Warehouse Heating... When Energy Matters

Cambridge Warehouse Heater You have probably considered energy efficiency as it applies to warehouse lighting and refrigeration systems, but what about the cost to operate your warehouse heating and ventilating equipment? The cost of energy to heat a warehouse has steadily increased more than 10-fold since the 70’s and has spiked more than 500% during recent years. Industry experts agree the era of very low energy prices is behind us and we will continue to see energy costs set “historic records” for years to come.

The good news is that you can save 40% to 70% per year on your combined gas, electric, operating and maintenance costs by using today’s most efficient warehouse heating technology. So if you are putting up a new warehouse, applying for LEED green building certification, rehabbing or expanding an existing warehouse, converting an old manufacturing facility to a warehouse or just replacing a worn out heating/ventilating system, it’s important to install the right type of warehouse heating equipment.

“When Energy Matters”, an efficient Blow-Thru®, direct gas fired space heating system is the best choice for a large warehouse or distribution center.

Learn More > Energy Modeling - Warehouse Heating Systems

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S Series Space Heaters What factors determine the BEST warehouse heating system? Is the heating bill for your warehouse facility too high? What about cold dock door areas and unbalanced temperatures? Is negative building air pressure a problem? Have you experienced employee complaints and lost productivity from heating or indoor air quality problems? How about high maintenance costs for existing heating equipment? These are just a few common problems that result from selecting the wrong heating system, misapplying space heaters or using obsolete heating/ventilating equipment in your warehouse or distribution center.

The bottom line is that both heating and ventilating requirements must be determined before selecting the most energy efficient way to heat a warehouse. Factors to consider include:

1. How will the dock door areas be heated and how fast are temperatures recovered?
2. Is spot heating or zone heating required?
3. How important are balanced temperatures throughout the building, from wall-to-wall and floor-to-ceiling?
4. What are the indoor air quality (IAQ) requirements? How much fresh outside air is required by local codes to dilute contaminants generated by LP forklift trucks, out gassing from stored materials, etc.
5. Is make-up air (MUA) needed to compensate for exhausted air?
6. What are acceptable noise levels?
7. Where will the heating system be located? Will it consume valuable floor, ceiling or vertical racking space?
8. Are you selecting heating/ventilating equipment that is compliant with ASHRAE 90.1 for a LEED green building project?

Gas-Fired Warehouse Heating Systems

Gas fired heating systems offer the most cost effective way to heat large warehouses and distribution centers. Electric and oil fired heaters are sometimes used for small or very specific space heating applications or when gas is not available for the building.

There are seven types of gas-fired warehouse heating systems that use either “indirect” or “direct” gas fired technologies. It’s important to know the difference.

Indirect-fired heating equipment, like boilers, unit heaters, air turnover systems and even tube-style infrared heaters require some method of heat transfer, such as a heat exchanger or radiant tubes, which lowers overall energy efficiency. Multiple flues are also required to vent products of combustion (and heat) outside the warehouse. Indirect-fired warehouse heaters recirculate inside air with little or no provision for ventilation which can affect indoor air quality.

Boiler Systems (Steam and Hot Water) - Centralized heating system used for space heating when energy costs were low, or when steam was a by-product of boilers used for a near-by process heating application. They are usually not well suited for larger warehouse facilities due to their initial high cost, poor efficiency, uneven heat distribution and high maintenance costs. Older facilities are now replacing oil-fired boilers with other, more energy efficient gas-fired heating technologies and using the energy savings to pay for the new equipment.

LEARN MORE > Cambridge Comparison Building Study for Boilers

Unit Heaters – Common method for heating small, open spaces. Multiple heaters are suspended from the ceiling around the perimeter of the warehouse. Initial installation cost is low for small buildings that require only a few heaters, but can get very high for large facilities that need many units. A significant amount of heat and energy go up the flue. Typical overall efficiencies vary from 60% to 75%. Due to limited air throw, their efficiency significantly decreases with mounting height. Other potential problems include stratification, inefficient heating of infiltration air, poor indoor air quality, cold dock areas and interference with fork-lifts, lighting and racking.

LEARN MORE > HOTLINE article: Cambridge Space Heaters versus Unit Heaters

LEARN MORE > Cambridge Comparison Building Study for Unit Heaters

Air Turnover (Air Rotation) Heating Systems – Tall, constantly running floor-mounted units that typically rotate building air 1-2 times per hour. Like unit heaters, this is an older method for heating warehouses with heat exchangers and indirect gas-fired technology. Provides only 70% to 80% thermal efficiency. Initial equipment costs can be high and operating costs are high, especially if used for cooling in the summer. For warehouse applications they have a very slow response to dock door activity. They also take-up valuable floor and vertical warehouse racking space. Electrical operating costs are a significant factor since the large, often noisy, blowers run continuously. Despite recent inaccurate claims, air turnover heating systems do not solve indoor humidity and condensation problems found in buildings with excessive moisture. When improperly applied, either indirect or direct gas-fired heaters can be part of this problem, or when properly applied, either heating system can be part of the solution. Building studies show both Cambridge direct gas-fired Blow-Thru Space Heaters (that use induced rotating air) and air turnover heating systems react the same way in these conditions.

LEARN MORE > HOTLINE article: Blow Thru® Space Heaters vs. Air Turnover Heating Systems.

LEARN MORE > Cambridge Comparison Building Study for Air Turnover (Air Rotation)

Tube-Style Infrared (Radiant) Heaters – A highly promoted method for heating objects, spot warming stationary people and specific zone heating applications. Infrared heaters are not the most energy efficient way to heat a large warehouse or distribution center. Provides only 80% to 90% thermal efficiency. They are effective when mounted only 15 to 18 feet above the floor. For warehouse applications they have a very slow response to dock door activity. Other potential problems include stratification, interference with racking and numerous roof penetrations for flue stacks. Infrared heating systems are very expensive to install in larger facilities. They provide no fresh air and must be used with an air make-up heating system if the building has an exhaust system for ventilation.

LEARN MORE > HOTLINE article: Cambridge Space Heaters versus Infrared Heaters

LEARN MORE > Cambridge Comparison Building Study for Infrared (Radiant)

Direct-fired heaters can be a very energy efficient way to heat a large warehouse because they do not use a flue or heat exchanger of any kind. They have a 100% combustion efficiency which means all of the available BTUs are delivered to the heated space. Direct gas-fired technology is an energy efficient way to provide both space heating and tempered make-up air (MUA). There are three types of direct-fired air heating systems. Again, it’s important to know the difference because not all direct-fired heaters are alike.

Cambridge Blow-Thru®, High Efficiency Space Heaters - Genuine Cambridge S-Series Space Heaters are the best way to heat large warehouses and distribution centers. Blow-Thru technology with the patented Cambridge burner provide the highest temperature rise, outlet temperature and BTU/CFM ratio for this type of direct gas-fired heating equipment. This translates into smaller units, lower horsepower motors; less heated outside air and lower energy costs. Cambridge warehouse heaters can be mounted on the roof, under the roof or through an outside wall so they don’t take up valuable floor or racking space. They provide very uniform heating (even at dock door areas), reduce energy costs and help improve indoor air quality. Cambridge space heaters are also recommended for LEED Certified Green Building Warehouse Projects. Blow-Thru space heaters are pre-qualified for EPAct Federal tax deductions when used in eligible buildings.

LEARN MORE > 10 Reasons why there is nothing else like a Genuine Cambridge® Heater

LEARN MORE > List of Cambridge LEED/Green warehouse projects

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“Draw-Thru” Make-Up Air (MUA) Heaters - This low temperature rise, 100% non-recirculating heater design provides a constant, high CFM output. It is best suited for applications where tempered make-up air for ventilation, not space heating, is the primary concern. Typical applications include spray paint booth areas, restaurant kitchens, wastewater treatment plants and manufacturing plants that exhaust large volumes of air during the heating season. Direct gas-fired MUA Heaters are often used in combination with other indirect gas-fired space heating systems that aren’t designed to handle negative building pressure problems. A large MUA heater will cost more to operate when used as a warehouse heater due to its lower temperature rise capability. Don’t be misled when someone says a direct gas-fired make-up air heater is “just like” a Cambridge Blow-Thru Space Heater. The technologies are different. Other manufacturers are now trying to hop on the Cambridge bandwagon. They are promoting direct gas-fired make-up air units as space heaters and calling it a "new technology." In reality, these lower temperature rise units are designed to heat replacement air, and are not the best choice for warehouse space heating applications.

LEARN MORE > HOTLINE article: That heater is just like Cambridge

LEARN MORE > Cambridge Comparison Building Study for Direct Fired (100% MUA)

“Draw-Thru” Air Recirculation Heaters - This is the only technology that re-circulates and re-heats indoor air with a direct gas-fired burner. They may not be appropriate for some applications where indoor air quality is important. This technology is not approved for use in Canada. These very large draw-thru blower systems typically heat up to 80% recirculated air from inside the warehouse and 20% outside air to maintain a fixed static pressure inside the building. They are often called “80/20” MUA units. Energy efficiency is compromised if dock doors are left open because then this pressurized system will act like an inefficient MUA heater trying to be a space heater. Electrical consumption is a big factor when the large blowers run continuously. Higher first cost, higher operating cost, additional roof structure required to support these large units and potential IAQ issues are all major concerns for warehouse heating applications.

LEARN MORE > HOTLINE article: "To recirculate or not to recirculate."

LEARN MORE > Cambridge Comparison Building Study for Direct Fired (80/20 MUA)

Recommendations - Insist on Genuine Cambridge Blow-thru® Space Heaters - Selecting the best and most energy efficient warehouse heating system is an important decision that should include a complete evaluation of what system provides the lowest total cost solution for all heating and ventilating needs. It also means don’t let the lowest bidder determine what’s important to you when comes to saving energy and improving indoor air quality. The benefits of installing the best warehouse heating system include low energy costs, good indoor air quality, maximum warehouse storage space, higher employee productivity, minimal maintenance and most important of all, a more profitable warehouse operation.

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