Heating Help

« Back

john coulson

Joined on November 18, 2005

Last Post on September 1, 2011

Contact User

Navien as a commercial water heater

@ September 1, 2011 2:36 PM in Navien as a commercial water heater

I work for a plumbing and HVAC wholesale supplier and am often asked to quote navien water heaters and a storage tank instead of the more appropriate chioce, an Lochinvar Armor water heater and storage tank. My contention is that the Navien and its limitations in terms of flow are a bad choice. The trouble is, the contractor sees that the Navien is 199,000 btu as would the Armor (in this case) My contention is that this heater is not going to last not to mention the pumping complications. Has anyone seen any publications that one might compare duty cycles of both products in such an application?

6 gpm flush valves

@ October 29, 2010 10:30 AM in flexing indirect

Did you ever eliminate the boiler pressure fluxuations?

engineer

@ October 29, 2010 10:27 AM in flexing indirect

They dont have a clue. They keep making suggestions that one would not require if the inner tank did not flex. They are coming out.

flexing tank

@ July 13, 2010 7:54 AM in flexing indirect

We are installing some slow opening and closing actuators on the pneumatic valves that fill the flush tank. We shall see...
I suspect that this will cure a large percent of our problem. Its a lot less expensive than replacing the tanks with coil style models.

flexing tank

@ July 1, 2010 7:17 AM in flexing indirect

I have been using Triangle Tube Tanks for 20 plus years with great success. I have never had to modify my expansion tank (potable or hydronic) sizing to account for such internal influences that aren't thermal in nature. This is hydraulic.
We actually tested that theory by adding a few HFT60s on the hydronic side as well as two st 12s on the potable side to no avail.
Trouble with that whole theory is how do you make the calculation to quantify how much expansion to include for the flexing of the tank. Hopefully, the new Lead Engineer from TTube will have the answer when we visit the site again.
A Coil style indirect would not have this problem.

flexing indirect

@ June 10, 2010 11:32 AM in flexing indirect

I have an installation with three Smart 120 indirect water heaters (tank within a tank style) heated by 2 PS250 gas boilers. When i draw hot water from the tanks it appears that the inner tank is contracting causing the hydronic pressure to drop to 0 momentarily and then when the hot water draw stops, the hydronic pressure bounces up beyond the 30lb relief valve setting spilling water on the floor and of course adding fresh water to the system.
This has caused the failure of both boiler's heat exchangers. It is confirmed that there is no breach between the hydronic side to the potable side on the Smart tanks.