nice presentation ! thanks

You are a great speaker

@greghahn4096

6 жыл бұрын

Thank you! I appreciate your comment.

good information very knowledgeable

@cod4blasterable

5 жыл бұрын

Thanks!

What kind of gas water heater can i use for a hydronics systems and the domestic water ? Thank you in advance

@Real_Tim_S

4 жыл бұрын

Best answer is "it depends". One must consider the rest of the system design before get into specifying a boiler - you're kind of asking the question backwards. What are the heating demands (both heating and domestic hot water in BTU/hr), do you have buffer volume? Residential home or commercial building? Occupied all the time or partially? Etcetera. once you figure out what temperatures the system needs/wants, THEN you can figure out if a condensing or non-condensing boiler is okay. Important to remember is that the more things one pulls into a system, the more the system must behave like a "system". Domestic hot water is typically specified at 120°F, but I prefer to see it leave the water heater at 150°F to prevent Legionella growth and circulated so that the return temperature is no less than 130°F giving 10°F margin (using a variable speed pump, and temperature sensors on the far end of the loop and both the supply and return from the water heater) - then using cold-water mixing at the faucets. One can use another buffer tank to separate the boiler from the hot water heater, and mix in with a double-walled stratifying coil on another variable speed pump (something like this SILJAN: kzread.info/dash/bejne/p6ujk89qpKnFYKw.html). In this way the temperature cascades from the hotter hydronic heating loads down to the lower temperature domestic hot water. The boiler will primarily see higher temperatures from the hydronic system, reducing the risk of boiler condensation in the first place - then proper buffering/plumbing to ensure that the boiler is allowed to stay above 140°F at the worst case heat load +10%. To cover shorter heat runs, you'd then figure out what heat capacity you can do and pick a boiler that can fire that low and stage more than one, or find a variable firing rate boiler that can go that low and up to the max heat load (again, perhaps with staging).

If a condensing boiler works at a lower return temperatures And outdoor reset keeps the water temp lower than 180 How does a fin tube baseboard create convection currents to effectively distribute heat in a space?

@cod4blasterable

2 жыл бұрын

The surface area of your radiating baseboard heater would need to account for the lower temperatures. But if you're only raising the room a few degrees then it's usually OK.. If it's an existing system, experiment with it. On a mild day lower the water temperature to 110ﾟ and see if the room can heat itself back to 70 or whatever your set point is.

So radiator needs to be oversized?

@cod4blasterable

2 жыл бұрын

Size the radiator for the inlet water temperature being supplied. The lower the water temperature the larger the radiating surface requirement - but calling it "over-sized" might not be entirely appropriate.

@hardcoreplayafromthehimala4888

2 жыл бұрын

@@cod4blasterable last few days reading a lot of stuff, all I see is that need to be minimum 30% bigger than the 90\70C calculation if I want exit water from boiler 55\45, and 50% more if want 45C exit water temperature.

Which is the best condensing gas combi today ?

@cod4blasterable

5 жыл бұрын

95% of my work is in the commercial world and combi's aren't of much prominence. I appreciate the question but reluctant to reply because I have no direct data.

@mikefournier7286

5 жыл бұрын

MrBazsi888 Viesmann

@goonzsquad1

2 жыл бұрын

They are all garbage, they are for tight spaces, go cast iron baby