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We changed our roof and cut CO2 emissions

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Re: We changed our roof and cut CO2 emissions

#71

Post by kleiba »

dghughes wrote: post #67

One thing people are not so much aware about other than insulation is air sealing. A tiny gap that may seem like nothing is in fact very bad. Take windows notoriously bad for heat and air leaks. A small seam along a window that isn't locked (it should be) could be the equivalent of having a 1cm hole in the wall. If insulated well and air sealed a home would lose very little energy. But also you'd need a good air hand…

That's right. The other day I drove by a house that's currently undergoing renovation, but the guy who owns the house does everything himself in a jack-of-all-trades kind of manner. He had put on a nice thick layer of insulation on the outside, but the sheets/blocks were apparently too short in some parts or simply fitted poorly, and in other areas I saw that he had just used some left-over cut-offs of various shapes and sizes in what looked almost like a mosaic. To make everything stick and fit, tons of sprayfoam has been used in an attempt to fill the inevitable large gaps (1 inch) between the blocks.

I kinda feel sorry for the guy, investing all the hard work and having good intentions, but due to poor workman ship he cannot expect to get the insulating effects he's surely hoping for.

Re: We changed our roof and cut CO2 emissions

#72

Post by lbriner »

dghughes wrote: post #67

One thing people are not so much aware about other than insulation is air sealing. A tiny gap that may seem like nothing is in fact very bad. Take windows notoriously bad for heat and air leaks. A small seam along a window that isn't locked (it should be) could be the equivalent of having a 1cm hole in the wall. If insulated well and air sealed a home would lose very little energy. But also you'd need a good air hand…

> But also you'd need a good air handling system to move and refresh the air.

And therein is the rub! Ventilation is critical in building design and many older houses cannot easily be retrofitted with a mechanical ventilation system, not to mention the costs.

Also, sealing air gaps is pretty much impossible in a house that wasn't built this way. I have been trying all kinds of things in my (30 year old) house to seal up gaps but there are spaces inside the floors to the outside through small mortar gaps, spaces behind electrical sockets, gaps in various parts of the floor and even around windows between the finishing.

I would personally like to see a more top-level view from governments. In the UK, for instance, they should be targetting the oldest housing stock and simply replacing it. I know this is hard because people own their freeholds but if we are serious and if someone would get a nice warm house in return for their old house then I think most people would be up for it.

Re: We changed our roof and cut CO2 emissions

#73

Post by lbriner »

toyg wrote: post #51
cbg0 wrote: post #43

Is triple glazing still not a thing in most places? It's become pretty much standard here in Romania in everything but the cheapest windows.

In UK double-glazing is basically everywhere, with triple typically replacing it as windows fail. However, there is still a significant amount of single-glazed properties in poorer areas or in listed historical buildings.

Yeah, Councils can be really bad at requiring people to either replace their old single-glazing with some exactly the same in double-glazed or keep the old inefficient windows. This is understandable for historical buildings but we experienced it with a box office building built in the 1970s, cost us another £11K to get cream coloured uPVC windows instead of white ones.

I think that might change as we go towards energy efficiency, we need to swing the needle back towards more efficiency = good.

Re: We changed our roof and cut CO2 emissions

#74

Post by lbriner »

DoingIsLearning wrote: post #64
IgorPartola wrote: post #53

Earlier quoted context omitted.

The biggest energy expenditure and as a result CO2 emission source per person is food. You like having peaches in February in Michigan? You like having meat 7 days a week? Guess what: all the industrial agriculture and transportation of that meat from a thousand miles away nets you an energy expenditure of about 10kW 24/7. In theory the biggest lifestyle change you can make to save CO2 is to go vegan and buy local fo…

> The biggest energy expenditure and as a result CO2 emission source per person is food? Do you have a source for this claim? All I have read until now points to a majority of individual emissions associated with vehicle emissions and Energy usage for Heating/Cooling houses/offices. I am all for a vegetarian lifestyle for animal welfare sake but I feel this focus on Agricultural emissions is misleading or at least mi…

I think people get confused because of double-counting.

If you move a load of produce in a truck, do the truck emmissions get counted as "transport" or "agriculture"? I guess depending on your angle, you could say either.

Re: We changed our roof and cut CO2 emissions

#76

Post by empiricus »

cbg0 wrote: post #70
empiricus wrote: post #69

Earlier quoted context omitted.

The interesting part of underfloor heating is that it is not the hot air that warms the room. It is the radiation from the floor. Smth like 10w/C/m2. And the heat profile in the room looks much better. For example https://www.researchgate.net/figure/An-example-of-vertical-t...

Well, the infrared heating warms the air which warms the room if you want to be pedantic. Unless you're losing heat through the floor I doubt that temperature difference between the floor and ceiling is accurate with a radiator system, perhaps if you measure it 30 minutes after you turn on the heat, but throughout the day the temperature should be mostly consistent throughout the room unless you're losing heat throug…

I think the air is almost transparent to infrared.

The underfloor heating uses a low temperature; the floor is ~24 C. There is little air movement because there is a very small temp gradient. With a radiator or a stove, its temperature is much higher, prob > 60 C. So you will have a column of hot air that rises to the top of the room and stays there. And at the floor level it is much colder.

Re: We changed our roof and cut CO2 emissions

#77

Post by danShumway »

KaiserPro wrote: post #28

One thing to point out is that yes, saving CO2 is grand, but this doesn't sell just how much more _comfortable_ decent insulation makes things. I live in a '30s UK semi detached. It had an air brick , a blocked up fire place and blown double glazing in each room. (barring two that were replaced) We had to re-render the place, as it was starting to fall off at the front, and the back was scarred from unfinished renova…

Specifically with insulation, have you had trouble with air exchange?

I keep hearing (to my naive/inexperienced/non-builder mind) contradictory advice about how insulated houses should be, and I've been trying to figure out how to square decreasing heating/cooling costs with keeping a house from feeling stuffy.

I guess for stuff like the triple glazing that's not really affecting air exchange in the first place, it's just preventing energy loss, since you're already not doing air exchange through your wall. And maybe getting better insulation in walls means you can crack open a window without it being as much of a problem?

Re: We changed our roof and cut CO2 emissions

#78

Post by balfirevic »

jb1991 wrote: post #7
sgt wrote: post #6

They may be saving energy, but 17.2°C average temperature indoors is freezing.

No it’s not. That’s a very normal temperature for our bedroom in the winter time. It probably depends where you’re from, in colder climates people are used to it.

I only found out that you don't have to be freezing your ass of for the entire winter (and a big part of fall and spring) when I went to a university and moved from my coastal home town to the colder continental city. It's cold enough there that they can't pretend that "it's not cold" with a straight face.

Re: We changed our roof and cut CO2 emissions

#79

Post by liveoneggs »

danShumway wrote: post #77
KaiserPro wrote: post #28

One thing to point out is that yes, saving CO2 is grand, but this doesn't sell just how much more _comfortable_ decent insulation makes things. I live in a '30s UK semi detached. It had an air brick , a blocked up fire place and blown double glazing in each room. (barring two that were replaced) We had to re-render the place, as it was starting to fall off at the front, and the back was scarred from unfinished renova…

Specifically with insulation, have you had trouble with air exchange? I keep hearing (to my naive/inexperienced/non-builder mind) contradictory advice about how insulated houses should be, and I've been trying to figure out how to square decreasing heating/cooling costs with keeping a house from feeling stuffy. I guess for stuff like the triple glazing that's not really affecting air exchange in the first place, it's…

As I understand it -- In a passive house you exchange air with an always-on air exchanger (HRV or ERV depending on your climate) which also has filters.

Re: We changed our roof and cut CO2 emissions

#80

Post by tenuousemphasis »

lbriner wrote: post #72
dghughes wrote: post #67

One thing people are not so much aware about other than insulation is air sealing. A tiny gap that may seem like nothing is in fact very bad. Take windows notoriously bad for heat and air leaks. A small seam along a window that isn't locked (it should be) could be the equivalent of having a 1cm hole in the wall. If insulated well and air sealed a home would lose very little energy. But also you'd need a good air hand…

> But also you'd need a good air handling system to move and refresh the air. And therein is the rub! Ventilation is critical in building design and many older houses cannot easily be retrofitted with a mechanical ventilation system, not to mention the costs. Also, sealing air gaps is pretty much impossible in a house that wasn't built this way. I have been trying all kinds of things in my (30 year old) house to seal…

Have you heard of AeroBarrier[0]? It's an aerosolized silicon sealant that is sprayed throughout a home while a pressure door system is used to negatively pressurize a house. The silicon is sucked through all the tiny gaps and fills them. It's pretty crazy.

[0] https://aeroseal.com/aerobarrier/how-aerobarrier-works/

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