How to Do Electrical Estimating for Roof AC Units (2020)


Estimating Roof AC Units is fast and easy when using Red Rhino Electrical Estimating Software.


Red Rhino Electrical Estimating Software has all the components needed to estimate electrical AC units mounted on the roof. (Or mounted anywhere).

In this blog, we show you how to do electrical estimating for roof AC Units.


Below is a drawing of an AC unit on the roof.

It shows a 3 pole 60 AMP 600-volt weatherproof fused disconnect switch mounted on the AC unit.

It shows conduit and wire size 1 ¼” Conduit 3 #4 & 1#8 wires feeding the disconnect.

For some reason, the designer oversized the conduit and wire feeding the disconnect switch (It does not take #4 wire to feed 60 AMP).

It is standard practice to estimate as per what the blueprint shows. So we will not change the conduit or wire size.


The drawing also shows 1 GFI receptacle and 1 duct smoke detector fed with #10 wire.

Blueprints do not show every detail. The image doesn’t show that the conduit must penetrate the roof.


Because it takes time (labor) to penetrate the roof, include roof penetration in the estimate.

Also, roof jacks or pitch pockets are needed. If you are required to provide them they would be included in your estimate. If you are not providing them, make sure to exclude them on your proposal.


Since blueprints are one dimensional, it does not show the height of the roof, But it is important to know the height because the conduit has to drop down from the roof to the panel below. 

The distance from the roof to the top of the panel is around 27 feet and we have to add that to the total conduit length.


Below is an example of a material take off:


Material Take off forms can be printed when logged in to Red Rhino.

The process goes like this; Count and measure materials from the blueprints, write it on the take off sheet, and input materials into Red Rhino. When you input materials from the take off sheet, check it off so you do not input materials twice.


Below is an image of Red Rhino’s conduit wizard. 


Using the conduit wizard you can estimate thousands of feet of conduit and wire fast and easy. 

The conduit wizard is set up to estimate 1 ¼” Conduit 3 #4 & 1#8 wires.

With the click of a button, it will input both material cost and labor, for conduit, connectors, couplings, supports, total footage of wire needed.


Red Rhino has thousands of items of materials loaded with labor built-in, and thousands of items with material pricing, commodity items like Conduit and wire roof jacks (pitch pockets) disconnect switches, circuit breaker termination labor, and motor connection assemblies that speed up the process of estimating.


Watch the video below to learn more:



Red Rhino is online so you can log on from any computer with an internet connection. 

The Cost of Red Rhino is $99.00/ Month with an affordable setup fee.

Red Rhino Electrical Estimating Software | 14 Day Free Trial






You will immediately get access to our online software. Training videos will guide you step by step to learn how to navigate.


Call us if you have questions.

888- 492-5565 x 1

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