Latest boiler room makeover.

This is a recently completed boiler system project that involved significant repiping and improvements to incorporate a new master bath radiant floor circuit and performance improvements. A buffer tank was added to eliminate boiler short-cycling and outdoor reset was added to the radiant floor circuits (master bath, family room and first floor bath) to prevent an over-temp condition. Variable speed circulators were added to reduce pumping costs and manifolds were added with zone valves and controllers for individual circuits. Slab sensors were added to the master bath and family room. Piping improvements were made to give the owner more predictable control over room and floor temperatures. The improvements will make this home more comfortable while saving fuel.

Here's how things looked before our make-over:

Some Things I’ve Learned in 30 Years of Business

This week marks thirty years since the incorporation of my business. I’m not a particularly nostalgic person so I hadn’t been thinking much about it. I just realized last week that April 1^st was coming up (the day my business was formally created) and, wow, has it really been 30 years?

That got me thinking about where I’ve been, where the industry has been, what I’ve learned and where things are going.

My business has had different iterations through the years. From d-i-y plumbing retail, new home construction, service, remodeling, HVAC, and my current passion and recurring theme from the very beginning — hydronic heating.

I’ve always had a desire to learn new things and stay on top of the latest industry trends, albeit with a healthy dose of skepticism toward flash-in-the-pan ideas. In some ways, keeping up with the technology is the easy part. It’s the other life lessons —learned through experience — that have really made things interesting.

I’ve seen some things I’d rather forget — like the squalor of a neglected elderly man’s home, or a basement, so full of bees, that the 100-watt light bulb at the bottom of the stairs looked like a night-light.

And I’ve been involved in many memorable projects — from landmark restorations to Homearama. From Habitat For Humanity to the Shepherd Home.

But people and relationships are what’s most rewarding about the last 30 years. I truly consider most of my clients to be friends. Friends that respect each other and are loyal to each other. Friends that want each other to succeed and live healthy, happy lives.

Thank you to all my friends. Thank you for allowing me to be part of your lives and welcoming me into your homes.

Hydronically yours,

Wayne

Punch Out the Holes

It was time for a new shower curtain in our bathroom. It’s a simple enough task. But as I started to hang the curtain on the first hook, I realized that the holes in the top of the curtain where the hooks are inserted are not punched out. Oh, they’re outlined and perforated, ready for punching — but they still need to be punched out.

I didn’t think much of it on the first hole, but by the time I was on the sixth hole I was starting to wonder, why wouldn’t the manufacturer finish punching out the holes? Are there really people who hang their curtain without using the holes? And would those people really object to the aesthetics of holes where they didn’t need them?

By the twelfth hole my arms were starting to ache and I was getting aggravated with the whole lack-of-hole thing. Why leave out the holes? Why make more work for your customers? Are you really saving that much in the manufacturing process by eliminating the hole-penetration step?

Maybe the curtain manufacturer cares. Maybe they don’t. Either way, I’ll probably never take the time to let them know. I’ll blow it off as not worth the effort.

It got me thinking about my clients. I wondered if maybe there are holes I’m not punching out in my process. Are there things I’m leaving undone that create little aggravations for you?

I try to cover all the bases. That’s why I perform heat loss calculations, and ask you how you use your heating system, and clean up after myself, show up on time, return your phone calls and emails, and do a multitude of other on- and off-the-job tasks intended to soften the impact of what I’m doing on your everyday life.

But I still wonder if I’m leaving some holes unpunched. Is there something I’m not doing, that despite my best efforts is even a small aggravation for you? Something that causes you inconvenience?

We all love to hear praise, and I’m no different. But without criticism how are we to improve? And I do want to improve.

So, please, tell me what aggravates you. I’ll listen. I promise. And then I’ll punch out the holes for you — whatever those are.

Hydronically yours,

Wayne

The Truth About Troubleshooting

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Most times, when things go wrong with your hydronic system (or any mechanical or electrical system) there’s a clear reason for the failure. Experience tells me where to look for the most obvious source of the problem in order to make a quick repair and get things up and running again.

But every once in a while a problem crops up that doesn’t lend itself to a quick diagnosis. Maybe it’s something I haven’t seen before or there are unique conditions affecting the equipment in unexpected ways.

I like to look at these situations as opportunities — to learn something new, to challenge my troubleshooting skills and to show you how committed I am to making things right. That’s not to say these opportunities are without their challenges.

It takes hard work, research and focus. Getting to the root cause and fixing the problem once and for all requires a complete understanding of what went wrong. And, more often than not, it takes patience. Patience on my part — and yours.

It’s relatively easy to throw a bunch of parts at a failed system and get a quick fix. But unless we take a systematic approach to troubleshooting, we’ll never know the true cause — and therefore won’t be sure it can’t happen again.

I’ve found the best way to get to the true cause is to make one change at a time and measure the effect of that change. That way I can be confident that the final fix will be permanent, because I’ve truly gotten to the root cause of the problem.

You play a big part in the troubleshooting process, too. Your feedback and observations of system performance are critical. So is your patience. It will likely take several visits and a fair amount of communication to get to the bottom of a stubborn issue. But together, we’ll get it done. And we’ll both be better off for having worked it through systematically.

Hydronically yours,

Wayne

An Ideal Heating/Cooling System for Your Small Addition

Last week I explained why the use of a ductless mini-split heat pump system as the sole source of heating and cooling is not the right application for the small (less than 1000 sq. ft.) addition. In order to properly size for the heating load on colder days, you’d be left with grossly oversized cooling capacity. And that will cause the heat pump to short-cycle when cooling on any day except for the very warmest. This short-cycling will result in less comfort, less efficiency, increased maintenance and shorter equipment life. Not good. After all, who wants to stress about their heating/cooling system.

You want to be comfortable all year long. If you want to expand your home with a small addition, I recommend ductless mini-split heat pumps for cooling in applications where the primary heat is supplied by another source — like radiant floor, finned-tube baseboard, radiant panel or hydro-air. That way I can size the cooling portion for ideal comfort and the heating portion of the heat pump can be used as a backup heat source if the main heat source is down for maintenance.

But now there’s an exciting new technology coming to the market. It combines the best of variable-speed compressor heat pump technology with hydronics to provide super high-efficiency performance with the awesome comfort of radiant heat and central cooling.

An air-to-water heat pump is the heart of this technology. During heating season it extracts heat from the outdoor air and transfers it to water using an indoor heat exchanger. In the cooling season, the process is reversed — indoor heat is transferred (via the same heat exchanger) to a refrigerant and expelled outdoors by the heat pump.

Since the heat pump has a maximum heating output temperature of approximately 120˚F, it’s a perfect match for low-temperature radiant — thin-slab, above-floor tube and plate, walls, ceilings, panel radiators and some types of finned-tube baseboard. This is the most comfortable heat around.

To cool the air, a pump circulates water (chilled by the heat pump) from the heat exchanger through a cooling coil located in an air handler. This distributes cooled and dehumidified air throughout your addition. If the design of the addition permits it, a standard air handler with the familiar ductwork can be used. But if equipment space is at a premium, a high-velocity mini-duct system with its 2” diameter ducts may be a better fit.

The efficiency of an air-to-water heat pump is rated in terms of its Coefficient of Performance (COP). COP is a ratio of the amount of heating (or cooling) produced to energy consumed. It’s not unusual for a variable-speed air-to-water heat pump to have a published COP of over 4.0 and an average COP of 2.7 to 3.0. In simple terms, for every one unit of energy consumed, the heat pump can produce almost three units (annual average) of heating or cooling. The only system more efficient than that is a geothermal system. (More on that comparison in future installments.)

Even though some of these heat pumps are advertised to operate in outdoor temperatures down to -4˚F, when the outdoor temperature drops to about 20˚F, the cost of energy input increases to the point where an alternate heat source is more efficient. A separate gas- or oil-fired boiler can provide a backup heat source for the coldest days as well as domestic hot water (DHW) production year-round. And if the main part of the house is hydronically heated, the air-to-water heat pump and the existing hydronic system are a match made in heaven!

But even if you need a backup/DHW boiler, the incredible efficiency of the air-to-water heat pump will offset the higher initial equipment cost with fuel savings in just a few years.

If there’s a small addition in your future, consider an air-to-water heat pump with radiant heat and chilled-water cooling as a renewable-energy alternative that pays for itself.

Heidronically yours,

Wayne

Ductless Mini-Split Heat Pumps and the Small Addition

The popularity of ductless mini-split heat pumps has grown tremendously in recent years. They’re a great way to add cooling to a hydronically heated home because they don’t need bulky ductwork. But like many new things, there’s a tendency to apply them to as many situations as possible, including some that they may not be well suited for. One such misapplication is as the sole heating and cooling source for a small addition.

Ductless mini-split heat pumps are usually an air-to-air heat pump — meaning it takes outside air and strips it of its heat value and transfers that heat to your home to provide space heating. For cooling, the cycle is reversed — it pulls the heat out of your house and expels it to the outdoors. You could think of a heat pump as an air conditioner that’s capable of working in reverse.

Heat pumps are nothing new, but the configuration of the ductless mini-split is. The condensing unit is located outdoors and a refrigeration lineset, small drain and wiring are run into your home through a 3˝ opening in an outside wall. They supply the indoor unit, which is usually mounted high on a wall and contains the blower and indoor controls. Ductless mini-splits are incredibly quiet (inside and out) and efficient.

I’m often asked to design a heating and cooling system for a small addition to an existing home (less than 1000 sq. ft). The first thing I look at is the capacity of the existing system to handle the addition’s extra heat and cooling load. More often than not, especially with forced air, the existing system can’t do the job. The system in a hydronically heated home can almost always handle the additional heating load but it obviously can’t provide cooling.

That usually leads to someone suggesting a ductless mini-split heat pump for heating and cooling the addition. It’s tempting, because it’s a relatively easy, quick and inexpensive installation. And here’s where the misapplication comes in. As an example, let’s apply a ductless mini-split heat pump to a typical 700 sq. ft. master bedroom, bath and laundry addition.

An addition like this would typically have about a 14,000 Btu/hr heat load on the coldest day of the year (considered 0˚F in the Rochester, NY area). It would also require just under 1 Ton (12,000 Btu/hr) of cooling on the warmest day of the year (considered 90˚F in this area). Both design loads would keep the indoor temperature at 70˚F.

Now, when sizing a heat pump, you size for the greatest load (heating or cooling) so you can be sure there’s enough capacity for both seasons. In our example case, as with most applications in this climate, the largest load is the heating load. So wouldn’t logic dictate that we’d need a heat pump rated for 14,000 Btu/hr? Not so fast.

We also need to consider the fact that as the outdoor temperature drops, so does the efficiency of the heat pump. In fact, even though some of the newer models are capable of providing heat down to an outdoor temperature of -4˚F, at those temperatures their heat output drops to near 50% of rated capacity. So now we realize that we need to DOUBLE the capacity of the heat pump to have any chance of maintaining our 70˚F indoor temperature on a 0˚F day.

That means we’re looking at installing a heat pump with a 28,000 Btu/hr minimum capacity, which actually works out fairly well, because heat pumps come in a 2-1/2-Ton size (30,000 Btu/hr). So now that we’ve decided that we need a 30,000 Btu/hr unit for heating, let’s see how that works for the cooling side.

Remember, the cooling load is 12,000 Btu/hr on the warmest days (90˚F). And there’s a 30,000 Btu/hr capacity. Simple math tells us that on even the warmest days, our heat pump is oversized (for cooling) by 250%. And, as you’ve heard me preach before, in cooling (and heating), bigger is not necessarily better.

Most of the better ductless mini-split heat pumps these days use inverter technology to modulate the compressor speed, which tailors the output to the load. With our example, the compressor would modulate down to 40% of capacity on the WARMEST day. That means that on a milder day it may need to be operating in the single-digit-capacity numbers. The problem arises when the compressor is only capable of modulating down to 30% of capacity, meaning that anything less than 75% of the maximum cooling load (in our example) will be asking the heat pump to work below its minimum capacity — which will be the bulk of the cooling season!

When a heat pump is asked to work in a range below its minimum capacity, it will short-cycle and, as a consequence, fail to properly dehumidify. We’ve discussed short-cycling and its consequences before — less comfort, less efficiency, increased maintenance and shorter equipment life.

For this example addition, the ductless mini-split “kind of” does the job. It can either do an acceptable job of heating with not-so-good cooling, or an awesome job of cooling with unacceptable heating performance.

So if a ductless mini-split isn’t the answer to heating and cooling your small addition, what is? Be sure to check next week’s Heidronics blog post for the answer.

Heidronically yours,

Wayne

When More Power Isn’t Always the Winner

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The Daytona 500 is all about speed and power and getting to the finish line first. Hydronics is basically the opposite — but you’d never know that from the way most hot water heating systems are installed these days.

Historically, North American hydronic designers and installers have specified and installed circulating pumps that pump more water and use more power than what is actually needed. It’s called “over-pumping.” And if a system underperforms, the first reaction of many technicians is to install a bigger, more powerful pump. But this almost never solves the problem.

It’s a chicken vs. egg thing. Installers either don’t have the knowledge or won’t take the time to calculate the pumping requirements for the system, and wholesalers don’t stock more than a few different pump models. I’ve heard installers justify their pump choice by the “bigger is better” mentality. And wholesalers have told me that they’d stock a wider variety of pumps but the installers aren’t asking for them. That’s a shame.

In hydronics, like stock car racing, the object is to go round and round until you cross the finish line and meet your goal. But unlike stock car racing, the winner in hydronics gets there with as little effort and speed as possible. The goal is delivering the right amount of heat from the boiler to the heat emitter (radiator, radiant floor panel or baseboard heater, for example). Pushing the water faster doesn’t make that happen any better. It just wastes energy!

Over-pumping can also create a condition known as velocity noise, which is caused by the water traveling too fast through the pipe and fittings. It can also cause erosion corrosion — a wearing away, or eroding, of the pipe wall due to the scouring action of high-velocity water flow.

But there’s hope. A new generation of circulators uses variable-speed technology and highly efficient electronically commutated (ECM) motors to vary their output to the specific needs of your system. If a zone valve closes, the pump slows down. If another opens up, the pump speeds up. Some are

Variable-speed ECM circulator

designed to operate on a pressure difference. Others operate on a temperature difference. But either type delivers just the flow necessary to heat the space, and either will consume much less electricity to accomplish the same results as compared to a bigger pump.

I’ve been using these variable-speed ECM pumps for several years now and have found them to be incredibly energy-efficient and versatile — especially for systems subject to changing flow-rate requirements. But they’re not the answer for a poorly designed system. While these pumps are capable of responding to a wider range of conditions, they still have their limitations. The application of solid design principles will determine the best application for these new-generation pumps.

You could compare great hydronic pumping to the tortoise and the hare. A bigger, faster pump will just wear out your system while a slower, steadier, variable-speed pump, like the tortoise, will win the race — every time.

Heidronically yours,

Wayne