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Tankless water heater solution for car washes

Nov. 7, 2014
Benefits of tankless: The space savings of tankless units in an overly packed mechanical room is one more benefit. The savings associated with tankless water heating can be as high as 40% of energy used.

As energy and operating cost continue to increase for all business owners there is no time like the present to offer the latest technology to our clients who seek a path to savings and a more attractive bottom line. Whether it is a plumbing, hydronics or HVAC system, there are real opportunities out there for us contractors looking to stay ahead of our competition.

Recently I answered a call from a longtime client looking for a water heater replacement at one of his many self-serve car washes. The situation was edging closer and closer to an emergency as his only seven-year-old firebrick lined tank type water heater had stopped working intermittently over the week prior to his call, but now it had also sprung a leak.

The car wash business, as you can imagine, relies heavily on hot water. It almost seems silly to say that, but in this instance the threat of cold weather looming over the Minnesota forecast had my client in an excited state. Located in a jam-packed mechanical room was a 100-gal. natural gas fired, power burner equipped tank taking up space and wetting itself all over the already limited floor space real estate. Glen, my client, had a previous contractor install a bypass piping arrangement for such an event as this many years ago. But bypassing a water heater in a Minnesota car wash will only get you through a couple months of operation during the summer. Summer ended here a few weeks ago and with overnight lows at or below the freezing mark his business was sure to take a huge hit until the water heater was replaced.

My phone call with Glen only lasted a couple minutes as he had to cut it short to address another problem arisen from the cold-water situation, but not before I suggested we replace the behemoth tank with multiple tankless water heaters to save space and operating costs. We quickly set up a time to meet on site and access the potential install.

Benefits of tankless

More and more commercial businesses are looking into the benefits of tankless water-heating technology in an effort to meet hot-water demands, minimize energy use and maximize savings. The savings associated with tankless water heating can be as high as 40% of energy used, just from eliminating standby losses associated with anticipating the need for hot water. This couldn’t be truer in the setting of a car wash business.

The typical gas bill for this property has averaged over $1,500 monthly.  We installed three 250K Btu/hr. stainless steel heat exchanger units set up to operate in a masterless cascading operation sequence and a much smaller insulated storage tank. Each of the units has an AFUE rating of 98% combustion efficiency. Compare that to the 50% to 60% operating efficiency of his leaking unit and my client stands to save $6,000 to $7,000 annually.

If you’re familiar with self-serve car washes you’ll know that the varied load can be the source of headaches for the installing contractor when it comes to sizing equipment. This property has 12 wash bays with both a spray wand and foam brush. Each bay can demand as much as 2.7 GPM of tempered water for a total of 32.5 gallons load on the water heating equipment. The low end operating capacity makes those old and outdated tank-type water heaters extremely inefficient with their inability to modulate the burner to meet only the demand of the system. When sizing a tank or tankless water heater we have to size for the peak load demand, but tank units can only offer the storage capacity needed for smaller loads. That’s where tankless units shine bright. With a firing rate between 30K to 250K each, and working in tandem, the new system is able to idle along leading up to peak operating times for my client’s business.

The space savings of tankless units in an overly packed mechanical room is one more benefit. Removing the leaking beast, weighing in at around 1K pounds (stone lined) freed up nearly 4 feet of usable floor space. A couple storage shelves were relocated to make room for the wall-hung units and single storage tank.

Our project began with a simple phone call from our client. While he was admittedly excited with the prospect of losing money I recognized the opportunity to not only save my client money in his business but also the potential for additional projects similar in scope considering this particular client owns multiple car washes throughout the Metro Area. I’m just glad we decided to hire a demolition crew to remove the overweight behemoth when we signed the work order. No way would I like to wrestle a stone lined tank!

Good luck, and as we near the end of another year I’d like to say thank you again to each of you who take the time to read my articles here. I appreciate the emails and personal conversations when we have the opportunity to meet at industry events.

Eric Aune started Aune Plumbing LLC in 2004 and specializes in residential and small commercial hydronic heating systems and service. He is a graduate of Dunwoody College of Technology and Plumbers Local 15, Minneapolis Apprenticeship Training Program, and is currently a United Association Instructor and teaches for the Plumbers Local 15 JATC. Aune is also founding partner and vice president of Contact him at: [email protected].

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