Condenser Water Temperature Chiller Efficiency

Water chillers the cooling tower is known to book a temperature of 25 degrees then how much is the condenser temperature of the water chiller.

Condenser water temperature chiller efficiency. Evaporation temperature 25 10 20 40 c according to the temperature and pressure table it is easy to find that the condensation pressure at this time is about1 55 mpa absolute pressure r410 refrigerant. Reduce entering water temperature. The condenser water enters at around 27 c 81 f so the refrigerant needs to be a greater temperature than this. Consequently the optimum condenser water.

As a rule of thumb the chiller efficiency can be increased by 1 2 per degree c the chilled water temperature is increased. So that chiller is currently running at 50 of its total capacity. Maximum efficiency occurs with most chillers running at approximately 70 75 percent load and the lowest entering condenser water temperature ecwt based on design. On some building systems operators can reduce the chilled water setpoint to overcome air handler deficiencies such as dirty coils.

Colder tower water isn t free. Condenser water temperature at these off design conditions. The difference between the hot condenser return air and the cold condenser supply air per the tower efficiency equation presented earlier also impacts chiller efficiency as illustrated in figure 5. Chiller capacity is measured by the evap delta t.

For variable speed chillers every 1 f increase in chill water temperature can result in a 2 to 4 efficiency increase. It requires additional fan energy. There are lots of ways to implement this you should first check with your chiller manufacturer if this is applicable to your chiller and ask what temperature or pressure limits should be imposed. Increase the chill water temperature and lower the entering condenser water temperature for constant speed chillers every 1 f increase in chill water temperature can increase chiller energy efficiency 1 to 2.

Chiller efficiency as a function of condenser water temperature differential data from best practices for datacom facility energy efficiency 2 nd edition ashrae tc9 9 2009 page 43. Lowering the temperature of the water entering the condenser can improve the chiller s efficiency. If the chiller is designed for 10 f 5 5 k delta and is currently providing 44 f 6 66 c water and the return water is at 49 f 9 44 c the delta t is 5 f 2 75 k. Lift is determined by subtracting the temperature of the chilled water going out to your building typically 42 46 degrees f from the temperature of the water that s leaving the condenser to be cooled by a cooling tower or fans usually around 85 95 degrees f.

Knowing a chiller s efficiency and the effects of load and ecwt will help the facility determine the most efficient chiller configurations saving the maximum on energy costs.