Articles

Choosing between High Mass or Low Mass boilers

By Jack Daniels

There has been much discussion on low and high mass boilers as of late. With high mass boilers now being available in highly efficient modulating and condensing configurations only adds more wrenches to that discussion.  The decision of what boiler to use is often made in the boiler room. Today, let’s discuss the real basis on how to choose what boiler is right for you. Wise contractors know the system will tell you what boiler is best.

Taking a look at how the ideal hydronic system should operate is as simple as considering the idea that what is produced is used.  In other words, if we can achieve equilibrium and have the boiler start up in the fall and not shut down until the spring then we will be as efficient as the boiler’s ratings. As we all know, this is not always possible, heck, it is almost never achieved, thus the need for options in the configuration or mass of the boiler.

Suppose we have all of the proper elements of a hydronic system in their proper locales. The heat source (boiler), circulator, expansion tank, make up water, and heat emitters all have their own temperature and flow requirements. The objective is to achieve a reliable, inexpensive, comfortable, and over all efficient system. Failure to look at all aspects of the system will ultimately add to costs (initial and ongoing), as well as under heating, overheating, wasted energy, and most importantly, a disappointed customer.

First, let’s look at the low mass boilers. A few of the obvious benefits include low cost, high efficiency, and space saving. Another benefit to the low mass boiler is recovery time. A low mass boiler will come up to temperature very quickly as it does not have a lot of water to heat. This is ideal in applications that handle heating and domestic hot water needs. So, if I have a 2,500 square foot house that has one zone of in-floor heat the boiler can go from 120 degrees for the heating of the floor to 180 degrees for heating an indirect water tank very quickly.  Sweet! End of discussion. No need for high mass boilers.

What?! Your customer wants the bedrooms a tad cooler than the living spaces and wants to have the master bath warmer than the rest of the house? This creates the need for micro zones.  Now we have created a zone that can only “use” 6,000 BTU’s. Our low mass boiler can only modulate down to 19,000 BTU’s. We are producing more than we can use. Houston we have a problem. The boiler is going to take the water for the small zone to temperature very quickly (which is one of the advantages of a low mass boiler) and be forced to shut down.  The small zone, however, is still calling for heat so the boiler has to fire again and again as it takes the water for that small zone up to temperature very quickly and shuts down.  Repeat. Repeat. Repeat. Considering that each time a boiler fires it takes a short amount of time for the flame to stabilize and be most efficient in addition to stressing the components of the boiler, short-cycling will lead to a very unhappy customer.

So the answer here is to use a high mass boiler.  Awesome! Always use a high mass boiler when micro-zoning. End of discussion.  But now we have to keep all of that mass up to 180 degrees even in the summertime to produce the domestic hot water in addition to needing a mixing valve for the central heating. Though standby losses have been greatly reduced, they still exist. This is a system that should have mass added to the central heating side but not to the domestic water side.  See our last article in Wisconsin perspectives titled, “Ailing hydronic systems: Is there a doctor in the house?”  As you’ll recall, in that article we discussed buffer tanks in detail.

So if we do not have a domestic load in the aforementioned scenario should we use a high mass boiler? This author says yes. It is the best of all worlds. It can take advantage of outdoor reset and handle the micro zones with the energy stored in the higher mass.

Now, let’s take a look at high mass modulating and condensing boilers. We are no longer restricted to using cast iron behemoths that are not very efficient.  Manufacturers have recently introduced very efficient boilers that have the mass or storage needed for the micro zoned applications.  Other advantages of high mass boilers include lower pressure drop, less maintenance, and ease of installation as there is no need for primary secondary piping.

I would also use high mass boilers in any system that you would suspect debris. Retrofit applications replacing cast iron boilers are an ideal place for a high mass boiler. Gone are the worries about plugged exchangers, water treatments, and endless flushing. Let’s not forget high mass boilers were first then the low mass boilers came on the market as higher efficiency options.  Now, with high mass boilers being as efficient as their low mass counterparts, I view them as another option in the arsenal of comfortable, money saving options heating professionals can offer their customer

So the answer about whether to use high mass or low mass boilers stays the same; it depends.

For information from the author, contact Gregory “Jack” Daniels, Hot Water Products, Inc, (877) 377-0011, HotWaterProducts.com

Success – by Jim Hinshaw

Just had a conversation with a client: what are the top three things that are standing in our way to improving profits this year?  I said, my view from 30,000 feet, here are three that I see.  Not enough leads, close rate too low on the few leads we have, and profits are lower on the few we do sell.  Sort of connected, one leads to the next in some ways.  Take the not enough leads opportunity: when the number of leads drops off, we look at our numbers, realize the bank wants the mortgage money even if the weather was beautiful, sale or no sale.  So we lower our prices, but turns out the competition is doing the same thing.  And even if we do sell one, it is at lower efficiency and/or price point than we hoped for, so the profits are not there.  How do we fix that?

First of all, don’t depend on the weather, the economy, or some government tax credit  to drive your business.  It will disappoint you.   How do we make the phone ring?  Simple, by picking it up and dialing it.  Yes, calling your customers.  Go ahead, tell me you can’t, against the law, all that sort of stuff.  Not if they are already clients.  So call your customers who have done business with you in the past, offer them a discounted tune-up, a safety inspection, or free analysis of their water in the home.  People are not doing maintenance as much as they used to in this economy, but they will spend money on three things: health, safety, economy.   They will not call in, you have to initiate the call, make the offer a decent one that gives them some assurance they will get a positive result (maybe a money back guarantee?), make it a positive thing.

Two other positive outcomes from calling out to your customer base.  The replacement job is not on the street.  You created the opportunity.  The customer who has used you in the past trusts you; you have become the trusted advisor.

Now, how do you build your customer base.  One way is to join a networking group.  Like BNI.  Business Network International.  Go to bni.com.  You can find a chapter near you, and search for chapter that is looking for your trade.  They only allow one company from each trade, if you are the plumbing company, there is not another one.  Cost is about $400 per year; a couple of service calls will repay that investment.  Typically you can sit in a couple of meetings without joining, see if the magic is there.  If not, try another group.  Find one that meets in the morning, with over 20 members.  Less than that, they are not an a fully functioning group, may be a while before they get traction.  Usually the real estate, insurance, and lawyer groups meet at noon for lunch.  Our best bet is in the morning meetings with the painter, roofer, floor covering company, ones that are getting engaged with remodeling projects.  So if you cannot make that happen, form your own networking group.  Meet for coffee once a month with a roofer, pest control company, alarm company, companies you trust and would like to refer people to.  See how their business is going, and something neat will happen.  They will actually help grow your business.  Have a formal program in place where your company knows who to refer a roofing job to.  Don’t ask or expect a referral fee, instead let them know you want reciprocity.

One creative idea that I heard recently, a heating/air conditioning contractor worked with a pest control company to build his business.  When someone signed up for a monthly pest control service, they also got a heating/air conditioning maintenance at no cost.  What does it cost to add a new customer?  Adams Hudson will tell you it can be as much as $400 to bring them into the boat.  So spend less than $100 in labor, pick up a new customer, which is also a positive thing for the pest control company.   That is the sort of thing you can test on a small scale, grow it if it works.

So when you begin to look at projects that are referral based, or your own customer base, the last two items are taken care of.  You close more, at higher prices.  You are a trusted advisor, and the customer will open up with their real concerns, and you will sell more of the cutting edge products, higher efficiency, higher priced.  Instead of having to beat the other guys price.  When you tell the customer the price is built on what they said they wanted, they realize it is not your fault, they actually asked for that investment number.

Another item that will glue the customer to your company is your maintenance agreement program.  I talk to contractors all over the nation, just spent some time with a company that has been in business since the 50s.  Over 60 years.  I asked them if they had a maintenance agreement program, they said yes they did.  When I asked how many agreements they had, it got real quiet.  Finally went to the service dispatcher, she said they had almost 300 in effect.  The owner challenged her, said it had to be more, but it wasn’t.  So they had about 5 per year in business.  Not good.  No matter if you have been in business 5 months or 5 years, start today to sell maintenance agreements.  Set up a goal to add 100 or 500 this year, break it down to so many a month, per tech, per day, make it easy to track.  Then track it.  Share the results weekly on a chart, get the entire company involved.  Have a weekly award for most sold, greatest improved, largest dollars, that sort of thing.  Your maintenance agreement can be on HVAC, or Plumbing, or both.  Why not combine them into one great maintenance program, where you drain the water heater each year, check all the hose bibs, that sort of thing.

If you need help putting that program together, let me know, have done that many times.  And thanks for listening, next month have a great testimony from a client who used some sales techniques to land a couple of interesting jobs totaling over $500,000.  Yep, half a million, two jobs.  From a company that does a lot of residential, and one of these was a public bid that had to get three prices.  All by listening and taking action, not doing what the other guys were doing.

Oh, thanks also from those who bought my book, had some great sales last month, just got a check from PayPal, that is a good thing!

New Commercial Water Heaters

Ask Chuck Appleby, president of Old Lyme, CT-based Appleby Plumbing Co. if he recalls an emergency job.  One he quickly remembers began with an urgent, Christmas day plea from a restauranteur who needed half a million BTUs of water heating at the height of their businest season (see sidebar story).

Appleby was there on site within 30 minutes.  While studying their need for hot water he discovered that the old, leaking beast was sized for peak load, making it at least 20 percent too large 90 percent of the time.  The big, atmospheric system could be replaced by a 400 MBH condensing unit that would be smaller in size, a whole lot less expensive to operate and – if need be – could be coupled with a smaller indirect water heater to meet peak loads.

The new water heater, which offered a much greater recovery rate, was also a lot less burdensome to install than the old one, not requiring the large, ducted air vent.  The new system, a condensing water heater, would require only a 3-inch PVC air intake and a 3-inch PVC flue gas discharge.  “A piece of cake,” said Appleby while marveling the extraordinary efforts taken (and expense) to install the intricate air passageway for the unit that would soon be replaced.

“The new unit’s sealed combustion is a huge benefit for restaurant jobs, eliminating all concern about one of the trickiest challenges with commercial facilities where food is prepared,” added Appleby.  “Large ventilation hoods are notoriusly adept at stealing combustion air from atmospherically-fired systems.  Those days – thanks to new, sealed combustion technology – may soon be gone.”

Appleby’s experience with the system he replaced is illustrative of the way water heating technology has changed in just the past couple of years.  Not long ago, contractors, engineers and building owners were routinely challenged by an inability to easily place and locate commercial water heaters.  The limitations of atmospherically-vented systems, facility design, aesthetics and close proximity to other buildings all factored-in.

Today it’s not uncommon for facility managers, late in the game, to express an aversion to visible venting, based purely on aesthetic reasons.  This is especially true in historic districts.

Fortunately, many of the obstacles to easy placement of water heaters – at least those tied to building design and construction – are overcome with the emergence of new water heater systems, making it much easier to achieve manufacturer-specified combustion air or venting runs.

The arsenal of commercial water heater products and associated technology has grown considerably, availing a wide range of fuel, venting and combustion air options.  There are also many new application-friendly components and techniques to enable trouble-free specification and installation, though – with the new, green systems – a few new needs emerge.

Higher efficiency, condensing systems are great for end-users in terms of energy consumed, chiefly because they harvest heat from waste condensate.  The energy advantage requires modest design and installation changes to meet the need for condensate treatment and drainage.  This may translate to an inability to use existing venting if the original water heater was atmospherically vented, and the availability of electricity.  Some systems require hard-wiring; other commercial systems need only a simple wall plug-in.

Condensate drainage is a likely necessity.  Often, fluids to be drained are too acidic for metal drain lines.  Routing the condensate through a simple, lime-bed acid neutralizer may solve the problem easily.  Better yet:  CPVC or PVC drain lines can handle the acidity.  Condensate typically has a pH of 4.0, about that of Coka-Cola – just enough to attack any metal it connects with.  Over time, the cumulative effect of exposure to acidic runoff threatens the integrity of the drain lines.

Venting.  If new, high-efficiency water heaters are planned as a retrofit, existing, single-wall B-vent must be replaced in favor of PVC, CPVC or ABS plastic.  The majority of venting lines are three or four inches in diameter, precisely matched to the design requirements of new blower motor assemblies that discharge from the top of water heaters.

Plastic vent materials are inexpensive and easy to work with, and yet present no compromise in safety or performance.  Some new water heater systems have the ability to vent through the roof and pull air in for combustion through the wall; this is a big advantage.  The need to improve flexibility of installation and placement has driven the development of power, power direct vent; through-roof and side-wall venting options.

Finally, if the application offers abundant atmospheric combustion air, some water heater models require only one pipe:  for venting.  

Multi-story and high-rise installations challenge traditional venting.  High efficiency water heaters often can accommodate to long venting runs.  Often, there’s no need to run vertical venting all the way to the roof, requiring a roof penetration.  Many systems are now just as well served with side-wall venting.

New codes are forcing all of us to be attentive to a broad range of emerging requirements.  National, state and local codes are changing in the wake of the green movement’s more stringent environmental policies and initiatives.  Among the applicable national codes is the need for water heater system over 199,999 MBH to be ASME-certified.

Historic settings are commonly guarded by restrictions that regulate the presence and appearance of modern building systems and attachments (i.e., wire, regulators, transformers and venting).  In fact, the presence of old and unsightly or loud venting systems has actually encouraged the replacement of aging atmospheric water heaters.

Case in point:  New system shaves cost of operation

Recently, Appleby received an emergency replacement call from the 232-year-old Griswold Inn, founded in 1776 near the banks of the Connecticut River and nestled among many other old and beautifully preserved buildings.

The Inn needed a substantial overhaul brought on by the sudden death of an eight year-old, half million BTU commercial water heater, the only source of domestic hot water for the Gris’ award-winning kitchen.

“Of course, the old Inn wasn’t built to accommodate modern mechanical systems,” said Appleby.  “He specified a new, 400 MBH, LP-fired, high-efficiency eF water heater by Bradford White to replace the quickly deteriorating system installed by another firm.

The water heater they replaced had required a 12-inch stainless steel draft hood and chimney.  “Too bad they had to spend that kind of money on a water heater with such a short life span,” said Appleby.  “The new system we installed requires only a simple, four-inch PVC stack, and at 98% efficiency, would cost them a whole lot less to operate.  The key advantage was the new, condensing unit’s super-high recovery rate.  Because we could heat so much more water, we were able to size it at 100,000 fewer BTUs, a move that also had a huge impact in their fuel consumption.”

Another attribute is that there are no stack losses because the new system is equipped with sealed combustion and uses both PVC exhaust and combustion air lines.  The water heater also offered several venting options, electronic controls, four protective magnesium anode rods, a sediment reduction system and factory-installed dielectric fittings.

Considering the sad waste of resources on the stainless steel stack, which Appleby left in place, he devised a plan that gave it new purpose.  “We used it as an intake air ventilation duct to cool the restaurant’s large refrigeration equipment,”  he said.   “They had a growing problem there because the equipment had been running hot, and this was consuming electricity [highest, by far, of all energy sources in the state] at an alarming rate.  Typically, the air around the refrigeration systems was 120 to 130 degrees, year-round.  Using the 12-inch duct to bring fresh air in, we were able to get those temperatures down substantially.”

“The biggest benefit of all was in the energy savings,” concluded Appleby.  “Today, no one can responsibly afford to waste energy.”