boiler return water temp

Jim P.

What is the best type of valving or piping arrangement to prevent flue gas condensation with too low return water temps? The boiler is a Crown CSC 150K sealed combustion unit that is installed in a migrant camp housing unit where the customer keeps the thermostat @ 55 during the off season thus compounding the problem. Radiation is standard baseboard, single zone. Lots of rust inside the burner vestibule and the thing goes through direct spark ignition elelectrodes very quickly. A high effciency boiler would have been ideal for this job but as always hindsight is 20/20! Is a simple connection between the supply and return pipes with a throttling valve enough? I believe there are valves out there that can do it with temperature sensing...thanks in advance!
Jim

Boilerpro_3

Check out The Esbe Thermix valve

Available through Danfoss. I use them on almost every noncondensing boiler install.

Boilerpro

Kal Row

if after the mixing valve, it still short cyles,

then, you need primary/secondary/mixing - with a tekmar 361,
that will be a lot more painfull but has the advntage of outdoor reset, and full boiler protection - etc

Allied

ESBE

Boilerpro_3

I pipe the Esbe's P/S

So you can get full flow to the system even when the boiler is not up to temp. Not sure how it would cause short cycling...the valve is temperature responsive so as the boiler warms up it takes on more load from the system. It does provide fgull return temp protection, maybe just a little slower in response than variable speed pumps, but I beleive about the same as motorized valves.

Boilerpro