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24

In reality, yes, it probably does matter. In each case, it will depend on a lot of detail, so I'll discuss the theoretical concepts, rather than any one particular application. How heat is lost Heat moves about through a combination of three ways. One, two or all three might be significant in any particular case. convection - the movement of hot air to a ...


14

My understanding is that it is an easy, cheap and pretty way to let light in. It avoids the trouble of putting in a larger square window with a frame and trim and everything. It also can be done with reused materials, which is popular among those who like to build mud houses.


9

One related difference between keeping heat in or out relates to the climate - it's temperature and humidity. In very warm and humid areas such as Florida, you place the vapor barrier on the exterior side of the insulation, In cooler climates that are not so humid, you place the vapor barrier on the interior side of the insulation. A vapor barrier can be ...


8

tl;dr: Yes, lowering the room thermostat at night will generally help save energy, assuming we are in the heating season (winter), rather than the cooling season (summer). Let's take two points in time, one before the night, one after it. Let's choose them so that the dwelling has the same amount of heat energy contained within it at each point, so all the ...


7

Here's the basis of the calculation you need for losses through conduction: heat loss rate = surface area x U-value of separater material x temperature difference. There will also be losses from convection. So, to compare the conduction losses through your external walls, to losses through your internal walls, do the calculation for each. I expect that ...


7

Short answer: it's unlikely to be cost-effective, if you consider only the energy savings. Longer answer: Yes, it's possible. Let's look at the issues one by one. Condensation If you only open the secondary glazing when the inside air is cool and dry that will reduce the chances of condensation. Put some dessicant in the gap, and dry it out occasionally, ...


6

Insulation can contribute to the sustainability of a home both by being sustainably-sourced and by reducing heating and cooling requirements. The longer the insulation lasts, the greater its contribution to your home's sustainability. It is also important to select insulation that can be installed easily, without tearing out walls and producing unnecessary ...


5

There isn't a single point. Circumstances vary widely, and depend on the detail of individual design. There are, however, well-established mechanisms to evaluate any single building. The best-established of these is the Passivhaus Planning Package, or PHPP, which will do the full set of calculations for a given dwelling design. As for using North-facing ...


5

I suggest you use a U-value kit from greenTEG. It is easy to use, very accurate and you get the U-value of any position of your wall or glass within a few days of measurement. I tested it on my new house and it resulted in the same value as predicted by the energy engineer.


5

There is no difference in the insulative materials, but there a different in their placement relative to the heat source. A radiation barrier is always placed closest to the source of radiation. So in a hot climate one would place the radiation barrier exterior to the other insulating materials. Conductive barriers are also most effective when placed ...


5

If you have a basement you can install a ground loop. It may not be available in your area, but "remote dive" boring equipment comes small enough now that it can be brought in through your front door. Obviously groundwater and underground utilities are concerns, but it's still possible. I don't think I'll ever understand people's carbon fixation, but if ...


5

Strictly speaking, your heat pump's CoP is not affected by the outside temperature, but by the difference between inside and outside temperatures. Given that there is a fairly narrow range of interior temperatures that we might want, that is nearly equivalent, but it does mean that there is only a limited extent to which this "pre-heating" approach can work -...


5

First, draught-proofing Close the gaps around windows, doors, between floorboards, gaps where pipes go into walls and floors. It's a cheap and relatively easy way to stop a lot of heat escaping, and to cut down on the convection currents that will take a lot of heat from the bottom to the top of the house. Curtains around the stairwell? Can you put a ...


5

The scientific approach would be to turn on all the heating and use heat cameras to see where most heat is escaping. Otherwise just guess it is the roof. I would start with the roof/top floor, then do the ground floor. Then the middle floors last. If you do find that heating living areas makes the top floors unbearably hot, consider moving your living area ...


4

I'm not an expert in this area, but: I think this depends a little on the layout of the house. Certainly insulating the top first will improve the overall efficiency much sooner than starting at the bottom, but as you identify it does mean increasing the temperature difference between floors, which might not be desirable. If you have an open staircase ...


4

First order approximation: R-1 (british units BTU/hr/sqft/DegF) per sheet of glass. So double pane is R2, triple pane R3. Second order approximation depends on the frame material, and to some degree on coatings, and gas fills, and years since the gas fill; also depends on your heating system, exterior wind exposure. It gets complicated enough that I have ...


4

Given that you have natural gas heat I have a hard time imagining that there is a lot you can do there. There are likely some additional constraints given the historical value of the house. I think in many cases it is more important to preserve historical character than to try to fully decarbonize but that's at least partly a personal preference. Here are ...


4

The glib answer is to use less energy. The best way of doing that is fixing the fabric of the house - massively increasing insulation, massively decreasing air permeability (and as a result fitting a ventilation system). There is no technical-wizardry answer. The simplest solution is best (but unfortunately outrageously expensive).


3

The U-value and R-value of glazing systems are not a single measure. Instead they are a composite number from R & U measures at several different places on the glazing system (center of glass, edge of glass, sash, frame, etc.) In Europe windows sold across member nation borders have to publish a U-value according to a predetermined formula. ...


3

A long-term consideration is increased condensation from cooler air in the far corners of rooms, which encourages fungal colonies. These are bad for health and eventually expensive to treat. Keeping a constant temperature diminishes the problem.


2

is it really worth it.. can mean something else as well: During the wintertime: Lowering the temperature has (sometimes) a nice side effect - you will lose weight. The amount of heat given from the body to the room will increase (lowering the temperature from 21 to 19 °C) by 15 % (in comparison for a normal adult person in a resting phase). This energy is ...


2

You should find the best time to lower/raise the thermostat. The more thermal inertia your house has (the better it is thermally isolated), the earlier you should lower the thermostat. The faster the heating gets the room warm, the later you can raise the thermostat. Both are best done automatically.


2

I would answer this as a comment, but comments don't accept multiple paragraphs. On the face of it this is a bad idea. Better to pull air OUT of the house, and let it sneak in where it can. Scenario 1. The building vapour barrier is perfect. Air put into the house can only escape through faulty weatherstripping at doors and windows. Net result. Too ...


2

I think EnergyNumbers' answer is pretty comprehensive! Basically, do 'low hanging fruit first' - i.e. the things that have a quick result such as draught proofing (sealing around gaps/cracks/skirtings/windows etc); install heavy curtains and if you can loft insulation, which you should be able to do yourself fairly easily and cheaply. Then you can start with ...


2

EnergyNumbers pretty much covered it all. I can only add two things. If you have vinyl windows already, adding a very thin sheet of rigid plastic (lexan, polyethylene, etc.) larger than the original glazing cut to fit the interior of the sashes using an adhesive (epoxy works best, but it's permanent) can reduce conductive and convective loss. It's easy to ...


2

For a thermos flask, insulation will both keep in cold and keep out warm & keep out cold and keep in warm. A house is different, because it has windows. Sunlight is warmth that can pass through windows. So, to keep your house warm, you should have windows that let in enough sunlight and make sure that you keep the warmth by proper insulating your house. ...


2

My challenge was slightly different. I was purchasing new NorthStar windows to replace all of the old windows in my house but wanted to make sure I was getting what I paid for, as the windows would look fine, but was their R-value or U-factor and SHGC performing as advertised. I used an IR scanner around the edges after install to look for possible ...


1

Without regard to individual site qualities; those living north of the equator but south of the Tropic of Cancer receive a positive net benefit from northern glazing. The benefit is so small to be meaningless. For those living in the tropics window orientation is decided exclusively by site characteristics. Of course those living south of the Tropic of ...


1

It's probably easiest to find a datasheet for the nearest comparable system to yours. The things to look for will be: the material of the frame (probably either aluminium or uPVC) if it's aluminium, whether the frames have a thermal break in them the spacing between the panes of glass the approximate age of the double glazing whether there are trickle vents ...


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