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Re: Need help with new install of radiant with Buderus cast iron boiler
A Tekmar 256 will provide ODR for the boiler. Using the manual 4way valve that hot_rod posted will allow you to mix down for the radiant.
Set the ODR at 130-160* to begin and adjust the 4 way to achieve 75-100* going to the radiant. In other words, a parallel shift. This is a suggested starting point, some tweaking may be necessary.
Leave the indirect in the boiler loop, but you should add a domestic tempering valve to prevent scalding. You won’t need to hold the pump off on the boiler side if you let the indirect’s aquastat call the boiler on. Let your room thermostat control the radiant pump.
Pipe like this:
The indirect would be piped after (down stream) of the boiler pump, but before the closely spaced Tees. The expansion tank should be before (upstream) the boiler pump. This is also where you want your air eliminator (MBR).
Ironman
Re: Disgusted by today's electricians, Today's rant
I only did HVAC work, mostly oil burners, when I started in this trade. Many of my customers were shocked when they found out I didn't have an electricians' license.
Re: Disgusted by today's electricians, Today's rant
It's rough out there, and getting rougher. Two days ago, I had to rewire a new 277 volt exhaust fan where Sparky had taken the feed from one leg of the old 3 phase power to the old starter, fed from the switchgear—but then picked up the neutral from a nearby panel. This is the guy who kept pulling off this job to go work in a hospital.
Whiskey Tango Hotel.
ratio
Re: 60 PPM outside of "snowman" boiler
gA
Gas companies are #1 on my CO ignorance list. A fart could make his meter read 60ppm. The test must be done in the flue ahead o dilution air. Any other test is useless.
Re: Hodge Boiler Plant Photo (1890s)
Sorry to derail further, but I just sat down and watched the second half of the Bulding of the Eiffel Tower on television. As I understand it, a top notch riveter could install 1700 rivets per day (up to 12 hours). There are two and a half million rivets in the tower. Riveters were paid seventy cents per hour, almost double what riveters received at other less glamorous sites. They used sixty-six tons of paint when they repainted the tower for the nineteenth time recently. I apologize for the almost worthless information.
Re: Need help with new install of radiant with Buderus cast iron boiler
I had thought of the same thing that Kaos just suggested. The possible downside might be from the 3/4” coil in the indirect, but if the heat load is only 40k btus, that shouldn’t be an issue.
Ironman
Re: Need help with new install of radiant with Buderus cast iron boiler
No kidding, I'm down in Cuba, like an hour south of Orchard Park.
Are you taking DHW into account for the heat load? I planned to use the indirect for that.
Last year when I had deeper pockets I had the local HVAC company build me a quote for a modcon combi boiler setup, and based on all of my specs they recommended/quoted a 115k BTU unit. So I figured I'd be in the ballpark with the output of the Buderus.
My wife was unexpectedly unemployed for 7 months. We have 2 kids in college. She is back to work now but we are still playing catch up with tuition payments hence the low budget.
Re: Need help with new install of radiant with Buderus cast iron boiler
my guess would be 3- 300’ loops
4-300’loops, so tube is 12” oc approximately
Tube length is usually printed on the tube
The shop looks well insulated. Not much glass. A load calc and design would answer some questions, I suspect you are covered
As for mix valve, the tekmar requires 3 pieces, valve, actuator and control, probably 1200 or so based on supplyhouse prices
The tekmar 360 control has more functions and would control the boilers operation. It is programmable with the digital display readout. Sometimes called a PLC, programmable logic control. So you would need to learn how to program and drive it.
Looks like the Taco uses dip switches for choices,
Like buying anything, how many features do you need or want?
https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Tekmar-360-install.pdf
What control is on the boiler? It may have some of the functions you need?
Another option, put in the tekmar without the actuator or control. Manually adjust the valve at design condition. If the boiler has a control with ODR, no need to have two ODR functions
A control could be added later if you want more control
That boiler is fairly radiant friendly as it is
hot_rod
Re: Objects found in heating systems
Thanks so much for these great stories. You keep America warm. Lives well lived. I am learning from all of you! Thanks.
Re: Need help with new install of radiant with Buderus cast iron boiler
How about this as a cost optimized setup.
Fixed bypass and hold off on P1 for boiler temperature protection. Thermostatic mix valve for floor heat. No zoning to limit short cycling.
The indirect is always on the heat loop, when the boiler runs, indirect is always heated. When only indirect needs to run, only P1 is turned. Will need a valve before P2 that can be closed in the summer to stop flow through the floor heat.
The indirect does double duty as a buffer to reduce cycling.
Kaos