If it's the whole house, turn the screw clockwise at the PRV to increase the pressure. If it is something else, you would have to explain it more.
Think of it this way. Somethings got to stop some time correct? If it has no more pressure behind it, or less, then its going to slow down. The pressure will get lower and lower.
Correct
Water has a high pressure all the time.
In regards to a water chiller unit, the terms low pressure and high pressure refer to the compressor, which takes low pressure and compresses it into high pressure gas, which is then turned into a liquid to cool the unit.
160psi
The water pressure could be low due to a leak in the line or water is being ran somewhere else.
turn up the water pressure
Water is evaporated at any temperature; a high pressure and a low pressure favors evaporation.
The solubilty of gases in water is increased at lower temperatures and higher pressures.
More than likely it is restiction in your water heater.
If you mean to ask if cold bodies of water are associated with high or low atmospheric pressure, they aren't. Atmospheric pressure can change independently of the temperature of bodies of water.
150 high 75 low