Digital Setpoint question again

Ken_40

Do constant circulation!

Pulse wave modulation is interesting technology. In some rare applications, it is ideal. Not necvessarily this one however. Simply continue to lower the slab water temp until "spikey" slab response is as minimal as possible. Simple O.R. may be an excellent "strategy." Anticipatory 'stat logic may be a simple solution in conjunction with O.R.?

Think K.I.S.S. first, not last.

Rob Blair

Setpoint question again

Okay, they say that the digital setpoint control will help to control a large slab using the PWM setting. I was looking at the wiring and see that there is power coming in, a sensor hookup (Where would you place the sensor? Air/Slab?), and the output relay would feed what (Circ)? How do you control the boiler? Could someone show me a wiring diagram showing an application using the setpoint to control a large slab?

The reason I ask is that I have a man who has a 7000 square foot building and when we have these 30 degree nights and 60 degree days the slab overheats and the temp overshoots. Granted, he has an old, should be insulated more, building and the slab is 6" working hard at night to keep up. Would the PWM help even out these overshoots? Or should I look into O/R mixing? He is not the first person that I had complain about this situation.

Thanks,

Rob

jp_2

PID

think you need PID controls with outdoor reset here.

i agree with 6" slab, night set back is not appropriate.

hot_rod

a 6\" slab

isn't going to do anything fast! if the building has other heat gains,lights, people, equipment, etc. that is where overshoot happens most often.

Outdoor reset and constant circ help a lot, but shoulder season heating may be better handled with unit heaters.

hot rod