I have two 8 inch penetrations that are ducted directly to the water heater, an inlet and exhaust. During summer I imagine I’m getting fantastic efficiency with source air being from outside at 80+ degrees (F). In winter we do have occasional freezing temps but usually above 40ish. I don’t have hard efficiency numbers but I’ve had it for over a year now and have definitely noticed savings on my monthly electric bill.
I should mention the water heater is in a closet, hence why it’s ducted.
I have two 8 inch penetrations that are ducted directly to the water heater, an inlet and exhaust. During summer I imagine I’m getting fantastic efficiency with source air being from outside at 80+ degrees (F). In winter we do have occasional freezing temps but usually above 40ish. I don’t have hard efficiency numbers but I’ve had it for over a year now and have definitely noticed savings on my monthly electric bill.
I should mention the water heater is in a closet, hence why it’s ducted.
Suppose it does depend on what you compare it to, still far more efficient than an overpowered electric kettle.