Question about home mirrored window tint

[Paul Jenkins]

I have a question about mirrored tint for heat reduction. 

 

My elderly parents live in a 5th wheel camper in Arizona.  Even being a fairly new camper, it is just too hot for the ac units to achieve or maintain a tolerable temperature inside. Right now, with both ac units running 24/7, the temperature remains above 100 degrees inside, and the next two months will bring even higher temperatures. 

 

I know there is no solution that will reduce the temperature to a comfortable 30 degrees cooler, short of moving into an insulated house that will stay cool.  But their home just sold in Illinois and they are still searching for a home in Arizona, so they are stuck living in this oven during this transition.  I am trying to do whatever I can to reduce the temperature inside, even if only a few degrees, hoping that multiple small improvements might overall provide them some relief. 

 

You can feel the heat coming in through the windows, so I thought I would try using mirrored window tint that is supposed to reflect and reduce the heat that comes through the windows.  However, after putting the tint on several windows, I went outside and noticed that the window glass is so dark already, that the reflective film isn't even visible through the glass.  Rather than a mirror look, it literally looks exactly the same as the windows that I haven't applied the tint to yet, like black windows.  From inside, it looks like darker tint during the day and reflective at night, as expected.  But outside, there is no visible difference between the windows with tint, or without, day or night. 

 

So my question is, if the window glass is so dark that the reflective tint isnt visible through the glass from the outside, will it still serve its purpose to reduce heat?  I feel dumb about how all this works.  Does the layer of tint work as a barrier, blocking heat from going through, or must it be visible, to reflect the sunlight off the "mirror"?  Would black glass along with mirror tint provide better heat reduction overall?  Or would the combination cause more heat to be absorbed and ultimately be counter-productive, cooking my parents even more than before? 

 

I know that this tint should not be put on the outside, but that would be the only way that the reflective "mirror" would even be visible on these windows, so I'm unsure if this tint will be of any help at all in reducing the temperature.  If the tint will be of no help since it is not visible from the outside, or if there are any suggestions that may be more effective in achieving a tolerable temperature, I would greatly appreciate any advice or information anyone is willing to provide, and I am grateful for your time and kindness to do so.  Thank you. 

[OBXTodd]

A duel reflective film will work. They also have exterior DR Film, but it will not hold up as well as an interior install. 

 

Heat will most likely still be an issue because campers/RVs are poorly insulated.

[Tintguy1980]

8 hours ago, Paul Jenkins said:

I would greatly appreciate any advice or information anyone is willing to provide, and I am grateful for your time and kindness to do so.  Thank you. 

One thing many overlook is that the sun's energy passes through glass one time. Having said this, what does get through to the film's surface (since the glass is doing something to thwart some of the sun's energy intrusion), will only be absorbed in the glass. Most especially if the unit is dual-pane. This creates a bit of a radiator effect, if there isn't sufficient air movement over the exterior surface.

Now, no matter how well insulated the cabin is you may only get a presumed 5 degree +/- drop in internal temp, if you were to install a total mirror film to the exterior surface (I'm basing this on a condo project I was involved with in the 90's). A travel home has to have the insulation capacity of ground based home to achieve the aforementioned 'presumed' 5 degrees +/-, especially in Arizona.

 

What would really help is to park the home in a daylong shaded area and even then, they'd be contending with air temps. Having outside canopies installed to shade the glass would be similar to parking under shade trees. Remember, heat always seeks out cold.

The reality is, they are certainly in a pickle.

 

[Paul Jenkins]

Thank you for the information. Unfortunately, they are in a mobile home park and there is no option to move the trailer.  As luck would have it, the side with the most windows is faced to the west, with a concrete slab and no shade on any side.  They do have awnings, but it just isn't enough. 

 

2 hours ago, Tintguy1980 said:

One thing many overlook is that the sun's energy passes through glass one time. Having said this, what does get through to the film's surface (since the glass is doing something to thwart some of the sun's energy intrusion), will only be absorbed in the glass. Most especially if the unit is dual-pane. This creates a bit of a radiator effect, if there isn't sufficient air movement over the exterior surface.

If I understand this correctly, would this mean that in order for the reflective film to help, it would have to block the heat before it comes through the glass, and because the reflective "mirror" isn't visible on the outside, it can't stop the heat before it passes through, and once it's through, there's no going back out?  Therefore, this type of tint will be ineffective when used on this type of window?

 

Since I'm not afraid to ask a dumb question... Would it be sensible to replace the windows with clear or regular windows, so this type of tint would be more effective? Or is that a moron move, like throwing away a dollar to pick up a penny? I have no idea if these black windows are better for the heat than clear windows with reflective tint would be, or if they absorb more heat.  I don't want to make the problem worse, but as you can tell I am clearly not knowledgeable in this subject. 

8 hours ago, OBXTodd said:

A duel reflective film will work. They also have exterior DR Film, but it will not hold up as well as an interior install. 

What is duel reflective film? Is it available for DIY or would I need to find someone to install it? Does it work as well to reduce heat when done interior as it would exterior? Or is the black glass always going to be an issue for interior tint? I don't mind if it doesn't hold up as long, being that this will hopefully be a short term situation.  My main priority is to make this camper survivable for a couple months of triple digit temperatures.  If it only lasts two months, but it provides any relief to the inside temperature, I would be greatly satisfied. Any product that only lasts a couple months but helps my parents survive those months is worth much more than the loss of longevity it has.  

[Dano]

Get a mini split ac unit rated for 1000sf and run it in the main room. Those campers let the wind pass through at every joint. Stuff some towels around or tape off the seals around the slide outs. Also every window has a small air channel at the bottom of each frame that you can stuff a piece of wet paper towel into to stop the hot air flowing in.

 

Those things are not at all suited for the extremes of hot or cold even if it says "four seasons" on the sticker.

 

After owning one for a few years I can tell you that they are about all made out of gorilla glue and cardboard then assembled by monkeys...yes, even the nice ones.

 

Best case would be to go north in latitude and higher in elevation for the next few months. 

[Paul Jenkins]

On 6/24/2024 at 6:01 PM, Dano said:

Get a mini split ac unit rated for 1000sf and run it in the main room. Those campers let the wind pass through at every joint. Stuff some towels around or tape off the seals around the slide outs. Also every window has a small air channel at the bottom of each frame that you can stuff a piece of wet paper towel into to stop the hot air flowing in.

 

Those things are not at all suited for the extremes of hot or cold even if it says "four seasons" on the sticker.

 

After owning one for a few years I can tell you that they are about all made out of gorilla glue and cardboard then assembled by monkeys...yes, even the nice ones.

 

Best case would be to go north in latitude and higher in elevation for the next few months. 

 

Thank you, that is all very good advice. When I was putting the tint on, I did notice that every window had about a half inch wide gap in the framing across the bottom of the window, underneath the hinges that open the window.  It's wide enough to drop a notebook through.  I assume this is to allow room for the hinges to open the window?  There are plenty of window designs out there that allow windows to open without leaving a gap that cannot be closed to the outside.  But those likely exceed the no quality level these luxury cardboard campers have.  

 

I think you may have over rated the quality of their materials.  I have a hard time believing they would splurge on Gorilla glue.  Not when Elmer's glue is available for less.  Lol.

 

I hadn't thought about a split unit.  I guess my thinking was that the two ac units are big enough to cool the space, if it weren't as thin as a paper bag and it would actually keep the cool air in and the heat out.  I have a small split unit that I can take over there and see if it helps.  Worst case, like when I was a kid and would leave the front door wide open and my parents would yell at me for cooling off the neighborhood, if it can't keep the cool air in, maybe the split unit will cool off the neighborhood and they can spend time on the patio to cool off... lol. 

 

I will definitely try the split unit and the other ideas you suggested to help seal the gaps etc. Between that and the DR Film OBXTodd suggested, it may be enough for them to get by until they find a house.  

 

I thought I had a good idea to help reduce the temperature inside, but the only knowledge I had was basic common sense...  "If I reflect the sunlight, it probably won't be as hot..."  Seemed simple enough.  I had no idea there was so much involved and so many things that would affect whether or not I could even reflect the sunlight, or if it would make any difference or not.  I expect all your suggestions will make a more noticeable difference than what I would have accomplished with the tint I was trying to use.  

 

Thank you all very much.  I respect your knowledge and appreciate your willingness to share it with me.  And I know my parents will be grateful as well. 

[Paul Jenkins]

Had I not received your helpful suggestions, I would have probably ended up wrapping the camper in that thick sticky foam duct tape.  Although I'm sure my dad would have helped me with that idea, I don't think my mom would have been very happy with that solution. Lol