Right Sizing a New Boiler... the easy way

great video. that steam radiator is beautiful.

Thanks and good day !

Great information for pro n navis

I need more of sizing boilers. Thanks

Slant fin makes that heat loss software , it works well. Doing a work up on an older house ( "r" and other values ) can be quite tedious.

I saw the Slant Fin display and thought for sure you were going to talk about the Slant Fin app for calculating heat loss. It's easier than a manual J heat loss calculation. There seems to be a 20% fudge factor built in so be aware of that and don't add any to it "just to be safe". I did a fuel usage calculation on my own house also and found it to be 80% of the Slant Fin app number. You need an honest heat loss figure AND the emitter radiation to determine if a modcon is going to run in the condensing range.

How can I hire YOU as my plumber? YOU are literally the only person I see. Doing this. Every other plumber coming in just “eyes” out the estimates and then somehow derives what boiler is appropriate... when I ask them to do this estimate they look at me like I’m growing a second head.

Thanks for such an informative, straight to the point video. Side question...I have a 1940 brick house with a boiler installed in 1997. We are looking to finish the basement. I've had a 2 local HVAC guys tell me No, but I want more opinions...we want to remove the steel supply and return lines in the basement and replace with PEX AL PEX to clear up some head room. Steel riser pipes would continue up through walls to feed cast iron radiators. I've been told that we shouldn't do it because it would cause short cycling issues. I understand a loss of mass will result in faster water temp drop, but clearly there must be a way to mitigate the loss of mass in the system to prevent short cycling the boiler isn't there?

I would love some input. We are building a house & business space with workshops and garages under one roof. Our total radiant heat area is about 12,000 square feet. It's a diy project so requiring a lot of researching. We are trying to figure out what boiler to get to handle the radiant heat, which will be in concrete on all floors. We will want to zone them (12 manifolds with their own zones) since many spaces won't require much heat on a regular basis. We don't have natural gas so we would need to do propane. We are doing ICF so luckily, we will already have a very efficient building to begin with. And to be able to run the domestic water in the house (less than 5 occupants full time so it isn't a huge domestic water load required). I would love to hear your input on which systems would be the right ones and if you have any videos on how to set up those systems.

Great videos! Ho do you calculate the BTU output of a Sunrad. Thank you.

Bill on the raiant would raising the temp from 90. Say to 110 change the btus of the concrete floor??

Thanks your video its very helpful. My mother has a boiler that runs on propane. She has to fill the propane tank every 2 months for $800. Only the boiler uses the propane tank. The boiler is about 20 years old and according to the calculation it is double oversized. Would replacing the boiler to the correct BTU's lower the propane cost a lot? I thought about high efficiency wall hung boilers, but read they aren't good because the water plugs them up. Would you recommend those? She's on a well.

Thank you. I'm doing some research on replacing a 30 year old unit in a home I have an offer on. Is there a boiler type you would recommend if I purposefully decided to over size? Obviously the system should be designed to avoid cycling. In the future, if I decide to put an addition on with baseboard heat and radiant flooring in the basement/shop space, can adding an extra 500-700 sf of living space be easily accommodated? Just wondering how I should go about planning for future additional demand.

Is the 550 - 600 BTU output of the typical residential fin you referenced per foot of fin?

So I'm building a house with radiant heat concrete floors and the SF X 40 = 93K. I would like to use a combi boiler to heat the domestic water as well. Is this 93K calculation including the domestic water as well? Or do you have an equation to add to this number? Forgive my ignorance, I'm still learning

my house came with Delco boiler 1 size fits every house it was like 3/4 of a refrigerator up to 250 thousand btu even after new burner and smaller tip it was a ridiculous monster i replaced it with smallest boiler i could get 3 sections around 80,000 and it was still plenty big enough my rule of thumb is you want boiler to just be able to keep up on coldest possible day of the year running constantly

Back in the day , Plumbers used the "finger method. They would stand across the street and hold their fingers up - how many fingers covered the house would be how many sections. True story. So many guys still put WAY too much baseboard in houses…I love sun-rads (semi-recessed ) myself, they are variable and don't take up wall space. No mention of them in this vid , but they work well also.

how do you do the calculations for a retrofit radiant underneath a wood floor?

My gas meter for the coldest month recorded 1430 cubic meters in 30 days, (I'm in Canada and it gets to -40 degrees). And since gas gives 35300 BTU/cubic meter, my usage was 140209 BTU/hr. That is the most accurate way. It shows that in the coldest month my boiler must put out 140209/hr so that I won't freeze. (Please correct me if my logic is wrong since I'm shopping for a new boiler to replace my ancient 60-year-old model).

I have a Beacon Morris kick panel heater that supposedly puts out up to 12500 BTU’s on high would I add the 12500 BTU on top of my Fin tube calculation. Any advice as always is much appreciated. Thanks for the great vids.