domingi
New Member
Hi folks, I have a question.
I live in the Florida keys where sunshine is almost always present. I am planning to replace my old 30 gallon electric tanked water heater and have been investigating a 30 gallon breadbox style passive as a partial replacement.
My big concern would be the few times we do not have a day of sunshine, yet still have family or friends visiting that like to take hot showers regularly.
I am trying to understand how the tankless portion works.
1. Would they run at a partial heat setting if the inlet water temp is high enough that they do not need to run full blast to heat the water to the desired exit temperature?
2. Can they take an inlet water temperature in excess of what their designed exit water temperature is?
My thought was to set-up the passive solar as a feeder(pre-heater) to a smaller tankless model. The tankless would then become something that at peak daylight hours would not even need to turn on to heat water that is already at or above the designed output temperature. My thinking is that the tankless just becomes a back-up to make up the difference in temperature if we had a high demand or an extended period of gray skies and cooler water coming in from the passive.
Since the output temperature of the solar can be quite high, my thinking was that a tempering valve would need to be installed at some point in the circuit. If the tankless can handle the higher input temperatures then it would be placed after the tankless unit. If not, prehaps it would need to be placed between the two?
Or, do the tankless not have the ability to automatically run at a partial heat input setting.
Or am I just whacked in my thinking?
Thanks for your replies.
I live in the Florida keys where sunshine is almost always present. I am planning to replace my old 30 gallon electric tanked water heater and have been investigating a 30 gallon breadbox style passive as a partial replacement.
My big concern would be the few times we do not have a day of sunshine, yet still have family or friends visiting that like to take hot showers regularly.
I am trying to understand how the tankless portion works.
1. Would they run at a partial heat setting if the inlet water temp is high enough that they do not need to run full blast to heat the water to the desired exit temperature?
2. Can they take an inlet water temperature in excess of what their designed exit water temperature is?
My thought was to set-up the passive solar as a feeder(pre-heater) to a smaller tankless model. The tankless would then become something that at peak daylight hours would not even need to turn on to heat water that is already at or above the designed output temperature. My thinking is that the tankless just becomes a back-up to make up the difference in temperature if we had a high demand or an extended period of gray skies and cooler water coming in from the passive.
Since the output temperature of the solar can be quite high, my thinking was that a tempering valve would need to be installed at some point in the circuit. If the tankless can handle the higher input temperatures then it would be placed after the tankless unit. If not, prehaps it would need to be placed between the two?
Or, do the tankless not have the ability to automatically run at a partial heat input setting.
Or am I just whacked in my thinking?
Thanks for your replies.