Choosing the Right Heating System for your Facility

Understanding the Pros and Cons of Each System Can Help You Avoid Poor IAQ and Unnecessary Cost

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Is the heating bill for your plant or warehouse too high? What about cold dock door areas and unbalanced temperatures? Is negative building pressure a problem? Do your employees complain about it being too cold making it harder for them to do their job? Do you have high maintenance costs from existing heating equipment?

These are just a few common problems that result from selecting the wrong heating system, misplacing your heaters so they can’t reach their full potential or using obsolete technology. What factors determine the best space heating system? Everyone wants a heating & ventilating system that meets their unique requirements at the lowest total cost. Before selecting a heater, define the heating/ventilating requirements and understand all the cost factors that determine the true lowest total cost solution for a specific facility.

BOILER SYSTEMS

One of the oldest forms of heating, boilers have been in existence since about the 1800’s and are still a preferred Boiler Heating Systemsystem of heating in large industrial facilities where remote plants deliver steam and hot water to satellite locations to circulate through heat exchangers. These exchangers can be part of unit heaters, make up air systems, or anywhere a heat exchanger can be installed. While huge advances in boiler technologies have evolved over the past few years, boiler systems are typically the most inefficient heating technology – with the highest overall installed cost, the highest cost to maintain and repair, and a huge level of stratification of the surrounding air. When discussing boiler replacements or supplemental heating with contractors, it’s very important to consider the overall operating and maintenance costs of these systems. Boilers require maintenance to ensure they operate at their peak efficiency.  Parts such as valves, traps and fittings wear out over time. While the boiler system generates the heat, they also require a distribution system – such as unit heaters or make up air systems.  A lot of mechanical components to consider.

Unit Heater Heating SystemUNIT HEATERS

The most basic of all heating technologies, unit heaters are inexpensive to purchase and have good familiarity by most contractors and engineers. The redundant design makes servicing by contractors very simple. They are fairly effective in zone heating. Unit heaters promote poor indoor air quality and huge levels of stratification in the space upwards of 20-30 degrees without adding additional HVLS fans.  They offer a low temperature rise versus direct fired technologies, a higher operating cost, and cannot combat dock door infiltration.

INFRARED OR RADIANT TUBE HEATERS

While infrared or tube heaters are good for zone and spot heating applications, they should never be used as the sole source of heating large spaces.  Radiant heaters offer a relatively low operating cost and a way to heat tools, work stations, and people without consuming floor space.  Radiant heaters do not offer indoor air quality benefits nor any ventilation in the summer. They do not promote air mixing and have a high installation cost due to line of sight restrictions and coverage limitations.

RECIRCULATION 80/20 SYSTEMS

Recirculation systems or 80/20 systems are typically thought to be more efficient than other technologies due to the fact that a large amount, up to 80% of the air moved is recirculated, thus not requiring a large amount of gas to heat it up. Recirculation units are widely used to combat facilities with mechanical exhaust systems, especially when variable CFM is needed. They typically regulate the amount of outside air they introduce, based off the CFM needs of the building itself. Typically, fewer units are necessary and they do a decent job of providing summer ventilation. Recirculation systems are draw thru systems with a minimal effective temperature rise of about 40-50F. When dock doors are open in a facility, the recirculation units will be driven to 100% outside air and with discharge temperatures ranging between 80-100F, they must run continuously to cycle enough CFM to make up the temperature and pressure drop. The recirculation units are very large and heavy, requiring larger cranes, structural modifications, and much larger first cost and operating costs. They are not certified for use in Canada and with recirculation of air and contaminants, products of combustion can build up in the space.

Air Turnover Heating SystemAIR TURNOVER (AIR ROTATION)

Air turnover has been marketed as a package system to industrial customers since its inception in the 1920’s.  While marketed as a single piece of equipment (a large tower set in the corner of a warehouse space), the greatest advantage of air turnover is the ability to provide BOTH tempered heating and cooling to a space.  Air turnover systems offer decent heating with limited stratification due to the massive volume of air they recirculate in the space.  This air mass is moved due to a continuous operation and very large horse power motors driving the fans.   Air turnover units provide a very low temperature rise of between 20-30 degrees and a discharge temperature of about 80-90 degrees.

DIRECT-FIRED MAKEUP AIR SYSTEMS


Direct-Fired Makeup Air units provide required ventilation to meet indoor air quality needs with efficiencies between 90-92% AFUE.   Widely beneficial in buildings with fixed CFM needs due to mechanical exhaust, makeup air units provide a fixed volume of air independent of the heat they provide.   With a lower discharge velocity at the plenum, air typically does not hit the floor to sweep and de-stratify the space and can lead to lower employee comfort levels.  The fixed CFM blowers require larger HP motors with over-pressurization of spaces a reality.  Larger motors, lower temperature rise, and less efficient design require more energy to run.

While Cambridge uses our Blow-thru design of the S-Series and SA-Series heaters to heat, a lot of manufacturers use makeup air units attempting to do the same.  In places where there are warmer climates and less winter cold, makeup air systems offer a way to temper the outside winter air thru a lower temperature rise of between 100° and 120°F and a draw thru design.  This places the mechanical components in the hot air stream.  For heating applications, we recommend our S-Series and SA-Series heaters.  With a Blow-thru design, our mechanicals are in the cold air stream.  The position of the blower relative to the burner and the burner’s ability to discharge 160°F, provides advantages over ANY makeup air unit – more air mass and higher temperature rise.  This provides the most BTUs per CFM from any manufacturer.

Cambridge’s M-series make up air units are designed to temper the air in situations where there is a lot of fixed or variable exhaust.  They can be interlocked with existing exhaust fans or outfitted with variable frequency drives.  Our units can come with fully modulating burners and automatic profile adjustment dampers.

Hopefully, the topic we’ve outlined today will help prepare you to address any technology claim from other manufacturers. As always, feel free to contact us with any questions. We can easily accommodate lunch and learns, audio and video conferencing, phone, or face to face sales calls.

Makeup Air with Cooling is Here!

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Cambridge is excited to offer our M-Series Makeup Air Unit with Cooling technologies! Our M-series products are used to provide both non-conditioned and cooled demand controlled ventilation and exhaust replenishment in both commercial and industrial buildings and facilities.

Cambridge M-Series Make-Up-Air units can provide up to 75,000 CFM of air, 140 tons of DX cooling / 250 tons of Hydronic cooling and evaporative cooling as well. We also have a wide range of performance features that include:

  • Motorized Inlet or Discharge Damper
  • Dual Rain Hoods
  • V-Bank Filter Sections
  • High Efficiency Filters
  • Mounting Curbs and Stands
  • Variable Frequency Drives

Some of the applications where our M-Series products are used are:

Automotive Service and Repair facilities, Greenhouses, Restaurants, Sporting facilities, Foundries, Paint Booths, Waste Water Treatment plants, Manufacturing facilities

Cambridge Engineering products are designed for simple installation, easy maintenance and reliable operation and they are available with certified and pre-engineered factory options and field-installed accessories.
For more information on our Make-up-Air solutions click here to visit our website!

Know the Difference Between HTHV and 80/20 Technologies – It Makes a Difference To Your IAQ!

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For years High Temperature Heating and Ventilation (HTHV), a direct-fired 100% outside air technology, and 80/20 direct-fired units have been heating solutions used for new construction and retrofit projects throughout the US with little attention to the differences in Indoor Air Quality (IAQ) from both products. However, when it comes to IAQ there are significant differences between these two technologies – HTHV being the clear winner.

The Occupational Safety and Health Administration (OSHA) was created to assure safe and healthful working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education and assistance1.

Among the frequently asked questions on the OSHA website is one concerning IAQ:

What is considered good IAQ?

The qualities of good IAQ should include comfortable temperature and humidity, adequate supply of fresh outdoor air, and control of pollutants from inside and outside of the building2.

It is these pollutants, and the amount of the pollutants in parts per million (PPM), that differentiate 100% outside air HTHV technologies apart from 80/20 units. Both OSHA and the Canadian Standards Association (CSA) set limits on what the acceptable PPMs for different pollutants are for working environments. The performance and safety standards set by the American National Standards Institute (ANSI) are z83.4 for 100% outside air non-recirculating direct gas-fired industrial air heaters and z83.18 for 80/20 recirculating direct gas-fired industrial air heaters. The infographic below helps illustrate the differing amount of pollutants in PPM between HTHV and 80/20 units along with the acceptable limits for these pollutants in both the US and Canada.

1 Reference OSHA website: www.osha.gov/about.html
2 Reference OSHA website: www.osha.gov/OSHA_FAQs.html

4 TIPS FOR PLANNING YOUR COMMERCIAL HEATER LAYOUT TO MAXIMIZE ENERGY EFFICIENCY AND IAQ

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Did you know that part of the Cambridge package includes a free and customized recommendation on unit placement in your facility? Our experts Denny DeGreeff and Mark Struckmann offer up some tips to consider when planning for ultimate Indoor Air Quality and Comfort using commercial heaters.

4 TIPS FOR PLANNING YOUR COMMERCIAL HEATER LAYOUT 

1. Consider your facility layout.

Locate the heaters near the perimeter of the building, blowing towards the center. Due to the high velocity discharge of a Cambridge heater, you might be able to locate the heaters near a gas main to save on piping costs. 

2. Find your source of Heat Loss.

Place the units near largest source of heat loss, typically dock doors. This can eliminate the need for extra heating equipment such as infrared tubes and door heaters. Also, make sure the heat from your unit can reach the floor (Refer to the Typical Discharge Height Chart in your Engineering Spec manual as a guideline).

3. Note Obstructions.

You do not want to blow directly in to an obstruction such as a rack or interior wall.  If the racking layout allows, align the heater up with an aisle and blow lengthwise. 

4. Adapt the heater configuration to work for your space.

Cambridge heaters can be customized to almost any building structure and installation requirement. If you have limited space inside the building for heater install, consider a different type of configurations, such as a vertical or roof-top installation. 

Economical, Efficient, and Cost Effective

That’s why Patten CAT prefers Cambridge Engineering products

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Patten CAT is a 4th generation Caterpillar sales and service organization that began back in 1933. Their relationship with Cambridge Engineering heating products started in 2005 when they purchased their first Cambridge S-Series unit to retrofit a less efficient heating system at their Oglesby, IL location. Fast forward 12 years later and Patten has over 25 Cambridge units heating 6 of their locations throughout the Chicagoland area.

  • Oglesby, IL –  5 Cambridge s-series units
  • Wauconda –  2 Cambridge S-Series units
  • Rockford – 5 Cambridge S-Series units
  • Hammond – 4 Cambridge S-Series units
  • Joliet – 1 Cambridge S-Series unit
  • Elmhurst – 7 Cambridge S-Series units and 1 Cambridge M-Series unit

In the beginning the units were purchased to retrofit older less efficient heating units which were not as effective in heating their facilities. Today they have used the Cambridge units to not only retrofit their existing locations, with the latest retrofit qualify for NiCor gas energy efficiency rebate, but to heat their location in Wauconda, IL which was a new construction project.

For Terry Flick, Patten’s facility manager, Cambridge is his go-to heating products for Patten facilities. According to Flick, “Cambridge units are long lasting and are economical enough for people to purchase. Whenever I have to update something I keep going back to Cambridge.”

There are other benefits that Patten realizes from using Cambridge equipment. Since the units are a 100% outside air heating technology the units help provide a little positive pressurization for their buildings. This helps keep the cold air out and improves the indoor air quality for their employees during the winter heating months.

As Flick points out, “even on a zero-degree day the units still provide a 160-degree Fahrenheit discharge temperature which keeps our facilities nice and warm.” The other competitor’s units struggled to achieve a 60-degree discharge air temperatures when the outside temperature drops down to zero. And with their many Chicagoland locations they see quite a few zero degree days during the Chicago winters.

Cambridge is honored to be the heating solution of choice for Patten CAT and we hope to continue our relationship with Patten for many years to come.