• 0 Posts
  • 15 Comments
Joined 1 year ago
cake
Cake day: August 2nd, 2023

help-circle





  • gas furnance that was somehow under-dimensioned – the idea is that in the real cold days you’d still have the good ole fireplace

    Oddly enough I’ve never encountered that in Germany, I only ever see catastrophically oversized furnaces that start cycling in March… Seems to me plumbers never really worry too much about correct dimensioning, they just put the same 20 kW furnace that they know and love to install in every apartment and single family home. For some it will be somewhat adequate, for some it’ll be oversized, who cares, customers never complain when the furnace cycles, but when it’s too cold, you’ve got a problem. Same as they’re never too worried about finding suitable supply water temps. Just set it to 80 and you’re good, it’s the customer who pays horrendous gas bills, not you lmao. That’s also why everyone thinks their Altbau has to have 80°+ supply water when they have never really tried anything lower to see if it maybe suffices. My parents had their oil-furnace on 80C supply for the past 40 years and last winter when everybody was trying to save as much energy as possible they figured out you can set it to 55 as well.


  • but assuming they’re saying that it’s saying that $0.63 worth of natural gas gives you the equivalent thermal output of 1kWh

    Correct (although $0.063), and interesting to see you seem unfamiliar with this, this is the standard way of listing energy prices in Europe, it’s not just that site. That site was just my first hit when I looked up Canadian energy prices. It’s the low heat value and it’s determined by the energy in a fuel if not allowed to condense (which is the relevant value for a traditional furnace, if you have a more modern condensing furnace you take the high heat value) and it makes it relatively easy to compare different sources of energy.

    Canada is huge, and some of that landmass is in the Arctic circle.

    What people never realise is that being far up in arctic climates doesn’t only impair an SCOP. Yeah the lowest temps are very cold, but that means temporarily bad COPs. An SCOP is made up of the whole heating period though, which in colder climates is longer, so in turn you have several months more of the time where heat pumps are extremely viable with temporary COPs above 5 or 6 saving loads of energy. The real problem is if your lowest temps are so low that a heat pump will stop working entirely, in which case you get a hybrid system or just leave your old furnace in as backup, which is even better for your SCOP because you omit the month(s) with the worst COP and only use the heat pump when it’s most viable. Let’s say you live in Tuktoyaktuk and heating period is basically all year, then you have your furnace on for 3-4 months but you’re saving massive amounts of energy with your heat pump in the other 8-9 months of the year.

    touching on the nuances of the word “efficiency”

    I actually tend to avoid using that term for heat pumps anyway, as it’s not really correct in terms of physics. What makes heat pumps so viable is a coefficient of performance, their actual electrical efficiency isn’t all that good at 50-60%, but it’s also kinda irrelevant. It’s sometimes easier to just call it efficiency, but like you say, once you go into the nitty gritty it falls apart.


  • if your energy cost for that source of power is high, it’s going to lose the financial argument every time.

    How high, is the question. How much more is electricity where you live that heat pumps “lose the financial argument every time”? Where I’m from a kWh of electricity is roughly 2.8-3x that of natural gas, so most modern heat pumps will beat that, some by quite a margin.

    If globalpetrolprices.com is to be trusted and Canadian natural gas is 0.063 CAD and electricity is 0.165 CAD you’re very much in the same boat with a 2.6 ratio. Most heat pumps should be able to beat a 2.6 SCOP even in Canada.

    So, sure, the study only looks at COPs and not at overall cost, but I think it’s not unreasonable to expect home owners to be able to divide electricity price by gas price and compare it to the SCOP of heat pumps on offer.







  • While y’all here:

    is there a terminal emulator that has “modern” text entry controls while still having tab completion? Like selecting text by going shift+leftarrow or deleting whole words by holding ctrl+backspace/del or replacing whole words that are selected while pasting text rather than it pasting at the point where the curser is at the start of selected text so you still have to manually delete the original characters. Maybe Undo, redo with ctrl (shift) z…

    Stuff like that. Just wondering. I always find it very cumbersome to fiddle with long commands especially if they contain long paths that you want to modify. Lots of backspace and arrow-keys hitting for every single character…