The K is for 1000. In other words, 60 kBTU/hr = 60,000 BTU/hr.
That must be a huge house! 200kBtu/hr for the heating system, for instance - a decent say 2500 sq ft house in this climate (Des Moines IA) might take an 80 kBTU/hr or maybe an 100 kBTU/hr furnace.
I don't know much of anything about Title 24 but my guess is that those sizes are 'design' sizes. Actual industry sizes, from my experience are more 'standard' and at least on the smaller units (ie: up to 100kBtu/hr) they go up in increments of 20,000 Btu/hr.
Rental Property Investor · Los Angeles, CA · Member since 2017 · 154 posts · 24 votes
6y
Thank you @Jim Goebel - makes perfect sense! (and it is puzzling since it is only 600 sq ft 1 bed/1bath dwelling). I saw those numbers under a section called "Equipment Notes" in the drawing plans. There's another section called "heating/cooling loads summary" that says the cooling system total output is 22,800 Btuh, which is probably more in line based on what you're saying.
Hey Bruce I'm speculating here, but I would guess those values are the design firms' ways of covering themselves for the CAPACITY of the supply system. In a nutshell, even though the actual loads (ie: Btu/hr) of the water heater, cooling, and heating system, are not anywhere close to that - my guess is that Title 24 dictates what the supply capacity (ie: the NG lines typically for the water heater and furnace) must be. In other words, the pipe sizes need to be large enough to support for instance a future 'on demand' (ie tank-less) water heater as an example. These on demand units use a lot more Btu/hr right then and there, vs using less but 'storing' the heat. So, you need higher capacity but tend to get better energy performance from those on demand units.
I'm also speculating, on the intent of the law/Title 24 but I'd bet those values are talking about the incoming supply lines into the house - for instance it seems reasonable to supply up to 200kBtu/hr for the overall NG capacity, perhaps more - given that it's a nominal additional cost when the ground is opened up for those lines - and it allows more flexibility for future work (ie: adding on to the house, or advances in technology like that tank-less water heater I mentioned).