Heat Exchanger is Finally Installed!

[Hunderliggur]

My in-tank heat exchanger is finally installed. I replumbed my main heat loop to allow for the HX loop, Rennai Tankless bypass, and larger pipe to reduce friction. The HX is installed in the top rear ofthe upper tank. Fired up the boiler last night and we are now 100% heating with wood (unless I want to enable the LP heater). I still have to wire in the Taco EBV for automatic control of the Rennai bypass but that will be easy enough and then insulate the tanks. I opted NOT to use the Taco "00-VS" series setpoint temperature pump and control because of cost (over $600) and schedule (4 week lead time). I opted instead for a $90 tempering valve and I can add a circulator later if I need to (but I don't seem to need it yet). I'll miss my 1000 gallor radiator in the basement (not really). In the pictures, the white/creame pipe in this domestic cold water supply in CPVC; the red and blue PEX is the domestic hot & Cold distribution in the house (home run for each fixture); the copper is the heating loop. Under floor is 7/8" PEX. Thank you to everyone who gave me installation and operation advice.

 

[jebatty]

Good job, well done. I think you took a balanced approach which makes lots of sense. I tend sometime to overdue, as I enjoy experimenting. Yet the core of my system is very simple. Time to give Thanks!

 

[Sawyer]

Looks good, the proof is that it is working!

Is your relay controlling three pumps? If so, that is what I will need, what model is it?

 

[sparke]

Hunderliggur, Just curious, when your tanks were uninsulated, how high(temp) could you get them? How quickly did they loose temp from stand by loss? When I had my tank uninsulated I could barely work in the cellar...

 

[in hot water]

Nice! Where did you source that HX? What is the diameter? I'm looking for a coiled HX that will thread into a 2" NPT threaded port, if you know of one.

hr

 

[EffectaBoilerUser (USA)]

Looks good,

Is that an Azel switching relay controlling the pumps?

Also, can you please tell me what brand/where you purchased the heat exchanger at.

Thanks,

 

[juddspaintballs]

That looks very similar to the domestic coil heat exchanger that you can put into Heatmor OWB's. About $200 IIRC

 

[Hunderliggur]

Controller - Azel I-Link 3 zone controller (with system pump relay) - Radiant Floor Company www.radiantcompany.com; They make a 6 zone system also and you can link up to 3 units (18 zones).

HX - 4" Diameter Threaded fitting. Sourced through AHONA™ - Alternative Heating of North America (where I bought my boiler and tanks) www.ahona.com. AHONA welded 4" fittings in the tanks for me - 1 for the radiant HX, 1 for future solar input HX (same model), and one "bonus" (needed for cleanout during tank mods). $398.00. The standard coil is rated at 6GPM 55 degrees inlet and 140 degrees outlet. I am using a 20F deltaT and a max flow of 9GPM if all zones are running so I believe this will work fine for me. Mark is the owner at AHONA and has been a great help. You may want to contact Mark and see if one could be fabricated for a 2" fitting - may be very hard to get through the hole but not impossible. I did not measure the as built width of the coil (and I am not taking it out to measure it either).

Tank temp. They have gotten over 160F (but my RadioShack indoor/outdoor thermometer has a high limit of 160F). Based on the boiler temp (outbuilding, 80 feets away, I would say the tanks have been up to 185F. When the tanks are the hottest the well insulated basement (2500SF, ICF walls with 2" styrofoam inside and outside with 8" concrete, buried on three sides) get up to 85F. Sure beats the days I was plumbing the original heat manifold with no heat except a little Buddy heater.

Now I have to insulate the tanks, finish my 1-wire Java program for monitoring, and wire in the Taco EBV control for automatic propane bypass.

Thank you for all the compliments.

Mark

 

[Sawyer]

Thanks Mark!

I assume that would be the Azel SP-83 - 3 Zone Switching Relay. I will check with Radiant Floor Company on Monday. I downloaded a installation manual this evening from the Azel site.

 

[Hunderliggur]

Looks like post #5 Effecta Boiler Agent (US) may be an Azel dealer also. Radiant Floor Company has been great to work with - no complaints about design, supplies or service. I do have too many 7/8" splice fittings left - we only kinked once while installing 5700 feet of 7/8 PEX in floor trusses (19 - 300 foot loops; 3 zones).