I would like to size an adhesive pad heater to use on a brazed plate heat exchanger to prevent freezing in low ambient temperatures. How should I go about calculating the wattage?
It's very basic and I expect to be shamed for asking, but I want to know simply why are chilled water systems pressurised to around 10-15bar? Is it to prevent vapour bubbles being released in certain areas of the system as pressure changes? Why choose 10-15bar?
Thanks
This might be a stretch but is there a way of calculating how much air is released from water due to pressure change such as a valve opening and closing? If so, what is the method and what do I need to carry out the calculation?
I am trying to find out if there's a tangible number I can...
I want to fit a thermowell at an angle against the flow of water in a copper pipe but need to fit a threaded socket for the thermowell to screw into. How would I do this on copper pipe? Are there dedicated angled threaded sockets available to purchase?
I have a set of sound power for frequencies 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz, 4000Hz, 8000Hz, and 16000Hz however I need data for 63Hz, 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz, 4000Hz, and 8000Hz. Is there any way I can use the data that I have to create values for 63Hz?
Using the ASHRAE tables I'm able to get an equivalent length for copper fittings if it's a short radius or long radius fitting. In some of our pipework we also bend to 2xDiameter bend radius and 1.5xDiameter bend radius. How can I find or calculate the equivalent lengths for these?
Hi, I'm looking for help on finding the change in pressure of water trapped in a section of pipe due to changes in temperature.
The scenario is, water is trapped in length of pipe which is full of water and no air, the ambient temperature rises causing the temperature of the water to also rise...
Hi everyone,
Can anyone recommend some software that will automatically generate the circuit patterns for fin and tube heat exchangers, with a specified number of tubes tall, rows deep, and number of circuits? Ideally if air flow direction can be specified as well.
Thanks
I have 3 sets of results from CFD analysis of different sized ducts in terms of length, width, and depth. I'm trying to find if it's possible to use the characteristic of just the scenarios to predict pressure drop in any duct size by changing the dimensions.
To begin with, I have created a...
Where is the best location for a control valve in a chilled water system, on the inlet or outlet of the cooling coil?
I recall reading somewhere that outlet is better as it provides a full coil of liquid at all times and temperature change reacts better to cooling demand.
Thanks
I have a target of X meters for water pipe, I'd like to calculate how much vertical pipework I can have that would equate to X meters for different pipe diameters.
I have tested data for airside pressure drop through a media which is above that of the predicted values calculated from raw data. There is a deeper media to be used that we don't have available to test, I was going to apply the same percentage difference to the raw data to assume the same...
We currently use a material that has been known to become brittle over time in sunlight. I have been given the material properties for the material and another material that could be a potential alternative. But I'm not sure which property to be interested in to determine it's capability in...
In a scenario an axial fan is positioned on the top of a box drawing air in from three of the four vertical faces. A portion, lets say a fifth, of the fan blade is covered by some metal on the bottom of the fan closest to the middle of the three face openings. Will this effect the airflow...
I am trying to create an interactive spreadsheet for refrigerant mollier diagrams in excel. So far I can plot the cycle from evap temp, condensing temp, sub cool and suction superheat, but with a perfectly isentropic relationship on the compression phase. I have the isentropic efficiency of a...
I'm currently designing a unit that's performance is very sensitive to the charge of refrigerant. I have a spread sheet that calculates the charge of refrigerant needed based on operating conditions, however the one part that remains a dark art is the percentage of liquid in the evaporator and...
I am looking at two concept layout to blow fresh air into a room space. I am trying to determine how the fan motor is located in each instance and was hoping someone could give me their opinion.
Instance 1: The centrifugal fan is placed in a box attached the external wall of the room. The fan...
I've been using an equation given by a fan supplier to calculate the correction factor based on the hydraulic diameter of the "box" around the fan. Does anyone know if this is effected if the box walls are perforated? Is there another equation to use?
I'm trying to animate part of a model, I only want the camera to change views in between steps but I can't change the duration and position of the camera path in the animation editor. I don't want the camera to slowly change one position throughout the entire animation. Is it possible to change...
