Posted by Tony Wesley on March 8, 2006, 4:58 pm
The risk that the system will not work exactly as designed.
Posted by SJC on March 8, 2006, 6:50 pm
These guys show a draindown system as one of their options.
I don't think that they would recommend something unproven.
Posted by meow2222 on March 9, 2006, 12:02 am
Why does he think there is a risk of incompetent engineering in one
system but not another?
Posted by Derek Broughton on March 9, 2006, 1:41 pm
"Those guys" show a system that is reliable as long as that valve opens.
Also, what makes you think they're "recommending something" for northern
climates - they're in Maryland, for heavens sake!
Valves fail. It's not incompetent engineering.
In a glycol-loop system, even if the pump breaks down there's no risk of
flooding. Even if it gets cold enough to freeze the glycol (!!) you have
at most a few gallons of it in the loop. So far, all you've told me about
drain-down systems is that they're safe. Convince me.
Posted by nicksanspam on March 9, 2006, 7:05 pm
Aha. I've been thinking drainBACK, as in "the water drains back when the pump
stops, by gravity, with no valve."