4 ms·
I think what the other poster meant is that “cooling in a warm client is less energy intensive than heating in a cool climate” which is generally true. This is
by D13Fd 4y ago
I think what the other poster meant is that “cooling in a warm client is less energy intensive than heating in a cool climate” which is generally true.
This is partially because the temperature deltas are smaller. If you are aiming for 70 inside and you have 95 outside, you are fighting a 25-degree delta. But if you want 70 inside and have 25 outside, that’s a 45-degree delta the system has to overcome.
- Scoundreller 4y agoDelta is one thing, but you're also fighting solar gain when trying to cool. Sure you can mitigate, but when heating, the sun is working in your favour. Winds are another variable.
- D13Fd 4y agoThat’s true, although solar heating in warm climates can be mitigated in some ways (roof color, attic structure/ventilation) and solar heating in cold climates is tough with a layer of snow on the roof. Bottom line is that there are many variables but a big delta tends to be energy intensive to overcome.
- Scoundreller 4y ago> cold climates is tough with a layer of snow on the roof Snow is actually helpful by insulating. The sun is closer to the horizon over winter, so it's your vertical windows doing the heating anyway. An obvious issue is how much sunlight you get over winter. Not just in hours, but in N. Europe, you might have continuous cloudcover and not see the sun for weeks at a time.
- D13Fd 4y agoSnow is not helpful for solar heating, as I said, and if your roof has a big r-value to begin with the snow is not adding a ton of insulation.
- Scoundreller 4y agooh yeah, and snow reflects light off the ground. It's much brighter outside after coverage by snowfall.
- legitster 4y agoIf you are in a weird climate that gives you cold temperatures but consistent sunlight maybe? But you are also dealing with angle of declination. Solar gain will be diminishing the further north you go even if you get sunlight.
- Scoundreller 4y agoHigh elevation can do that, but cloudcover is a lot heavier than much of Europe over winter than in much of North America.
- jdgoesmarching 4y agoYep, and it’s why building codes are usually more rigorous in northern states. The approach to homebuilding in the south is to assemble our flimsy, leaky boxes as quickly as possible and slap an oversized AC on it.
- eesmith 4y agoPassive houses are much easier to build in cold climates than warm. Your analysis left out that the occupants and their machines generate heat. "Together with the comprehensive energy conservation measures taken, this means that a conventional central heating system is not necessary, although they are sometimes installed due to client skepticism." - https://en.wikipedia.org/wiki/Passive_house#Space_heating https://en.wikipedia.org/wiki/Passive_house#Space_heating . See also https://en.wikipedia.org/wiki/Zero_heating_building https://en.wikipedia.org/wiki/Zero_heating_building .
- D13Fd 4y agoNeither of your links say that passive houses are easier in cold climates.
- eesmith 4y agoUnder the section "Tropical climate needs" at https://en.wikipedia.org/wiki/Passive_house#Tropical_climate_needs https://en.wikipedia.org/wiki/Passive_house#Tropical_climate... > Passive cooling, solar air conditioning, and other solutions in passive solar building design need to be studied to adapt the Passive house concept for use in more regions of the world. > There is a certified Passive House in the hot and humid climate of Lafayette, Louisiana, USA, which uses energy recovery ventilation and an efficient one ton air-conditioner to provide cooling and dehumidification. Earlier, "In August 2010, there were approximately 25,000 such certified structures of all types in Europe. The vast majority of passive structures have been built in German-speaking countries and Scandinavia."
- D13Fd 4y agoI saw that, nothing there says that cold climates are easier.
- eesmith 4y agoI see "easier" as meaning different things. 1) it's easier in the Scandinavian and German-speaking countries because passive house building materials are easier and cheaper to acquire ("other countries may spend 8% more on constructing Passive Houses than conventional buildings because the Passive House components may not be readily available" - "Examing the Prospective of Implementing Passive House Standards in Providing Sustainable Schools", https://aip.scitation.org/doi/pdf/10.1063/1.5031991?casa_token=1mS5tC87w2cAAAAA:pSa-3L_Xkw6hD4OzhtbdKR9PBd6RFgC7WNNDLM39R7Wn9TYj1hWQKzxTPMayQ0_0Ui4sx12DJi5QbQ https://aip.scitation.org/doi/pdf/10.1063/1.5031991?casa_tok...) 2) it's easier in cooler areas because there's more experience in how to build for those climates (as Wikipedia points out). 3) it's easier in cooler areas because the energy saved is higher, and so easier to justify economically. "Passive Houses for different climate zones" at https://www.sciencedirect.com/science/article/pii/S0378778815301481?casa_token=J2iuQFwFvasAAAAA:xqevsxcea3IhIm77-y261NysqChNZDnLg51ETKOdBfk3ip6U0sS7gc7IkRPMfDulHl0xh0vYHQ https://www.sciencedirect.com/science/article/pii/S037877881... shows "Energy demands of the Reference Passive Houses in the different locations" in Table 3, with: Yekaterinburg Tokyo Shanghai Las Vegas Singapore Abu Dhabi Total saving 96% 90% 87% 86% 79% 77% Those are all good savings in power use, but clearly better in colder climates. (Sorry, I can't find TCO.) 4) From my understanding, it's easier to well-insulate and let body heat and appliances provide the heat, using the cool exterior to regulate temperature, than it is to deal with cooling and humidity issues in warmer climates to bring the internal temperature to the "inner comfort range" specified by the Passivhaus Institute, Fig. 8 of the link in 3).
- phpisthebest 4y agoAs the other commenter posted you have solar effects, and as I stated you have other things that are putting off excess heat. For me even when it is 25 outside occupied my home will settle at about 40-50 or so with no heat, due to just cooking, lighting, compters, TV etc that are all outputing heat... so the delta I am attempting to heat is not really 25 to 70, but more like 50 to 70 due to the waste heat and solar heating effect For cooling I am not not only battling the outside delta, but also all of that waste heat and solar heating effects