Condensing Boiler Tips

1. Make sure there are enough run hours with load at low water temperature to make condensing viable. If not, a hybrid system may be a better option. Call Rounds Company for details.

2. When comparing boilers go for stainless steel tubes, they don’t corrode or rust.

3. Always use AL294C stainless steel flue and it should be positive pressure design.

4. Check the water pressure drop through the boilers. Some coil types have drops as much as 100 feed TDH requiring much larger circulating pumps and they will use more electricity. Also check the design pressure. Some are less than 60 psi.

5. Check the electric motor size on the boilers, some require a lot more motor horsepower for fans. No fans, or VDF are preferred.

6. Be conscious of noise, but not frightened. Early pulse designs were noisy but current generations are very reasonable and perfectly acceptable in most normal mechanical rooms. New models have sound levels near 60 dba. For sensitive jobs such as thin wall buildings, libraries, look at Clear Fire.

7. Remember the treatment tank to neutralize the outflow of water before going to drain.

8. Cleaver-Brooks Clear Fire and Fulton Pulse and Vantage models allow for VFD pumping, but many types do not.

9. When using a common breeching consider mechanical fan assistance such as Exhausto.

10. If the number of boilers for the job are more than 5 or 6, consider a large non condensing boiler such as a Flextube for when large heat load exists. Remember, too many burners, controls, parts and pieces will greatly increase service and maintenance costs.

11. Forget about using 3 way mixing valves, simply reset the water temperature as desired.

12. Don’t forget to balance the flow. Clear Fire boilers and Fulton do not require a dedicated pump on boilers, but proper balance is a must.

13. While direct venting is allowable, it is not preferred. All boilers run better with dry tempered make-up air. Outdoor air varies widely in density, temperature, humidity all of which affects the combustion process. Consider an Exhausto make up air fan in the boiler room.

14. When selecting a product, make sure there is a good service and parts company locally to assist the user. Control panels and BMS systems associated with high efficiency boilers are typically more complex than “standard” boiler systems. Make sure you local representative has excellent field support to complete jobs on time and budget.

If you have questions, contact your Rounds Company sales engineer.