• Sign In
  • Create Account
  • Sign Out
  • My Account
  • NEWS
  • PRODUCTS
  • CONTRACTORS
  • ENGINEERS
  • RADIANT & HYDRONICS
  • INSIGHTS
  • MEDIA
  • RESOURCES
  • EMAGAZINE
  • SIGN UP!
cart
facebook instagram twitter linkedin youtube
  • CONTRACTORS
  • BATH & KITCHEN PRO
  • BUSINESS MANAGEMENT
  • HIGH EFFICIENCY HOMES
  • TECHNOLOGY
  • WATER TREATMENT
  • PMC COLUMNS
  • PMC COLUMNS
  • Dave Yates: Contractor’s Corner
  • John Siegenthaler: Hydronics Workshop
  • Kenny Chapman: The Blue Collar Coach
  • Matt Michel: Service Plumbing Pros
  • Scott Secor: Heating Perceptions
  • ENGINEERS
  • CONTINUING EDUCATION
  • DECARBONIZATION | ELECTRIFICATION
  • FIRE PROTECTION
  • GEOTHERMAL | SOLAR THERMAL
  • PIPING | PLUMBING | PVF
  • PME COLUMNS
  • PME COLUMNS
  • Christoph Lohr: Strategic Plumbing Insights
  • David Dexter: Plumbing Talking Points
  • James Dipping: Engineer Viewpoints
  • John Seigenthaler: Renewable Heating Design
  • Lowell Manalo: Plumbing Essentials
  • Misty Guard: Guard on Compliance
  • RADIANT & HYDRONICS
  • RADIANT COMFORT REPORT
  • THE GLITCH & THE FIX
  • INSIGHTS
  • CODES
  • GREEN PLUMBING & MECHANICAL
  • PROJECT PROFILES
  • COLUMNS
  • SPONSOR INSIGHTS
  • COLUMNS
  • Codes Corner
  • Natalie Forster: Editorial Opinion
  • Guest Editorial
  • MEDIA
  • PODCASTS
  • VIDEOS
  • WEBINARS
  • RESOURCES
  • INDUSTRY CALENDAR
  • DIRECTORIES
  • EBOOKS
  • PM BOOKSTORE
  • CE CENTER
  • MARKET RESEARCH
  • CLASSIFIEDS
  • EMAGAZINE
  • EMAGAZINE
  • ARCHIVE ISSUES
  • CONTACT
  • ADVERTISE
  • PME EMAGAZINE ARCHIVES
search
cart
facebook instagram twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
  • NEWS
  • PRODUCTS
  • CONTRACTORS
    • BATH & KITCHEN PRO
    • BUSINESS MANAGEMENT
    • HIGH EFFICIENCY HOMES
    • TECHNOLOGY
    • WATER TREATMENT
    • PMC COLUMNS
      • Dave Yates: Contractor’s Corner
      • John Siegenthaler: Hydronics Workshop
      • Kenny Chapman: The Blue Collar Coach
      • Matt Michel: Service Plumbing Pros
      • Scott Secor: Heating Perceptions
  • ENGINEERS
    • CONTINUING EDUCATION
    • DECARBONIZATION | ELECTRIFICATION
    • FIRE PROTECTION
    • GEOTHERMAL | SOLAR THERMAL
    • PIPING | PLUMBING | PVF
    • PME COLUMNS
      • Christoph Lohr: Strategic Plumbing Insights
      • David Dexter: Plumbing Talking Points
      • James Dipping: Engineer Viewpoints
      • John Seigenthaler: Renewable Heating Design
      • Lowell Manalo: Plumbing Essentials
      • Misty Guard: Guard on Compliance
  • RADIANT & HYDRONICS
    • RADIANT COMFORT REPORT
    • THE GLITCH & THE FIX
  • INSIGHTS
    • CODES
    • GREEN PLUMBING & MECHANICAL
    • PROJECT PROFILES
    • COLUMNS
      • Codes Corner
      • Natalie Forster: Editorial Opinion
      • Guest Editorial
    • SPONSOR INSIGHTS
  • MEDIA
    • PODCASTS
    • VIDEOS
    • WEBINARS
  • RESOURCES
    • INDUSTRY CALENDAR
    • DIRECTORIES
    • EBOOKS
    • PM BOOKSTORE
    • CE CENTER
    • MARKET RESEARCH
    • CLASSIFIEDS
  • EMAGAZINE
    • EMAGAZINE
    • ARCHIVE ISSUES
    • CONTACT
    • ADVERTISE
    • PME EMAGAZINE ARCHIVES
  • SIGN UP!
Plumbing NewsWater Treatment

Aquatics meets hydronics

Using condensing boilers to heat swimming pools.

By Tom Soukup
pool heating retrofit

The pool heating retrofit at Kendal-Crosslands included a lap pool, therapy pool and spa.

Apprentice Ben Dyson

Apprentice Ben Dyson works to install two condensing boilers.

Apprentice Ben Dyson

Apprentice Ben Dyson changes setpoints on a K2 condensing boiler.

Gage

Gages are installed near the heat exchangers.

pool heating retrofit
Apprentice Ben Dyson
Apprentice Ben Dyson
Gage
May 29, 2020

The pool industry — or the aquatics industry as it’s referred to by insiders — shares many similarities with the hydronic heating industry. Water quality is vital. Movement of water is also a consideration that has a profound impact on the system as a whole.  

When designing pool heating systems, the efficiency, serviceability and longevity of heating equipment are nearly as important as control and safety.

I’ve been in the plumbing and hydronic heating trade for most of my adult life. Through Patriot Water Heater, a company I founded in 2009, I’ve done work all across the northeast, primarily in New York, New Jersey and Pennsylvania.  

Hydronic systems in all variety of new construction projects are becoming a premium solution, niche product. Several years ago, I began to seek out opportunities to grow the hydronic side of the business and ultimately move toward 100% hydronic work. I network more than I advertise, focusing on becoming a resource for engineers, architects and facility managers. I’ve also found ways to apply my skillset outside of conventional hydronic heating.

EcoDronics was born out of that effort. It’s a brand within Patriot Water Heater, concentrated on “unconventional” hy-dronic applications like snowmelt, greenhouse heating and root zone warming and pool heating applications.

I’ve learned since diving into pool heat (pun intended) that there’s great opportunity to improve upon the methods and materials used in traditional pool heating systems. Not surprisingly, hydronics can provide that solution. The most recent and, to date, largest pool heating project I’ve been involved with is a prime example.  

 

SEEKING IMPROVEMENT

I was working on a pool heating system last year when I met Don White, of Wallover Architects. The 30-year-old firm is known internationally as a leader in the aquatics industry. When Wallover Architects was called to renovate the natatorium, pools and replace the filtration systems including several heaters at Kendal-Crosslands Communities — a four-property retirement community — he asked me to collaborate.  

“This pool facility was built around 2005,” says Joe Deckman, plant operations supervisor at Kendal-Crosslands. The original equipment has been labor-intensive over the years, requiring ongoing maintenance.”

The project, as bid and contracted, started out as a simple, in-kind replacement of the pool heaters as requested by the owner,” White says. “Ultimately, after hearing Tom’s reasoning to use condensing boilers, they decided to spend more for a much better, long-term solution.”

There are three bodies of water at this facility, all maintained at different temperatures: A 31,000-gallon lap pool, a 21,000-gallon therapy pool and a 1,300-gallon spa.

“There was a lot of room for improvement at Kendal-Crosslands,” White says. “The pool heaters were lasting about three years on average, maintaining precise pool temperature was a struggle, fuel consumption was higher than expected and there was no redundancy. If a heater went down, that pool went cold until it was replaced. Exacerbating the issue, the pool heater parts were proprietary and only available from a pool equipment wholesaler.”

“Reducing the maintenance, replacement work and downtime were our priorities,” Deckman says. “But once we start-ed looking at energy savings — a gross reduction of gas input by 52% — I didn’t realize how much we had been leaving on the table. For Kendal-Crosslands, this is more important from an environmental prospective than a financial one.  If we can lower our carbon footprint in the process, that’s fantastic.”

 

AQUATIC CHALLENGES

Pool equipment rooms are often caustic environments. Heating equipment generally shares a mechanical space with concentrated water treatment chemicals, in this case chlorine. I specify only non-ferrous components for use on aquatic installations for this reason.

Because the existing heaters at Kendal-Crosslands were atmospherically vented, they failed quickly. The stand-alone, 80% efficient units were each rated for 250,000 Btu/h. They also suffered from decreased flowrate, resulting in pool temperature swings and short cycling heaters. This was compounded by the fact that all three heaters were oversized, one of them drastically. The end result was an underperforming system that ran very inefficiently and required too much service and frequent component replacement.  

My aim was to design and install a system that addressed each of these issues. The best solution is one that’s foreign to the aquatics industry. I specified condensing boilers, a primary-secondary piping system and stainless steel heat ex-changers to isolate the pool water from hydronic system fluid.

 

UNIQUE SIZING 

Months before the actual retrofit took place, I met White and Deckman to discuss the project and calculate the heat load of each body of water. As you might imagine, sizing a pool heat source is a far cry from sizing a boiler for space heating.  

The calculation starts with the amount of water in the pool, the surface area of the water and the ambient air temperature (83° F) in the pool area. Combined with the desired setpoint, these figures provide a fixed heat loss.  

After deducting the efficiency loss across each of the three DHC shell-and-tube heat exchangers, I found I could provide all the heat needed by the three pools with two, 180 MBH U.S. Boiler Co. K2 high-efficiency boilers. Shell-and-tube heat exchangers were used for low head loss. Had these pools been salt water, or treated with bromine instead of chlorine, titanium heat exchangers would have been selected instead of stainless steel.  

 

HYDRONIC SOLUTION

To speed up the retrofit process, we pre-fabricated much of the near-boiler piping. The heat exchangers — two with a capacity of 250,000 Btu/h and a single 150,000 Btu/h model — were installed where the pool heaters had originally been connected.

I wanted to keep the boilers as far from the chemical storage area as possible. My apprentice, Benjamin Dyson, and I constructed a wall in one corner of the room, keeping the boilers off the floor. Three Grundfos circulators, a Caleffi hy-dro separator and the U.S. Boiler Co. Sage Zone Control panel are installed on the reverse side of the wall.

I chose condensing boilers for this project not only for efficiency, but also because sealed combustion was a must. The K2 boiler has been my go-to model for a number of years because it’s reliable, affordable and easy to service.  Adding to that, the controls are intuitive and simple to configure for any application. That was especially important on this job since there was no outdoor reset, in the traditional sense. 

Instead of determining supply water temperature based on outdoor air temperature, the boiler control is set to respond to return water temperature. The minimum supply water temperature is 140°, and the boiler control looks to maintain a 20° ΔT.   

The K2’s “boost” function is programmed to raise the supply water temperature by 20° every 20 minutes. That’s longer than would typically be used in a residential application. Once the boilers are maintaining heat, I’ve found that it never goes into boost mode for more than 15 minutes, which tells me that the units are condensing almost constantly.

One boiler can handle the load to maintain setpoint temperature if all the pools call for heat simultaneously under normal conditions. The boilers are set up as lead/lag with a 10-minute delay before firing the second unit, which generally happens after a large filter backwash, draining or cleaning.  Two boilers were installed instead of one larger unit for re-dundancy. My design met Wallover Architects’ filter design at the heat exchangers.

 

ACCURACY AND SUCCESS

Immediately before the retrofit, Wallover Architects’ new filtration and water treatment design was installed. The new, VFD-powered filter pumps were chosen to provide the turnover rates required by ANSI Standards for Swimming Pools ANSI/NSPI-1 2003 and ANSI/NSPI-2 1999, American National Standard for Spas.

The lap and therapy pool each need 71 gpm on the pool side of the heat exchanger, while the much smaller spa re-quires 30 gpm. This impacted both the sizing of the heat exchanger and selection of the three “zone” circulators. Source-side flow rates are 4.1, 3.7 and 1.1 gpm, respectively. Flow rates, and the ability to maintain precise setpoint temperatures, are just as important in aquatic applications as in heating systems. Maybe more so.  

Per ANSI code, pool temperature setpoints must be maintained within .3° of setpoint temperature. This is critical be-cause as water temperature changes, so does the rate at which chlorine oxidizes. Sanitizer levels (chlorine dilution) must be recorded on an hourly basis. Before the retrofit, Kendal-Crosslands was having trouble with fluctuating pool tempera-tures. Now, the system maintains temperature to .2°.  

Maintenance was greatly reduced as a result of the boiler installation. When the boilers are cleaned annually, so are the heat exchangers.  

“Traditionally, pool heating systems are installed and maintained by pool companies,” White says.  “I think this installation is evidence that savvy hydronic installers with a properly-designed condensing boiler system will become a major disrupter in the aquatics industry in the years to come.”

If more consistent pool temperatures, improved fuel consumption and reduced maintenance aren’t proof that the pro-ject was a success, Kendal-Crosslands’ response is. They’re thrilled with the result and are considering implementation of a similar system at an adjacent property.

KEYWORDS: heating systems hydronic systems plumbing water filtration

Share This Story

Looking for a reprint of this article?
From high-res PDFs to custom plaques, order your copy today!

Tom Soukup is the principal of Patriot Water Heater Co. with more than 20 years as a hydronic designer and installer. He specializes in high-efficiency and green technology, and brings his expertise to custom commercial work, pool heating and agricultural projects. Reach him at: twsoukup@patriotwaterheater.com.

Recommended Content

JOIN TODAY
to unlock your recommendations.

Already have an account? Sign In

  • Worker using the Milwaukee Tool SWITCH PACK drain cleaner

    Pipeline profits: Drain cleaning, pipe inspection create opportunities

    Drain cleaning and inspection services offer lucrative...
    Green Plumbing and Mechanical
    By: Nicole Krawcke
  • Uponor employee, Arturo Moreno

    The reinvestment in American manufacturing and training

    Plumbing & Mechanical Chief Editor Nicole Krawcke and...
    Plumbing News
    By: Nicole Krawcke and Natalie Forster
  • March 2024 Women in Plumbing hero image of woman engineer overlayed by circle of hexagon shapes with numbers from 1 to 10

    Celebrating 10 Influential Women in the Plumbing Industry

    Celebrating Women's History Month and Women in...
    Plumbing News
    By: Nicole Krawcke
close

1 COMPLIMENTARY ARTICLE(S) LEFT

Loader

Already a Registered User? Sign in now.

Subscribe For Free!
  • eNewsletters
  • Online Registration
  • Subscription Customer Service
  • eMagazine
  • Manage My Preferences

NIBCO Press Solutions

NIBCO Press Solutions

IPEX celebrates grand opening of new Florida distribution center

IPEX celebrates grand opening of new Florida distribution center

Bell & Gossett Illustrates Path to Net-zero at AHR Expo

Bell & Gossett Illustrates Path to Net-zero at AHR Expo

AI can boost efficiency and profitability for plumbing, HVAC contractors

AI can boost efficiency and profitability for plumbing, HVAC contractors

More Videos

Sponsored Content

Sponsored Content is a special paid section where industry companies provide high quality, objective, non-commercial content around topics of interest to the Plumbing & Mechanical audience. All Sponsored Content is supplied by the advertising company and any opinions expressed in this article are those of the author and not necessarily reflect the views of Plumbing & Mechanical or its parent company, BNP Media. Interested in participating in our Sponsored Content section? Contact your local rep!

close
  • J.J. Keller CMV vehicles on road
    Sponsored byJ. J. Keller & Associates, Inc.

    The dash cam game-changer for small business safety

Popular Stories

Figure 1 is a sketch of the flow problems of the current plumbing system.

Hydronic heating glitch solved: Why adding a circulator won't fix primary loop flow issue

The interior of a government building.

President Trump signs executive order promoting skilled trades and apprenticeships

Underfloor heating installation with drain sewer hole in bathroom close up on water floor heating.

Using hydronics to leverage time-of-use electrical rates

PM BEMIS June 25 Free Webinar: Optimizing Plumbing Solutions for Single-Family, Multi-Family & Public Spaces

Events

November 13, 2024

Future Proofing MEP: Navigating the 2026 High Efficiency Water Heating Standards

Join our deep dive into DOE’s new standards so you can future-proof your MEP practice.

EARN: 0.1 ASPE CEU; 1 AIA LU/HSW; 0.1 IACET CEU*; 1 PDH

View All Submit An Event

Poll

Will business be up or down in 2025?

Do you anticipate business in 2025 to be up or down in comparison to 2024?
View Results Poll Archive

Products

The Water Came To A Stop

The Water Came To A Stop

See More Products

Download the FREE Water Conservation, Quality & Safety eBook: Plumbing Trends Increasing Safe Water Availability

Related Articles

  • BMCC Pool 644 med

    NY contractor upgrades Manhattan school's aquatics center

    See More
  • Vancouver Island Schools local Sooke School District school in Greater Victoria for 1,200 elementary and middle school students.

    New school meets energy efficiency needs with pre-insulated PEXa pipe

    See More
  • Aquatherm-logo

    Aquatherm Pipe meets California Plumbing Code

    See More
×
The pool heating retrofit at Kendal-Crosslands included a lap pool, therapy pool and spa.
Apprentice Ben Dyson works to install two condensing boilers.
Apprentice Ben Dyson changes setpoints on a K2 condensing boiler.
Gages are installed near the heat exchangers.

Keep your content unclogged with our newsletters!

Stay in the know on the latest plumbing & piping industry trends.

JOIN TODAY!
  • RESOURCES
    • Advertise
    • Contact Us
    • Directories
    • Store
    • Want More
    • Supply House Times
  • SIGN UP TODAY
    • Create Account
    • eMagazine
    • eNewsletter
    • Customer Service
    • Manage Preferences
  • SERVICES
    • Marketing Services
    • Reprints
    • Market Research
    • List Rental
    • Survey/Respondent Access
  • STAY CONNECTED
    • LinkedIn
    • Facebook
    • Instagram
    • YouTube
    • X (Twitter)
  • PRIVACY
    • PRIVACY POLICY
    • TERMS & CONDITIONS
    • DO NOT SELL MY PERSONAL INFORMATION
    • PRIVACY REQUEST
    • ACCESSIBILITY

Copyright ©2025. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing

search
cart
facebook instagram twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
  • NEWS
  • PRODUCTS
  • CONTRACTORS
    • BATH & KITCHEN PRO
    • BUSINESS MANAGEMENT
    • HIGH EFFICIENCY HOMES
    • TECHNOLOGY
    • WATER TREATMENT
    • PMC COLUMNS
      • Dave Yates: Contractor’s Corner
      • John Siegenthaler: Hydronics Workshop
      • Kenny Chapman: The Blue Collar Coach
      • Matt Michel: Service Plumbing Pros
      • Scott Secor: Heating Perceptions
  • ENGINEERS
    • CONTINUING EDUCATION
    • DECARBONIZATION | ELECTRIFICATION
    • FIRE PROTECTION
    • GEOTHERMAL | SOLAR THERMAL
    • PIPING | PLUMBING | PVF
    • PME COLUMNS
      • Christoph Lohr: Strategic Plumbing Insights
      • David Dexter: Plumbing Talking Points
      • James Dipping: Engineer Viewpoints
      • John Seigenthaler: Renewable Heating Design
      • Lowell Manalo: Plumbing Essentials
      • Misty Guard: Guard on Compliance
  • RADIANT & HYDRONICS
    • RADIANT COMFORT REPORT
    • THE GLITCH & THE FIX
  • INSIGHTS
    • CODES
    • GREEN PLUMBING & MECHANICAL
    • PROJECT PROFILES
    • COLUMNS
      • Codes Corner
      • Natalie Forster: Editorial Opinion
      • Guest Editorial
    • SPONSOR INSIGHTS
  • MEDIA
    • PODCASTS
    • VIDEOS
    • WEBINARS
  • RESOURCES
    • INDUSTRY CALENDAR
    • DIRECTORIES
    • EBOOKS
    • PM BOOKSTORE
    • CE CENTER
    • MARKET RESEARCH
    • CLASSIFIEDS
  • EMAGAZINE
    • EMAGAZINE
    • ARCHIVE ISSUES
    • CONTACT
    • ADVERTISE
    • PME EMAGAZINE ARCHIVES
  • SIGN UP!