Just as an exercise I'm trying to find a way to calculate required hot water boiler temperature with known EDR and heat loss values. I want to compare what I've observed over the winter with our new modcon boiler to what an established way of calculating boiler water temperatures says.
Emitters are 10 cast iron radiators with 164 total sections, 23 in tall. 164 x 3.50 sq ft = EDR 574
EDR 574 x 170 for hot water hydronic = 97,580 btu output.
Our house is a 1874 sq ft two story federal style built in 1850 with modern windows, doors, siding insulation. I tried to be as accurate as possible room by room with wall construction, insulation type etc. Design temperature for this area is 5 degrees. Heat loss per slant fin app is 70,400 btu
Thermostat is at 72, nice even heat throughout. ODR is set at max water temp 130 @ -5 outside. Min water temp 85 @ 60 outside temp.
The boiler runs almost non stop. I notice some cycling on mild sunny days or when we're using the kitchen oven for long periods. On the other hand, on very windy days the indoor temperature may sag a degree or two but catches up eventually. Today with light winds and 35 degrees outside the boiler is heating with 100 degree water. The highest observed boiler temperature was 125 at around -3 outside late in December.
You may think I need something better to do but I was curious if there was a way to project what the boiler temperature would be with known EDR and heat loss figures.
Emitters are 10 cast iron radiators with 164 total sections, 23 in tall. 164 x 3.50 sq ft = EDR 574
EDR 574 x 170 for hot water hydronic = 97,580 btu output.
Our house is a 1874 sq ft two story federal style built in 1850 with modern windows, doors, siding insulation. I tried to be as accurate as possible room by room with wall construction, insulation type etc. Design temperature for this area is 5 degrees. Heat loss per slant fin app is 70,400 btu
Thermostat is at 72, nice even heat throughout. ODR is set at max water temp 130 @ -5 outside. Min water temp 85 @ 60 outside temp.
The boiler runs almost non stop. I notice some cycling on mild sunny days or when we're using the kitchen oven for long periods. On the other hand, on very windy days the indoor temperature may sag a degree or two but catches up eventually. Today with light winds and 35 degrees outside the boiler is heating with 100 degree water. The highest observed boiler temperature was 125 at around -3 outside late in December.
You may think I need something better to do but I was curious if there was a way to project what the boiler temperature would be with known EDR and heat loss figures.
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