Whether you&#;re considering a new commercial HVAC unit or simply upgrading your existing one, it&#;s crucial that you take into consideration its size and suitability for your building.
OUTES contains other products and information you need, so please check it out.
That&#;s because the size of a commercial HVAC system directly affects its performance, cost, and other maintenance factors. How to properly size a commercial HVAC unit involves intensive number crunching alongside knowledge of important HVAC principles.
How to Size Commercial HVAC
So, what&#;s the ideal method of how to determine the size of an HVAC unit in a commercial building or project? Let&#;s take a closer look.
First of all, you must consider factors such as:
The difference between outside temperature and your desired indoor temperature range
The building design and the amount of insulation in the ceiling, walls, and windows
Position relative to the sun (for example, is it in a shaded area?)
Average room size and total number of occupants
Specific type and amount of lighting in the room (LED vs fluorescent)
Activities in the room (cooking? hot baths?)
HVAC sizes are measured in tons - most commercial HVAC systems range between 2 tons and 30 tons. A 1-ton HVAC can remove around 12,000 BTU (British Thermal Units) of heat per hour. You will need to calculate the building's cooling load to know the appropriate capacity of the air conditioner to use.
As discussed earlier, your building's cooling load depends on several factors such as average external temperature to building design, orientation, and its primary purpose. However, a general rule of thumb is that it takes approximately 25 BTU to cool one square foot.
Here are some steps you can take for the purpose of a Rough estimate:
First, calculate the square footage of the building space you want to cool.
Divide the space area by 500.
Multiply the result by 12,000 to get the approximate space cooling load in BTUs.
Add about 380 BTU per occupant in the building, and 1,200 BTU for every kitchen.
Add BTU to account for solar radiation in windows per window.
Convert the number back to tons by dividing by 12,000 to get the size of the HVAC you need for your commercial building.
How to Determine the Size of the HVAC unit in a Commercial Building
Read this section to determine how to size commercial HVAC systems and save money. We&#;ve outlined a rough estimation of the cooling capacity that a commercial HVAC system would need based on data by EnergyStar.gov.
Cooling Area (square feet)
HVAC Capacity Needed (BTUs per hour)
350 sq.ft./ton
2,000
ft.2
68,568 BTUs
5.7 tons
4,000 ft.2
137,143 BTUs
11.4 tons
8,000 ft.2
274,286 BTUs
22.8 tons
16,000 ft.2
548,572 BTUs
48.6 tons
Want more information on Commercial Air Source Heat Pump? Feel free to contact us.
Air Conditioner Sizing is Critical for Performance, Energy Efficiency, and Low Installation Costs
Bigger isn&#;t always better - an oversized commercial HVAC can have adverse effects on heating and cooling. For example, your office space cooled by an oversized HVAC might have poor humidity control that would lead to occupant discomfort, the risk of asthma, and building mold.
The economic implications of oversized HVAC units are also significant because it contributes to energy wastage. This will lead to increased wear and tear, high installation costs, and frequent maintenance.
Similarly, undersized HVAC units are unable to cool the space efficiently. They&#;ll work harder to produce the requisite amount of cooled air, which means the compressor will be pushing its limits. Expect wear and tear, longer wait times for desired temperatures, and much higher energy costs.
How to Size Commercial HVAC System
Let&#;s make your job easier - when it comes to commercial systems, many HVAC professionals prefer to use 1 ton per 350-400 sq foot of floor area as a general rule of thumb. This estimation comes in handy when contractors need a quick reference point of HVAC equipment size.
The estimation is, however, presumptive of the significant HVAC sizing factors mentioned earlier (from building design, to activity and type of lighting installed).
Heat load and cooling load calculations
Another thing you must take into consideration are heat load and cooling load calculations. That requires precise estimates for heat gain vs heat loss in your building. The procedures published by the Air Conditioning Contractors of America (ACCA) are useful for this purpose.
Heating load calculations help to estimate the amount of heat loss from the building during the coldest climates. In some cases internal heat sources such as occupants, lighting, and building activity can help to compensate for heat loss.
Cooling load calculations are for estimating the heat gain in a building during the hottest part of the day. Internal factors add to the cooling load, similar to what we outlined in the previous sections.
Heat flow rate calculations
You can also get an accurate HVAC sizing estimation by calculating the space heat gain (the amount of air entering the building) and the space cooling load (the amount of air that needs to be removed).
The space heat gain is the rate at which heat enters the building or is generated within it at a given point in time. For accuracy, you will have to factor in solar radiation through the windows, conduction through the roofs and walls, and heat generated by occupants, equipment, lighting, and appliances.
The ASHRAE Task Group developed a standard procedure for these calculations, known as the transfer function method (TFM). This method simplifies the cooling load and heating load calculations, and factors in all the other determinants that increase or reduce heat gain and heat loss.
The formula is based on conduction transfer functions for the walls, roof, occupants, and glazing and room transfer functions for lights, appliances, and other radiant components. This formula involves complex calculations that require special computer applications, as shown here.
The bottom line: how to size commercial HVAC systems effectively
You can calculate HVAC sizing by following industry best practices for cooling and heating load calculations. For accurate predictions, one must factor in the building's design and orientation, lighting, and type of windows, among other aspects.
Get your HVAC systems compliant with San Fran Building Code and reduce energy costs by 30% using UFAD
In order to cool your building efficiently in the Delaware and New Jersey area&#;s hot and humid summers, your air conditioner must be the correct size. Calculating the optimal commercial A/C size takes some time, but it will pay off in terms of greater comfort and lower building operating costs.
The Basics of Air Conditioner Sizing
Air conditioner size is rated in tons and the sizes available increase in 1/2-ton increments. The average commercial A/C size ranges from 2 tons for small buildings to as much as 30 tons for very large buildings.
A 1-ton air conditioner can remove around 12,000 Btu, or British Thermal Units, of heat per hour. To know what size air conditioner your building requires, you&#;ll need to calculate the building&#;s cooling load in Btu. The cooling load is the amount of heat the cooling system must remove from a building to maintain a comfortable temperature.
Many factors affect a building&#;s cooling load, including the building&#;s design, its weatherization, and the amount of sunlight it receives.
Estimating Your Ideal A/C Size
If you&#;re planning to install a new air conditioner, you can calculate the approximate size you&#;ll need.
- Step 1. Calculate the square footage of the space (building or group of rooms) you want to cool. Note that the following calculation assumes 8-foot ceilings and a space with higher ceilings will require a larger system.
- Step 2. Divide the space&#;s square footage by 500. Step
- Step 3. Multiply the number from Step 2 and by 12,000. This is the number of Btu your system will need to remove to cool the space.
- Step 4. Add 380 Btu for each person who works in the space all day. If the number varies, take an average.
- Step 5. For each window in the space, add 1,000 Btu. For each kitchen, add 1,200 Btu.
The result of this calculation gives you a rough idea of the minimum Btu of cooling capacity your air conditioner must have.
If you have a 5,000-square-foot space, divide that number by 500 to get 10. 10 times 12,000 is 120,000 Btu. If four people work there, add 1,520 (380 Btu x 4). If the space has three windows, add 3,000 (1,000 Btu x 3). This space will need a commercial A/C size with 124,520 Btu of cooling.
Remember, however, that air conditioners are rated in tons. To determine the size of system you&#;ll need, divide the amount of Btu you need by 12,000. For example:
- 100,025 to 125,000 Btu is 8 to 10 tons
- 125,025 to 150,000 Btu is 10 to 12 tons
- 150,025 to 175,000 Btu is 12 to 13 tons
How Professional Sizing Helps
Your air conditioner must be precisely sized in order to reach its optimal energy efficiency and performance level. An undersized system won&#;t cool sufficiently and will work overtime in attempt to compensate, causing early wear. An oversized system will cycle on and off frequently, causing temperature swings and hot and cold spots, leaving behind excess humidity, and wasting energy.
By following industry-accepted procedures for cooling load calculation, a heating and cooling technician can accurately determine your optimal commercial A/C size. One such procedure is outlined in Manual N from the Air Conditioning Contractors of America (ACCA). This procedure factors in not just floor space and other basic data, but also window size and type, ventilation, the building&#;s physical orientation, and many other aspects of the building for precise sizing.
Our goal is to help educate our customers about Plumbing, HVAC, Fire Protection, and Alarm Systems in Mechanical, Commercial, and Residential settings. For more information on choosing the optimal commercial A/C size, contact us below!
Are you interested in learning more about Air Source Heat Pump Manufacturer? Contact us today to secure an expert consultation!
Comments
Please Join Us to post.
0