A Primer for Today’s Self-Service Laundry Operator
Hot water – along with total water usage (and the demand for both in the latest generation of washers) – is as much as 65 percent less than it was for most washers when I started in this business in 1979.
With that said, we regularly hear from laundry owners, who always have a lot of questions about their water heating:
“How much hot water do I really need?”
“What efficiency is right for my store; in fact, what design or style is best for my store – and, more importantly, my budget?”
“How do I get good long life from my heater and keep it running efficiently?”
Read on for answers to these and other questions related to your water heating system.
How much hot water do I really need? For the sake of this article, we will assume you have decided you want hot water available anytime you have customers in your store; if you only have enough on slow days, why have it at all?
What do I need to know to ensure that my water heating system is sized properly?
- Maximum number of turns per model washer in your busiest hour.
- Percentage of cycles run on a hot, warm and cold setting.
- Exact brand and model washers you are using in your store – this can make as much as a 150 percent difference in water consumption!
Without all of the above information, you cannot accurately size the system your store needs. Contrary to popular belief, there is no rule of thumb that works; you may have two identically equipped stores in two completely different demographics, and the hot water demand can vary as much as 70 percent!
What efficiency is best for your store? A general rule of thumb is that 50 percent of your annual gas bill is for hot water; the other 50 percent covers dryers and building heat, etc. This could vary by 10 percent in either direction, but this is close enough to enable your decision-making process.
Let’s make it easy and say your total annual gas bill is $12,000 (so $6,000 would be for hot water). What is the estimated operating cost difference between the systems you are comparing? There could be as much as 30 percent difference, or $1,800 per year in this example. As to your crystal ball on fuel prices and acceptable ROI, that is completely up to you.
What design is best for my store? Having equipment that is (1) properly sized using the data above, (2) properly installed and (3) properly maintained will do an adequate job of providing hot water as needed. Here are the three basic types of water heating systems that are used in a self-service laundry:
Self-contained tank type – as described, storage and heating are one big component. When any one major failure occurs, you must replace the entire unit. Most stores require multiple units.
On-demand with no storage – utilizes no storage, so requires significantly more BTU/hour input to ensure no drop in delivered water temperature or hot water flow rate. Has no standby heat loss whatsoever if operated as a true on-demand heater.
Circulating tank system – the water heater and the stored water are separate. This also includes on-demand heaters connected with storage. These systems come in hundreds of shapes, sizes and efficiencies, and generally all individual components can be rebuilt or repaired making it the most common and longest life system in our industry.
To ensure no drop in delivered water temperature, the storage tank should have 30 percent of the maximum calculated hot water demand in capacity. Properly insulated, a storage tank will lose less than half of 1°F per hour, or for a 200-gallon tank at ½°F loss, heated with natural gas – less than $100 per year.
How do I get the longest life from my water heating system? First, it must be sized properly; under-sizing drastically shortens life. Next, make sure it has the proper amount of combustion air, whether piped directly to the heater or through openings in the walls – follow the manufacturer’s installation manual to the letter. Maintenance is required on all styles and designs of water heaters: be sure it is on your monthly checklist and gets a full preventive maintenance by a qualified contractor at least annually. Lint from dryers not only causes loss of combustion efficiency, but may also ruin burners and combustion air blowers. Keep everything clean of lint.
The chemistry of the water you are heating can make all of the difference in the world in the operating life of the water heating system. Water utilities are required to record a variety of factors, including hardness, alkalinity, pH and total dissolved solids. This means calculations can be made with pinpoint accuracy to determine whether your water will be neutral, or have eroding or scale-forming tendencies; contact your local water utility for data specific to your area. Hardness alone cannot tell you the propensity for scale formation your water may have. Depending on what your water will tend to do, there are specially designed hot water systems that can overcome poor water chemistry and still give you a 15- to 20-year lifespan.
Should I call a plumber when I have a hot water problem? We say no. Since self-service laundries have very specific sizing requirements, rarely do the generic rules of thumb most major water heater manufacturers use even come close to being accurate. Your laundry machinery distributor network is the best source for accurately sized system recommendations and solutions. Many laundry equipment distributors have factory-trained technicians for your typical service or troubleshooting needs. Some of the hot water suppliers to this industry also have 24/7 technical support lines that can work directly with you or your distributor to determine the source of the problem and the proper fix, and to get required parts out to you promptly.
Your water heating system is one of the most expensive individual pieces of equipment in your laundry. Take the time to purchase the right one and maintain it, and it will be an asset, not a liability to your laundry business.