Controls Needed!

Chris_6

I am trying to select smart controls for a primary/secondary/tertiary system I've set up in my six-family home, and someone suggested Tekmar.

Here's what I have set up now for 2 of the 6 apartments:
- One standard cast-iron gas boiler that heats to 180 degrees whenever the thermostat I placed in the bulkhead reads below 50. The boiler circulator runs along with the boiler.
- The secondary loop circulator runs all the time.
- The two tertiary circulators are controlled with a thermostat in each apartment, via relays.

For the remaining 4 apartments, I have 3 old boilers and 1 furnace running independently, but as those systems die, I want to tie these apartments into the central system, therefore:

- I’ll want to be able to control a minimum of 5 tertiary zones, but up to 8 maximum.
- I’ll want the potential to control a 2nd boiler so I don't have to install a single large one when the existing unit dies.
- I don't want the boiler heating if no zones are calling.
- I don’t want any circulators running if the boiler isn’t heating.
- I want to reset the water temp to 140 in mild weather, or lower if I no longer use cast-iron boilers in the future. Future boilers would be high-efficiency & direct-vent.

I am also combining DHW, and am down from 5 tanks to 2, one of each end of the basement. I wondered if it would be a good idea to install indirect storage DWH, but that would bring the number of tertiary zones to 7-9.

Although I did all the plumbing myself, I have no experience with controls, let alone anything this complex.

Any advice would be appreciated!
Thank you,
Chris

Boilerpro

Controls

I continue to use tekmar exclusively. For the finished system you are looking at probably a tekmar 262 is what you want with a 361 variable spped injection cotrol fto provide boiler return protection so the system can run down to 70F on warm days, byt the boilers will stay above 140. I'd wouldn't necesary use an integrated zone control because if people leave strom windows, windows, and doors open, the system will respond by providing more heat. I'd stick with on/ off thermostats and just closely set the reset curve to what the structure needs for heat. This way, if people abuse the heat you pay for (ie. leaving windows open, etc) they will get cold and be forced to close the windows since the heating system will only provide enough heat to keep them warm if everything is closed up properly. Just some ideas.

Boilrpro

PJO

Piping...

How about putting in a secondary loop for the boiler? Make it a manifold for the (future) second boiler, and if it's a condenser than run that baby first...calling in the (existing) non-condenser when needed. Then you could just run the primary circ and the boiler(s) may not fire right away. Adding an Ergomax-type of "reverse" indirect may help here, too. Siggy has an article in PM magazine that used that a set-up like this w/ a boiler on the secondary...here's the article (wouldn't attach - operator error!)

http://www.pmmag.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2379,78589,00.html

Still use the set-up that Boilerpro mentioned...he knows far more than I ever will...just a thought on piping.

Take care, PJO

Chris_9

Thanks!

Thanks for the great advice, guys. I'm going to start by looking at the tekmar 262...