Modulating Boiler

When the snow is falling the last thing you want to think about is shoveling the driveway.  But no matter how nice the falling snow looks, and how much fun it can be, eventually the driveway, sidewalk, steps, and patio need to be cleared.  Today's hydronic heating systems can solve this problem with Radiant Snow Melting. 

Radiant Snow Melt systems circulates warm water / glycol solution through flexible tubes just under the surface.  Advanced systems monitor the moisture and temperature and automatically turn on to melt the snow as it falls.  These systems have been used for many years at ski resorts, hospitals and nursing homes where it is critical to keep surfaces clear to minimize falls.

Radiant Living Magazine recently examined a unique snow-melt application in Greenwich, CT. Click here for the entire article (Spring 2012).   Triangle Tube's Prestige 399 condensing boilers were used in this featured application.  The Prestige Condensing, Modulating Boilers will operate at peak efficiency in snow melt applications.  Snow melt systems operate at low temperatures which maximize the efficiency of condensing boilers. 

Triangle Tube Condensing Boilers provide for all of your heating needs,  The most common use is for space heating with traditional radiators, baseboard, or radiant floor installations.  Pairing a boiler with a Smart Indirect Water Heater provides efficient domestic hot water.  Snow Melt and Pool Heating are perfect for the condensing boilers as they operate at maximum efficiency.

The unusually warm winter in North America has cut everyone's heating costs this year - but the biggest winners by far are homeowners heating with high efficiency condensing hydronic heating systems.  The two features of condensing boilers that contribute to these large savings are Modulation and Outdoor Reset.

Modulation is the process that increases or decreases the heat output, or firing rate, of the boiler.  Just like your kitchen stove, a modulating boiler can adjust its heat output but it doesn't need a person there to make the adjustment.  The boiler's control monitors the heat absorbed by the house by measuring the temperature of the boiler water as it leaves and as it returns to the boiler.  The larger the temperature difference, the more heat the boiler must add to the water, and the higher the firing rate that the control will create.

Non-modulating boilers operate at full fire all of the time.  This is inefficient for two reasons.  First, the boiler is least efficient at full fire, and most efficient at low fire.  So the longer the boiler can run at low fire, the more efficient it is.  Second, each time the boiler starts and stops it loses efficiency.  Modulating boilers run longer at lower temperatures, minimizing the starts and stops.

Outdoor reset is a simple yet extremely important part of a high efficiency system.  An outdoor sensor tells the boiler's control what the temperature is outside.  The boiler uses this information to adjust the temperature of the water that the boiler supplies to the radiant emitters.  This supply water does not need to be as hot during warm weather as it does during cold weather.  By supplying lower temperature water to the system, the boiler can maximize its efficiency.  Click here for outdoor reset basics.

Triangle Tube provides three models of condensing boilers.  The Prestige models feature a stainless steel fire tube heat exchanger with a full featured TriMax control and are available from 60 to 399 MBH.  The Prestige Excellence provides heat and up to 180 gallons per hour of hot water from its indirect water heater.  The Challenger models are available for both heating only (Solo), and combination heat and hot water (Combi) applications.  Challenger boilers are sized from 85 MBH to 150 MBH.   The Keystone models feature a stainless steel water tube heat exchanger and are available in sizes from 399 to 850 MBH for larger residences and light commercial applications. 

Contact Triangle Tube today for more information.

O&G Industries, a global construction materials and services company purchased and converted a Torrington, CT post office building into office space.  As part of the conversion, O&G wisely decided to remove a 40 year old, 1 million Btu/hr oil fired boiler.  They called in Stafford Mechanical Services to perform the conversion. 

Stafford Mechanical Services focuses on designing and installing energy saving projects. After performing a comprehensive energy audit, they determined that natural gas boilers would provide superior energy cost savings compared to oil fired boilers.  Triangle Tube’s 95% efficient Prestige boilers were the best replacements for the old boiler.  Gary Reviczky, of Stafford Mechanical Services noted, “I selected the Triangle Tube Prestige boilers based on my experience with them.  They have proven to be both easy to install and highly reliable.”

Two Prestige Solo 399 boilers, with a total input of nearly 800,000 Btu/hr. replaced the old 1 million Btu/hr. cast iron boiler.  A Triangle Tube Mini-Mod Control provides for the outdoor reset feature to modulate the system water temperature, while the full parallel modulation maximizes the system’s efficiency by operating the boilers at the minimum possible firing rate.  The Triangle Tube boilers increased the heating system turndown to nearly 8 to 1, which minimized boiler cycling and optimized the efficiency.

The Prestige boilers were vented using PVC piping in the existing 30 foot chimney.   This prevented the need for additional holes in the wall and visible vent piping on the exterior.  The wall mounted Prestige boilers freed up the floor space in the boiler room and allowed the piping to be neatly organized.

The old boiler consumed 4,850 gallons during a normal heating season.  At a price of $3.60 per gallon of heating oil, this would cost $17,460.  During the 2010-11 heating season, O&G’s heating cost with the Triangle Tube system was just $7404.  This is a 58% reduction.  The 2010-11 heating season was one of the colder ones in recent memory, so further savings are expected in the future.

Stafford Mechanical Services selected Triangle Tube Prestige boilers helped to convert an old post office to an energy efficient office building.  The building’s owners, O&G Industries will have a more energy efficient workplace for many years to come.

When the Anchorage Housing Authority approached Bittner Plumbing and Heating to upgrade the heat and hot water for their 44 unit apartment building, they wanted a system that would be efficient and reliable.  Paul Bittner of Bittner Plumbing and Heating worked with Mark Herrington at Heating and Ventilation sales to design in a Triangle Tube Prestige Cascade boiler system with Smart Indirect Water heaters to do the job.

The 44 units are heated with baseboard radiation and the hot water for all units is provided by the twin 120 gallon Smart tanks.  ThePrestige Cascade Condensing Boiler unit is built with three 399 MBH boilers.  This provides a highly efficient and effective boiler plant.  By combining the three boilers, a turndown of over 10 to 1 is achieved.  This helps the plant run efficiently with parallel modulation.  With three boilers, the building has the reliability of redundancy in the event of a boiler error or maintenance.  The three boilers are vented with a common vent manifold to minimize the vent piping and provide a single vent pipe.

The Smart Indirect Water Heaters are also both highly reliable and efficient.  The inner stainless steel tank is designed to expand and contract as the water temperature changes during use.  This tank expansion eliminates scale build-up which reduces efficiency and leads to tank failures.  The unique tank-in-tank design provides a large surface area for heat transfer which reduces the amount of time required to heat the water.  These two Smart units replaced conventional direct fired water heaters.  The Smart tanks have 2" of foam insulation completely surrounding the tanks, keeping heat loss down to less than 2 degrees F per hour.

The Housing Authority's decision to upgrade their cast iron boilers and conventional water heaters with Triangle Tube's efficient Prestige and Smart models is saving money every day. As the heating season progresses I will post the savings data. 

The new Challenger Solo Condensing Boiler joins the Challenger Combi Boiler in providing high efficiency hydronic heating in a compact package.  The Challenger Combi boiler provides both heat and domestic hot water, eliminating the need for a separate water heater.  The Challenger Solo boiler provides heat and can provide domestic hot water when paired with an indirect water heater.

The Challenger Solo boiler features a copper tube heat exchanger with an aluminum combustion block.  This unique design is durable and suitable for glycol applications because the system water or glycol flows only in the copper piping.  The aluminum block efficiently transfers the heat from the combustion air and it's light weight makes installation easy.

The Challenger Solo is available in 85, 105, and 125 MBH sizes.  These models are sized to meet the needs of today's homes.  By modulating its output to match the radiant heating needs, the Challenger Solos will operate longer at lower temperatures, which improves efficiency.  These sizes of the Challenger Solo have an AFUE of 95% and operate on either natural gas or propane. 

The Challenger Solos can provide domestic hot water when paired with a Smart Indirect Water Heater.  The Smart can be sized to fit the needs of the residence, providing the instant hot water response that is expected from traditional tank water heaters, with the efficiency of an instantaneous water heater.

Click here for information about the Challenger Solo Condensing Boiler or other Triangle Tube products.

Most of us don't think about the size of our boiler until we are either cold and the boiler is running or buying a new boiler.  In the first case the boiler is undersized for the house.  When we are buying a new boiler we have the opportunity to avoid buying an undersized boiler.

It is a rare case where a boiler is undersized for a home, and while this prevents a cold house on the coldest days of the year, it also reduces potential efficiency gains.  In most of the year, the full capacity of the boiler is not required, and with low heating loads a boiler will need to cycle on and off to meet the needs.  Modulating boilers reduce this cycling as they can run at a low firing rate.  Traditional boilers operate simply on or off at the highest firing rate.

In a home with multiple zones, a condensing boiler works better than conventional boilers due to its ability to modulate, or adjust its firing rate from full fire to a rate that is only 1/3rd of its full firing rate.  Therefore, when a single zone in a home requires heat, the boiler is able to handle that requirement at firing rate that is better suited for the job.

Triangle Tube's Prestige and Challenger Condensing boilers are designed  to meet the needs of homes with single or multiple zones.  When combined with a Smart Indirect Water Heater they make an energy efficient solution to most hydronic heating needs.

There are rapid advances in the use of the sun's energy that are making it attractive to a growing number of homeowners.  While solar power has been available for decades (even the White House had panels in the 1970's), the activity in this market is reaching a fever pitch.  These advances are reducing the costs of installation, which is driving new business, driving new investment, further reducing the costs.  That is the power of progress.

One of the best paybacks today in the solar market is solar thermal - using the sun to heat a home's hot water - and even help with some space heating.  The concept is actually very simple.  Circulate water or glycol through rooftop tubes that heat the water and then transfer that heat to domestic water.  Of course it is more complicated than it sounds and there are a lot of ways to get this done.  But the bottom line is that these relatively simple and compact systems can offset much of the energy used to heat the hot water in a home.  And this is significant because hot water heating makes up 25% of household energy costs.

Triangle Tube offers a solar hot water solution for homes with hydronic heating.  The Smart Multi-Energy (SME) Indirect Water Heater is designed to integrate solar energy into the complete hydronic system.  The  SME contains a heat transfer coil that transfers the heat from the solar panels to the hydronic system water that surrounds a domestic water tank.  This large volume of water (both hydronic system and domestic) is able to maximize the  heat energy from the solar panels.

When the solar panels are not able to meet the demand, the hydronic system provides heat from a boiler.  Triangle Tube's Prestige and Challenger natural gas or propane boilers are green choices as their AFUE's are 96% and 95% respectively.  They feature low NOx emissions and modulating controls using outdoor reset to minimize their carbon footprint.

Modern boilers gain 5 to 10% increases in efficiency versus their traditional “on-off” counterparts by being able to adjust their output to meet the demand.  “On-off” boilers are either on at full-fire or they are off.  Modulating boilers can operate at anywhere from 20% of 100% of their full fire capacity.  (For more on boiler modulation please read my previous posts by clicking here.)

By operating at lower fire, the boilers gain efficiency and cycle less.  To maximize this performance, and minimize boiler cycling, which is a drag on efficiency, the boiler must be properly sized.  In the past, it was common for boilers to be sized up to 50% greater than their “coldest day” demand.  This further increased boiler cycling. 

When replacing an old boiler or installing a new one, it is worth the time to perform a proper heating load analysis.  This will help avoid paying for a boiler that is bigger than needed, or installing a boiler that cannot meet your heating needs.  If a larger boiler is installed than needed you will overspend not only on the initial cost of the boiler, but also by extra fuel cost due to the less efficient operation due to boiler cycling.  While a modulating boiler will operate longer and cycle less than an “on-off” boiler, it still will cycle when the load is lower than the minimum output of the boiler.  Therefore, an oversized boiler should be avoided.

While it may seem logical to simply size your replacement boiler based on the one that is being replaced, a heating load analysis can better determine the size required.  Even if the original boiler had been properly sized when it was installed, there probably have been significant improvements to the house since then.  It is very common for extra insulation and more energy efficient doors and windows to have been installed.  All of these will impact the heating load.

Triangle Tube’s Prestige and Challenger boilers are able to modulate down to between 25% and 30% of the boiler’s maximum output.   This helps improve efficiency especially during the warmer days in the heating season.  This modulation is also helpful when using an indirect water heater like Triangle Tube’s Smart series.  Make your radiant heating system as green as possible by properly sizing your boiler.  Contact Triangle Tube today for more information of click here to locate a certified installer near you.