BTU Sizing for baseboard heating
I understand a manual J will be the best to get the right answer but I need to put a budget in with my GC on the runtal baseboard radiators and was hoping the guideline would work for 40 BTU/sqft of space in Brooklyn, New York weather as said on the runtal radiator website. This is a new construction building, cast in place concrete foundation, with supermaxxx joists and steel decking with poured concrete floors. Insualtion will be mostly rigid but have been discussing with my GC and spray might be a better option for us. Large 8 foot windows.
I attached a doc to show sizing of the apts window sizes etc.
Space 1: 560 sqft Basement concrete walls below grade. 5 windows and a door. 8 feet ceiling height. Was looking at only putting in 10K BTU worth of baseboard underneath the windows which is significant less if we use the their guidlines which would warrant me to use around 20K BTU.
Space 2: 220 sqft not counting kitchen hallways or bathroom. concrete block party walls, 120 sqft of double pane glass windows and doors. North West Facing. I have allocated roughly 10K BTU baseboard underneath the window which goes about in line with runtal’s suggestion.
Space 3: 130 sqft not counting bathroom (which I plan to add floor radiant heating since there is a window in the bathroom), and closet. South East facing and I have allocated 5.5 K BTU baseboard heat which is about in line with runtal’s suggestion.
Space 4: 520 sqft all together for each apt. All the regular 1 bedrooms will have the same features except 1 side facing North west and the other south east. Sizing recommendations would be around 20K BTU of baseboard heating but with the baseboards underneath the entire windows, I only have around 6K in the bedroom and 6K in the living room for a total of 12K which is significantly less.
Space 5: 650 sqft total of floor area. Same features as the Space 4 1 bedrooms but these apts have an added mezzanine making the height of the apt approximately 18 feet tall in the living. Not sure if height makes a significant difference but for this apt given we have the mezzanine I was able to add another 5.5K of BTU of baseboard giving the total of 17.5K BTU for this apt which may not be enough for such a high ceiling apt and apt size.
Please let me know what you guys think as runtal baseboards are the most expensive I have worked with but I have heard good things, they are reliable but cost wise I need to be close to what I allocate to it.
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