfer switch or UPS (e.g. Duracell Powersource 1800 – 1440 W, $500) or Xpower PowerSource 1800 from Backup-Power.ca.)
- . Circuit includes selected LED or CFL lighting, refrigerator (if efficient enough), computer, TV, etc.) See also this UPS comparison guide.
- Install more efficient and more environment-friendly air conditioners. An air conditioner with VFD (variable frequency drive) condensing unit, uses R134a or R410a refrigerant which is more ozone friendly than R22. The condensing unit modulates to meet demand instead of on/off, so is more efficient. Replacing the Air-Pro units currently installed in Villas could have a possible 2 yr payback. Read more…
Note that these energy measures are not just additive, but multiplicative. Every watt of electricity consumed in the space (whether from appliances, computers, lighting, water heating or air movement) ultimately ends up as waste heat — which further adds to the AC load. More efficiency in each saves you twice. If done well enough, you can even save on capital costs — e.g. by eliminating the need for AC unit entirely. The more of these measures that are implemented, the higher the percentage of the total load that can be done with renewable energy. Getting to 100% is the definition of ‘sustainable’.
For an extreme example of the art of the possible, here is an off-grid house in California that produces more energy than it uses. Sailboats, Tugboats, Negawatts, Extreme Efficiency.
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