Termovar loading unit

[chuck172]

Does the termovar loading unit automatically vary the circ. pump speed to maintain a desired delta t from the boiler to the storage tank?

 

[flyingcow]

Mine does not. I think mine is set on high.

 

[chuck172]

Installing accurate usb digital temp. sensors have taught me how important the bypass valve above the termovar and the circ. pump speed from the boiler to storage is.
I think efficiency and convenience would be improved with the above automation.
Right now I'm physically throttling pump speed and termovar bypass while watching my computer. Very interesting.!

 

[Singed Eyebrows]

Does the termovar loading unit automatically vary the circ. pump speed to maintain a desired delta t from the boiler to the storage tank?

I may not understand the Termovar properly. My understanding is that this holds the boiler inlet temp at a minimum of approx. 165 degrees. The thermostat with the pump speed(3 speed) holds the Delta T across the boiler inlet & outlet. My Lado is about 10 degrees Delta at #3 speed. I am confused about the question of Delta between the boiler outlet & storage tank, this is always going to very widely as you are charging & never held to some value. I am not aware of any variable speed loading units, Randy

 

[DaveBP]

In the loading unit the thermostatic element controls two valves. One of the valves throttles the cold return water and the other throttles the hot recirculating water (this acts as the balancing valve that is manually adjusted on the simpler and cheaper loading valve). As the proportion of cold water in the mix going back to the boiler is increasing the recirculating hot water is decreased. When the temperature of the return water is above the setpoint of the thermostatic element the hot water from the boiler supply is shut off completely and water going to the boiler is all coming from the return circuit.

 

[Singed Eyebrows]

In the loading unit the thermostatic element controls two valves. One of the valves throttles the cold return water and the other throttles the hot recirculating water (this acts as the balancing valve that is manually adjusted on the simpler and cheaper loading valve). As the proportion of cold water in the mix going back to the boiler is increasing the recirculating hot water is decreased. When the temperature of the return water is above the setpoint of the thermostatic element the hot water from the boiler supply is shut off completely and water going to the boiler is all coming from the return circuit.

Dave, Is the Lado & Termovar LU basically the same? I can't see where my Lado thermostat does anything except open a passage for mixing. Thanks, Randy

 

[Chris Hoskin]

Does the termovar loading unit automatically vary the circ. pump speed to maintain a desired delta t from the boiler to the storage tank?

The loading unit has one thermostatic element that mixes hot boiler supply water (coming into port one) with cold return water (coming into port two) to maintain a minimum return temperature of 140 degrees (going out of port three). As the return water temperature increases, the amount (GPM) of hot supply water being mixed into the return flow decreases and vice versa. At some point the return water will be above 140 degrees and port one will close completely and flow into port one will cease. That is one of the key differences between the loading unit and the simple Termovar valve: port one on the simple valve never closes completely so there will always be some supply flow through the valve. This is why we recommend a half-closed ball valve located just above port one on a simple Termovar valve - in order to introduce some flow resistance there so that the flow tends more towards the zones at higher return temps.

The loading unit does NOT vary pump speed, only the ratio of gpm flowing into port one and port two.

hope that helps, have a great weekend everybody!

Chris

 

[flyingcow]

Installing accurate usb digital temp. sensors have taught me how important the bypass valve above the termovar and the circ. pump speed from the boiler to storage is.
I think efficiency and convenience would be improved with the above automation.
Right now I'm physically throttling pump speed and termovar bypass while watching my computer. Very interesting.!

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