Hot water. We all want it instantly when we want it and get frustrated when it runs out! One of the most common conversations we have with clients revolves around water heating options. Should they go for the currently heavily on demand tankless system with its appealing promise of ceaseless hot water, or go the traditional tank route? It is not a simple question.
Tankless systems are touted as the space saving energy efficient way to go because you are not heating water in a tank, but as it is needed. But is this true? It all depends on how you look at it. Gas fueled heaters have an electrical requirement that is not intermittent. Traditional tank systems use 40,000 btu of gas, tankless systems use up to 160,000 btu which may require an increased gas supply pipe.
Water usage is another component of the equation. A certain volume of water flowing through the unit is required to turn it on. I experimented with an electric unit once and found myself waiting longer for water which resulted in wasted water. Another unconsidered side effect of unlimited hot water is that it actually promotes longer showers, more water down the drain. Other factors include higher initial cost for purchase and installation, especially in retrofit situations.
Other cons for tankless systems are the annual maintenance costs, the systems should be serviced annually. Water source is also critical, hard water is rough on various components of the system and it is best to provide softening for it before it enters the chamber. Another key point of potential dissatisfaction is that the final temperature of water at the tap is dependent on the temperature of the water entering the system which presents a real issue in colder clients. The temperature of tankless systems is not a constant, but dependent on the differential between incoming and outgoing water being limited to about 50 degrees. When using them at vacation homes, you want to make sure that exterior installations are totally drained to prevent freezing.
The traditional tanked systems have several positives going for them. Their initial costs are less. Adding a recirculating pump to the system creates instant hot water at the tap reducing water waste. This is not an option for tankless systems. Their temperature can be set and remains constant. They are also more reliable without maintenance, although it is recommended! Recent advances in insulation have greatly reduced the efficiency differences between the two types of systems.
The major drawback to the traditional tank is the limit to hot water capacity (although this could be seen as a positive for households with teens!). Another negative is the amount of space required for the tank and flue. Filling a garden tub will also deplete the supply and needs to be planned for. Finally the expected life of these units is 10-15 years, although 20 is not uncommon.
The bottom line is there is no one right answer. There are situations that lend themselves to both types of water heaters. We help our clients make an educated decision by looking at all the factors and selecting the right solution to meet their needs. Sometimes it is a combination of both systems!
image source: bostonplumber.com
Leave a Reply