Prepare for Stormy Weather
If you're a carwash operator in sunny California, this story is probably not for you. But if your business is based in a part of the country that sees irs share of snow, read on.
There are several ways to hear a carwash location during those cold winter months, and operators have their own preferences. One way carwash owners are keeping their facilities and their employees warm is with direct gas-fired air hearers. The hearers can be used for space hearing as well as hot-air drying of cars.
Types of heaters
Direct gas-fired air heaters are efficient and provide a lot of heat because the burner fires directly in the air stream, rather than through a hear exchanger. This results in no washed energy. One hundred percent of available BTUs are delivered to the heated space because there are no Hue or heat-exchanger losses. They are used in a wide variety of commercial and industrial buildings for space (comfort) hearing, tempering outside make-up air (ventilation) and process heating (drying) applications. But no( all direct gasfired air heaters are alike and some are better suited for carwash applications than others. The following are some types of direct gasfired air heaters:
Make-up air heaters:
This type of heater
uses 100 percent outside air, low temperature
rise, high cfm/low velocity and is a large
unit with a draw-thru blower. Direct gas fired
heaters were originally used almost
exclusively for make-up air heating
(ventilation) applications. Even today, most
direct gas-fired air heaters reflect this heritage
because they are designed around a large
draw-thru blower/burner configuration that
moves a large volume of air through a low
temperature rise that normally is less than
120 degrees. This is a great design for
applications that need a large, constant
volume of tempered make-up air for
ventilation. However, it is nor usually an
efficient design for a carwash that needs
primarily space hearing or drying.
Recirculating heating:
This heater is similar
to the make-up air heater, but uses less than
100 percent outside air.
This approach rakes the make-up air
hearer design and modifies it to recirculate
and reheat up to 80 percent of the building
air. This is an attempt to be more efficient for
applications that need both space heating
and make-up air. However, the result is a
design that does neither the best and is
limited to a low temperature rise. Indoor air
quality and heater longevity suffer because
the moist, corrosive air is recirculated. This is
probably nor the best direct gas-fired air
hearer design for carwash applications.
High-temperature heater:
This uses 100
percent outside air, has a high temperature
rise, low cfm/high velocity and is a small unit
with a blow-thru blower. This design
provides high-velocity, high-temperature
outer air for both space hearing and drying.
It's characterized by a blow-thru configuration
where the gas burner is located
downstream from the blower. Therefore, the
blower and other temperature sensitive components, such as bell'S and bearings, are
located upstream from the burner where they
always stay cooler. This increases reliability
and allows this construction to be certified
for a much higher JGO-degree temperature
rise in space-heating applications. Designs
are also available with discharge temperatures over 200 degrees for car-drying applications.
One hundred percent outside air is utilized
for improved indoor air quality and longer
service life. It also supplies more BTU/cfm
than any other direct gas-fired system. That
means it can heat a space or provide hot air
for drying using the minimum amount of
outside air. This keeps the blow-thru heater
small and makes it more economical to
operate. It requires a lower horsepower motor
that results in lower utility bills than a larger
draw-thru unit that would be required for a
similar application. The high-velocity hot air
generated by this design is ideally suited for
use in carwash door heaters, space heaters,
thermal air curtains and hot air dryers.
Mounting configurations
Another big advantage of the high temperature rise blow-thru heater is that it can be mounted outside the harsh carwash tunnel environment. Therefore, it is easier to maintain than heaters mounted in the wet and corrosive carwash tunnel. It's great for carwash owners because it does not take up valuable equipment space inside the tunnel. Many mounting configurations are available to accommodate building aesthetics and space requirements.
Space-heating applications
Direct gas-fired systems are used to heat both conveyor and rollover type carwashes from 40 feet to more than 200 feet in length. The thermal air curtain design with linear slot diffusers is a popular heating approach for carwash tunnels where the major heat loss is at the open doors. The objective of a thermal-air curtain is to blend sufficient heat to raise the inside air temperature of the carwash and sufficient air velocity to provide a barrier to the outside cold air. This allows the carwash doors to remain open, which Gm speed up the car-per-hour rate. Open doors can also increase business on a cold day. Closed doors often keep customers away since it appears the carwash is closed.
Non-recirculation, high temperature rise, direct gas-fired heating offers the following benefits:
- The high Btu/cfm ratio gives increased heating capacity allowing the carwash to stay open on even the coldest days when other carwashes are forced to close. This means more business, more revenue and more profit.
- No recirculation of inside air improves indoor air quality. It also prevents corrosive chemicals from being ingested into the heater and that means less heater maintenance and longer life for the heater, other equipment and the building itself.
- It can eliminate icing problems associated with carwash equipment, brushes ;md floors. Icing can damage cars, create unsafe working conditions and even shut down the carwash on critical, busy winter days.
- It does the best job of eliminating fogging conditions in the carwash runnel that create problems for drying equipment and can be dangerous for both customers and employees.
Hot-air drying applications
Direct gas-fired heaters can economically supply hot air on demand for better and heater drying when outdoor temperatures drop below 65 degrees. They can be used to supplement an existing cold-air blower drying system with high temperature air that can exceed 200 degrees. In some cases, the same direct gas-fired heating system can be used for both space heating and hot-air drying.
Direct gas-fired hot-air drying offers the following benefits to the carwash operator:
- Hot air dries cars far better than cold-air blowers thus reducing customer complaints and lost customers who are unhappy with their wet cars after going through the drying cycle on cool days.
- A hot-air system can reduce the required runnel length devoted to the drying cycle, leaving more room for other "moneymaking" carwash operations.
- The carwash owner can significantly speed up his operation with hot-air drying, especially during cold winter months when customers are more willing to pay extra ~or a dry car.
- Expensive manual towel drying is eliminated or dramatically reduced with a hot-air drying system. This has many benefits, including a significant reduction in employee and towel laundry expenses. Staff scheduling problems often disappear bec.1use the heater will show up every day for work. Part-time employees are not that reliable, especially on cold winter days when they are most needed to hand-dry cars still wet after going through a cold-air drying cycle
- Heating a carwash runnel is a tricky issue due to its dynamic environment. However when done right, it can have many benefits including a more-profitable carwash operation.