Frequently Asked Questions

Question: What are 'direct gas-fired' heaters?

Question: Are all direct gas-fired air heaters alike?

Question: Isn't a BTU a BTU when comparing different gas-fired heaters?

Question: How can heating 100% fresh air with Cambridge® heaters be efficient?

Question: Do direct gas-fired heaters create humidity and condensation problems?

Question: What is the benefit of the S-Series Blow-Thru® design?

Question: How does Cambridge get that much heat out of such a small S-Series Heater?

Question: What's the big deal about 160°F temperature rise/discharge temperature?

Question: Will 160°F discharge air stratify?

Question: How does Cambridge get even temperature distribution?

Question: Will Cambridge® heaters blow hot air directly on people?

Question: Why doesn't Cambridge recirculate existing building air?

Question: How can Cambridge® S-Series Space Heaters be competitive against conventional unit heaters?

Question: How does Cambridge compare to indirect gas-fired Air Turnover (Air Rotation) heating systems?

Question: Are Cambridge® S-Series Space Heaters more energy efficient than gas-fired infrared heaters?

Question: What does Genuine Cambridge® mean?

Question: What is the Cambridge Warranty?

Question: Does Cambridge offer factory design assistance?

Question: Are Cambridge heaters recommended for LEED/Green building projects?

Question: What are 'direct gas-fired' heaters?

Answer: The burner fires directly in the air stream being heated rather than through a heat exchanger. This results in no wasted energy and 100% of available BTUs are delivered to the heated space because no flue or heat exchanger is required.

Back to Top

Question Are all direct gas-fired air heaters alike?

Answer: NO, selecting the wrong direct gas-fired heater can result in higher installation costs and higher operating costs.

Direct Gas-Fired Air Heating - Space Heating vs. Make-Up Air

Direct Gas-Fired Air Heating - Recirculating vs. Non-Recirculating

Back to Top

Question: Isn't a BTU a BTU when comparing different gas-fired heaters?

Answer: For Blow-Thru and draw-thru heaters with the same input capacity, a Blow-Thru™ heater delivers:

More useable heat to the space
Less outside air to the space

Let's Compare Numbers

That Heater is Just Like Cambridge®

Back to Top

Question: How can heating 100% fresh air with Cambridge® heaters be efficient?

Answer: All heating systems must heat outside air entering the building via natural infiltration. The Cambridge system manages infiltration by supplying more BTUs per cfm than other heating systems. Additionally, with Cambridge® heaters there is no flue loss as with other indirect-fired equipment.

Back to Top

Question: Do direct gas-fired heaters create humidity and condensation problems?

Answer: No, actual building studies show that Cambridge® direct gas-fired heaters can help solve humidity problems, not cause them.

Humidity: Just the Facts, Please

Back to Top

Question: What is the benefit of the S-Series, high temperature Blow-Thru design?

Answer: It attains 160°F temperature rise/discharge temperature. The Blow-Thru design also extends component life by mounting all critical parts in a cooler environment that is out of the hot air stream.

Don't be fooled when a competitor says "Our Heater Is Just Like Cambridge®."

Back to Top

Question: How does Cambridge get that much heat out of such a small S-Series Heater?

Answer: Our patented Blow-Thru design achieves 160°F temperature rise/discharge temperature and requires less space between the burner and blower.

Back to Top

Question: What's the big deal about 160°F temperature rise/discharge temperature?

Answer: It is the industry's highest rating for this type of space heating equipment and allows us to deliver the maximum amount of heat with the minimum amount of outside air. The maximum 160°F temperature rise/discharge temperature rating is crucial because it translates into lower horsepower motors, less outside air and reduced energy costs.

Let's Compare Numbers

That Heater is Just Like Cambridge®

Back to Top

Question: Will 160°F discharge air stratify?

Answer: Due to our high velocity discharge air, we are able to drive the heat to the floor resulting in a rapid mixing with surrounding air. Floor to ceiling variation typically does not exceed 3° F to 7° F. Our Building Study Program has confirmed this with real data at existing Cambridge installations.

Building Studies

Back to Top

Question: How does Cambridge get even temperature distribution?

Answer: By utilizing a combination of discharge velocity, discharge volume, air displacement and heater location.

Back to Top

Question: Will Cambridge® heaters blow hot air directly on people?

Answer: No, not directly. Cambridge mixes high volumes of ambient air which rapidly cools the high discharge air temperatures. Also, directional elbows can be redirected to adjust airflow.

Back to Top

Question: Why doesn't Cambridge recirculate existing building air?

Answer: The Cambridge design with high temperature rise/discharge and intermittent operation, delivers the maximum useable heat without the need for re-circulation. This reduces the potential build-up of contaminated building air. Therefore, the non-recirculating Cambridge® S-Series Space Heater is both safer and more energy efficient than "80/20" recirculation type systems.

"To Recirculate or Not to Recirculate" - Details and Case Study

Back to Top

Question: How can Cambridge® S-Series Space Heaters be competitive against conventional unit heaters?

Answer: Simply compare the total installed cost of both heating systems:

Equipment cost
Equipment installation
Gas piping
Electrical wiring

Or compare operation costs:

30% to 50% energy savings per year with Cambridge

Cambridge® Space Heaters versus Unit Heaters

Comparison Study - Cambridge® Space Heaters vs. Unit Heaters

Back to Top

Question: How does Cambridge compare to indirect gas-fired Air Turnover (Air
Rotation) heating systems?

Answer: If you are still using indirect gas-fired recirculation heating systems it is time to reconsider your options. Cambridge heaters are up to 70% more energy efficient, have a lower first installed cost and can
eliminate stratification problems associated with air rotation units used in warehouses with high ceilings.

Blow-Thru® Space Heaters vs. Air Turnover (Air Rotation) Heating Systems

Back to Top

Question: Are Cambridge® S-Series Space Heaters more energy efficient than gas-fired infrared heaters?

Answer: Comparison building studies show Cambridge Blow-Thru Space Heaters can reduce energy costs for insulated buildings with large open spaces that require ventilation.

Cambridge® Space Heaters vs. Infrared Heaters

Comparison Study - Space Heaters vs. Infrared Heaters

Back to Top

Question: What does Genuine Cambridge® mean?

Answer: Being the best at saving energy, reducing operating costs and improving indoor air quality has made Cambridge heating technologies very popular. Other manufacturers now describe their heater as being "Just Like Cambridge®". Don't believe it.

"Here are 10 reasons why there is nothing else like a Genuine Cambridge® Heater."

Back to Top

Question: What is the Cambridge Warranty?

Answer: The quality of the warranty and the company that stands behind it are what is really important. Our unit warranty is 2 years and our patented burners carry a 5-year warranty.

Back to Top

Question: Does Cambridge offer factory design assistance?

Answer: Yes - Take advantage of our 40+ years experience calculating heat loads and let us help design the most effective and energy efficient heating system for your building. Our proprietary Cal-Q-Heat® Program has become an industry standard for heat load calculations associated with warehouses, distribution centers, manufacturing plants, aircraft hangars, indoor recreational facilities, automobile service areas and other large commercial/industrial buildings.

The Cal-Q-Heat® form can be downloaded from our website, filled out and faxed or emailed to Cambridge or your local representative.

Click here to download Cal-Q-Heat® PDF file.

Back to Top

Question: Are Cambridge heaters recommended for LEED/Green buildings projects?

Answer: Yes - Cambridge Engineering is an active member of the U.S. Green Building Council (USGBC) and Cambridge heaters are compliant with ASHRAE Standard 90.1-2004, a requirement for all LEED buildings.

Click here for a partial list of Cambridge LEED projects.

Back to Top