Safety support requirements for air conditioners:

Tthis article explains and illustrates the need for safe, secure supports beneath window, through wall, and wall-mounted air conditioners and heat pumps.

Not only can an unsupported air conditioner fall from the building, risking injuring or killing someone below, but there is also a risk of simply dropping the entire unit out the window or down the wall during installation or removal - an annual project for some window and through-wall units.

Proper Support for Wall-Mounted Exterior Air Conditioners & Heat Pumps

Watch out: inadequately-supported outdoor window air conditioners or inadequately-supported wall-mounted outdoor compressor/condenser units (referred to as the "inverter unit" in some literature) pose a potentially fatal hazard should one of these units fall from the building onto someone below.

Our through wall room air conditioner shown in our photo at left looks as if it is supported by the roof downspout - perhaps not the most reliable installation.

In 2012 the New York Times reported that that city has increased enforcement of proper exterior supports for air conditioners at public housing after air conditioning units fell out of two windows in a housing project on the upper East Side of New York City.[5]

While those air conditioner falls, one onto a playground near children, luckily didn't hurt anyone a falling A/C unit (window air conditioners) or compressor/condenser unit (split system air conditioners with an outside wall-mounted compressor unit) are very dangerous.

The Times article noted that indeed, in 1988 a pedestrian was killed when an air conditioner fell from the seventh floor of a building in New York.

The window air conditioner unit shown at below left actually fell out of this window during installation (I was there - Ed.). It bounced down the lower roof, rolled over a few times, and fell another eight feet to the ground. Luckily no one was below at the time.

Remarkably the unit survived and still worked after it was reinstalled in the window opening - you can see the smashed condensing coil fins on the rear of the unit - damage that occurred during the unit's fall to the ground below.

Just below we see work by an owner who felt his air conditioner would work more efficiently if it were shaded from the hot sun.

Construction focused on installing a roof over the A/C unit but forgot to support it from below.

A through-wall air conditioner is supported by the friction of the air conditioner case against the wood frame of the opening.

Above you can see how a through-wall air conditioner looks from inside the building.

If no safety bracket is installed on the exterior wall beneath this unit, and considering that most of the weight of the air conditioner is cantilevered outside the building (photos above), one can surmise that it is principally the friction between the 2x4 opening framed in the wall and the air conditioner's steel case that is holding this unit from falling out of the wall and to the ground below.

At below left the accordion-type expanding window-mounted air conditioner opening bracket upper edge, braced against the lower edge of the window sash, is the principal connection that keeps this unit from falling out of the window opening.

Simply raising the window sash can result in the whole assembly falling off of the building.

Short screws, often sheet metal screws secure the expanding bracket and window-filler on the sides of the air conditioner to the window sash bottom edge near the left and right ends of the upper sliding metal bracket.

And two additional screws secure the accordion expanding fillers to the trim on either side of the window frame. These little screws are not structural and do not provide much additional security against losing the whole air conditioner out the window.

The outside view of this type of window air conditioner makes clear that it has no other support.

Examples of Supported Window or Wall-Mounted Air Conditioner or Split System Compressors

Our photos below illustrates different types of exterior, wall-mounted split system air conditioner compressor/condenser units high on an apartment building in Buenos Aires.

Our second photo of outdoor wall-mounted A/C compressor/condenser units (below right) illustrates the use of supporting brackets. A similar bracket is required beneath most window air conditioner units.

Examples of Brackets & Other Supports for Window Air Conditioners & Through-Wall Air Conditioners

The through-wall air conditioner at below right is supported by an owner-built plywood shelf and diagonal wood bracket - better than nothing, but a design exposed to risk of eventual collapse from rot and water damage.

Steel brackets sold for supporting window or through-wall 9or wall-mounted equipment are in our OPINION a safer alternative. At below left, the Friedrich brand air conditioner is indeed supported by metal brackets (red arrows).

Below we illustrate an add-on wood-framed platform and brace below a window air conditioner at a resort in Olivera, New York. We notice that the air conditioer iteslf is quite tipped - perhaps someone noticed that it was about to fall out of the window opening.

The adequacy of the wood platform and angled bracket and block as an air conditioner support depends on details we cannot see here: what was the type, size, and placement of the structural fasteners that secure the wood support platform for this air conditioner to the building?

Use exterior-use rated structural screws of adequate length to connect the supporting bracket to the wood frame of the structure. Don't just tack the wood brackets to the building siding or the whole assembly may still fall.

Below we see a makeshift window air conditioner support, making do with what was at hand: a table and some bricks at this Amenia New York home.

...

---

---

ADVERTISEMENT

---

---

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

What are the best brackets to use for a wall-mounted A/C unit?

I'm asking about WALL BRACKETS not WINDOW UNITS

Best wall brackets On 2019-07-12 by Paul F Haugh

Reply by (mod) - wall brackets for air conditioner support

Paul

The best wall bracket selection, assuming we're talking about an angle support fastened to a wall and intended to carry the weight of something above - depends on several variables:

1. what is to be supported, what size, what weight

2. Is it indoors or outdoors

3. what is the wall material / construction to which the bracket must be connected

To get more specific help you'll need to be more specific about what problem we're solving.

Our photo shows a home-made through-wall A/C unit support using a bit of 2x6 wood nailed to a plywood platform.

Watch out: You're probably rightly-focused on air conditioner support bracket strength and ease of mounting, but you need to choose a bracket in part depending on the type of wall to which the mount must be connected. For example the wood support system shown above would be a lot more trouble to install on a masonry wall building.

Also, when affixing the window cooling unit support bracket remember to set the support to give 1/2" of slope downwards towards the exterior so that the unit's condensate will drain properly to the outdoors.

...

Continue reading at WINDOW / WALL AIR CONDITIONERS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• AIR CONDITIONER BTU CHART - choose a window or through-wall air conditioner of the right size or capacity
• AIR CONDITIONER COVER USE
• DIAGNOSTIC GUIDE A/C or HEAT PUMP 
• PORTABLE AIR CONDITIONER BTU CHART - portable room air conditioner BTU sizing advice.
• WINDOW / WALL AIR CONDITIONERS
• WINDOW / WALL A/C SUPPORTS

Suggested citation for this web page

WINDOW / WALL A/C SUPPORTS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to AIR CONDITIONING & HEAT PUMPS

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Citations & References

In addition to any citations in the article above, a full list is available on request.

---

ADVERTISEMENT

---