insulation solutions
energy products

What can I do if I can't afford double glazing?

If you can’t afford to install double glazing,

  1. quality curtains properly installed on pelmets or closed curtain rails
  2. effective use of curtains
  3. DIY window insulation 
  4. adding extra lining to your curtains

can help to reduce heat loss through windows.

How to make sure your curtains are effective

The way in which curtains are hung, the materials used and how they are used will influence whether they are effective or not. The diagram below shows a poorly performing curtain system:

There is no effective seal between the lower part of the curtain and the window ledge. Air cooled by the cold window surface will drop, creating an air current that will draw warmer room air in at the top.

The curtains are hung with a simple rail/hanger and nothing prevents warm air from entering the top so a circulating air current is created. The window is fully exposed to room temperature warmth (and hence loses more heat), and the room is cooled.

Thin curtaining material allows air movement from the warm to the cool side (and vice versa).

 

Diagram of poorly installed curtains

 

 

 

The diagram below shows an effective system. The essential requirement is to create an almost still air zone between the curtain and the window. 

Hanging curtains best practice

 

1.     The curtaining material is thick and lined. It is not essential to use thermal backing, and it is possible to reline curtains with another layer of material like calico. Extra linings trap air between the different layers of material, which in turn helps to reduce heat loss.[1]

 

2.     There is an effective sealing of the curtain against the window frames – at the top by a pelmet or closely fitting track and curtain up-rise, and at the bottom through close contact with the window ledge or (preferably) the curtains are full length and seal against the floor, or drops at least 10cm below the window sill.

 

3.     Pelmets provide a seal at the top of the curtain to prevent the convection process.  Pelmets can be made of any material as long as it creates a barrier. They need to be fixed to the wall and reach to, or past, the top of the curtain. Temporary pelmets can be made from wood, cardboard, plastics, bubble wrap or even a thick scarf. 

 

4.     If you don’t like the look of pelmets, try to source ‘enclosed’ curtain rails, which have a pelmet-like strip built into the whole unit above the rails, without the same visual impact as pelmets.

 

How to hang curtains

Hanging curtains properly will keep in the heat better:


1. Place hooks in the bottom row of the curtain tape every 3-4 pockets apart. Use new hooks and track gliders as they become brittle and break with age.
2. Pull all 3 strings of the tape to gather each curtain to half of the track width. Make sure that the curtains meet in the middle then tie the strings all together at the correct width. Do not cut the strings off. Spread out gathers until they are even.
3. Start hanging your curtains on the track by placing the first hook into the cap at each end of the track. Count the number of hooks in each curtain to match the amount of gliders on the track.

Effective use of curtains 

Curtains are only effective when they are pulled!  Within reason, keep curtains closed as long as possible in cold weather (and as long as the sun is not being prevented from shining through).  In the evening pull curtains late afternoon to retain as much daytime heat as possible. Pull curtains across tightly together, to eliminate air gaps as much as possible.

DIY window insulation

DIY window insulation acts like double glazing but is much more affordable than permanent glazing. It may be a good solution if permanent double glazing is not an option. DIY window insulatio consists of a thin, clear plastic film taped to the inside of your window frame but not on the glass itself. It prevents condensation and reduces heat loss. The film is easy to install and all you need to install it is a pair of scissors and a hair dryer so it looks tidy.

How to add detachable linings to your curtains

If you can't afford double glazing in your house, it might help to add an extra lining to your existing curtains, especially if they are thin.

  1. Plain, (usually cream or white) thermal backed fabric for curtain linings is available from most curtain or fabric shops, e.g. Spotlight.
  2. Tell them you are wanting to make detachable linings, and bring this instruction sheet with you - fabric shop advisors should be able to assist easily!
  3. If you can't afford thermal lining, consider calico lining. Linings work because they trap air between the different layers of fabric - calico is very good at achieving this effect. The Curtain Bank in Christchurch regularly line donated curtains with calico at a fraction of the cost of using thermal lining.
  4. Make the linings as long as the front curtains, plus about 8cm for a hem. Each lining should be about three quarters the width of the curtain track (this is assuming you have two curtains). However, the width doesn't have to be exact and often you just make the width the same as one drop, or one and a half drops, or two drops of lining fabric, whatever comes closest to the desired width.
  5. If you need more than one drop of fabric for each side, stitch drops together at the sides. Neaten the outside edges if required and do the hem.
  6. The total width along the tops of the curtains is how much tape you will need, plus a few centimeters extra.
  7. Sew the tape along the top of the lining curtains, turned over and neatened at the ends. Then gather in the tapes slightly, so the width of the lining curtains suits the front curtains.
  8. Take the hooks out of the front curtains.
  9. Lay the front curtains out on the floor wrong side up. Place the linings over the front curtains right side up.
    Replace the hooks, by catching up a slit in the lining tape and a loop in the main curtain tape on the same hook.
    Once all the hooks are in place, lift up the curtain and lining together (it may be quite heavy) and hook back up onto the track.

                                   


[1] Call the Energy Advice Service for more information on how to reline existing curtains.

 

Community Energy Action is supported by: