Vitodens in Operation

Mike T., Swampeast MO

Pulse...

Digital...

Modulation...

The nosedive to the lowest return temp was when TRVs for two spaces with about 12° of setback were turned up to 72°.

Boiler reports actual supply temperature about 9° higher than what you see here. My sensors are strapped on to black iron near the end of the near-boiler piping. May move the supply temp sensor to the copper connection point in the boiler.

Boiler has a display for "Return Temperature" that is some calculated measure I guess as the "Actual Return Temperature" right below in the display is always blank.

The "Return Temperature" it displays matches my measured SUPPLY TEMPERATURE to the degree while the unit is modulating... Bizarre!

Mike T., Swampeast MO

Here's a VERY Interesting Link

that Cliff Brady sent me...

DOE Presentation

I find it illuminating that a DOE publication says that standard boiler testing does not reflect reality and thus cannot properly reflect the operation of a condensing/modulating boiler. Remember: the DOE essentially prescribes the test and ASHRAE determines the methodology to conduct...

don_52

broken link


link was broke,

http://www.rebuild.org/attachments/presentations
/RIHVACRimassa.pdf

according to that presentation, either boiler must
be oversized to hit the 25% to 50% "sweet spot" or
use more radiation and different pump speeds to the
same effect.

of course that doesn't help someone with existing
radiation.

interesting, confirms my thoughts on oversized
rads and wider delta - t, like to hear others
chime in, agreed, it may not be desirable or
practical to do so,

thanks Mike T,

Mike T., Swampeast MO

Link Fixed Now

Sorry about that...

S Ebels

You're preaching to the choir...........or

Tell me something I didn't know.

The trick is getting customers, be they owners of large buildings or small, that this stuff works. The return on investment into a good modulating, condensing boiler is more than just the raw AFUE numbers indicate.

I did raise my eybrows about "how the industry modulates".
Quite "antique" compared to the servo controlled burners from Riello and Wieshaupt. Most residential boilers of this type are more advanced than an old linkage setup.

Mike T., Swampeast MO

Long Modulation Period

Finally have my own program working.

Nearly a 20-hour burn with heat loss averaging right near the low-end modulation rate.

Glen

return temp

Your control has not been told that it does not have a RTS. Look in both coding 1 and 2 to turn this sometimes annoying screen off. Or - buy the sensor and program control accordingly. The number you see right now doesn't mean a darn thing.

Mike T., Swampeast MO

Fuel Consumption

Have a discrepency in my meter reading and that previous description was WRONG!

Not sure what's up--will have to wait for the gas bill.

Something is impossible.