Articles from COAX on tankless water heating, with technical explanations, calculations and experience from over 30 years in the business.
‘Flow-through heaters give you unstable temperature, cold and hot by turns.’ The experience is real, but it comes from old hydraulic units. Modern sensor-controlled electronics solve the problem. Here is the difference.
Your conventional water heater sits at 65 to 75 degrees. You shower at 38. That difference costs you money every single day. Here is why a tank has to store the water hotter than you use it, and what flow-through does differently.
When choosing a water heater, your consumption determines how much power output you need. It is easier to calculate than people think: litres per activity, kroner per shower, and why it is simultaneous use, not the total, that decides which model you pick.
Legionella thrives in stagnant, lukewarm water. A hot water tank is by definition a store of water that has to be kept hot enough. Here is why the challenge is bound up with how the hot water is produced, and why a decentralised system does not have it.
The conventional water heater sits in the basement, the shower is on the first floor. On the way between them, electricity you have paid for disappears: in the tank, in the pipes and down the drain. Here is the arithmetic, and why it looks different when the heat is made where the water is used.
A hot water tank works around the clock, even when the house is empty. The standby loss is electricity you pay for without getting any hot water in return. Here is the calculation in kroner, with the assumptions on show.
Per switches off and drains the hot water tank before every cabin trip, just as recommended. Even so, the hot water costs him over 30 kWh per trip, before anyone has had a shower. Kari has switched to a COAX water heater and avoids the whole calculation.