This blog explores changes in the energy industry from an insider’s perspective as it transitions from the old centralized utility model to the new paradigm of distributed generation.
This blog was previously called Inside the Housing Evolution and focused on energy efficient homes. Ultimately, it’s all linked. Soon, every building will have the potential to generate, store, and sell energy. Welcome to the era of the transactive grid – the greatest shift the electricity sector has seen in over 100 years!
Water Heaters – What you need to know to heat your H2O
As part of our upgrade to the 2012 ENERGY STAR® standard, we changed our standard water heaters from regular tank water heaters to condensing tank water heaters. In this post I’d like to discuss the main types of residential water heaters, so purchasers will have a better understanding of what system is best for them.
Standard Tank Water Heaters
Typical water heaters operate by using either electricity or natural gas to heat water inside an insulated tank. The water rests in the tank at the desired set-point temperature until it is needed. These systems are well proven and inexpensive, though unfortunately not very efficient. System efficiencies vary from 60% to 67% depending on the amount of insulation surrounding the tank.
Condensing Tank Water Heaters
Condensing tank water heaters operate similarly to a standard tank, however they are designed so that the flue carrying the hot combustion gases is coiled inside the tank instead of a direct vertical vent. This extra surface area allows the escaping combustion gases to further heat the water inside the tank. Condensing tank water heaters are around 90% efficient. Their high efficiency has a secondary benefit, which is that the water will heat up almost as quickly as it is being used, so it is much less likely to run out of hot water, even with a smaller tank. According to the ENERGY STAR® website, a condensing tank water heater can save a family of four around $170 per year, compared to a standard tank.
Tankless Water Heaters
Tankless water heaters, sometimes referred to as instantaneous water heaters, have been popular in Europe for many years and have recently gained popularity in North America. These systems heat the water as it is needed so there is no need for a tank. These systems are quite efficient because there are no standby losses from water sitting in a tank. System efficiencies are typically around 90%, similar to condensing tanks and sometimes a bit higher depending on the manufacturer. These systems have some other benefits as well; they are smaller and need less space, they offer a continuous supply of hot water (for those of you that love long showers), and they typically have a longer life than tank systems (20 years instead of 12). These systems do have some drawbacks however. They take longer to reach the desired temperature, since the water is only heated as needed, and these systems have to be installed on an exterior wall for venting, making them unsuitable for some home designs.
Solar Water Heating
Solar water heaters are by far the most energy efficient system available; however they do require a backup system for cloudy days, so they would have to be used in addition to a regular system. A solar water heater in Ottawa will reduce heating costs by 50%. Today’s systems are extremely reliable and have a life of around 20 years. These systems consist of copper pipes filled with a non-freezing liquid (glycol) that is heated by the sun in flat solar collectors on the roof. The heated glycol is pumped down to the mechanical area where a heat exchanger is used to pre-heat your household water before it goes into your regular tank heater. Because the water is hotter when it enters the tank, it requires less energy to bring the water up to the desired temperature. Solar water heaters are not suitable for all homes as they require ample south facing rooftop for the solar collectors.
Urbandale offers ENERGY STAR® condensing hot water heaters as standard, however we do allow purchasers to upgrade to tankless or solar systems if their housing design allows for it. We’ve selected tank systems as our standard because they are proven, efficient, cost effective and suitable for all of our home layouts. All of our single family homes also include a conduit from the attic down to the basement mechanical area, making it easy for homeowners to add a solar system anytime in the future.
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Peak Power is a Microgrid project development company focused on delivering innovative solutions to offset the most expensive hours of electric demand. We specialize in optimizing the revenue streams from energy storage, advanced building automation, and renewable technologies for customer sited and utility scale projects. Please visit www.peakpowerenergy.com.