DT pumping a mod/con

4Johnpipe

Anthony THANK YOU!!!
BUFFER TANKS as a hydraulic separator in my humble opinion is so overlooked it's a crime. If I have. VV circ controlled by the boiler before the tank, DT circ's on the system side, the boiler has plenty of time to react and settle into a low firing rate when that smaller zone you designed for the coldest day of the year and its loss was only 10K BTU's but now on a 35 degree day it's half that, there is NO mod/con made anywhere, in any country that can handle that smoothly. A buffer tank is the distance between you and an 18 wheeler driving down the highway at 65 miles an hour in rush hour traffic with cars on both sides. A buffer tank keeps the proper distance between you and the truck and gives you plenty of reaction time to adjust.

I was just going to bring this to the groups attention...The DT circ doesnt care what temp the boiler is making or the system requires. It simply allows for adjusting or setting the "sweet spot" for optimum heat transfer of the heat emitters designed for or in place.

Boilers make water hot...houses loose heat...emitters give off the heat to the houses and keep us comfortable. Let the mod con fire in its sweet spot on one side of the buffer and let the heat emitters do their job and the other side of the buffer...

End result comfortable people and efficiently running equipment as per manufacturers design and installers design...

AnthonyReikow

John,
Nicely said. Thanks.

Paul48

Which mod/cons provide a 0-10v signal voltage? You seem to have figured out how to make the DT circ work on the secondary side. I didn't reallize so many installers were using VV circs on the boiler side, with buffer tanks.

Rich_49

HTP products have the capabilities

Gordy

Lochinvar has it.

AnthonyReikow

Lochinvar has had it for years. They can even receive a signal from a system pump that when the system circ slows from a BMS, the boiler fires lower and then sends a signal to the boiler circ to slow down. It is on ALL models of the condensing products. 50,000 - 5,000,000 BTU's.

AnthonyReikow

Lochinvar also has the ability to control the firing rate in stages. A feature called "Ramp Delay". The boiler can be set to only fire at 20% for 3 minutes upon a call for heat so that when a s all zone calls it will not allow it to go to high fire. It can be staged for 6 different levels and the tech has the ability to set the percentage output and the length of time for each one of its 6 stages until it reaches 100%. I am not aware of any other manufacturer that has this and they have had it for years. I've always believed that a condensing boiler will only condense unless you make it condense. There are way to many variables happening in the system throughout the heating season to prevent condensing and unless you have a cycle counter and hour run meter installed on the boiler, one can only hope that it condenses. Lochinvar has the items built into it. Now upon return to the unit after it's been running for a time, you can look at that information and make adjustments to achieve more opportunities of condensing. They've had these features for years.