Turning off Commercial hot water boiler for a few days - good idea??

elfie

have a large 14 section HB Smith Boiler and it appears that the weather will be warmer for an extended period (boiler water feeds into a 24/7 pump and does not cycle on an off like a normal residential boiler)



have heard in the past that its not a good idea to turn off a commercial size boiler till end of season (to mininimzed thermal stress) - ie. turn it on once at beg of season and off at end of season



my question is - would it be a good idea to turn off the boiler for a few days?

Mark Eatherton

Shouldn't be a problem...

I have seen MANY large commercial multi family boilers that were on an automatic warm weather shut down, and in the shoulder seasons, they cycle daily, and I've never seen a problem. You should be fine.



ME

elfie

turning off commercial boilers on and off during shoulder season - good idea?

i have heard its thermally stressful for large boilers to reap efficiency savings by having it turn off and on when it gets warmer for only a few days





thanks

Mark Eatherton

If you can't stand the heat, stay out of the kitchen....

That is what my mother used to tell me as a kid growing up. Boiler manufacturers run under the same premise.



What is MORE important, is understanding exactly WHERE the "neutral" energy point of your building is, and I can tell you that it is NOT 65 degrees F that has been tossed about for so many years. The only correct answer to the question "Where should I set my optimum start/stop at?" is, wait for it........... "It DEPENDS!", but you already knew that, right?



It is based on the internal gains (every KWH regardless of the end use, ends up as heat inside the envelope), the mass of the structure, the tightness of the structure, the solar gain potential of the structure, and the R value of the structure. And the ONLY way to determine it for YOUR building would be to monitor the run time of the gas valve of the boiler, chart a graph of cycles per hour against the outdoor air temperature. Even going through all of these paces is no guarantee that EVERYONE will be comfortable at whatever temperature you choose as your "neutral" energy point. I've set some as low as 40 degrees F and received very few complaints.



Adding the feature of ODR lessens thermal stress on system components (piping and boilers). The flame still has to go to the same temperature, but that side of the system is built for that differential. All the above pertains to cast iron boilers. I have seen some water tube boilers (Ajax) that leaked at the access doors gaskets, but if it leaks when its cold, it probably leaks when its hot, but the water evaporates as fast as it leaks, hence it doesn't look like its leaking. If it leaks whenever, then it needs fixed regardless of wether its on or off.



ME

elfie

Commercial boiler stress issues? turning on and off

trying to better understand the consensus about turning a cast iron 14 section commercial boiler on and off every few days when temps are warmer and then get colder again



is this an acceptable way to treat a commercial hot water boiler?

Mark Eatherton

If in doubt...

ask the MANUFACTURER.



http://www.smithboiler.com/



ME