The Hot Water Tank Dilemma – Shrink Your Energy Bills
One of the comforts of modern living is hot running water, but it comes at a price. There are a number of ways to save money on heating the water in your home whether it is a conventional hot water tank or a demand heater. Most of us remember to turn down the furnace when we leave the house for the day or weekend, but how many of us turn down the hot water tank while on vacation? The vacation setting found on most tanks is a simple means to save energy costs on domestic water heating.
Demand Water Heater Problems
Reader comments in the article “saving energy around the house” indicate a thirst for information regarding demand water heaters. Some homeowners find themselves unhappy with their demand water heaters because of the initial cold shock when the water is first turned on or if the equipment purchased was under-sized for the demands being placed on it or if the source water is very cold. This would require up-sizing the heater. If your household has poor water pressure, the demand water heater might not be for you. Check the manufacturer’s recommended minimum water pressure and flow rates before making your purchase.
Solutions on Demand
A plumber can put a circulating pump at the end of the line to send the water back to the heater, keeping the water hot at the tap. This could be put on a timer or switch intended for use prior to high-load periods. For example, you get up in the morning and flick on the switch. By the time you are finished your morning toilet business, the hot water will be circulating. While you have the plumber in the house, get him or her to install a hot water recovery unit on the main sewer drain so that it preheats your supply water before entering the demand water heater. The total cost is typically between $600-$1000 Canadian to install and claims are that it will save 20-40% on costs depending upon the home’s individual circumstances. The recovery unit will pay for itself in 2-6 years.
Is a Demand Water Heater for You?
Before you purchase a demand water heater, do your homework. Confirm that the specifications of the heater will meet your household requirements and water conditions:
- source water temperature (at its coldest)
- number of hot water taps used at the same time
- the distance from the heater to the furthest fixture
- water pressure
- water mineral content.
Insulating Your System
Another consideration is that many people neglect to insulate their hot water lines running from the demand heater. This can easily be accomplished by purchasing foam tubes from your local hardware store. It’s a great do-it-yourself project whether you have a demand heater or a conventional water tank.
With respect to insulating the conventional hot water tank, it is important to remember that wrapping or adding extra insulation to the exterior does not solve the heat loss going up the center tube and out the chimney. The most costly factor is that you are still keeping the water up to temperature all day long even though you are not using it.
Both conventional and demand water heaters need yearly maintenance. If they are not flushed, they will use more energy to heat the same quantity of water, thereby increasing your costs. Regions with higher mineral content may require flushing more often.
How much can you cut your water-heating bill if you implement these ideas?
About the Author: Dave is a builder, renovator, and do-it-yourself guy who has spent years researching and experimenting with home energy-saving concepts with the goal of saving money and the environment. He designed and built his own home in Alberta taking advantage of many of these ideas and is keen to update as new technologies become available.