Green Building Tips From a Homeowner GC

29 Jan

What green building techniques and design options make sense? Which ones save you, the homeowner, a few greenbacks in the long-term? Here I’ll share my experience with energy efficiency choices while building a two-story, 40 ft. by 20 ft. home addition. But before I jump into the details, I’d like to tell you I opted to be the “Homeowner General Contractor” (Homeowner GC) for our addition project. Let me explain.

I have more than a few years of project management experience as well as an extensive environmental consulting background. I’m a registered professional geologist, entrepreneur, and the former publisher/editor for environmental magazines. For the record, I know a little bit more than your average homeowner about the environment and what “green” really means. So what do you do when it comes time to consider green building techniques and make purchasing decisions for a construction project?

For starters, I did my homework and extensively researched building methods and the science behind numerous green-building recommendations. Once I understood how certain things worked (or didn’t work), it was a lot easier to evaluate not only the building design choices but also the sub-contractors bidding on the tasks at hand. One more thing, before making the final decisions I loaded up the spreadsheet and ran the numbers. I wanted to know the potential return for the green investment (ROI). After all, green is the color of money as well.

Below I’ll explain a few green building techniques I went with for our addition project based on my findings. And in addition to that, why the investment was made to upgrade beyond local building code requirements, in certain cases.

Structural Insulated Panels (SIPs) – Walls only (not the floors or the roof): Structural Insulated Panels (SIPs) were chosen for the walls. I went with 6 1/2 inch SIP walls with an R-Value of 24. In our area (Central Virginia), this exceeds code requirements. whole wall insulation R-values, performance of SIPs verses stick-built wallsOne important thing to note: SIPS “perform” at a much higher R-Value than a stick-built wall. For example, a 4 1/2 inch stick-built wall with R-13 insulation likely only gets you around R-9 performance. SIPS perform a lot better. You can either spend a little more for a SIP wall upfront (with respect to material costs) or pay more in energy bills month after month, after month… Several builders and General Contractors I interviewed told me SIPS cost too much compared to stick-built walls; they really don’t when all aspects of the project are considered. Below are a few reasons why.

Significantly less labor is required to put up a SIP wall compared to a stick-built wall. The SIP walls were installed in three days. A comparable stick-build 6 1/2 inch wall finished with insulation and electrical chases cut in would have taken about three weeks; according to the local builders/General Contractors that I interviewed for the job. With SIPS you generate less waste at the construction site which means less labor moving trash around and less waste disposal fees. You also save on labor when it comes time to run the electrical wires; chases are cut into the SIPS at the factory and it takes less time to rough-in the electrical. Another benefit is the fact that you need one less sub-contractor involved in the project given you don’t need to wait for the walls to be insulated once they are put up (they come insulated). I could go on but I won’t. Once you truly understand all of the construction costs involved with the walls, the numbers tell the story. SIPS are worth the investment and the ROI is hands-down better than a stick-built wall based on the true cost of construction. I have more information about SIPs here for those interested.

Conditioned Crawl Space

For our addition, I basically had to have a crawl space – the existing home my wife and I were adding on to has a crawl space. We wanted level floors going into the addition. Therefore, a conditioned crawl space under the addition was added to the project cost. If you “must” have a crawl space, condition the space.  For me it was a no-brainer; less moisture under the floors, less air infiltration, fewer rodents/insects, and a conditioned crawl space allowed me to run the HVAC ducts under the floors in “conditioned space.” I’m convinced it saves energy and maintenance costs associated with the HVAC system. For the crawl space wall insulation, I went with 2″ Thermax on the exterior walls and a 10 mil liner. I considered a 20 mil liner but the 10 mil liner was sufficient given I don’t plan to store anything in the crawl space or frequent it often; the 10 mil liner seems plenty thick to me.

Roof Trusses

Energy efficient roof trussWhen designing the roof trusses, I increased the “heal height” (where the roof meets the top wall plate) by a foot. Why? The extra foot of space on top of the wall plate (basically, in the attic) allows more attic insulation where you need it; at the pinch point where the roof meets the walls. According to several energy efficiency studies I came across while researching, homes lose a lot of energy where the insulation basically goes to zero thickness where the roof line meets the walls. This made sense to me so I had the truss engineers add the extra heal height. It didn’t add much to the costs of the roof trusses.

Rainscreen – Underneath the Siding

To lower the risk of wall rot, it makes sense to provide a ventilated air gap between your siding and your sheathing. I went with an advanced building technique for the siding known as a rainscreen. SIP manufacturers, as well as many experienced siding professionals, recommend “rainscreens” for the exterior walls under the siding. Rainscreens using furring stripes are also recommended if you are using spray-foam insulation on your walls. It is smart building science and I believe it might be code a decade from now – already is in some jurisdictions. Basically, a rainscreen allows the wall to dry out much more efficiently. Even with Tyvek house wrap (which we also used), the walls under your siding will get wet and you want them to dry. Rainscreens allow that to happen.

Rainscreens do add additional costs to the siding budget; both in material and labor. In our case, I removed the old pine-board siding from our existing home since we wanted consistent siding for the entire home. We ripped the 3/4 inch pine-board siding and used it for furring strips for the rainscreen. This reduced our material cost of construction but added more labor costs. On the other hand, the rainscreen lowers your long-term maintenance costs (less frequent painting, siding replacement, etc.) and extends the life of your walls.

Our rainscreen includes Cor-A-Vents to enhance performance. Cor-A-Vents allows the gap between the siding and the sheathing/Tyvek house wrap to vent and stops insects from getting behind the siding. The Cor-A-Vent added to the overall project cost as well. For more information pertaining to rain screens, read All About Rainscreens on the Green Building Advisor website.

Energy Efficient Water Heater

I purchased and installed a GeoSpring Hybrid Electric Water Heater (GE GeoSpring 50-Gallon Hybrid-Electric Heat Pump Water Heater – ENERGY STAR) to lower our energy costs. This water heater is a significant upgrade from your standard water heater. Although it costs more than the typical water heaters, it pays you back year after year. It is one of the most efficient 50-gallon water heaters, using 62% less energy and saving $365 a year on utility bills (SOURCE: GE GeoSpring). What makes this water heater so energy-efficient are the compressor and evaporator that are incorporated into the unit to draw in ambient heat from surrounding air, using two variable-speed fans. When in heat-pump or hybrid mode (warmer months), the unit exhausts cool, dry air; it lowers humidity and cools the room while heating the water. Basically, the water heater is an air conditioner too.

For more information on energy efficient water heaters, read Choosing the Best Energy Efficient Water Heater.

Upgraded HVAC System – Conditioned Space

I replaced our existing HVAC system which was 13-years old while building our addition. We needed a HVAC system for the addition and we needed a replacement for the old unit serving the rest of the house. During the design phase, I decided based on extensive research that the best thing to do was install the new HVAC system inside the building envelop. Therefore, we built a utility room, conditioned the room (it is heated & cooled), and subsequently located the new HVAC unit inside instead of in an unconditioned attic. Also, the majority of the ducts are now within conditioned space. Locating your HVAC system and ducts within conditioned space reduces your energy use, lowers maintenance costs, and extends the life of your HVAC system. It is a good investment if you think about it during the design phase of the construction project. It really doesn’t cost much more to do when it is considered early in the design process.

Floor Joists

Hanging Floor Joists and SIPsI found several articles that discussed the energy loss associated with second floor joists and the rim board that holds the joists. When joists are set on the wall plate the joists/rim extends to the outside of the wall. Insulating a rim is difficult to get right and it is a common area for energy loss according to energy audit results. A better way to build includes hanging the second floor joists “inside the building envelop” (joists don’t contact the outside at all – no need to try and fill every void at the end of the joists at the rim board). Hanging the joists inside is more energy efficient and results in a stronger building according to engineering data (search online, numerous articles support this conclusion). The figure to the right shows how we constructed our addition with hanging floor joists.

Energy-Efficient Dryer Vent

One of the easiest things I did to further reduce air infiltration and save energy was replace the old dryer vent exhaust seal (Energy-Efficient Dryer Vent Seals – HEARTLAND Dryer Vent Closure). I replaced the “builder grade” exterior dryer exhaust vent with one designed for energy efficiency; it seals when not in use. The old vent was basically a hole in the wall and the washer/dryer area in our laundry room was freezing cold during the winter. The new vent was inexpensive and easy to install. Basically, it lets warm air escape when open and prevents cold air (or hot air in the summer) from entering when closed. The dryer vent seal also prevents insects and rodents from entering your home. Any homeowner with basic DIY skills can install one and start saving money right away. I could not find one at Home Depot or Lowes so I purchased our dryer vent online.

How did we do?

Our electric bill received the other day (January 2014) was LESS than our January 2013 electric bill even after adding about 1,600 sq. ft. of additional space to our home. I was amazed given it was a really cold January this year and we added our energy efficient water heater to the home before January 2013.

Nest Thermostats Facing Challenges

08 Jan

Nest, the company that makes what they claim to be the “next generation thermostat” is facing a few challenges. Out-dated HVAC systems, Wifi connectivity, and vocal, unhappy customers during a national cold spell  are in the forefront in today’s news. TechCrunch discusses the situation on a recent blog post here. You can learn more about the product and read reviews on Amazon – Nest Thermostat product info and reviews.

I seriously considered purchasing a “smart” Nest thermostat when we built a large addition on our home last year. We upgraded our HVAC system throughout the home. We installed a Carrier Infinity HVAC system and Mitsubishi Mini-splits. The Carrier is a 3-zone system and 3-thermostats; the mini-splits have their own thermostats. In our case, the cost of the Nest for the potential savings appeared questionable when compared to other energy saving investments and the respective ROI (6″ walls, insulation, smart building techniques, etc.). Today’s programmable thermostats are pretty good w/o being “smart” – the stupid things have worked (always) as advertised.

On Nest’s website they claim, “Programming thermostats is complicated and irritating – but an un-programmed thermostat can waste 20% of your heating and cooling bill. So the Nest Thermostat programs itself.”

Programming our standard thermostats wasn’t complicated or irritating – it was simple. One control panel programs all three; it took about 20 minutes. I focused on energy savings when I programmed them; tweaked them during the first few months. I likely have them set for less demand then the Nest would allow based on living habits; I only turn them up/down when I feel uncomfortable in the home. They appear to be saving us money without the need for software upgrades, wifi connectivity, etc.

WRT energy conservation and saving money, the smart thing to do is focus on containing the energy you generate; over insulate the attic, stop air infiltration, etc.

Simple is a solution.

Understanding Cool Roofs and Insulation For Energy Efficiency

05 Dec

Can you benefit from a Cool Roof? Or are you better off investing in more insulation? No doubt, a cool roof can help many building owners save money while protecting the environment but not everyone should rush to get one.Your money might be better spent on attic insulation depending on where you live as well as your specific attic situation.

The U.S. Department of Energy has published an excellent guidebook on cool roofs (link below). The guidebook was created to help builders and home owners understand how cool roofs work. Read more

Is Geothermal Always Worth It?

26 Oct

Earlier this year, I wrote a post on the Pros and Cons of Geothermal Heat Pumps (GHP). As it turns out, there is more to the story. I am in the process of evaluating HVAC systems for an existing home that is getting an addition. The addition is almost the size of the existing home; a new HVAC system is required as you can imagine.

After looking into several HVAC options with a focus on GHP, the consensus is to first focus on “tightening” the envelope of the existing home while considering the most effective methods of building an energy efficient addition. And, do this before worrying about your HVAC considerations. For my wife and I, it comes down to “first things first.” And, first on our agenda is “air infiltration” and insulation.

We are currently building an addition to an existing 1930s home. Understanding the energy use in the existing home and the addition we are building (or the home/addition you plan to build) is, IMHO, by far the most important aspect of HVAC considerations that come later. A “tight” home requires less energy to heat and cool, which in turn requires a significantly smaller HVAC system. And, what that means is a much lower overall energy bill.

It is important to note that lower overall energy use “increases” the “pay back time” required to recover the additional capital costs of a geothermal system.

Paying to “save energy” by investing in better windows, doors, and stopping air infiltration (conditioning your attic and crawl-space, for example), gives you the highest ROI (return on your investment). But, investing in “energy efficiency” leaves you with less money in the overall project budget. So, you need to consider this, is it better to invest in a GHP system or first invest in energy efficiency?

Cutting a big energy bill in half saves you a lot more money than cutting a relative small energy bill in half (basic math). For example, a poorly insulated home may have a $400/month energy bill on average, cut that in half and it saves you $200/month ($2,400/year). But, a “tight” home of the same size (sq. ft.) may only have a $150/month energy bill; cutting that in half only saves $75/month ($900/year).

Over the course of 1-year, the difference is $1,500/year and $15,000 over 10-years. My point here is if you have a well insulated home (SIPs, conditioned attic and crawl-space, great windows and doors, etc.), the initial capital cost of geothermal systems (GHP) requires a lot more time to “pay you back” because your overall energy use is low and so is your savings, in the short-run.

Say you have or plan to build a tight, energy efficient home and your monthly utility bill with a traditional HVAC system is projected to be the $150/month  example above. Say installing a GHP cuts that in half to $75/month. If the GHP system costs you $15,000 more to install than it takes over 10-years to “break-even” (I’m assuming the $15,000 in the bank would be worth more 10-years from now; maybe $20,000).

What I have concluded after a significant amount of research is this; a home that uses significantly less energy because it was built or remodeled to be very energy efficient may not benefit “financially” all that much from a GHP system due to the initial capital cost involved.

Unless you have a huge McMansion or you are using the GHP to also heat a pool, etc., may I suggest you run the numbers for your project? And, definitely consider the best solution of all, invest in cutting your total energy use by “tightening” up the home and stopping all possible avenues of air infiltration.

In short, first take a hard look at the energy efficiency of your home or project before considering any of the possible HVAC systems. There are several new HVAC technologies (mini-splits, high efficiency heat-pumps using air – traditional type systems) that are making GHP a hard sell for energy efficient homes of say 4,000 t0 5,000 sq. ft. or less.

Green Remodeling For Baby Boomer Homes

27 Jul

Remodeling a home is possibly one of the highest levels of “green.” It is one of the best sustainable housing initiatives around. While researching the remodeling industry I came across the website dubbed, Home for Life. The site includes a wealth of resources that explain opportunities to upgrade an existing home’s energy and resource efficiency to reduce environmental impact. The website is a product of Remodeling Magazine, a Hanley Wood publication. Read more

Best Available Research on Attic Fans and Power Ventilators

09 Jul

Do attic fans lower the cost of cooling your home?

Solar attic vents are not good for energy efficiencyAre solar attic fans worth installing? Common sense suggests they would be but are powered attic fans really a good idea for energy efficiency based on research and science? I have a master’s of science degree and my initial belief was it made sense. It just seems logical that a cooler attic would lower the cost of cooling the house in summer. While researching radiant barriers for the attic and reflective paint (Kool Seal Premium White) for our metal roof, I came across a few articles strongly suggesting powered attic fans were a dumb, and possibly dangerous, idea based on science. Here’s what I found so far and why I removed my attic fan:

  • The Scientific Spin on PAVs (powered attic ventilators – fans): Cooling off hot attics with powered attic ventilators (PAVs) seems like a good idea. After all, doesn’t cooler attic air mean less work for the HVAC system, longer shingle life, and reduced energy costs? Unfortunately that’s more myth than fact.
  • Drawbacks Of Powered Attic Ventilators:Powered attic ventilators, already suspected of using more energy than they save, can also create excess moisture, structural problems, discomfort, and combustion safety problems for home occupants, according to a recent study. John Tooley of Natural Florida Retrofit, and Bruce Davis of Alternative Energy Corporation’s Applied Building Science Center in North Carolina, presented “The Unplanned Impacts on Houses by Powered Attic Ventilators” at the 1995 meeting of the Energy Efficient Building Association.The paper describes research conducted on eight homes over a period of three months. As a result of this research, Davis said that he wouldn’t recommend the use of powered attic ventilators. He emphasized, “If someone chooses to use a powered attic ventilation strategy, they need to do additional performance tests and take responsibility to be sure that it won’t cause other problems.” The potential for hazardous conditions is particularly high in homes with combustion gas appliances, because the ventilators can create negative pressures that cause backdrafting.
  • Energy Star: Attic Fan Ventilation – Attic fans are intended to cool hot attics by drawing in cooler outside air from attic vents (soffit and gable) and pushing hot air to the outside. However, if your attic has blocked soffit vents and is not well-sealed from the rest of the house, attic fans will suck cool conditioned air up out of the house and into the attic. This will use more energy and make your air conditioner work harder, which will increase your summer utility bill.
  • Ask the Builder: Powered Attic Fans – Attic Insulation Facts: “I used to recommend PAVs [powered attic ventilators – fans] for houses, but I don’t anymore.”
  • Building Science, Unvented Roof Summary Article

The best solution appears to be making sure your attic is well insulated and well-ventilated using passive vents and natural air flow. Inspect your attic insulation and ventilation, or have a contractor do so for you. Just add more insulation or natural (passive) ventilation, if needed. Both measures will reduce the cost of cooling and heating your home; no electricity required and they are perfectly quiet.


  • Contact the local power company website and local energy associations for more information on constructing an energy efficient home in your area.
  • Building Science Corporation, Unvented Roof Summary Article: Excellent resource with in-depth research and hard-core science. Building Science is dedicated to teaching and providing factual information concerning building science and energy efficiency. This resource is used extensively by builders “in the know” when it comes to energy efficiency.
  • Building Science Guides and Manuals: Good place to start if you want reference documents for some of the most important building science topics.
  • Building Science Information Sheets: Fact sheets and overviews; another great place to start for those relatively new to the field.
  • Energy Star : The Energy Star website has extensive information on energy efficiency.
  • Geothermal Heat Pump Consortium: Geothermal is the most energy efficient method known today for heating and cooling. However, you will benefit by first making sure your home or building is insulated properly and as air tight as possible (within the limits of the appropriate building codes and safety concerns) before considering an expensive geothermal system.


Whether or not you are using an attic fan and you own a fireplace, a great product to consider is a fireplace plug. Battic Door sells several energy conservation products including a simple fireplace plug; stops drafts and saves energy by sealing the chimney when not in use:

Fireplace Plugs Save Energy Stops Fireplace DraftsThe Fireplace Draft Stopper is an inflatable urethane chimney plug balloon pillow measuring 38″ x 16″. A round Fireplace Plug is also available. It is quickly and easily installed in the fireplace just below the damper level. The Fireplace Plug can be adapted to work in almost all fireplaces. Even if you have an unusual construction, the Fireplace Plug can be successfully installed in less than 2 minutes.

The Fireplace Plug is provided with 5 “slittable” areas that can be cut to provide an opening for a damper handle. As the Draftstopper is inflated it seals around the damper handle sealing the opening (helps reduce energy costs). Easy, quick and clean installation.


Will You Reduce Energy Costs by Painting Your Roof White

08 Jul

My metal roof was red, hot, and desperately needed painting. After spending some time inspecting the roof, I quickly realized how incredibly hot the red paint became even on a modestly hot spring afternoon. Why repaint the roof red since it gets so hot? I thought there must be a better solution so I started investigating roof paints. Fortunately, I wasn’t the only one wondering if a lighter-color roof would reduce heat gain inside the attic and save energy. Also, I quickly learned a lot about “reflective” paints, radiant heat, and the best ways to insulate the attic to reduce cooling and heating costs.

One research article I found informative and one I recommend reading is, Cool Roofs For Hot Climates by Dan Parker, a senior research scientist with the Florida Solar Energy Center (2003). The following is from the article:

Reflective roofs work because they stop the rooftop heat before it ever gets going. The sun’s rays hit the roof at the speed of light, and at the speed of light they bounce back into space. White or light-colored materials work best, but some new dark pigments reflect enough invisible infrared radiation to reject a lot of solar energy. And whether you’re applying tile, metal, membranes, or even asphalt shingles, choosing a more reflective version seldom adds cost.

The figure below graphically depicts the best solution for energy efficiency is a reflective white metal roof:

energy savings research white roof

After reading this article and numerous others, I painted my metal roof with Kool Seal® Premium White Elastomeric Roof Coating which I purchased at the local hardware store (ACE Hardward has it here in Richmond, VA).

Additional Metal Roof Information

Roof Costs and Energy Savings: According to the Metal Roofing Alliance, white-painted metal roofing has the highest solar reflectance value of any roofing product available and can save you up to 40% of your annual energy bills.

According to statistics from McGraw-Hill Construction Research and Analytics®, the number of homes with metal roofs has more than tripled over the past decade, moving metal from 3% of the overall U.S. market to 10%.

Some homeowners’ insurance programs allow discounts for homeowners with specific weather-resistant metal roofing products. Contact your insurance agent to determine if your home qualifies.

metal roof benefits fire resistant

Photo taken after the 1991 Oakland, California firestorm. Burning embers destroyed all of the homes in the neighborhood, except the masonry home that was roofed with Stone-Coated Steel Roofing.  While all of the neighbors fought (without success) to save their homes by watering down their asphalt roofs, burning embers did not ignite the steel roof. The house with the steel roof survived while all others around it were destroyed. (SOURCE: Metal Roofing Alliance: Lower Your Insurance with Weather-Resistant Metal Roofing)

Kool Seal® Premium White Elastomeric Roof Coating

(SOURCE: Provided by the manufacturer, see product description, surface prep, etc. here – PDF)

  • Energy saving up to 35%
  • Reflects 90%+ of the sun’s rays
  • Designed to be durable in any climate
  • Higher solids for better coverage
  • Forms a thick rubber-like blanket of protection
  • Expands and contracts – clings to your roof in all temperatures
  • Protects against moisture
  • Cured elastomeric film is mildew and algae resistant
  • Helps to absorb sound
  • Environmentally compliant
  • Soap and water cleanup – while wet

Energy Efficient Roofing Video by Tod Miller

Other Useful Articles Pertaining to White Roofs:

What to Consider Review of Geothermal HVAC Pros and Cons

02 Jul

Geothermal Heating and Cooling – How it Works

Geothermal heating and cooling uses the relatively constant temperature of the earth below the ground to heat and cool. Geothermal systems use 40% to 70% less energy than conventional systems. While conventional furnaces and boilers burn a fuel to generate heat (traditional HVAC systems), geothermal heat pumps (GHP) very efficiently use electricity to transfer heat from the earth into buildings; your home or a commercial building. In fact, the most efficient fuel-burning heater can reach efficiencies around 95%. That sounds great but consider a geothermal heat pump that transfers up to 4 units of heat for every unit of electricity needed to power the system. What this means in comparison is geothermal energy results in over 400% efficiency.

A geothermal heat pump transfers heat stored in the earth (soil, surface water or ground water) into a building during the winter, and transfers it out of the building and back into the ground during the summer. In other words, the ground acts as a heat source in winter and a heat sink in summer. The technology is used for space heating, cooling, and hot water.

PROS of Geothermal

The US Environmental Protection Agency considers geothermal the cleanest and most energy efficient heating and cooling (HVAC) system for any home.

Geothermal heat pumps cost significantly less to operate than traditional HVAC systems; you benefit from lower monthly utility bills. And, geothermal systems have fewer moving parts which tends to lower maintenance costs compared to traditional HVAC systems. In addition, GHPs equipped with a device called a “desuperheater” can heat the water in your home. During the summer heat that is taken from the house is used to heat the household water (hot water supply). In the winter, water heating costs are reduced by about half.

Tax credits are available to home owners that install geothermal systems (until 2016 currently). And, tax credits are dollar for dollar reductions in the amount you owe in taxes – every dollar credited is one dollar less you pay in taxes. Tax credits are far better than tax deductions which only reduce your taxable income. The IRS energy tax credit program is called the“Credit for Residential Energy Efficient Property” and the purpose of the program is to encourage people to build green.

Geothermal Tax Credit Summary:

  • 30% of cost with no upper limit for ENERGY STAR qualified geothermal heat pumps
  • Expires: December 31, 2016
  • Details: Existing homes and new construction qualifies. Both principal residences and second homes qualify. However, rental properties DO NOT qualify for geothermal tax credits.
  • More information on Energy Star and Geothermal Tax Credits
  • Some restrictions may apply and it is recommended that you consult your accountant and/or the specific IRS code for all of the details.

NOTE: All geothermal heat pump components certified by the manufacturer in the “Manufacturer Certification Statement” will be covered by the 30% tax credit according to the IRS (see IRS code for details), as well as the installation costs associated with these components. There may be some add-on components that will not be covered such as an emergency back up system and the ducts. According to certain IRS guidance, these components are not directly related to the efficiency of the covered geothermal heat pump property.

IRS Guidance: Notice 2009-41 Section 3. (1)(e) Qualified geothermal heat pump property expenditures are expenditures for equipment which uses the ground or ground water as a thermal energy source to heat the dwelling unit or as a thermal energy sink to cool the dwelling unit, meets the requirements of the Energy Star program which are in effect at the time that the expenditure for such equipment is actually made (even if under § 25D(e)(8) the expenditure is deemed made at a later time for purposes of determining the taxable year for which a taxpayer may claim the credit), and is installed on or in connection with a qualifying dwelling unit. (SOURCE: Energy Star: What parts of a geothermal heat pump are covered by the tax credit?)

CONS and Disadvantages of Geothermal Systems

The initial capital cost for geothermal systems is higher, often 2x or more higher. The upfront cost is the main disadvantage and it might take anywhere from 2 to 10 years to recover your initial investment through reduced utility expenses. Another possible disadvantage might be the availability of a qualified and experienced contractor in your area. It is typically easy to obtain references for contractors that are experienced with the installation of traditional HVAC systems but you might find it more difficult to obtain references for geothermal contractors.

The installation of the equipment in the ground requires heavy equipment (backhoe for horizontal loops or drilling equipment for well installation). In most cases, there is a cost associated with landscaping. For example, horizontal loops require up to 250-300 feet of trench per ton; a 3,000 sq. ft. home might require a 4-5 ton geothermal heat pump. The loop and trench design is highly dependent on your situation; the size of your yard, accessibility, etc. You may incur the expense of removing a fence or other landscaping. Also, the yard will almost always require landscaping after digging the trenches and/or installing vertical wells. Heavy equipment does tear up a yard.

Most GHP require the system to be “running” to produce hot water. However, newer systems are being designed that will produce hot water without the main system running. Read about ClimateMaster’s “Q-Mode” and the Trilogy 40 (see below) – a new development in technology that allows hot water to be produced without the system running. Also, WaterFurnace’s 7 Series (41 EER) run very efficiently with variable speed compressors. Little energy is used while running the system in a powered-down state that allows for hot water production (not as much of an issue with the latest and greatest GHP systems introduced this year, 2012).


Evaluating Geothermal Heat Pumps

Ground source heat pumps are rated in terms of Coefficient of Performance (COP) for the winter. The higher the COP, the higher the efficiency. Where gas furnaces have COP values in the 0.78 to 0.94 range, ground source heat pumps have COP values in the 3.0 to 5.0 range.

When comparing geothermal heat pumps, first determine the EER; the EER is the ratio of effective cooling (heat removed) to the energy used at maximal load. EER is the standard measure of cooling effectiveness for geothermal heat pumps. One way to compare both the COP and EER is to review the list of Energy Star qualified GHPs. Until recently (July 2012), the highest EER rating currently available was 30; note that many Energy Star qualified heat pumps have EERs as low as 17.

ClimateMaster facilities operate in Oklahoma City, Oklahoma; the GHP units are manufactured in the United States. They offer a complete line of geothremal heating and cooling systems. For example, the TRANQUILITY 30 DIGITAL series units are two stage with a variable speed fan and a variable speed loop circulation pump for added energy savings. They also feature advanced “iGate” controls, a stainless steel drain pan, and coated air coils for durability. The THW series water to water units are higher temperature units for hydronic systems and provide higher water temperatures for improved heating. The TMW models are for normal temperatures. All of the units are backed by a warranty. (visit the products page at for more info)

ClimateMaster recently announced that their new Trilogy 40 geothermal heat pump (GHP) had been certified by the Air Conditioning, Heating, and Refrigeration Institute (AHRI) to exceed 40 EER under ground loop conditions.Therefore, this makes the Trilogy 40 significantly more efficient for cooling; it is now one of the most efficient commercially available GHP. Also, note that 40 EER is more than twice as efficient as some Energy Star qualified GHPs. The following is from the ClimateMaster website:

The Energy Department’s Oak Ridge National Laboratory has partnered with ClimateMaster — a leading manufacturer of geothermal and water-source heat pumps — to develop an appliance that could provide space conditioning and all domestic hot water needs while consuming at least 50% less energy than conventional minimum efficiency equipment.

The partnership between the Department and ClimateMaster began in 2008 in an effort to develop a more efficient ground-source integrated heat pump. Based on field tests and analysis, the new Trilogy 40 Q-Mode™ could save about 60% of annual energy use and cost for space conditioning and water heating in residential applications compared to new minimum efficiency conventional systems. Also, it’s about 30% more efficient than any other available ground-source heat pump [Editor’s note: The statement that it is “30% more efficient that any other availabe” was true when the statement was published. However, Waterfurance recently released the “Series 7” GHPs (41 EER) which are significantly more efficient than their Series 5.

ClimateMaster Press Release: Oklahoma City, OK March 19, 2012 – ClimateMaster announced an efficiency breakthrough with introduction of the Trilogy™ 40 series, the first geothermal heat pumps ever certified by the Air Conditioning, Heating, and Refrigeration Institute (AHRI) to exceed 40 EER at ground-loop (GLHP) conditions.

The revolutionary new Trilogy™ 40 utilizes variable speed technology to provide an extremely wide range of heating and cooling capacities, with the ability to perfectly match loads to as low as 30% of maximum. In addition, patent-pending Q-Mode™ technology produces year-round domestic hot water on demand, even when space conditioning is not required.

The Trilogy 40 Q-Mode series is the outcome of a five year collaboration between ClimateMaster and Oak Ridge National Laboratory (ORNL), which was sponsored by the U.S. Department of Energy (DOE) Building Technologies Program. Based on field tests and analysis by ORNL, the Trilogy 40 Q-Mode can save 55–65% of annual energy use and cost for space conditioning and water heating in residential applications versus new minimum efficiency (SEER 13) conventional systems and 30–35% versus current state-of-the-art two-stage geothermal heat pumps. (Read the full press release from ClimateMaster here)

WaterFurance offers a wide variety of geothermal units using the latest technologies. They are backed by one of the best standard warranties in the industry according to a few website geothermal forums. (visit the product page at for more info)

The WaterFurnace 7 Series is a new level of innovation and performance with all new advanced controls mated with variable speed compressor technology. Featuring the highest efficiencies (Over 40 EER and 5.3 COP ISO/AHRI 13256-1 GLHP) available in AHRI, the 7 Series is available in 3 variable speed capacity sizes (3 to 5 ton) with Danfoss Variable Speed Compressors.

Company Description: WaterFurnace Renewable Energy, Inc. specializes in the design, manufacture and distribution of geothermal and water-source systems. It’s the United States subsidiary companies are WaterFurnace International, Inc. (WaterFurnace) and LoopMaster International, Inc. (LoopMaster). In December 2010, it incorporated two Australian subsidiaries: WaterFurnace International Asia Pacific Pty. Ltd. (WaterFurnace Asia Pacific) and Hyper WFI Pty. Ltd. (Hyper WFI). WaterFurnace designs, manufactures and distributes geothermal water source heating and cooling systems for residential, commercial and institutional buildings. LoopMaster installs geothermal loops for residential applications, does commercial conductivity testing and provides design and installation assistance. Hyper WFI designs, develops and builds devices that limit the inrush current, which electric motors draw upon start up. On January 21, 2011, the Company acquired inventory and fixed assets from Binary Engineering Pty. Ltd. (SOURCE: WaterFurance)

Additional Resources

ENERGY STAR Guide to Energy Efficient Cooling and Heating (PDF)

Dept. of Energy Report – Assessment of Hybrid Geothermal Heat Pump Systems

Forbes article: Geothermal Heat Pumps: Waterfurnace verses ClimateMaster

Forbes article: Geothermal Heat Pumps: The Next Generation

Energy Star: COP and EER table for review – List of Energy Star Qualified GHPs

RECOMMENDED READING: The Elephant in the Room, HVAC for High Performance Homes, 2009 RESNET Conference, David Butler – Optimal Building Systems

In new homes, poor HVAC design and installation practice accounts for more energy waste than any other single factor. Unfortunately, when it comes to HVAC, it’s easier to sell high efficiency boxes than high efficiency systems, a distinction invariably lost in a competitive marketplace. As a result, HVAC remains the weakest link in most high performance homes.

As homes have become more efficient, oversized HVAC equipment has emerged as one of the more serious problems in building science. Although there’s general awareness of this issue among industry practitioners, few understand the full extent of the problem or its consequences.

There are numerous reasons why oversizing is a bad idea:

  • Oversized equipment costs more and requires larger electrical circuits
  • Oversized compressors have a shorter life expectancy
  • Excess capacity compromises comfort (larger temperature swings)
  • Excess cooling capacity compromises moisture removal, a big deal in humid areas
  • Larger compressors and blowers produce more noise
  • Excess capacity compromises indoor air quality (less run time = less filtration)
  • Excess cooling capacity increases the potential for structural damage from moisture
  • Oversized equipment is less efficient, thus increases operating costs

Said differently, right-sized HVAC systems cost less up front, last longer, provide better comfort, improve moisture removal, run quieter, provide better filtration, and cost less to operate. (SOURCE: Optimal Building Systems)

Geothermal Heat Pumps Definitions

GHPs are also known by a variety of other names: geoexchange heat pumps, groundcoupled heat pumps, earth-coupled heat pumps, ground-source systems, ground-water source heat pumps, well water heat pumps, solar energy heat pumps, and a few other variations. Some names are used to describe more accurately the specific application but most are the result of marketing efforts and the need to associate (or disassociate) the heat pump systems from other systems.

Geothermal Heat Pumps – Common Abbreviations

  • cfm = airflow, cubic feet/minute
  • EWT = entering water temperature, Fahrenheit
  • gpm = water flow in gallons/minute
  • WPD = water pressure drop, psi and feet of water
  • EAT = entering air temperature, Fahrenheit (dry bulb/wet bulb)
  • HC = air heating capacity, MBtu/h
  • TC = total cooling capacity, MBtu/h
  • SC = sensible cooling capacity, MBtu/h
  • kW = total power unit input, kilowatts
  • HR = total heat of rejection, MBtu/h
  • HE = total heat of extraction, MBtu/h
  • HWC = hot water generator capacity, MBtu/h
  • EER = Energy Efficient Ratio
  • = Btu output/Watt input
  • COP = Coefficient of Performance
  • = Btu output/Btu input
  • LWT = leaving water temperature, °F
  • LAT = leaving air temperature, °F
  • TH = total heating capacity, MBtu/h
  • LC = latent cooling capacity, MBtu/h
  • S/T = sensible to total cooling ratio

Energy and Environment Links

Energy Management Important to Healthcare Leaders

17 Dec

Energy efficiency, Wind MillWe tend to either love or hate the current healthcare industry. Rising insurance costs and outrageous healthcare bills upset us all. But, it appears the industry leaders are taking energy management seriously. According to a recent survey, energy management is more important to healthcare leaders than to executives in other industry sectors.

According to new research from the American Society for Healthcare Engineering and Johnson Controls, energy efficiency continues to grow in importance in the healthcare sector as organizations do more than ever to “go green.” (SOURCE: Johnson Controls Institute for Building Efficiency)


In March 2010, Johnson Controls’ Institute for Building Efficiency, the International Facility Management Association (IFMA), and the American Society for Healthcare Engineering (ASHE) conducted a survey of
executives and managers responsible for making investments and managing energy use in commercial buildings across the world. As part of the Energy Efficiency Indicator (EEI) broad survey to look at the trends in energy efficiency throughout the worldwide business community, Johnson Controls wanted to include a separate analysis of responses from organizations in the healthcare industry. Of the 2,882 respondents polled worldwide, 288 operated in the healthcare industry, and 246 were ASHE members.

The EEI survey examines what healthcare organizations are doing in response to rising energy costs, what factors are motivating efficiency improvements, how many organizations are planning to make investments, what payback they expect on energy efficiency investments, and what technologies and practices they have been implementing in their facilities.The Johnson Controls Institute for Building Efficiency, the International Facility Management Association and the American Society for Healthcare Engineering conducted an online survey of decision-makers responsible for managing energy. The Energy Efficiency Indicator survey results included a separate analysis of responses from healthcare organizations. (SOURCE: 2010 Energy Efficiency Indicator – Healthcare Sector Report, Oct. 2010)

Here’s an excerpt of the findings reported by the Johnson Controls Institute for Building Efficiency:

The survey looked at issues such as what organizations are doing in response to rising energy costs, what factors are driving efficiency improvements, what payback they expect on projects, and what technologies and practices they are applying. Highlights of the survey include:

  • 59% of healthcare organizations believe energy management is extremely or very important, compared to 52% of respondents across all industries.
  • 66% of healthcare respondents are paying more attention to energy efficiency than they were a year ago.
  • Cost savings is the biggest factor driving energy efficiency investments in healthcare; enhancing image and taking advantage of government or utility incentives are next.
  • Nearly 50% of healthcare respondents cited energy efficiency in buildings as their top strategy for reducing greenhouse gas emissions.
  • The average maximum allowable payback period for energy efficiency investments in healthcare is 3.3 years, down from 4.2 years in 2008.
  • The top barriers to capture of potential energy savings are lack of internal capital and inability to identify projects with sufficient ROI.

Click here to visit the Institute for Building Efficiency and read or download the complete survey report.

Has LED Lighting Finally Arrived?

17 Oct

Light-emitting diodes (LEDs) have been around for a while but their manufacturing cost prohibited their practical use for consumer lighting applications. Since LEDs use about 85% less energy and last 30 times longer than conventional light bulbs, many companies have been interested in the technology. Phillips Lighting among them. According to the Wall Street Journal,

Philips Lighting, part of Netherlands-based Royal Philips Electronics, sees LEDs as the future. It has spent $4.2 billion in LED company acquisitions over the past two years. Philips has been one of the largest manufacturers of compact fluorescent lights, or CFLs, another energy-efficient alternative to incandescent lighting.

Given the cost of producing LEDs is coming down and they use about half as much energy and last five times longer than compact fluorescent lights (CFLs), their use in commercial applications may have arrived. When you consider the cost associated with lighting that is on for extended time periods (and in some cases, all of the time) plus the labor cost associated with changing the light bulbs, LEDs may now be the less expensive alternative.

Resource: WSJ article published Sept. 15, 2008, Bright Future – Thanks to improved technology, LEDs may be ready to take off.