This thread is the first of a series of monthly open threads. If anyone wants to pose a question about household energy efficiency in the comments below then please feel free.
This thread is the first of a series of monthly open threads. If anyone wants to pose a question about household energy efficiency in the comments below then please feel free.
Comments
7 responses to “January Open Thread”
Great to meet you yesterday.
I have a question about insulating the solid brick walls of our 1920s semi. I’ve done a fair amount of research on the EST site, green building forum, and the Green Building Bible vol1.
I was making good progress in my research until I read pages 204-208 in the Green Building Bible – a section titled “Caring for Older Buildings.
It said, “There are significant dangers in adopting standard solutions…. In most cases this means avoiding vapour barriers and checks and looking at traditional materials and modern materials in similar character and performance, which will minimise the creation of problems.”
Can you advise?
Hi Tim, good to meet you too.
With old buildings you need to get it right but it is very possible. Old dwelling construction made use of materials that are permeable so you need to be careful not to seal moisture in the fabric.
Generally speaking, external wall insulation is better than internal as you retain the thermal mass of the brickwork (with internal wall insulation, the brickwork is on the cold side of the insulation so you don’t get the thermal mass benefits).
Done badly, internal wall insulation can damage the fabric of the home. Done well, it won’t.
As you live in a semi, you could look at external insulation on the side and back first and then think about what should be done with the front (possibly nothing for the moment, possibly internal wall insulation).
But I’m not an expert on this side of things. Fran, who I’m running this project with, is. You should come down to one of our meetings to talk to her. Send an email to the email address in the contact page up there ^ and we’ll try and arrange something.
Have you seen the EST publication Practical refurbishment of solid-walled houses (CE184)? It’s not on the main part of the website but sits in the publications library on the building professionals section of the website.
Hi Jamie,
I have a question about the reletive efficiency of having a hot water tank vrs a combi boiler that heats water as you go. Are there any sources that give the reletive efficiencies of these given all the other elements stay the same?
And depending on the answer above is it really going to be worthwhile replacing a tank with solar thermal if the combi is performing better?
Or does it not matter really given that most of the gas will be used for heating the home rather than the hot water in any case?
I was asked on sunday about room thermostats by a guy whos family turn up the thermostat to either 25C or 30C depending on the person who is feeling cold whilst he is out of the house. So he is looking for a thermostat with a maximum for people who are in this bad habit (some people think that turning the thermostat up will make it warm up faster).
During the discussion I also remembered a Honey well walk around programmable thermostat which somebody told me could be programmed with different temperatures at different times of the day, any idea what it is.
Are you going to do a thread on these things for all of us out there who know there must be a better way but get dwarfed by the volume of sales pitches on the internet or get short shrift from technical suppliers?
25 or 30!? Blimey. As you rightly point out, the higher temperature won’t make the home warm up any quicker but it will lift the temperature to way above what should be necessary.
One guy was so annoyed with some members of his family cranking up the heat that he was asking about thermostat locks! Turns out they do exist.
“Programmable room thermostats” can be set for different temperatures at different times (particularly good for the different heating needs between the weekdays and weekends. They’re also usually portable so you can take them into the room you use most.
Not sure about whether there’s one you can put limits on but I’ll have a dig.
I will be doing more on heating control settings soon – best do it before the end of the heating season!
Not 100% sure I get what you’re saying in your boiler question…
I briefly covered the efficiency differences in Boilers Part 1.
The Energy Saving Trust recently undertook in situ condensing boiler monitoring trials. Essentially it showed that actual real world boiler efficiency is about 5% below SEDBUK efficiencies. The report contains data on a load of boiler installations including combis and regular boilers. The “summer efficiency” gives a guide to how efficiently they heat water.
You need a tank if you’re going to have solar water heating to store the hot water produced so it wouldn’t replace it. I would say if you have a regular boiler and cylinder and a roof suitable for solar then keep the cylinder.
If you have a regular boiler and cylinder and a reasonable hot water demand then keep it.
If, like me, you have a regular boiler in a 1 bed flat then I would probably think about replacing the regular boiler with a combi because I don’t get close to using a whole cylinder of water (although it’s a very well insulated cylinder). Plus I couldn’t fit SWH.
I think I’m missing something in your question though… Care to elaborate?
Great answers, Jamie. Very informative.