Great news from our favorite friends in Allendorf, Germany. Viessmann Manufacturing, the world leader in high-performance boilers, have re-designed their signature wall-hung condensing boiler, the Vitodens 200. Not only have they improved the boiler, they've made the price more attractive, too.
The two biggest changes are to the burner and the control system. The previous version of the Vitodens 200 utilized a burner and gas-train provided by a third-party manufacturer. The new Vitodens 200 now features a Viessmann-manufactured "Lambda" burner.
The new "Lambda" burner offers ultra-clean combustion by contiuously monitoring and adjusting the fuel-to-air ratio. The result is near-perfect combustion no matter the quality of the fuel, firing-rate of the boiler, or the ever-changing conditions within the combustion-chamber itself. While we loved the previous matrix burner of the Vitodens 200, the new Lambda burner is a dream to service, allowing a tech to disassemble and re-install in a matter of seconds.
The second major change is to the control system. The previous version featured the "Comfortrol" control system, found only on the Vitodens 200. The new version utilizes the same Vitotronic control platform used on their other boilers, such as the Vitola 200. This gives the boiler greater flexibility in special situations where multiple motorized mixing-valves are required, or for staging multiple boilers. It also allows for the use of the Vitotrol remote programming units and/or room sensors.
In addition to the changes to the burner and control system, the jacket has been modernized and updated. Viessmann also eliminated the separate domestic hot water connections and diverting assembly, as well as the internal circulator. These changes may be viewed as a negative by some, however, it has simplified the boiler mechanically, which means fewer moving parts and less chance for failure down the road.
As a result of these changes, coupled with Viessmann's construction of a new, streamlined manufacturing facility, the price of the Vitodens 200 has been reduced by approximately 30 percent. This is good news all the way around. Can't way to install them this winter.
To learn more about Viessmann boilers, visit www.enhancedliving.net.
Overstock heating equipment -- act fast, save big!
Thanks to our longstanding relationship with local HVAC wholesalers, we have exclusive access to a limited number of boilers, warm air furnaces, water heaters and air conditioning units, which are being sold to us at below wholesale cost.
Because we save at the wholesale leverl, we can pass these dep discounts on to you.
By choosing to replace your outdated heating or cooling equipment now rather than later, you stand to save up to $2,000 on a new system installation.
Why so cheap? The slow economy has left wholesale suppliers with excess inventory, especially big-ticket items like boilers, furnaces, water heaters and air conditioning systems. Rather than take up valuable warehouse space or risk damage, our suppliers are willing to sell their overstock at or below their cost. Available equipment includes high quality brands with factory-backed warranties.
So, if you're worried about getting through one more winter on an aging boiler or furnace, or want to spend the summer in the luxury of air conditioning, now's the time to buy!
Just remember, once it's gone, it's gone!
Below is a sample of available of what's available. For a cost estimate on installation, please e-mail or call (518) 235-0311.
Boilers:
New Yorker CLW-5 oil-fired boiler (148,000 or 189,000 btu)
New Yorker PVCG Direct-vent boiler for LP gas (107,000 btu)
Burnham Direct-vent boiler for LP gas (140,000)
Warm air furnaces:
TempStar 106,000 btu oil-fired furnace
TempStar 80+ AFUE furnace for natural gas (100,000 btu)
TempStar 80+ 2-stage furnace for natural gas ( 75,000 btu)
TempStar 95 AFUE gas furnace (60,000 btu)
Coleman oil-fired mobile home furnace (66,000 btu)
Air conditioning:
Comfort Air 18,000 btu ductless mini-split
EMI 12,000 btu ceiling mount ductless mini-split
Comfort Air 24,000 2-zone ductless mini-split
ECW 9,000 btu ductless mini-split
ECW 12,000 btu ductless mini-split
Water heaters:
(2) Rinnai tankless water heater for LP (2532FFUC-P)
This is just a sampling of available units. Please e-mail us what you are looking for and we'll check on availability.
Because we save at the wholesale leverl, we can pass these dep discounts on to you.
By choosing to replace your outdated heating or cooling equipment now rather than later, you stand to save up to $2,000 on a new system installation.
Why so cheap? The slow economy has left wholesale suppliers with excess inventory, especially big-ticket items like boilers, furnaces, water heaters and air conditioning systems. Rather than take up valuable warehouse space or risk damage, our suppliers are willing to sell their overstock at or below their cost. Available equipment includes high quality brands with factory-backed warranties.
So, if you're worried about getting through one more winter on an aging boiler or furnace, or want to spend the summer in the luxury of air conditioning, now's the time to buy!
Just remember, once it's gone, it's gone!
Below is a sample of available of what's available. For a cost estimate on installation, please e-mail or call (518) 235-0311.
Boilers:
New Yorker CLW-5 oil-fired boiler (148,000 or 189,000 btu)
New Yorker PVCG Direct-vent boiler for LP gas (107,000 btu)
Burnham Direct-vent boiler for LP gas (140,000)
Warm air furnaces:
TempStar 106,000 btu oil-fired furnace
TempStar 80+ AFUE furnace for natural gas (100,000 btu)
TempStar 80+ 2-stage furnace for natural gas ( 75,000 btu)
TempStar 95 AFUE gas furnace (60,000 btu)
Coleman oil-fired mobile home furnace (66,000 btu)
Air conditioning:
Comfort Air 18,000 btu ductless mini-split
EMI 12,000 btu ceiling mount ductless mini-split
Comfort Air 24,000 2-zone ductless mini-split
ECW 9,000 btu ductless mini-split
ECW 12,000 btu ductless mini-split
Water heaters:
(2) Rinnai tankless water heater for LP (2532FFUC-P)
This is just a sampling of available units. Please e-mail us what you are looking for and we'll check on availability.
Condensing boiler problems (and their solutions)
If you've recently installed a new condensing boiler -- Baxi, Viessmann, Buderus, MZ, Munchkin, etc. -- and are experiencing problems, we can help. As a "new" technology, condensing boilers require a special knowledge and new set of rules when it comes to piping and controls.
Unfortunately, many "old school" plumbers and heating guys don't fully understand or appreciate the new piping and control methods that condensing boilers require in order to work effectively, efficiently and trouble-free. As a result, many new condensing boiler installations are rife with problems -- frequent lock-outs and failures, excessive heating bills, over-heating and under-heating of rooms throughout the home, etc..
While the list of symptoms are long and varied, most fall within one of three categories: 1) piping problems, 2) under-control, and 3) poor commissioning.
Let's start with the first category -- piping problems. Conventional non-condensing boilers are a relatively simple affair. When the thermostat calls for heat, the boiler turns on and gets hot (180 degrees +), hot water leaves the boiler, goes through the radiators, and comes back at about 160 degrees. When the room is sufficiently heated, the boiler turns off. The piping to accomplish this is also simple -- supply-piping out, return-piping in. Done deal.
Unlike their bigger, meatier non-condensing cousins, condensing boilers, by and large, are designed with smaller, narrower heat-exchangers. As a result, there is a substantial "pressure-drop" through the boiler. In condensing boilers, the heat-exchanger acts as a bottle-neck that gives standard circulator pumps a heck of a time pushing sufficient flow through both the boiler and the radiators it's connected to.
Many installers fail to take this high pressure-drop into consideration when piping a new condensing boiler into an existing system. The result of this oversight is often a house that becomes under-heated, particularly as the weather gets colder.
The fix is simple -- read the boiler's installation manual! Most, if not all, manufacturers provide detailed piping diagrams for their boilers. And most, if not all, involve some form of "primary-secondary" piping and/or hydraulic separation. The theory and practice of hydraulic separation is too much to get into hear, but to read more visit here.
As an aside, homes with small heating loads, say, less than 70,000 btus, depending on the boiler, may not need hydraulic separation. Because the load is small, the boiler pump can move enough btus, despite the bottle-neck, to heat the home sufficiently. Also, homes with large diameter pipes (originally designed for an old, gravity-type system), can also often be heated without hydraulic separation, since the flow-rate requirements and pressure-drop through the pipes are usually very low. For everyone else, hydraulic separation is the way you need to do it.
The next category of problems results from under-control. Condensing boilers are typically designed with modulating burners, which (theoretically) ramp up or down depending on heating conditions. Most boilers have one or more mechanisms to tell the boiler when to step on or let off the gas, but the usual starting point is feedback from temperature-sensors within the boilers supply and return pipes. When the temperature difference between supply and return increases, the boiler assumes more heat is need to the house and steps on the gas. As the temperature difference decreases, it steps down.
This is fine for many applications, but also has some shortcomings that, under certain conditions, can cause over-firing and/or short-cycling. Some cheaper condensing boiler rely solely on boiler supply/return temperature-sensors to modulate the burner. Higher quality, more sophisticated models, however, also utilize one or more forms of external feedback in the form of an outdoor-reset control and/or indoor temperature-feedback. Such controls often convert outdoor or indoor temperature feedback into a 0-10vdc electrical signal that ramps the burner up and down depending on the weather outside or the indoor ambient temperature. Such controls do a superior job at matching the boiler's output to the actual load of the home, and maximizes the boiler's efficiency.
Some boilers, like the Viessmann Vitodens 200, provide both outdoor-reset and indoor temperature feedback as a standard feature. Other boiler manufacturers sometimes offer such features as an optional upgrade. In these cases, unfortunately, many installers fail to inform homeowners of the importance of such controls and fail to integrate them into the home.
Why are such controls so important? They are often the main means by which the boiler actually condenses its flue-gases and provides combustion-efficiencies in the 90 percent + range. In order for a boiler to actually condense, its flue-gases must drop below the magic number of 137 degrees fahrenheit (in natural gas-fired boilers). In order to meet this target temperature, the boiler must produce lower than normal water temperatures, which, in turn, means it must lower its burner-output. If, on the other hand, the boiler fails to maintain sub-137 degrees, its efficiency is only in the 85 percent ballpark at best. Or, if it maintains low temperatures, but must run short cycles to do so, you add significant wear and tear on the boiler and in some cases may not be actually achieving high combustion efficiencies.
The third category of problems often associated with condensing boilers is often due to poor commissioning practices by the installer. Some condensing boilers are equipped with sophisticated computers. That said, the computers are only as smart as the user and require some basic inputs by the installer that affect the modulation and control of the boiler. Some installers fail to provide such inputs and allow the boiler to run off its default settings. That result is a boiler that fails to operate at maximum efficiency.
In other cases, some boilers require an initial adjustment to the boiler's modulating gas valve. Failing to match the incoming gas pressure to the appropriate outputs (high and low fire) can result in over or under-firing and, short-cycling, or even outright malfunction and breakdown. Proper commissioning is crucial to owning a happy condensing boiler.
Finally, another often-seen problem with condensing boilers is the failure to properly match the boiler with the right distribution system (i.e. radiators, baseboard, etc.). As efficient as condensing boilers can be, they're not always a good candidate for some homes, and aren't worth spending the premium to install. Some homes, particularly those with finned-tube baseboard, require high boiler supply water temperatures to remain heated comfortably. Since condensing boilers can't condense above 137 degrees, it doesn't make sense to employ one if the home's baseboards require higher temperatures.
Now, if you're in a position where you've had a condensing boiler installed on a baseboard system and you have't noticed a significant drop in fuel bills, you can always upgrade your standard-output baseboard to a "high-capacity" model and/or increase the length of it whereever feasible.
Have a problem? E-mail it to us by clicking here.
Unfortunately, many "old school" plumbers and heating guys don't fully understand or appreciate the new piping and control methods that condensing boilers require in order to work effectively, efficiently and trouble-free. As a result, many new condensing boiler installations are rife with problems -- frequent lock-outs and failures, excessive heating bills, over-heating and under-heating of rooms throughout the home, etc..
While the list of symptoms are long and varied, most fall within one of three categories: 1) piping problems, 2) under-control, and 3) poor commissioning.
Let's start with the first category -- piping problems. Conventional non-condensing boilers are a relatively simple affair. When the thermostat calls for heat, the boiler turns on and gets hot (180 degrees +), hot water leaves the boiler, goes through the radiators, and comes back at about 160 degrees. When the room is sufficiently heated, the boiler turns off. The piping to accomplish this is also simple -- supply-piping out, return-piping in. Done deal.
Unlike their bigger, meatier non-condensing cousins, condensing boilers, by and large, are designed with smaller, narrower heat-exchangers. As a result, there is a substantial "pressure-drop" through the boiler. In condensing boilers, the heat-exchanger acts as a bottle-neck that gives standard circulator pumps a heck of a time pushing sufficient flow through both the boiler and the radiators it's connected to.
Many installers fail to take this high pressure-drop into consideration when piping a new condensing boiler into an existing system. The result of this oversight is often a house that becomes under-heated, particularly as the weather gets colder.
The fix is simple -- read the boiler's installation manual! Most, if not all, manufacturers provide detailed piping diagrams for their boilers. And most, if not all, involve some form of "primary-secondary" piping and/or hydraulic separation. The theory and practice of hydraulic separation is too much to get into hear, but to read more visit here.
As an aside, homes with small heating loads, say, less than 70,000 btus, depending on the boiler, may not need hydraulic separation. Because the load is small, the boiler pump can move enough btus, despite the bottle-neck, to heat the home sufficiently. Also, homes with large diameter pipes (originally designed for an old, gravity-type system), can also often be heated without hydraulic separation, since the flow-rate requirements and pressure-drop through the pipes are usually very low. For everyone else, hydraulic separation is the way you need to do it.
The next category of problems results from under-control. Condensing boilers are typically designed with modulating burners, which (theoretically) ramp up or down depending on heating conditions. Most boilers have one or more mechanisms to tell the boiler when to step on or let off the gas, but the usual starting point is feedback from temperature-sensors within the boilers supply and return pipes. When the temperature difference between supply and return increases, the boiler assumes more heat is need to the house and steps on the gas. As the temperature difference decreases, it steps down.
This is fine for many applications, but also has some shortcomings that, under certain conditions, can cause over-firing and/or short-cycling. Some cheaper condensing boiler rely solely on boiler supply/return temperature-sensors to modulate the burner. Higher quality, more sophisticated models, however, also utilize one or more forms of external feedback in the form of an outdoor-reset control and/or indoor temperature-feedback. Such controls often convert outdoor or indoor temperature feedback into a 0-10vdc electrical signal that ramps the burner up and down depending on the weather outside or the indoor ambient temperature. Such controls do a superior job at matching the boiler's output to the actual load of the home, and maximizes the boiler's efficiency.
Some boilers, like the Viessmann Vitodens 200, provide both outdoor-reset and indoor temperature feedback as a standard feature. Other boiler manufacturers sometimes offer such features as an optional upgrade. In these cases, unfortunately, many installers fail to inform homeowners of the importance of such controls and fail to integrate them into the home.
Why are such controls so important? They are often the main means by which the boiler actually condenses its flue-gases and provides combustion-efficiencies in the 90 percent + range. In order for a boiler to actually condense, its flue-gases must drop below the magic number of 137 degrees fahrenheit (in natural gas-fired boilers). In order to meet this target temperature, the boiler must produce lower than normal water temperatures, which, in turn, means it must lower its burner-output. If, on the other hand, the boiler fails to maintain sub-137 degrees, its efficiency is only in the 85 percent ballpark at best. Or, if it maintains low temperatures, but must run short cycles to do so, you add significant wear and tear on the boiler and in some cases may not be actually achieving high combustion efficiencies.
The third category of problems often associated with condensing boilers is often due to poor commissioning practices by the installer. Some condensing boilers are equipped with sophisticated computers. That said, the computers are only as smart as the user and require some basic inputs by the installer that affect the modulation and control of the boiler. Some installers fail to provide such inputs and allow the boiler to run off its default settings. That result is a boiler that fails to operate at maximum efficiency.
In other cases, some boilers require an initial adjustment to the boiler's modulating gas valve. Failing to match the incoming gas pressure to the appropriate outputs (high and low fire) can result in over or under-firing and, short-cycling, or even outright malfunction and breakdown. Proper commissioning is crucial to owning a happy condensing boiler.
Finally, another often-seen problem with condensing boilers is the failure to properly match the boiler with the right distribution system (i.e. radiators, baseboard, etc.). As efficient as condensing boilers can be, they're not always a good candidate for some homes, and aren't worth spending the premium to install. Some homes, particularly those with finned-tube baseboard, require high boiler supply water temperatures to remain heated comfortably. Since condensing boilers can't condense above 137 degrees, it doesn't make sense to employ one if the home's baseboards require higher temperatures.
Now, if you're in a position where you've had a condensing boiler installed on a baseboard system and you have't noticed a significant drop in fuel bills, you can always upgrade your standard-output baseboard to a "high-capacity" model and/or increase the length of it whereever feasible.
Have a problem? E-mail it to us by clicking here.
Thermal solar water heating design primer
With the re-authorization and expansion of federal tax credits for solar technologies, 2009 is expected to be a growth year for solar installations. With a much lower initial cost and faster pay-back than photo-voltaics, thermal solar systems (aka solar water-heating) will be of particular interest to architects and homeowners alike.
In the realm of thermal solar systems, many options are available — from drain-back and closed-loop systems to a near infinite number of ways to configure and integrate into the existing space and water-heating infrastructure. Here’s a quick and dirty overview.
Drain-back vs. closed-loop
All thermal solar systems consist of collectors, either flat-plate type or vacuum-tube, usually mounted on the roof, an insulated storage tank, a pumping mechanism to transfer heat collected at the roof and move it to the storage tank, and piping filled with a water/anti-freeze solution used as the heat-carrying medium.
In drain-back systems, the collectors have the ability to drain themselves of their water/anti-freeze solution in order to protect against freezing or over-heating (under certain conditions, collectors can exceed 212 degrees F). A small secondary reservoir tank is required to store the water/anti-freeze solution when not being used in the collectors. In addition, since drain-back systems are “open-loop,” a large, high-head pump is required to lift the solution from the reservoir tank into the collectors.
Closed-loop systems have no such drain-back mechanism and rely on anti-freeze for wintertime protection; and sound engineering and system design to protect against over-heating. Mechanically simpler than drain-back systems, closed-loop configurations require no reservoir tank and only a small low-head pump to move the water/anti-freeze solution through the system.
Our take: Reserve drain-back systems for special situations only (i.e. large commercial systems). For typical residential installations, closed-loop systems, with fewer moving parts, offer a simpler, less expensive and easier to maintain option for homeowners. Properly designed and maintained, closed-loop systems will not freeze and will not cause over-heating problems. Keep it simple!
Thermal solar for space-heating
The Catch-22 of thermal solar is that when you need the most heat, the sun produces the least energy. So, the question is whether it’s worth the additional expense and effort to integrate a thermal solar system with a home’s (hydronic) space-heating infrastructure.
In upstate New York, for example, during the month of October a typical 30-tube collector array collects, on average, between 25,000 and 30,000 btus per day. In a modest home, this represents around 5 percent of the home’s total space-heating needs. In January, on the other hand, the same collector will produce less than 1 percent of the home’s space-heating needs.
Yes, you can add more collectors to capture more heat, but that would require considerable amount of additional storage capacity — I mean considerable. There’s two problems to contend with. First, the collectors only produce heat during the day — when it’s the night you need the most heat. The second problem is the overabundance of heat you’ll be left with in the summer. Unless, you have an Olympic-size swimming pool to heat, you’ll have paid for equipment that heats water you can’t use.
Our take: Integrating a thermal solar system into a home’s heating circuit adds at least $2,500 on the cost of installation, and increases its complexity and long-term maintenance. In the cold Northeast, we say spend the money elsewhere — upgrade insulation or improve the efficiency of the space-heating system.
Simple, cost-effective design
In thermal solar design, less is more. Keeping a system simple will shorten its pay-back and cost less to maintain over the long-term. With good, direct exposure to the sun, we recommend a modest three-panel array connected to a single-coil indirect-fired storage tank serving as a pre-heater to the home’s primary water heater. This configuration will produce approximately 75 percent of a home’s total annual domestic hot water load, uses the least moving parts, is a cinch to trouble-shoot and repair (one pump, one control device), and finds a perfect balance between maximizing the efficiency of the collectors at a relatively low installation cost.
In the realm of thermal solar systems, many options are available — from drain-back and closed-loop systems to a near infinite number of ways to configure and integrate into the existing space and water-heating infrastructure. Here’s a quick and dirty overview.
Drain-back vs. closed-loop
All thermal solar systems consist of collectors, either flat-plate type or vacuum-tube, usually mounted on the roof, an insulated storage tank, a pumping mechanism to transfer heat collected at the roof and move it to the storage tank, and piping filled with a water/anti-freeze solution used as the heat-carrying medium.
In drain-back systems, the collectors have the ability to drain themselves of their water/anti-freeze solution in order to protect against freezing or over-heating (under certain conditions, collectors can exceed 212 degrees F). A small secondary reservoir tank is required to store the water/anti-freeze solution when not being used in the collectors. In addition, since drain-back systems are “open-loop,” a large, high-head pump is required to lift the solution from the reservoir tank into the collectors.
Closed-loop systems have no such drain-back mechanism and rely on anti-freeze for wintertime protection; and sound engineering and system design to protect against over-heating. Mechanically simpler than drain-back systems, closed-loop configurations require no reservoir tank and only a small low-head pump to move the water/anti-freeze solution through the system.
Our take: Reserve drain-back systems for special situations only (i.e. large commercial systems). For typical residential installations, closed-loop systems, with fewer moving parts, offer a simpler, less expensive and easier to maintain option for homeowners. Properly designed and maintained, closed-loop systems will not freeze and will not cause over-heating problems. Keep it simple!
Thermal solar for space-heating
The Catch-22 of thermal solar is that when you need the most heat, the sun produces the least energy. So, the question is whether it’s worth the additional expense and effort to integrate a thermal solar system with a home’s (hydronic) space-heating infrastructure.
In upstate New York, for example, during the month of October a typical 30-tube collector array collects, on average, between 25,000 and 30,000 btus per day. In a modest home, this represents around 5 percent of the home’s total space-heating needs. In January, on the other hand, the same collector will produce less than 1 percent of the home’s space-heating needs.
Yes, you can add more collectors to capture more heat, but that would require considerable amount of additional storage capacity — I mean considerable. There’s two problems to contend with. First, the collectors only produce heat during the day — when it’s the night you need the most heat. The second problem is the overabundance of heat you’ll be left with in the summer. Unless, you have an Olympic-size swimming pool to heat, you’ll have paid for equipment that heats water you can’t use.
Our take: Integrating a thermal solar system into a home’s heating circuit adds at least $2,500 on the cost of installation, and increases its complexity and long-term maintenance. In the cold Northeast, we say spend the money elsewhere — upgrade insulation or improve the efficiency of the space-heating system.
Simple, cost-effective design
In thermal solar design, less is more. Keeping a system simple will shorten its pay-back and cost less to maintain over the long-term. With good, direct exposure to the sun, we recommend a modest three-panel array connected to a single-coil indirect-fired storage tank serving as a pre-heater to the home’s primary water heater. This configuration will produce approximately 75 percent of a home’s total annual domestic hot water load, uses the least moving parts, is a cinch to trouble-shoot and repair (one pump, one control device), and finds a perfect balance between maximizing the efficiency of the collectors at a relatively low installation cost.
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