In a primary-secondary system, the source flow rate is separated from the terminal flow rate by the common pipe. If the system is not primary-secondary, the engineer should find out if the reduced flow rate would cause an issue with the boiler or chiller. The following shows a system set up for constant flow.
It would not be prudent to reduce the flow rate in this system without understanding the effect of the minimum flow rate through the heat or cool source. As the temperature rises, we know that flow rate is being bypassed somewhere and therefore, we do not need as much flow. In this case, the engineer could reduce the speed of the pump in response to the return temperature.
This could be accomplished using a drive and temperature sensor. On smaller systems, the ECM smart circulating pump would also work well. A word of warning is important at this point. Why do most systems use pressure differential instead of temperature? The temperature is a blend of the return temperatures from all of the coils.
If one coil is asking for a lot of flow rate while others are not, the mixed return temperature will reduce the speed of the pump. That reduced speed may not have enough head to provide full flow to the coil that needs it. Deppmann Monday Morning Minute. The Ecocirc has all the circuitry needed for a quick addition of variable speed. The temperature sensor is an option supplied with and wired directly to the pump. No external building management system is needed. If the pump happens to be located on the return you will not even need the external sensor since the pump has an internal sensor built into it.
The return temperature will vary even more if the system has boiler reset. The Ecocirc-XL has an internal temperature sensor. Once the external sensor is installed, the pump operation can be changed to differential temperature. Nothing more is needed. The setup changes slightly. What happens if there is a combination of three-way and two-way valves? This means there is no need for any bath taps, so a minimalist look can be maintained. However, as we were building the stud wall into which this valve would be placed from scratch we could accommodate this design.
Top tip A laser level is used to ensure that the fixed shower head is placed directly above the shower valve, and this is important as a grout line will run vertically straight through the centre of both fittings so any horizontal deviation will be easily noticed when the tiling is done. The valve turn down ratio is calculated by multiplying the inherent range ability factor times the square root of the valve authority.
Hence, a valve that has decent range ability say but poor authority say 0. Many globe style HVAC control valves do not have high range ability factors; a major manufacturer lists values from 6.
Average rating 4. Vote count: No votes so far! Be the first to rate this post. Figure 4 shows two typical three-way mixing valve schematics. How useful was this post? Click on a star to rate it! We are sorry that this post was not useful for you!
Let us improve this post! Tell us how we can improve this post? Submit Feedback. Related for you. We use cookies to improve your experience. We'll assume you're OK with this, but you can opt-out if you wish. Accept Reject Read More.
Close Privacy Overview This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website.
These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may have an effect on your browsing experience. Necessary Necessary.
0コメント