Author Archives: Chris Williams

About Chris Williams

Chris Williams works with HeatSpring developing products and managing online content. Chris is a NABCEP Certified Solar PV Installer and an IGSHPA Accredited Geothermal Installer. He has installed over 300kW of solar PV systems, tens of residential and commercial solar hot water systems and 50 tons of geothermal equipment. Chris is the Chairman of the Government Relations Committee of New England Geothermal Professional Association and he consults with renewable energy companies on sales, marketing and design.

Troubleshooting Condensing Boilers in Hydronic Systems – What is the System Doing?

This a guest post from Roy Collver. Roy is a condensing boiler expert. Here’s what John Siegenthaler, author of “Modern Hydronic Heating,” says about Roy’s work: “When I have a detailed question about the inner operation of a modulating / condensing boiler, Roy Collver is the first person I contact. The investment in Roy’s HeatSpring course is a fraction of the cost of a single mod/con boiler, but it will teach you concepts, procedures, and details that will return that investment many times over.”

Learn from Roy

  • Free. Roy is teaching a two-part free course on how to sell mod-con boilers. The second live lecture is happening on Wednesday, July 30th. Sign up for the free mod-con course here.
  • Paid: Roy Collver teaches an advanced 5-week course on mastering condensing boiler design in hydronic systems with the folks at HeatSpring. If you need to increase your skills and confidence around selling, quoting, designing, setting up controls, or troubleshooting condensing boilers in new construction or retrofit applications, this course is for you. Each session is capped at 50 students, but there are 30 discounted seats. Get your discount and sign up for Condensing Boilers in Hydronic Systems.

Enter Roy…

Understanding the Simple Basics

Cold weather is never too far away in most parts of North America. Be ready when it hits, and review the basics of hydronic system operation so you can quickly locate the problems that always come up. When you approach an operational hydronic system it will exhibit one of the following six states. Quickly understanding what you are dealing with will greatly reduce head-scratching time and point you in the right direction. Standing slack-jawed in front of a boiler with no clear path to determining what is wrong is very uncomfortable and a waste of time. Confidence is a key factor in successful troubleshooting, and to be able to indicate to a customer what the BASIC problem is right away buys you time to be able to work the problem, find out the SPECIFIC cause, and fix it. Using this guide as a quick reference should help speed the troubleshooting process along.

heatsourceoff
Hydronic systems are all about Delta T (the difference in temperature between the heating fluid, the system components and the surrounding air and objects). Heat always travels to cold, and if heat is not added to the heat transfer fluid (usually water), the fluid and all of the components in the system will eventually cool down to the temperature of the surroundings.

THINGS TO LOOK FOR:  NO POWER – NO FUEL – PILOT OUT – MANUAL RESET SAFETY OFF – NO CALL FOR HEAT – FLOW SWITCH OR LOW WATER CUT-OFF TRIPPED – DEFECTIVE BOILER COMPONENT (GAS VALVE, VENT DAMPER, IGNITOR, ETC.)

normaloperation

The boiler is on and the hot combustion gases create a large Delta T between the combustion chamber and the water in the surrounding heat exchanger. Because heat travels to cold, the water heats up. The circulation pump moves the hot water through the distribution piping to the terminal units. The terminal units heat up and a Delta T develops between the hot terminal units and the colder air. The air will get warmer at the expense of the water, which cools slightly. The cooler water circulates back through the system back to the boiler where it is heated up again. If the heat going into the boiler is more than the system can use, the water will continue to get hotter until the boiler cycles off on its operating control. The temperature difference between the water leaving the boiler and the water returning to the boiler will be “normal” for the system (usually 15°F to 40°F depending on the load and system design).

noflowThe boiler is on, adding heat to the water, but for some reason the hot water is not circulating through the distribution piping to the terminal units. The terminal units will cool down to the temperature of their surroundings and a “no heat” condition will result. The water in the boiler will continue to get hotter until the boiler cycles off on its operating control or internal high limit control. The supply and return piping near the boiler will be close to the same temperature.

THINGS TO LOOK FOR:  –  NO POWER TO PUMP – DEFECTIVE PUMP (BURNED OUT MOTOR, WORN IMPELLER, ETC.) – BLOCKAGE IN PIPING (TOTALLY PLUGGED “Y” STRAINER, CLOSED VALVE, CRUD BUILDUP BLOCKAGE, ETC.)

notenoughflow

The boiler is on, adding heat to the water, but the hot water is not circulating fast enough through the system. The first terminal unit may become warm, but because the water is moving so slowly, all of the usable heat is transferred out of it before it gets very far. The last terminal units do not become warm enough to heat the space and a “not enough heat” condition will result. The water in the boiler will continue to get hotter until the boiler cycles off on its operating control or internal high limit control. There will be a large Delta T between the water leaving the boiler and the water returning to the boiler. (The supply will be a bit hotter than normal, but the return will be much colder than normal.)

THINGS TO LOOK FOR:  –  DEFECTIVE PUMP (WORN IMPELLER, ETC.) – PARTIAL BLOCKAGE IN PIPING (PLUGGED “Y” STRAINER, CRUD BUILDUP, PARTIALLY CLOSED VALVE, ETC.)

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New Massachusetts Solar Bill H.4185 Would Destroy Community Solar Potential In the Commonwealth

This is a guest post from Sam Rust from SRECTrade about new solar legislation in Massachusetts.

(Editor Note: A note about the importance of community solar for lowering customer acquisition costs, something EVERYONE in the solar industry cares about. Everyone is talking about lowering customer acquisitions costs and soft costs and community solar has the potential to instantly drop acquisition costs by 50% to 80% for solar companies offering roof mounted and community solar projects. Why? It’s simple math. If you had 100 solar leads, a good conversion rate of leads to customers would be 10%. This equals 10 customers. Here’s the thing, in order to find 10 customers that WANT to invest in solar and HAVE a good roof, you must bump into 3 to 4 people that WANT solar but DON’T HAVE the roof space. If those 3 to 4 people could become community solar customers, then the conversion rate of those 100 leads would become 30% to 40% instead of 10%. This would then drop the acquisition costs because you’re getting more customers with the same marketing spend. Food for thought.)

Enter Sam Rust.

In 2013 Massachusetts was ranked 4th, behind California, Arizona, and New Jersey for most solar installed. Despite this success, legislation, officially known as H.4185 (An act relative to net metering), is pending at the Massachusetts State House that could drastically change the direction of the Massachusetts solar industry. Touted in the media as successful compromise between regulated utilities and the solar industry, H.4185 might be more of a step back, than a step forward. The bill could pass in both the Massachusetts House and Senate before the end of the legislative session on July 31st, despite the opposition of many solar owners, installers, and representatives of the community solar movement.

Here’s a short explanation of how we got here and what H.4185 is.

Currently there are limits on how much Massachusetts solar capacity can qualify for net metering in each utility territory. These limits, which only apply to larger solar facilities, are nearly maxed out for each utility and prevent the Commonwealth from meeting Governor Deval Patrick’s 1,600 MW by 2020 solar goal.  H.4185 would remove the net metering limits and put in statute Governor Patrick’s 1,600 MW target in exchange for a radical adjustment in the structure of Massachusetts solar policy of which the primary adjustments are:

  • The removal of annual capacity restrictions on large “solar farm” projects
  • The creation of yet-to-be defined minimum electric bills for all ratepayers
  • The reduction of the virtual net metering rate from compensation at the retail rate to the wholesale rate of electricity
  • A limit on the size of behind-the-meter projects to 100% of the on-site load
  • A transition away from the successful market-based SREC program to an unknown program managed by the Department of Public Utilities
  • Transfer of all of the “environmental” attributes of solar arrays to the utilities

In translation, H.4185, a bill that is ostensibly about net metering would remove or weaken most of the policies that have made the Massachusetts solar industry so successful. It is a bill that exchanges a set of known, highly successful policies, for a new set of untested policies.  The bill has not yet passed and many stakeholders are calling amendment language that would remove most of the major policy language in exchange for an incremental increase in the net metering caps and a formal commission to be convened next year to review the more contentious aspects of the legislation. This more cautious approach would stabilize an already jittery Massachusetts solar industry and ensure that all stakeholders are at the table the next time net metering limits need to be addressed.

How this could negatively impact solar installers.

  1. Anybody working to do community solar will be negatively impacted because the VNM credit is being reduced
  2. H.4185 removes the protections in place under the SREC-II program for incentivizing distributed/ rooftop/ carports/ general behind-the-meter projects
  3. The declining block incentive program will be set at the DPU, rather than at the DOER. This means that installers will need to lawyer up and deal with the regulated utility lawyers in order to argue for favorable incentive targets. Solar in Massachusetts goes from a decentralized system, where everyone and anyone can participate in the rule making process to a system where the big player have the negotiating advantage
  4. The utilities receive all of the attributes of the solar, including the RECs and will be able to lead the discussion on monitoring and other equipment requirements. This reduces the possibility for innovation in the solar space regarding capacity markets, battery storage, voltage regulation etc
  5. The minimum bill imposition will hurt anyone with a low electric bill, which means smaller projects will be most affected by the minimum bill
  6. Anybody doing business in Muni territory is left out. Currently the SREC program covers Munis
  7. Above all else this just adds more complication to the system. We just spent a year implementing SREC-II and now we have to work on implementing another program for which installers will need to fight to be part of the process for negotiating the declining block targets and minimum bill. This just adds more uncertainty, which is bad when you are trying to mature an industry.

WANT TO HELP? Contact Sam

First. Here is Sam’s email address: contact@competitivesolar.org

Send him an email and he’ll figure out how you can help.

Massachusetts voters are encouraged to research this bill further and to contact their state legislators. Here is a link to a site that makes legislators searchable by zip code.

For more information please read this well written opinion piece in Commonwealth magazine and visit the Facebook page for the Massachusetts Stakeholders for Competitive Solar or www.competitivesolar.org.

 

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Free Solar Design Tool: String Sizing Tool For Commercial Solar Projects That Works with All Inverters

One of the most important aspects of designing a solar array is sizing module strings to operate within the parameters of the selected inverter. This is especially true for commercial and megawatt solar projects. To help in this process, we’re providing a free solar design tool to our readers.

Ryan Mayfield and Renewable Energy Associates has developed a free solar design tool to help in that process. Most inverter manufacturers offer some type of sizing tool, whether it’s simple or advanced, it’s usually limited to selecting only their products. The REA System Sizing Tool lets you select from a wide variety of products and manufacturer’s. Ryan is teaching a 10-week advanced solar design class with SolarPro called Megawatt Design.

You can click here to down the string sizing tool. 

Key Features of the Solar String Sizing Tool

A quick note. The tool now requires you to turn on macros. For those concerned about security we can not guarantee that the tool will work well, accurately or at all without macros enabled.

  • Thousands of modules.
  • Hundreds of inverters.
  • Add your own module or inverter.
  • World Wide ASHRAE locations. 5,000+
  • Create your own custom sites.
  • Dual MPPT’s configuration possible.
  • Voltage drop calculator.
  • Performance calculator.
  • Quick Printing features.

Screen Shots of the Solar Design Tool

Inserting Array Characteristics

Screen shot 2014-07-16 at 10.50.25 AM Inserting Weather Conditions

Screen shot 2014-07-16 at 10.30.36 AMLogging Other Project Specific Activities

userinput

Download the Solar Design Tool

You can click here to down the string sizing tool. 

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Designing Wood Gasification Boiler Protection Systems: T & ∆T Pumping: An application that leverage both strategies

This is a guest article from John Siegenthaler. In the fall, John is teaching an advanced design course on Hydronic-Based Biomass Heating Systems. This is the most advanced and technically challenging biomass design course that you’ll find anywhere. The capstone project for the class will be designing a system and getting it reviewed by John. The class is capped at 50 students, and there are 30 discount seats. You can get a discount and sign up for a test drive here. Click here to join our Linkedin group to connect with professionals and share best practices for selling, designing and installing hydronic-based biomass systems

Download: Wood Gasification Protection Tutorial

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Enter John

The market for wood gasification boilers is growing in North America. Most are used in rural areas where natural gas in not available, and thus cost of firewood is often very competitive against the alternatives of #2 fuel oil or propane.

I my area of upstate, NY, fuel oil is currently selling for about $3.80 gallon, and propane at about $2.80 per gallon.  Firewood is available in the range of $65 per face cord.  If one assumes a conversion efficiency of 85% on oil, 93% on propane (via a mod/con boiler), and 80% on firewood (burned in a wood gasification boiler), the unit cost of these fuels is as follows:

• #2 oil: $31.92 / MMBtu

• Propane: $33.28 / MMBtu

• Firewood: $12.11 / MMBtu

From the standpoint of fuel cost, it not hard to see why the demand for wood gasification boilers is growing.

Wood Heating Done Right: When properly applied, wood gasification boilers allow dry firewood to be converted into thermal energy at efficiencies far higher than those of non-gasification type wood burning devices.  These boilers can also be matched up with the latest hydronics hardware such as radiant panels, high efficiency circulators, and even mod/con boilers (in cases where fully automatic heat delivery is required if the wood fired boiler is not operating).

One critical detail that must be addressed with any wood gasification boiler is protection against sustained flue gas condensation.  The situation is very similar to the boiler protection issues we’ve discussed in many past columns.  It can be summarized as follows: If the water temperature entering the boiler allows the fire side of the boiler’s heat exchanger to drop below the dewpoint of the exhaust gases, some of those gases will condense into an acidic liquid that is very corrosive to materials such as steel or cast iron.  In the case of wood fired boilers, the condensate also leads to formation of creosote within the boiler, the vent connector, and chimney.  Think of creosote as solid fuel.  If it’s exposed to suitably high temperature, creosote will combust.  The resulting heat can quickly destroy a steel or masonry chimney, and possibly the building with it.

Dry Fire: There are several ways to provide boiler protection.  Currently, the most common approach uses a “loading unit,” as shown in figure 1.

Figure1

Figure 1

The loading unit combines a high flow capacity 3-way thermostatic mixing valve, circulator, and flapper check valve. When the boiler is warming up, the 3-way thermostatic valve routes all flow through the bypass, and back to the boiler inlet.  This allows the boiler to warm up quickly, since no heat is being released to the load.  When the water exiting the loading unit reaches a minimum set temperature, such as 130 ºF, the valve modulates to allow some hot water flow to the thermal storage tank.  When the water temperature leaving the valve is several degrees above the minimum temperature setting, all water leaving the boiler goes to the storage tank.  Thus the loading unit acts as a “thermal clutch” between the boiler and tank, smoothly increasing or decreasing the rate of heat transfer, as necessary to keep the boiler inlet at an appropriate temperature.   The loading unit is also internally configured so that it allows thermosiphon flow between the boiler and thermal storage tank during a power outage.  Thus, no external heat dump is required when the system is piped as shown in figure 1.

Alternate Approach: Another method of boiler protection use a variable speed circulator as the thermal clutch between the boiler and a high thermal mass load such as a thermal storage tank.  The water temperature entering the boiler is sensed, and the electronics controlling the circulator slow it, as necessary, so that the rate of heat transfer to the load doesn’t exceed the rate at which heat is being produced in the boiler.  This approach has been used for years in the form of variable speed injection mixing pumps between conventional gas-fired and oil-fired boilers, and lower temperature / high thermal mass loads such as radiant floor slabs.  Figure 2 shows how it can be used to protect a wood gasification boiler.

Figure2

Figure 2

In this system, circulator (P1) operates, at a fixed speed, whenever the wood gasification boiler is being fired.  The circulator would be sized to provide a nominal 20 to 25 ºF temperature drop across the boiler when it’s operating at maximum output.  If the boiler has relatively low flow resistance (which is typical of most wood gasification boilers), and the piping loop is short, there isn’t much head loss in the boiler loop.  Thus, circulator (P1) could likely be relatively small.

Circulator (P2) is a variable speed circulator that monitors the temperature at sensor (T1), installed at the boiler inlet.  This circulator operates at a very low speed until the boiler’s inlet temperature rises to where flue gas condensate will not continue to form. For dry firewood and a typical air/fuel ratio, this temperature is about 130 ºF.

Once the boiler’s inlet temperature rises above this “dewpoint” temperature, circulator (P2) speeds up, and thus starts transferring heat from the boiler loop to the thermal storage tank. When (if ?) the temperature at sensor (T1) reaches 5 ºF above the  minimum boiler inlet temperature, circulator (P2) would be operating at full speed.  As the temperature at sensor (T1) drops back toward the dewpoint, circulator (P2) slows as necessary to prevent condensation in the boiler.  Thus, boiler protection always remains in effect.

Another important consideration in the piping design is to allow natural convection between the boiler and thermal storage tank to remove residual heat from the boiler if a power failure occurs while it’s firing.  The piping shown in figure 1 will allow this to occur.  However, it’s crucial that the check valve shown near the upper left connection on the storage tank is a swing check, rather than a spring-loaded or weighted plug flow check.  The forward opening resistance of a swing check is very low, and compatible with natural convective flows.  That’s not the case with either spring-loaded or weighted plug flow checks.

Upping the Offering: The schematic in figure 2 keeps the same piping as figure 1, but adds differential temperature control between a temperature sensor in the upper portion of the storage tank, and the outlet of the wood gasification boiler as the means of turning on fixed speed circulator (P1), as well as supplying power for variable speed circulator (P2).  The differential temperature controller determines when the boiler is a fixed number of degrees above the temperature in the upper portion of the storage tank, and in effect “enables” the heat transfer process, including boiler protection. It’s essentially the same control action used to start and stop operation of a solar thermal system.  Just think of the boiler as the heat source rather than a solar collector.  Adding this control functionality eliminates the need for some to manually turn the boiler circulator on and off.

Figure3

Figure 3

One More Variation: The schematic in figure 3 uses the same logic as the system in figure 2, but adds speed control to circulator (P1).  The “∆T” logic controlling circulator (P1) would modulate its speed to maintain a user-set temperature difference between the outlet and inlet of the boiler.  The objective is to reduce power demand to circulator (P1) when the boiler output is reduced, and thus reduce overall electrical energy use.

Figure4

Figure 4

There you have it; modern variable speed circulators matched with state-of-the-art solid fuel boilers.  This combination is highly scaleable to larger systems using larger circulators controlled by variable frequency drives (VFDs). It’s also applicable to pellet-fired boilers, which also require protection against sustained flue gas condensation.  Keep these details in mind if you have a solid fuel boiler project coming up.

© Copyright 2013, J. Siegenthaler, all rights reserved
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How to Normalize Energy Consumption For Weather Influences Using RETScreen ® Plus

This is a guest post by Michael Ross from RER Energy Inc. Michael is teaching a 6-week, 30 hour class on Mastering RETScreen for Clean Energy Project Analysis. The class is capped at 50 students, and there are only 30 discounted seats. Get your discount here.

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Article Goal 

This article shows engineers and energy data analysts how to “normalize” energy consumption or production to account for the variation in weather over time. By the end of the article, you should understand why normalizing for weather is important, and how it can be done, either in a spreadsheet or using a free tool called RETScreen® Plus.

Why Normalize for Weather?

The need to “normalize” for weather arises very often. For example, you have a year or two of utility bills for a facility, you plan on improving the energy efficiency of the facility, and you need to estimate what the energy savings will be in the future. One challenge is that the past energy consumption is determined not just by the equipment at the facility, but by the variations in the weather experienced by the facility. What if the winter covered by the utility bills was especially cold, and as a consequence gas consumption was higher than typical? Basing your estimates of savings on a single year, without “normalizing” for weather, or explicitly adjusting the consumption to reflect typical weather conditions, will cause you to overestimate the typical savings in the future.

Normalizing for weather is a good idea whenever an accurate understanding of the current energy consumption of a facility (a “baseline”) is needed; otherwise, as suggested in the previous example, estimates of future savings arising from improvements to the existing facility may be too high or too low, and consequently inferences that a proposed improvement is cost-effective may not turn out to be correct (or, conversely, a truly cost-effective opportunity may be missed).

The need to normalize may also appear in energy production projects. For example, a photovoltaic system might produce more electricity in one year than in the previous year. Is this merely because there was more sunshine in the second year? If so, did this additional sunshine hide deterioration in the system operation?

Sometimes normalizing for weather is not merely a good idea, but rather a requirement of a client or a utility or government funding program. For example, I recently conducted a study for a client who was seeking funding from the Federation of Canadian Municipalities (FCM). The client needed to show how much connecting his building to a district heating system would reduce overall natural gas consumption (and thereby greenhouse gas emissions). The FCM program stipulated that any study had to first normalize past energy consumption for variation in the weather, and then project savings into the future based on typical weather.

Normalizing for Weather: the Theory

Normalizing for weather is, in principal, straight forward:  you “fit” a statistical model (i.e., an equation) that relates you consumption data (e.g., utility bill consumption) to one or more variables that you think exercise an influence on consumption (e.g., heating or cooling degree days).  When “fitting” the model to the data, you adjust the coefficients of the equation until sum of squared differences between the actual consumption data and the modeled consumption data is minimized. Often a linear equation is used for the statistical model, and the process is called “linear regression”.

So, for example, you might produce a scatterplot of daily average gas consumption for each billing period against the average number of heating degree days per day for the billing period, as shown in the figure below.

imageone

 

I’ve superimposed a straight line on the scatterplot to make it evident that there is a linear relationship between the fuel consumption and the heating degree days. That is, I should be able to estimate with some accuracy the fuel consumption using an equation of the form[1]:

This equation has the right form, but what should I use for the coefficients a and b? A common approach is to select a and b in such a way as to minimize the “sum of squared errors”, or SSE.  To do this manually, I start out with a guess for these coefficients, and then I use this equation to estimate the fuel consumption for each billing period. I then compare these estimates with the actual fuel consumption for each billing period. If I square the difference of the two and sum over all billing periods, I’ll have the SSE. This is a measure of how well my choice of coefficients fits this equation to the data; I adjust the coefficients until the SSE is as small as I can make it (unless the line passes through every data point exactly, the SSE will not go to zero).

 

equationone

Then I’ve got my equation. For the data from the example above, it would be:

equationtwo

I can then use this equation to estimate the gas consumption based on the heating degree days. So, for example, imagine that for the location of this building, a typical month of March will have 620 heating degree days (°C·day). That works out to 20 heating degree days per day. If I wanted to know what the facility’s gas consumption in a typical March would be, I’d plug this into the equation:

equationthree

This would tell me that on an average March day, I’d require 6.6 GJ of gas, so over the whole month I’d consume around 206 GJ of gas. To determine the gas consumption in a typical year, I do this same exercise for each month’s typical number of heating degree days.

Normalizing for Weather Using RETScreen® Plus

While this normalization can be done using a spreadsheet, my tool of preference is RETScreen® Plus, a sister program to the better known but completely different RETScreen® 4. (Both tools are available for download, for free, from the Government of Canada: www.RETScreen.net).

RETScreen® Plus is designed precisely for this type of exercise (as well as much more in-depth analyses to be discussed in later articles), and consequently much quicker and (less error-prone) than doing the manual exercise outlined above. The main program features that make it quicker and easier than the manual exercise are:

1)     Rapid access to up-to-date daily weather data for locations across the globe

2)     Tools for combining and regrouping data sets on different time bases.

3)     Automatic fitting of equations

4)     Optimization of the heating degree day reference temperature

Let’s examine each of these advantages by going through the key steps for normalizing for weather data using RETScreen® Plus.

I’ll start by asking my client for utility bills. He sends me a spreadsheet for the period of 2012 through 2013, indicating for each bill the billing date and the billed gas consumption (in GJ) for the period:

two

Note that the “monthly” bills are not all dated on the same day of the month, and the number of days in the billing period changes from bill to bill. Also note that I’m missing the bill for May 23. Such are the complications of the real world.

Next, I open RETScreen® Plus. The first key step is to tell it where my building is located; it will be apparent why we need to do this when we need to get weather data. There are a variety of ways to specify the project location, but the fanciest is through a map interface that lets me indicate the project location with a thumbtack:

imagethree

 

Then I import my Excel spreadsheet of utility data into RETScreen® Plus. I tell it that the data I want to investigate is for “Fuel Consumption”, specifically natural gas measured in GJ. It opens a blank table:

Screen shot 2014-06-19 at 10.24.00 AM

I fill this table by “Importing from file…” and selecting my Excel file. A dialog box pops up and I see that it has correctly interpreted the headers in the file, with the exception of the gas consumption, which I have to pick from a drop down list:

fiveimage

 

When I click on the green checkmark, I get another dialog box identifying the missing data for May and giving me some choices for dealing with this, such as using the average for the whole data set, interpolating between adjacent data points, deleting the whole row, or repeating the previous value. I chose to simply ignore the missing data for now. RETScreen inserts this data into my table, automatically calculating the number of days in each billing period:

six

With that half my data is in the tool. But now I need to tell RETScreen what the “factors of influence” in this data are: that is, what variables are likely to exert an influence on the gas consumption. When normalizing for weather, the answer is pretty clear (it’s the weather, obviously), but in different applications of the tool it might be factory production, hotel occupancy, or something else.

Thus, I need to get weather data for 2012 and 2013. Ideally, this weather would be on the same time basis as my utility bills. That is, I’d have the average weather conditions for my site for the first, second, etc. billing periods.

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[Free Floor Plan] 10 Ways Passive House Design is Different Than Normal Home Design

If you want to download the floor plan, please scroll to the bottom of the article.

This is a guest post by Mike Duclos. Mike is founder of The DEAP Energy Group, a firm providing a wide variety of deep energy retrofit, zero net energy, and Passive House related consulting services. Mike has real-world experience with the design, construction, certification, and delivered performance measurement of Passive House, and is a Certified Passive House Consultant. Mike will be teaching a 6-week course on Passive House Design as part of NESEA’s Building Energy Master Series that will teach builders, architects, and engineers the fundamentals of Passive House design. In the class you’ll design your own passive house and get it reviewed by Mike using “PHPP Lite.” The class is capped at 50 students with 30 discounted seats. Sign up for the Passive House Design training here. 

Passive House Design vs Normal Home Design

Passive House is a hot topic, and we get a lot of questions about how to design and model these homes. Most people are familiar with design principles for “normal” residential homes, so we wanted to provide a sample as-built for an actual Passive House with a number of comments on how its design is different from traditional construction.

A Real Passive House Design

passive house plans

Here are 10 Key Design Features That are Different From Normal Residential Home Design

  1. The long elevation of the home faces close to due South, providing more wall area for windows.
  2. Home is positioned on lot so views are to the South so that the larger South window area is used to advantage for both the view and solar gain.
  3. Room layout centers around a ‘great room’ comprised of a living and kitchen/dining area for entertaining a modest number of people in 1152-square-foot home.
  4. Master bedroom receives sun from the East and South; the other front bedroom receives sun from the South and West.
  5. Point source heating efficacy is optimized by use of a central great room in which a single, 9 KBTU/hr  ductless mini-split is used for all space conditioning.
  6. Bathroom door is located immediately below ductless mini-split, for best localized space conditioning.
  7. Mechanicals are located between bathroom and kitchen sink, minimizing delay to hot water and stranding of hot water after a draw. Solar DHW tank can contribute 300-500 BTU/hr next to the bathroom door.
  8. Glazing is maximized on the South elevation, minimized on East and especially West to help manage overheating , and is minimized on the North to minimize space heating losses.
  9. South elevation has one entry door which is glazed to take advantage of the view and the sun.
  10. Mudroom on the North is the entrance used on a daily basis by occupants.

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How to Identify and Eliminate the 7 Forms of Waste in Residential Solar Installations

800px-Rube_Goldberg's_latest_war_machine^_-_NARA_-_534875

This is a guest post by Pam Cargill. Pam is an expert at optimizing residential solar operations. She’s helped scale operations both at Alteris Renewables (now RGS Energy) and Sungevity. She knows all the secrets of the larger installers and is now running her consulting practice, Chaolysti, to spread what she’s learned.

Here are a few ways you can learn more from Pam.

Enter Pam Cargill. 

Soft costs. While analysts have been long on talk analyzing what they are and how they are impacting the industry, they have been short on solutions. Why? Because residential solar is, by nature of its need to interface with a varied landscape of regulatory and policy issues, a complex business. It is equal parts finance, construction, and high-tech. Since there is no common formula to apply to reduce soft costs nor a single soft cost category that installers should universally tackle first, installers should use a more individualized approach to evaluating their project delivery process to find out which areas would be most impactful to improve first.

This post, geared for owners and/or operations managers of residential solar installation companies, will teach you about the 7 Forms of Waste, a powerful categorization methodology you can apply in your operations to begin to learn where time, energy, and money is misspent, a leading causes of customer dissatisfaction. In residential solar, maximizing customer satisfaction is crucial because the leading source of low-cost leads is from the referrals of currently installed customers according to solar analyst Nicole Litvak, author of GTM Research’s U.S. Residential Solar PV Customer Acquisition: Strategies, Costs and Vendors.

What is the 7 Forms of Waste?

The 7 Forms of Waste is a framework used in proven cost reduction methodologies from the Toyota Production System (TPS), now commonly referred to as “Lean Production” or simply Lean. Using this framework, you can begin to reframe your operations in the language of what your customer considers valuable. By classifying all process activities into these two categories of “value added” and “non value-added” activities, you can begin to take action improving valuable parts and removing or reducing non value-added waste.

Who is the Customer?

In order to begin categorizing waste activities, employees must identify and understand their internal customers and the final customer. These relationships are key to meeting customer expectations. For example, design staff drafting plan sets must meet the needs of the AHJ, Utility, installers, and the final customer. Without seeing the AHJ, Utility, and installers as customers of their product, the designer could overlook important safety or design requirements in order to meet a customer-specified design constraint, which could cause rework and delays if in conflict with AHJ or Utility requirements or real-world installation practices. When each employee frames the recipient of their work as a customer, they are more likely to see how their activities could be value-added or non-value added. When framed in this way, management can also work more intelligently together to streamline handoffs and minimize or remove re-work related to misalignment of goals.

What Defines “Non Value-Added?”

A value-added process is an activity that a customer is willing to pay for that contributes to the end product they expect. Non value-added processes, on the other hand, fall into two categories – business requirements and pure waste. Business requirements comprise the overhead of the company: your fleet of vehicles, HR activities, compliance-related activities (especially if you deal with finance or credit). Examples of pure waste are excessive coordination meetings, generating reports that are not read or acted upon, multiple layers of approval, and any kind of rework. The 7 Forms of Waste are comprised by these two-types of non value-added activities.

7 Forms of Waste and Common Residential Solar Examples

Now that you understand how to identify your internal and external customers and know how to identify value-added and non value-added activities, let’s look at the 7 Forms of Waste: What they are, what they mean, and an example of each one so you can learn how to see them in your own company.

Transport

The unnecessary motion or movement of materials or information, including work-in-process, from one operation to another. This adds time to the process during which no one adds value.

Example: Ordering from a vendor that cannot drop ship directly to the customer site or to your warehouse, hence product must move through several channels, adding time and potential for loss or damage in the process which could further delay the project.

Inventory

This refers to inventory that is not directly required to fulfill current Customer orders. Inventory includes raw materials, work-in-process and finished goods. Inventory all requires additional handling and space. Inventory is often closely associated with Waiting and Over-Production.

Example: Ordering more rails, mid-clamps, and wire than is necessary for the amount of projects currently in progress and run rate of equipment. This thinking compounds and causes company capital to become tied up unavailable for other uses and causes warehousing space to become crowded which can lead to demand to expand.

Motion

Built-in extra steps taken by employees to accommodate inefficient process, rework, reprocessing, overproduction or excess inventory.

Example: Developing and automating queues for plan set rework instead of reducing or eliminating the need for rework.

Waiting

This refers to downstream inactivity that occurs because previous activities are not delivered on time. Idle downstream resources are then often used in activities that either don’t add value or result in overproduction.

Example: Installers cannot perform installations because plan sets are not completed fast enough to pull permits and schedule jobs. These installers are then sent out on site evaluations or given warehouse “housekeeping” tasks.

Over-Production

Overproduction occurs when an operation continues after it should have stopped.

Example: Plan set is “overproduced” — it includes additional sheets, viewports, and data points above and beyond what the AHJ or Utility needs to approve the permit or installer needs to build the project.

Over-Processing

This occurs any time employees put more work on a project than required to satisfy the customer. This also includes using components that are more precise, higher quality, or expensive than absolutely required.

Example: A designer spends extra time on a project researching and specifying a non-standard piece of equipment deemed necessary due to site conditions that the customer did not pay extra money for.

Defects

This refers to products or services not conforming to the company’s internal specification or expectation of internal or that of the final Customer thus leading to Customer dissatisfaction.

Example: AHJ redlines and rejects a plan set because design did not follow a local municipal code unknown to or forgotten by the designer. The designer cannot work on a new plans and must now research the issue and schedule rework of old plan set.

Now that you understand how to see the 7 Forms of Waste, you can begin to categorize activities. In our next post, we will build on this understanding to cover the next step in process improvement: mapping your process using the Critical Path Method.

Pamela Cargill is Principal and Founder of Chaolysti, a strategic consulting firm that helps residential solar installers operate more efficiently through direct relationships and program development with solar services providers. Follow her on twitter: @chaolyst

 

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Robert Bean + HeatSpring = Integrated HVAC Engineering Training

The way a building functions represents an incredibly complex intersection of numerous fields, including architecture, design, engineering, environmental and health sciences, and construction. As each field evolves, it becomes increasingly necessary, but also difficult, to understand how they are interrelated. If you find yourself looking for a way to marshal the knowledge from each of these fields into a comprehensive and  comprehensible framework, look no further: “Integrated HVAC Engineering: Mastering Comfort, Health, and Efficiency” is a multidisciplinary online design course based on thirty years of data and experience. The course goes beyond ASHRAE and LEED standards to the heart of HVAC engineering: integrating comfort, health, and efficiency to the maximum benefit of the building occupants.

The course is capped at 50 with 30 discounted seats available. View a full course outline for Integrated HVAC Engineering: Mastering Comfort, Health, and Efficiency

The course is taught by Robert Bean, R.E.T., P.L.(Eng.), a registered engineering technologist in building construction and a professional licensee in mechanical engineering. Robert is president of Indoor Climate Consulting Inc. and director of www.healthyheating.com. He is a volunteer instructor for the ASHRAE Learning Institute and serves ASHRAE TC’s 6.1, 6.5, 7.4 and SSPC 55 Thermal Environmental Conditions for Human Occupancy. He is a special expert on IAPMO’s new Uniform Solar Energy and Hydronics Code committee.

This integrated design course, based on thirty plus years of data-driven experience, goes beyond ASHRAE and LEED standards to the heart of HVAC engineering. ASHRAE 55 addresses comfort. ASHRAE 62 addresses ventilation. ASHRAE 90 and 189 address efficiency. LEED and others attempt to address the entire universe. You cannot understand these dogmatic systems without truly understanding first how to integrate comfort, health, and efficiency to the maximum benefit of the building occupants. This course is crafted for the select few who thirst for comprehensive knowledge. Those who desire a deeper understanding of the fundamental principles of designing great indoor environments, buildings, and HVAC systems. Includes numerous field-ready calculators and design tools. Scroll down this page for the course outline.

This course is for working design practitioners (who may be a recent graduates from architectural, mechanical engineering, or interior design programs) as well as those from the manufacturing, distribution, contracting, and inspection professions. Experienced professionals who may want to expand their knowledge of building science, indoor environmental quality, systems controls, radiant heating and cooling, and fluid hydraulics will also benefit from the program. This course will help students understand the principles behind: ASHRAE Standards 55, 62, 90, 189, ASHRAE Guidelines 10 and 24; and IEA Annex 37, 49 and 59.

Graduates of the class will be able to:

  • Assess materials of construction, buildings and systems from a thermal comfort, indoor air quality, energy, eXergy, entropy, efficiency and efficacy perspective.

  • Assess buildings from a durability perspective.

  • Understand how building enclosures act and serve as a filter, sponge and capacitor.

  • Make enclosure recommendations to improve IEQ whilst conserving energy and maximizing eXergy efficiency.

  • Explain thermal comfort and indoor air quality from a human physiology perspective and communicate how the outdoor and indoor environments affect occupants in subjective and non subjective ways.

  • Assess and recommend HVAC systems based on characteristics which enable acceptable IEQ, and maximum energy efficiency using less heat of a lower temperature in heating and of a higher temperature in cooling.

  • Use heat transfer principles to define loads and operating conditions for building and HVAC systems

  • Explain effectiveness coefficients for temperatures used in HVAC systems.

  • Explain the characteristics of different heat terminal units and the associated percentile splits in heat transfer mechanisms (radiation, conduction, convection).

  • Assess the difference between the safe, acceptable, good, bad and ugly in mechanical rooms and systems.

  • Describe the various components, sub assemblies and systems in radiant based hybrid HVAC systems.

  • Convert heating and cooling loads into flows; select pipe and ducts based on velocity and pressures, and determine differential pressure requirements in the distribution system.

  • Assess control valve selection and perform a control circuit pressure authority calculation.

  • Assess fluid and operating characteristics and size expansion tanks and air separators.

  • Select circulators and pressure control options based on system head losses.

  • Explain control theory and approaches including non-electric and electronic using PI, PID and fuzzy logic.

  • Design a radiant-based hybrid HVAC system for a reversible surface (heat/cool) in parallel with a dedicated outdoor air system for dehumidification, deodorization and decontamination of incoming air.

  • Perform thermal comfort calculations to comply with ASHRAE Standard 55.

This is a unique and incredibly valuable opportunity to become Robert’s student for 10 weeks and learn from his decades of experience. He’ll provide all the resources you need to understand integrated hybrid HVAC design and answer all the questions that come up along the way. In the final week of the course, you’ll submit a capstone project that incorporates everything you’ve learned. This will include running thermal comfort calculations and designing a radiant-based hybrid HVAC system with a dedicated outdoor air system (DOAS).

In the capstone project, students will:

  1. Perform thermal comfort calculations.

  2. Design a radiant-based HVAC system with a dedicated outdoor air system (DOAS).

  3. Make recommendations to improve IEQ and energy efficiency through architectural, building, and interior systems.

The course is capped at 50 with 30 discounted seats available. View a full course outline for Integrated HVAC Engineering: Mastering Comfort, Health, and Efficiency

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Learn how to Design and Build Best in Class Commercial Building Enclosures from Terry Brennan

All commercial building enclosure designs are not created equal. All too often, critical factors like airflow, insulation, vapor barriers, condensation, longevity, construction cost, and time frame are not given proper consideration. This results in an underperforming structure, an unhappy client, and a blow to the reputation—and bottom line—of those involved in the project. A good commercial building enclosure design carefully analyzes numerous factors and ensures that they come together harmoniously in a final product that will perform well over a long period of time. Architects must understand the the factors that contribute to a good commercial building enclosure in order to design high-quality products that will stand out in the RFP process and enable efficient and cost-effective construction. Contractors must be able to identify design elements that should be modified or may require an RFI and manage the construction process to protect the integrity of the enclosure and minimize their own risk.

If you’re an architect who needs to stay at the cutting edge of commercial building science or a contractor who needs to perform quality checks and manage commercial construction projects properly, Terry Brennan’s ten-week course, “Commercial Building Enclosures That Work” is one that you’ll wish you had taken before your last project. The course is capped at 50 students and we provide 30 substantial discounts for professionals that sign up early.

A Terry Brennan workshop is a rite of passage. Terry was the well-deserving inaugural recipient of and the inspiration for NESEA’s Professional Leadership Award. Terry has extensive experience studying all the factors that make or break commercial building enclosures. He is on the editorial boards of Environmental Building News and Heating Piping and Air Conditioning Magazine. He currently chairs the U.S.A.C.E committee developing new air leakage protocols. Past work includes consulting on a research project to restore three homes in the Seventh Ward of New Orleans after Hurricanes Katrina and Rita, teaching healthy housing courses for the National Center for Healthy Housing and working on a research project to study unplanned airflows in commercial buildings in New York State. He is a member of ASHRAE 62.2 Ventilation and Air Quality Committee and served as consultant to the National Academy of Sciences Committee on Dampness and Health in Buildings.

This course is an opportunity to study under Terry—to ask him questions and become his pupil for a full ten-week semester. He’ll teach you to diagnose and fix problems with commercial buildings using data and current best practices. Successful students will complete a design for a commercial building enclosure.

Architects who complete the course will learn:

  1. Best practices for material selection, layers, and detailing, for designing an air-tight, highly-insulated, cost-effective, and buildable structure.
  2. How to create drawings, write RFPs, and specify QA processes so designs can be implemented with minimal confusion.
  3. How to specify a building structure that will eliminate change orders from general contractors.
  4. How to specify enclosure details so the design is done right the first time, avoiding costly mistakes and angry customers.
  5. The most up to date code on commercial building enclosures.
  6.  How to respond to client RFPs to stand out from the competition
  7. How to apply all of the lessons above for all types of buildings and including new construction and retrofit applications.

Contractors who take the course will learn:

  1. How to identify red flags in a design that will require an RFI
  2. Best practices for writing a RFI to reduce risk
  3. How to review design and specifics of insulation, air barriers, vapor barriers, dealing with condensation
  4. How to manage moisture and mold during construction
  5. How to use construction documents to maximize project quality and efficiency

Click here to sign up for Terry Brennan’s ten-week course, “Commercial Building Enclosures That Work”

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John Siegenthaler, Biomass Thermal Energy Council, and HeatSpring Launch Hydronic-Based Biomass Design Course

Hydronics expert John Siegenthaler, the Biomass Thermal Energy Council (BTEC), and the online technical training experts at HeatSpring have teamed up to launch a 10-week online course: Hydronic-Based Biomass Design.

The course starts on September 15th. The course is capped at 50 students but we provide 30 discounted seats for those that sign up early. Click here to read more about the course and reserve your (substantial) discount.

The Hydronic-Based Biomass Design course is technical, rigorous, and challenging. It’s the most intense 10-week course on hydronic based biomass heating system design that you’ll find on the market.

With increasing fuel costs, the very low cost of biomass as source of fuel, and more state policy support for biomass heating systems, the demand for biomass-based heating systems is steadily increasing.

We’ve developed this course for professionals who see biomass heating as a large growth opportunity and the future of their business. The course will be useful for business owners, salespeople, engineers, plumbing contractors, HVAC contractors, and project managers who need to understand how to design, sell, quote, and install biomass-based hydronic heating systems in residential and commercial applications for both new construction and retrofits.

Graduates of the Biomass and Hydronic Design course will understand:

  1. The best applications for biomass-based heating systems

  2. How biomass-based heating systems differ from traditional heat sources

  3. How to select the best equipment and distribution system for a given application

  4. Boiler sizing and distribution strategies

  5. How to calculate installed costs and operating costs and how to communicate this to the customer

Course Outline

  • WEEK 1 – When should a wood fueled boiler system be considered?

  • WEEK 2 – Energy in Wood

  • WEEK 3 – Why High Efficiency Wood Combustion is Important

  • WEEK 4 – Why Hydronic Heat Delivery is Important

  • WEEK 5 – Operating Characteristics of Wood Gasification Boilers

  • WEEK 6 – Operating Characteristics of Pellet-Fuel Boilers

  • WEEK 7 – Operating Characteristics of Wood Chip Boilers

  • WEEK 8 – Pellet and Wood Chip Storage & Conveyance Options

  • WEEK 9 – Modern “Building Blocks” for Low Temperature Hydronic Systems

  • WEEK 10 – Example Systems & Putting it All Together

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