The Architect's Blog

Is a Tankless Gas Water Heater Right for My Application?



In Architectural studies at the university, we were taught to design interesting and beautiful buildings for clients and to create construction drawings that accurately convey these concepts. While I still get to do some of that, a more significant part of my daily activity surrounds ensuring that people and products deliver on their claims.

Whether it’s motivating a client who has promised to select interior finishes to make a decision on tile, reviewing a contractor’s work to see that he is building per plan or checking out the claims of a new product, much of my day is focused on cutting through the “noise” to get to the reality. One product I’ve recently reviewed is the tankless water heater.

A lot has been said over the past several years about the energy savings that gas tankless water heaters can provide. Given the right conditions, I’m convinced that these units can save money. Increasingly, however, my sense is that the typical residence in California is NOT the correct application.

Tankless water heaters became popular in Japan, where space limitations make storing a large water tank unrealistic. Here in Long Beach and Southern California in general, where space is relatively more abundant, the appeal of the tankless water heater is different.  Because it doesn’t continually re-heat water like the traditional water heater does, the tankless water heater potentially reduces energy use.

The reality however is that tankless water heaters have a higher initial cost, they often do not work well with state mandated flow rates and they appear to waste water.

The gas tankless water heater unit typically costs about twice what you would pay for a traditional water heater.  Add to that the cost of installation of a gas line large enough to provide increased gas volume to the tankless unit and – if installed indoors – the required stainless steel venting system and you are up to about 3 times the cost of a traditional water heater.

Frequently, we find tankless water heaters installed as part of a larger remodel.  Often as part of these remodels, faucets & shower valves throughout the house are changed out for new ones. These new State mandated low flow faucets & shower valves create another problem. The gas tankless water heaters are activated when a certain flow rate through the pipes is achieved. According to a recent conversation I had with one of the tankless water heater companies, minimum flow rates consistent with the State requirements make it difficult to achieve the normal hot water flow rates needed to continuously activate the tankless unit.  In other words, water either takes longer to heat up at the tap or goes cold in the middle of use. So the choices seem to be, you either remove the faucet restrictor or you have a faucet running while you’re showering – either way, water use goes up.

I’ve come to the conclusion that the best application for these gas tankless water heaters is in a home where space is at a premium and/or the occupants are normally not present and/or in a house where shower and faucet use is minimal, otherwise, in my opinion, it makes sense to stay with a traditional water heater.

Contact us if you’d like help with remodel options or discussing design considerations for energy savings. We’re experienced architects and designers serving Long Beach and the surrounding areas.

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