Greetings,

I live in a VERY old house in New England and the windows look like
they could easily be 40, 50 years old. Obviously replacing the
windows with better models would be sane but that isn't an option at
the moment.

I'm taking it for granted that the plastic film-type window insulating
kits are worth installing but I'm trying to figure out *how*
worthwhile they are in terms of cost savings. Obviously nobody can
give me a precise dollar amount without a detailed analysis of the
windows, the temps, the heating elements and floorplan ...but are we
talking a marginal savings, moderate or downright huge? 3% less oil
consumed? 5%? 10% or more?

Thanks much in advance,
Jason

(bodhiSoma) wrote in

:

Obviously nobody can give me a precise dollar amount without a
detailed analysis of the windows, the temps, the heating elements
and floorplan ...but are we talking a marginal savings, moderate or
downright huge? 3% less oil consumed? 5%? 10% or more?


3M claims that their films "[increase] the R-value of single pane
window by 90%."

Not much to go on, I know.

--
Bert Hyman | St. Paul, MN |

On Nov 29, 1:18 pm, Bert Hyman wrote:
3M claims that their films "[increase] the R-value of single pane
window by 90%."

Thanks Bert, that does help. It sounds to me like adding the film is
giving me roughly 90% of the cost savings of adding another pane of
glass. That should be substantial.

Jason

bodhiSoma wrote:
On Nov 29, 1:18 pm, Bert Hyman wrote:
3M claims that their films "[increase] the R-value of single pane
window by 90%."

Thanks Bert, that does help. It sounds to me like adding the film is
giving me roughly 90% of the cost savings of adding another pane of
glass. That should be substantial.

I found it helped air infiltration and drafts a lot, but what's the R value
of a single pane of glass? 1? I'm guessing an R value of 1.9 isn't too
much to get excited about, but overall we found it beneficial until the
windows could get replaced.

"bodhiSoma" wrote...
3M claims that their films "[increase] the R-value of single pane
window by 90%."

Thanks Bert, that does help. It sounds to me like adding the film is
giving me roughly 90% of the cost savings of adding another pane of
glass. That should be substantial.

Not necessarily!!!

IF the film is the type that sticks on the glass itself, that 90% savings is
ONLY from the radiative loss through the window glass plus a minor amount of
convective loss from the thickness of the film. If you have old aluminum-frame
windows, and/or they were poorly installed, your savings will not be very much
at all.

The major convective losses from the free flow of air around the single-pane
window will be essentially unchanged, as will be any losses from the
installation (frames, gaps, insulation/caulking...).

What the film WILL do is help keep the room cooler in summer if you get direct
sunlight through that window. The offset is that the room will be a bit darker
in the day time ALL year long. We have such film on our [double-pane] kitchen
windows, where the afternoon sun used to make it almost unbearably hot in
summer. The film helped substantially for that purpose.


OTOH, if the film is the type tacked/stapled around the entire outside frame, it
may help somewhat better. However, the offset is that you won't be able to see
well at all out the window. While you may save some in heating costs, it will
likely reduce the value of your house, rather than increase it as new windows
will.

(John Weiss) wrote in
:

"bodhiSoma" wrote...
3M claims that their films "[increase] the R-value of single pane
window by 90%."

Thanks Bert, that does help. It sounds to me like adding the film
is giving me roughly 90% of the cost savings of adding another
pane of glass. That should be substantial.

Not necessarily!!!

IF the film is the type that sticks on the glass itself, that 90%
savings is ONLY from the radiative loss through the window glass
plus a minor amount of convective loss from the thickness of the
film. ...

The 3M films here are the sort that are taped to either the inside or
outside window frame and maintain an air gap. While in place, the
windows can no longer be (effectively) opened.

--
Bert Hyman | St. Paul, MN |

(John Weiss) wrote in
:

OTOH, if the film is the type tacked/stapled around the entire
outside frame, it may help somewhat better. However, the offset is
that you won't be able to see well at all out the window.

Properly applied, they have little effect on the ability to see
through the window, although they do prevent you from getting any
ventilation by opening the window if it should warm up. The 3M
varieties use double-sided tape, not tacks or staples.

--
Bert Hyman | St. Paul, MN |

On 29 Nov 2007 20:08:23 GMT, Bert Hyman wrote:

(John Weiss) wrote in
:

OTOH, if the film is the type tacked/stapled around the entire
outside frame, it may help somewhat better. However, the offset is
that you won't be able to see well at all out the window.

Properly applied, they have little effect on the ability to see
through the window, although they do prevent you from getting any
ventilation by opening the window if it should warm up. The 3M
varieties use double-sided tape, not tacks or staples.

And they work very well if you're trying to stop drafts and retain as
much heat inside the house as possible. On warm days, they catch a
lot of the sun's radiant heat, and that continues to exude into the
room as the outdoor temperature goes down. We use these on our
even-older windows (1930! wow! old, old, old!), mainly in the attic,
and they're cheap and effective.

I installed double pane energy star windows in my house. Before they were
installed, I needed two window air conditioners to keep the house cool.
After they were installed, I only needed one window air conditioner to keep
the house cool! So cut my cooling cost in half!

(I have a woodstove for heating, so don't know about heating cost savings.)

I feel it is worth it to get a loan to install new energy saving windows. It
will be less expensive now than 5 years from now. And the energy rates will
probably continue to go up in the future. If you plan to live there forever,
best to get it done now.


"bodhiSoma" wrote in message
Greetings,

I live in a VERY old house in New England and the windows look like
they could easily be 40, 50 years old. Obviously replacing the
windows with better models would be sane but that isn't an option at
the moment.

I'm taking it for granted that the plastic film-type window insulating
kits are worth installing but I'm trying to figure out *how*
worthwhile they are in terms of cost savings. Obviously nobody can
give me a precise dollar amount without a detailed analysis of the
windows, the temps, the heating elements and floorplan ...but are we
talking a marginal savings, moderate or downright huge? 3% less oil
consumed? 5%? 10% or more?

Thanks much in advance,
Jason

On Nov 29, 11:57 am, bodhiSoma wrote:
Greetings,

I live in a VERY old house in New England and the windows look like
they could easily be 40, 50 years old. Obviously replacing the
windows with better models would be sane but that isn't an option at
the moment.

I'm taking it for granted that the plastic film-type window insulating
kits are worth installing but I'm trying to figure out *how*
worthwhile they are in terms of cost savings. Obviously nobody can
give me a precise dollar amount without a detailed analysis of the
windows, the temps, the heating elements and floorplan ...but are we
talking a marginal savings, moderate or downright huge? 3% less oil
consumed? 5%? 10% or more?

Thanks much in advance,
Jason

40 or 50 year old windows generally seal pretty well, as compared to
say, 100 year old windows.

I think the 3M kits run about $25 / window. If you have 20 or 30
windows on your house, this really adds up, and then there's the time
factor. The simple truth is that every situation is different, and
it's hard for us to tell you how much you will benefit from the kits.
If you were telling us that your VERY old house (1840's?) has original
windows with no storm windows, it would probably make lots of sense,
but my 1938 house has original windows with good storms, and I can't
imagine that I am losing $25 in heat out of each one during the
winter. If I was, I would be cutting my heating bill in half with the
kits. I'm also not a huge fan of putting that double sided tape on my
wood trim.

Instead, you might want to consider "Seal & Peel" caulk, to seal up
particularly drafty windows.

Just my $.02.

JK

In
Lainiw wrote:

I think the 3M kits run about $25 / window. If you have 20 or 30
windows on your house, this really adds up, and then there's the time
factor.

I've seen the outdoor variety (62"x126") for under $10 on sale at local
hardware stores.

But you're quite right about how that adds up if you have a lot of
windows, plus the time and effort to get the stuff up and then take it
down.

I'm also not a huge fan of putting that double sided tape on my
wood trim.

We use the outdoor variety to avoid that.

Even though we have double-glazed, argon-filled windows with "low e"
glass throughout, my wife insists that we also put up the plastic every
fall.

So, we do.

--
Bert Hyman St. Paul, MN

On Dec 2, 1:45 pm, Bert Hyman wrote:


Lainiw wrote:
I think the 3M kits run about $25 / window. If you have 20 or 30
windows on your house, this really adds up, and then there's the time
factor.

I've seen the outdoor variety (62"x126") for under $10 on sale at local
hardware stores.

But you're quite right about how that adds up if you have a lot of
windows, plus the time and effort to get the stuff up and then take it
down.

I'm also not a huge fan of putting that double sided tape on my
wood trim.

We use the outdoor variety to avoid that.

Even though we have double-glazed, argon-filled windows with "low e"
glass throughout, my wife insists that we also put up the plastic every
fall.

So, we do.

--
Bert Hyman St. Paul, MN

Sorry about the oops on the price. I saw them today at my local
Menards for $11 for a kit that would do up to 5 windows...

JK