Wet sprinkler system freezes - moving to another system

[sanbap]

Our church's wet sprinkler system has frozen twice. The facility is used about 100 times a year, on weekends. On weekdays we turn down the temperature to 59 degrees.

The pipes that freeze are the ones closest to an uninsulated portion of the building that does not receive any heat. While we have tried to insulate that portion, we are not sure that the solution will work since that area is not heated. The rest of the building gets heated up to 59 degrees.

One solution that was given to us was to move over to a dry system. However, I assume that the change will be expensive. I was wondering if there is an inexpensive way of doing the same thing. What if the water is made to circulate all the time in the system? In that case, the water would not freeze. A pump that senses the outside temperature and starts circulating the water when the temperature drops below a set threshold, may solve our issue. I don't know how these systems work - perhaps, they are not designed to circulate the water. Maybe, that fix may also violate a NFPA code.

Thanks in advance for your answer.

 

[cdafd]

1. suggest you have 2 or 3 competent sprinkler companies come in and give you fixes they see and price.


2. insulate and heat the area where you have had freezes

3. you are right to convert to dry would cost a little to a lot, more on the lot side

4. You can ask them about changing to an anti freeze system, it does cost a little up front , and a little added each year for maintence

5. Your circulating idea for YOUR system will not work.


6. Some cities not to many allow heat trace, you would have to check with your city

7. CRANK up the heat on the colder days, pay a little extra on the heating bill, to save a repair/ clean up cost.




WHAT STATE ARE YOU IN?????????????????

 

[TravisMack]

Convert to dry system and you have to recalculate the system, slope all of the pipe and change low point drains to drum drip type. It is rare for a wet system to be able to be converted to a dry system without pipe sizes changing.

Convert to an anti-freeze system will likely require use of a reduced pressure backflow preventer. This will add another 5 psi or so of pressure loss. If the system is greater than 40 gallons capacity (very likely) you will need to recalculate the system using the Darcy Weisbach method. Depending on the safety factors in the original system, this may or may not be feasible. You may need to upsize pipe sizing. Again, changing pipe sizes in an occupied building gets expensive.

As stated above, you could just insulate and heat the area where the issues occur. That may or may not be your least expensive issue. You should get quotes from a few in the area to get an idea of costs involved.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[MGXFP]

Heat tracing in practice seems to be a short term fix rather than a solution. The evidence I've seen is that it becomes brittle and falls away after a few years in some cases.

Others have mentioned potential solutions but without seeing what you are describing its hard to give a verdict. Find a sprinkler contractor near you with a good reputation and ask them to look at it. I could dream up a dozen solutions but without seeing it, there's little chance my input would be worthwhile.

 

[ContractorDave]

I agree with cdfad's first suggestion, get some input from a couple of companies who can physically look at your situation. It's possible a small glycol loop in the unheated area would suffice. Sprinkler systems are not designed in a manner that permit circulation. Heat tracing is not permitted.

Regards
Dave

 

[chicopee]

About adding antifreeze to the wet sprinkler system, however, you'll need a backflow preventer so that the antifreeze does not travel back into the domestic water supply line.

 

[Tmoose]

Maybe can't heat the pipe with a trace element, but would there be objections to adding a few incandescent light bulbs near the pipes "just for illumination" or a small thermostatically controlled electric heater ? Could a freeze sensor and temp sensor be added to some piping in problem area, to trigger an alarm, dial a phone, and display the temperature real time?