Water temp & convector efficiency

Spudwrench

I was wondering how lower water temps effect the operation of panel radiators. It seems that at higher water temps, the convector/ panel rad will create much stronger convective air currents in a room, which would lead to more even temp across the room? Or would the greater convective air currents increase air infiltration?
Secondly, is the main advantage of reset & running lower water temps that it reduces losses due to cycling? (I came across an older HVAC book which touted increasing water temps and downsizing radiators, claiming that the increase in fuel use was negligible...made me wonder a bit.)
Just a hydronics dabbler trying to learn from others...thanks!
Nathan

hr

Panel radiators

are a bit more of a radiant emitter than a convective. Baseboards and fan coils are convection type of emitters, and yes as the supply temperature to baseboards is increases the air movement is. generally the high temperature baseboards are the ones that streak the walls

And we all know how dirty a FA unit can be without properly installed and maintained filters

When you move air you move dust and other airborne "stuff"

Reset controls will help supply just the proper amount of supply temperature to whatever emitters you chose. This cut down cycles and gives optimum comfort.

hot rod

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EBEBRATT-Ed

Reset controls save fuel because the greater the temperature between the boiler water and the surrounding air the greater the loss from piping, boilers etc. It is true(sometimes) that this heat loss remains in the building envelope and is not truly lost-but you are not putting the heat wher you want to. Why make the boiler hotter than you need to?? It cost more fuel. Also as was pointed out comfort --it puts the system into balance

Spudwrench

Thanks for the info, gents...i definitely get the points about greater losses from piping & the boiler at higher temps... and I can see that as a heating system gets progressively more convective, it might behave more like a forced air system. Personally, I don't notice any large comfort difference between running my panel rads at 140* for long cycles or 180* with much shorter cycle times, but maybe I'm just not that sensitive to small room temp variations with on/off cycling. The panel rads do make less "pinging" noises at the low temp, long cycle settings though!