Cleaning Low E Glass Without Damaging It

cleaning low e windows

cleaning low e windows

As window cleaners, we are required to continually work with glass suppliers to ensure we are up to date with the latest glass technology. One type of glass which is becoming increasingly common in Sydney homes is Low E Glass.

It’s made the same as standard glass but has a thin metallic oxide film fused to one side of the (usually facing inside) and this can be an inexperienced window cleaners worst nightmare.

The glass was originally used in commercial office buildings due to it’s ability to increase energy efficiency (reduces heat loss) and is starting to become a popular choice for residential setting (especially new homes built in Sydney’s North Shore) due to it’s ability to reduce the amount of UV rays, heat and glare coming into the home when compared to standard glass.

The outside of Low E Glass can be cleaned like standard glass (eg. Squeegee) but the insides requires special care due to the metallic oxide coating –

DO NOT use the following things on the metallic oxide coating –

  • Abrasive Cleaners
  • Ammonia based products
  • Powder based cleaners
  • Alcohol based products
  • Harsh Alkali  or acid based cleaners (unless under special circumstances outlined below)
  • Scrapers, Blades or Squeegees
  • Metal based objects like scourers

Routine Cleaning

Follow this process for to remove dust and fingerprints.

Cleaning Solutions

  • Plain water
  • Water with a little dish detergent (soapy water)
  • 10:1 Water to Vinegar Solution

Directions

  1. Use a spray bottle filled with water and spray generous amount onto the glass from top to bottom removing dust and dirt particles
  2. Fill another spray bottle with soapy water (dish detergent and water) and spray down the glass with it
  3. The 10:1 water to vinegar solution can be used instead of the soapy water if you have stubborn stains
  4. Rinse with a generous amount of plain water
  5. Remove excess water with a lint free cloth – The trick to having streak free Low E Glass is to leave a thin film of moisture on the glass after cleaning leaving it to evaporate (ensure it’s just a thin film, no drips!)

Spot Cleaning for Stubborn Stains

The following products can be used safely on stains which can’t be removed after routine cleaning –

  • Denatured Alcohol
  • Mineral Turpentine
  • Acetone
  1. Wet a corner of a lint free cloth with one of the above solvents
  2. Use the cloth and gently rub the stain out – Be cautious of any  painted surfaces which could react negatively to the solvents

Removing Scratch / Stains from Metalcleaning scratched low e glass

Never allow the low E coating to come into contact with metallic objects (blades, watches, rings, scourers etc) as it can leave behind deposits which show up on the glass as stains or scratches.

The following solution can be used to remove staining caused by contact with metal objects –

  • 99:1 Water and hydrochoric acid (for safety, ensure you add acid to water and not the other way round)
  1. Wet lint free cloth with some of the acid solution
  2. Gently try to rub the stain out

 

Simpo cleaning works with builders and glass suppliers on a regular basis, in fact they hire us to clean all their windows during the post builders clean.

12 thoughts on “How to Clean Low E Glass Windows

  1. Hi – have just installed $25k worth of windows and doors all with eVantage low e glass by Viridian and we absolutely hate it!
    Any tips on how or if it can be dissolved/taken off ? It looks grimy and and is so reflective we can’t we the views outside properly. Terrible product.

    • You won’t be able to remove it because the Low-E coating is fused / laminated onto the glass during the manufacturing process. Unfortunately, you’ll have to either live with it or get them replaced entirely. The grime can be taken off using some acetone and a lint free cloth.

  2. Hi, same issue as Jane we have the E glass windows installed.
    We had them cleaned post build which has left all types of marks and scratches on them. I’m now looking for a business who understands the cleaning process and can get them looking new!
    I’m located in Melbourne and was wondering if Simpo Cleaning was also in Melbourne or know of a business that could assist. Thank you

    • At the moment we only serve the Sydney Area.

      You should speak with the cleaning company which caused the damage as it’s their responsibility to fix an issue which they caused and a homeowner who paid for a service shouldn’t have to waste their own time worrying about it.

      Light marks can be removed using a cotton terry cloth (no lint) with 1 part hydrochloric acid to 99 parts water solution, be careful as you don’t want to get any of the solution on the frame and seals. Also remember to add acid to water and not the other way round (it releases a lot of heat)

      More than likely the windows are already damaged beyond repair if the cleaners used any sort of blade or squeegee on them (the coating is very sensitive and can be damaged by the slightest contact with metal objects). The cleaning company should pay for a replacement if this is the case.
      Traditional windows can be repaired using an abrasive paste and polisher, unfortunately, you can’t do this with Low E.

  3. I use spiff towels on my glass. Can this be used low e glass. No chemicals, just water and the lint free towel.not familiar with Spiff, it’s on the internet but I can’t find any info on using spiff on e glass

  4. We have low e glass and it doesn’t come up clean! We can see the round suction marks from the manufacturing process and there are now streaks where kids have run their fingers in the condensation. Any tips? Is it just something we have to live with?

    • Hi Camelia,
      I think what you mean is that there are stains caused by the suction cups which were used during the window installation process (not manufacturing). This is something we encounter from time to time during after construction cleaning and we’ve had success removing it with a little acetone on a soft lint free cloth.

      You can try 99:1 Water and hydrochoric acid if acetone doesn’t remove it.
      Not sure how long you’ve had the windows installed, but you should bring it up with the builder if the marks don’t come off after cleaning as they are usually considered a defect (this is because low e glass manufacturers don’t recommend the use of suction cups during installation unless no other option is available since it’s possible that the suction cups can cause irreversible damage to the coating of the glass, especially if they haven’t been cleaned with denatured alcohol beforehand).

      In regards to the streaks, you can just clean these off with acetone or denatured alcohol. Use 10 parts water to 1 part vinegar to clean and maintain it on a weekly basis. NEVER use regular commercial window cleaning products like blue windex or ammonia to clean low E glass as these can damage the coating.

      By the way, I can see that you are from St Malo Bakery by your email, Just want to say that I tried some of your bread and pastry from a small stand in Bondi Junction and they tasted marvelous!! 🙂

  5. HI Simpo

    We are a cleaning company based in South-Africa and the Low E windows are introduced here. We have received a contract to do a builders however some idiot applied BOX tape to the inside of the window directly on the Low E glass and decided to pull it off leaving the adhesive side on the Low E for us to clean . Any advice for removing the adhesive (glue)

    Regards

    • Hi Wynand,

      We come across this almost on a daily basis as we get a lot of work from builders. Acetone is the best remedy for it. Just apply a bit on a lint free cloth and it should start to come off. Also works for removing silicone residue.
      This will mean the job will also take a lot longer (depending on how much adhesive is left on the glass) so you need to charge accordingly.

  6. Thank you, thank you. I was ready to pay to have my very large mirrors cleaned. But, instead, I tried your method even the water and vinegar solution. I will never buy the blue stuff again. My husband even noticed how shiny and streak free my mirrors were.

  7. I am getting black marks which won’t come off (kind of looks like charcoal stains) on my low e glass.
    Any idea what could be causing this and if it can be removed?

    • Black stains on low e glass can be caused by contact with any sort of metal (eg. the use of metal scourers, kids resting metal objects on glass etc). We’ve had success removing these marks by using a 100:1 water to hydrochloric acid solution and a lint free cloth.

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