Usage cost

What is the cost of a door to use?

We will help you!

We can help you with your needs analysis and usage cost calculation. To find out the real cost of your door, you need to consider more than just the purchase cost – also look at what your door costs to use and what energy loss it has. That’s what we call the usage cost. Please contact us for help with your needs analysis.

Our production cost calculation is developed by the Royal Academy of Engineering Sciences and the Transport Commission’s calculations in their report No. 80.

What is the usage cost of an industrial door?

A door in a building charges you with costs that depend not only on the purchase price. Your industrial door price also includes energy and costs due to operation, maintenance, road transport for service, repair and spare parts and when not in use. If you choose the wrong type of door or a low-quality door, it could be an expensive history in the long run. Both for your finances and the environment.

To be able to choose the right door for the correct location, one must take into account many of these “door system dependent” costs as possible. We do this by calculating the so-called usage cost.

To the right is a real case of how a utility cost is clarified when selecting different ports. The blue bar is a Torverk Q-Door (with a U-value of 1.27) and the analysis shows how much savings will be per year compared to competing products with poorer U-value!

Calculation industrial door Price-usage Cost

Direct and indirect costs

The utility cost includes all the costs that are directly or indirectly affected by the selection of door. In other words, it affects the total price of your industrial door. These costs are:

Direct costs

  • Capital cost
  • Passage cost
  • Heat loss Cost

Indirect costs

  • Operating cost
  • Maintenance cost
  • Service cost
  • Repair cost
  • Spare part cost
  • Downtime Cost

Wrong choice of door and door quality, indirect costs are likely to increase sharply without direct reduction. Maintenance, servicing, repair costs are strongly related to the quality and dimensioning of the door.

With almost 60 years in the industry, we know what it takes for high quality and long durability
– for both your and the environment’s sake.

Direct costs

Direct costs consist of:

  • Capital costs
  • Heat loss costs
  • Passage cost

1. Heat loss costs

Heat loss consists of three parts (at closed and open door respectively):

  • Losses by transmission (U-value or K-value: W/m2 * K) – at closed door
  • Losses by air leakage (T-value: m3/m2 * h) – at closed door
  • Air exchange losses (m3/m2 * h) – open door

Losses through transmission (closed door)
Arises by heat energy wandering through the material from the hot and out to the cold side. The U-value is the measure of the port’s heat-through resistance, or simpler; Insulation capacity of the door. Often, only the “best incisions”, that is, the U-value of the best place through the door panel (surface layer-insulation-surface layer). However, for a correct usage cost calculation, the U-value of the entire door is needed including connections to the frame and floor, rubber seals, all edges and reinforcements, and also the values of windows and pass door if in the door.

Losses by air leakage (closed door)
The air leak through the door depends on quality of sealing system and the pressure differential between in and out side (ventilation and wind pressure). More or, preferably, less air always leaks through a closed door. Particularly sensitive is the corners where the door panels meet and at the four corners of the door.
The density value of the door (T-value) is tested in a laboratory environment, which is why it is important to also create an idea of how the sealing system will work in practice and in the long run. Best is to examine a few different types of doors that have passed the warranty period and check how the tightness in corners has managed to withstand usage. Choosing a durable sealing system is important because it can be expensive and time-consuming to replace. Pinching seals are preferable to sliding/trailing.

Air Exchange (open door)
losses
The magnitude of heat loss for a open door is normally of much greater significance than heat loss for a closed door and is largely affected by whether the door has automatic or not.

Summary heat loss costs

  • The difference between a good or poorly chosen door from an energy point of view, can easily be about many thousand crowns per year. Per Door!
  • If you then add heat loss when the door is open, you realize its not very wisely to bargain on the investment in an automatic control system for a few crowns lower price. When you can usually cover this cost already in the first year if you have several gates in the property.
    It is really about what is written in the introduction to the door manual:
    “Although the purchase price depends on the capital cost per year is only part of the annual cost of a door, it is usually chosen from the purchase price.

All other factors and costs that should affect the choice of door are often forgotten or one do not have sufficient information and knowledge about their impact on the purchasing decision. “

2. Passage cost

Passage cost = number of passageways X passage time X time cost

In order to be able to calculate the total passage cost,you need to know the passage time and the total passage frequency for one year.

The passage time covers all the elements that make up the extra time that it takes to pass the gate.
Passage time = Total time to pass the door, minus the normal transport time for the corresponding distance without door.

Door system risk value for passage time (SEK/passage) * Manual door 60
Stationary Impulse for manual impulse (note 1) 40
Likewise with automatic closure 20
Stationary impulse for automatic open-close-impulse 10
Mobile impulse devices (note 2) 5
Extraordinary impulse actuators >0
* Alternatively, the benchmark can be obtained by taking time on an existing door system similar to the desired one.

Note 1: Stationary impulse actuators are synonymous with fixed-mounted impulse devices, such as push-button, pull cord, radar, photocell, induction loop and similar.

Note 2: Mobile impulse devices (i.e., movable) are those that enable impulse from the vehicle, such as radio signal, infrared light or ultrasound.

Note 3: Extraordinary impulse devices mean combinations of impulse gear, special positioning and special automatic open and close function that allow the passage time to be almost completely eliminated. The right combined impulse and open-close automation can also eliminate the need for fast-track door, which is sometimes preferable because the quick door could increase the risk of injury and the risk of collisions and often has poorer energy properties at closed door. A harmonised movement time in combination with a well-balanced door automatics can provide the same or shorter passage time as for a fast-moving door and also provide better energy properties.

The passage frequency points to the need for interference in transport systems. The time cost for vehicles, wages and payroll expenses is the parameter when the passage cost is calculated.
Passage frequency = number of passages in and out per hour converted into per year.

Indirect costs

Indirect costs (upper part of the bar) consist of:

  1. Operating cost
  2. Maintenance costs & other costs

1. Operating cost
(the cost of the energy spent on operate a motorized port)

The cost of the doors drive unit kilowatts consumption over a year, equals the operating cost. The cost varies so slightly between different door types and is so small that it can be neglected in normal case. In general, the operating cost calculation usually sets to about 100 SEK as an annual operational cost. (However, exceptions may need to be made for extremely heavy and at the same time high-frequency doors and gaps, such as overhead cranes. For these, the energy consumption can be significantly higher and may need to be calculated).

2. Maintenance costs & other costs

These costs are allocated to:

  • Maintenance costs
  • Service costs
  • Repair costs
  • Spare part costs

Maintenance costs
Maintenance costs are the supervision and everyday maintenance that the door owner or door responsible can perform. Supervision and functional control a few times a year is a requirement. For electrically operated doors, it is legal requirement for regular supervision.
Supervised and everyday maintenance refers to regular inspection and control of functions (according to instructions for use), simpler procedures such as cleaning, adjusting a time for, for example, automatic closing, replacing fuses, easier lubrication, etc., and note and report on what needs to be addressed and which parts need to be replaced at the next service.

Service costs
Service refers to preventive and remedial measures that must be carried out by a professional. The cost of a knowledgeable door assembler is usually about 800 – 1200 SEK per hour incl. subsistence allowance and accommodation costs; see also travel expenses etc. below. One option is to educate your own staff.
For electrically operated doors, it is the legal requirement (compare lifts) that the service-performing staff must possess the necessary competence. It is also legal requirements for periodic maintenance and that service should be performed according to the instructions provided in the instruction manual.

Repair costs
The need for repair is caused by:

Collision Damage:

  • Damage due to rough treatment
  • Wear and tear due to use

Fatigue in materials due to:

  • Use
  • Constant load (when not in use)
  • Corrosion due to material choices and environmental factors
  • Panel cracking due to excessive wind load

Port panels are (due to collision) the most expensive to repair or replace. Then comes the replacement of worn sealing systems and for spring-balanced doors, the regular changes of springs. Corrosion is primarily a problem for frame-built steel doors. Completely galvanized doors or doors in sandwich design can cope significantly better. From a utility cost point of view, perhaps completely stainless steel doors and fittings would be the best, but the additional investment for this is so big that the “scare” many.

To say something in general about the repair costs is difficult because they are so dependent on the local environment, how often the door is crossed and not least how the staff handles the gates. However, it is generally said that high-frequency doors that go upwards more often suffer from collision damage. See more on this page on the rules of thumb (step 2).

Spare part costs
These costs are entirely dependent on door type and supplier. Some suppliers keep “normal” prices while many make sure to charge substantially when the customer is dependent on such a supplier. The best way to avoid expensive spare parts is to buy a door type that requires minimum service and spare parts, and request a long warranty period for the product and a fixed-price service agreement including spare parts, work and any travel.

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