Quote:
Originally Posted by buffalobillpatrick
Why delay between In & Out pumps?
|
I'm not completely certain of Ormston's rationale, but it is required to have a delay between a power lapse and the restarting of the compressor, to protect the compressor against starting when filled with liquid.
This is vital.
Then there is the issue that you want to assure that water is flowing before you start the compressor, so that you don't chill the evaporator HX to sub freezing by running the compressor, with no water circulation. This would burst the evaporator HX in an very short time.
This is vital. There is a corollary to this which is that you need to make sure that water that has flowed through your evaporator HX is exiting at a temperature that is comfortably above freezing. You need to assure that you have water flowing here to make a measurement of water exiting the evaporator HX.
There is an additional issue that it would be preferable, that you have a heated condition in the condenser HX before starting the condenser pump, so you don't pump cold water into the hot water storage tank.
This is preferable.
Quote:
Originally Posted by buffalobillpatrick
Why delay between pumps & compressor?
|
See above. Plus Ormston is going with flow measuring sensors (I don't yet see any other way to do it other than the way he has chosen), so it could take some time to get everything up to speed before measuring.
Quote:
Originally Posted by buffalobillpatrick
Why delay on powering down Compressor & pumps?
|
So that you can squeeze every last BTU out of the condenser HX before shutdown. This delay shouldn't require too much time.
I see no reason why the outside loop pump (evaporator HX circuit) could not be shut down at the same time as the compressor.
I hope Ormston chimes in here, I'd be interested to see what his thinking is regarding the various delays.
Best,
-AC