Heat Pumps have been used widely for decades but recent developments have made them “cooler” than ever. Here’s what you should know: a heat pump is, simply put, a device that transfers heat from a colder area to hotter one using mechanical energy, typically using a vapor compression refrigeration cycle. Refrigerators, air conditioners and freezers are good examples, although the term heat pump (HP) is usually used for systems that heat spaces and possibly air condition.
There are many sources or, “heat sinks,” used to extract and deposit thermal energy. They can be air, the earth or water. For example, a geothermal heat pump transfers energy from the earth or water to air, which is then used to distribute the heat inside the conditioned area. There are numerous types of heat sinks, and associated terminology such as air-to-air, air-to- water, water-to-water, etc. The simplest and most common is air-to-air which has also been getting the most buzz lately.
When used for heating, HPs can improve comfort and indoor air quality while significantly reducing heating energy costs. Here is a recent chart of comparative heating energy costs.
Here is a model of a typical indoor ductless split unit.
As you can see, air-to-air HPs can be one of the least expensive ways to heat a space. Costs rival geothermal, natural gas and even firewood, which begs the question as to why haven’t they been used more in the past. There are characteristics that challenge their usage. The performance and efficiency of air-to-air HPs drop as the temperature difference between heat sinks increase. For example, the capacity and energy use of an air conditioner gets considerably worse on really hot days. Similarly, performance and efficiency drop when using HPs to heat a space on extremely cold days. The performance of a HP is rated by its coefficient of performance, or COP. This is a ratio of the energy moved divided by the energy required to run the device. Simple electric heat, for example, has a COP of one. For every kilowatt purchased it yields one kilowatt of heat energy. Modern and efficient air-to-air HPs have COPs ranging from approximately 3-4 when used for heating. Not bad, compared to electric heat, huh?
The challenge is that the heating output or capacity drops during the coldest outdoor temperatures precisely coincident with the times increased capacity is needed. Historically, air-to-air heat pumps were sized less than the maximum heating capacity needed since they would be grossly oversized for cooling (air conditioning) use in the summer months. This especially the case in northern climates where the winter has colder outdoor temperatures. The use of HPs in more southerly States has been more widespread because of the milder winter design temperatures. The “capacity droop” challenge historically required the use of supplemental or backup heat sources such as fossil fuels, or most commonly electric heat. These sources made the economics of HP heating much less attractive.
So what changed? The reliability, availability and use of variable frequency drives (or VFDs). Nearly all new and modern HPs are variable speed. This solves a major technological challenge; we can now size the system for the heating load without causing the equipment to short cycle, or rapidly start and stop while cooling, which tears up equipment and prevents good performance for cooling and dehumidification. During both heating and cooling modes the systems will ramp the speed and performance from anywhere between 10-100 percent. This enhances performance, equipment longevity and reduces noise. Dehumidifying performance is greatly improved as the unit runs longer at lower speed, enhancing moisture removal.
HP systems can easily be installed during new construction, but until recently they were more challenging as retrofits. Air-to-air systems distribute thermal energy via airflow. Many, if not most homes in the northeast have hydronic heating systems, thus no existing ductwork. Achieving a good outcome retrofitting ductwork can be expensive, invasive and challenging. In the heating mode, the typical warm supply air temperature is 80-110 degrees F, thus poorly designed airflow can create draftiness and discomfort. Fortunately, the “ductless” option alleviates this challenge.
Here is a model of a typical outdoor ductless split unit.
In the early 1980’s, the first imports of ductless split system heat pumps began to arrive from Asian manufacturers. These were popular in countries like Japan, where typical living spaces are quite small by American standards. These ductless systems distribute air indoors directly from wall or ceiling mounted air handlers. They are compact, and very quiet to operate. One manufacturer even sells a unit disguised as a wall mounted fine art painting, where air silently passes in all directions from behind the frame. American manufacturers fought off the market penetration of this new disruptive technology for almost thirty years mainly by tightening codes, standards and implementing arcane testing criteria. Asian manufactures found ready markets in less developed countries of the Middle East, Caribbean and South America, where their use became commonplace in smaller commercial and residential spaces. Finally, the American market embraced the technology about five years ago, and today utilization has increased substantially. Several major US producers have purchased manufacturers in Asia and began production in the US as well.
Although these high efficiency air-to-air units come in a variety of systems configurations, the wall mounted indoor unit is most popular. Due to the size of the unit and low powered fans, air filtration is very limited. The ducted version can be supplied with much higher efficacy filtration and can even have central humidification added for the dry winter months.
In commercial applications, both ducted and ductless split system heat pumps are an effective solution for difficult to heat and cool areas due to their installation flexibility. Centralized HVAC systems serving the building might not offer such flexibility.
It is important to note that most split system heat pumps do not satisfy criteria for fresh air required by those versed in “best practice” and building codes. Outside air can be introduced in the ducted versions, but typically require an uncoupled parallel ventilation system such as an air-to-air heat exchanger to adequately introduce fresh air. Thus, unless additional provisions are made, the ductless split system heat pumps do not satisfy building ventilation needs alone.
At Thayer, we first witnessed testing of the innovative ductless split systems in 1982. They performed well and could have been very useful to our customers. The bad news is that we had to wait nearly twenty years for them to be commercially attainable and UL certified in the US. The good news is that now they are available, competitively priced, very reliable and extremely efficient.
In the last year or so, we designed several geothermal heat pump systems but found the high efficiency air-to-air systems have similar performance at a lower installed cost. An ironic twist to the relative ease of installation is the recent proliferation of installing contractors who do not have HVAC experience, qualifications or expertise. Maine was lobbied by special interest groups to make exceptions to normal technician licensing and this has resulted in a sharp increase in faulty installations. Although they are relatively easy to install compared to other system types, they still require proper selection, sizing, location and commissioning for a well working system.
In our state, Efficiency Maine has been promoting heat pump use for select high efficiency models with a $500 incentive which helps defray new system cost.
There are no “silver bullets” in the HVAC and energy efficiency marketplace. No one source of energy is “best.” We have what we like to call “silver birdshot;” We evaluate each building, and explore all possible options.
If interested, we can have one of our engineers evaluate your needs and develop options. “Call in the Experts” at Thayer.
We ventured up to a rooftop unit the other day because it dispatched an emergency message, and it made the perfect opportunity for us to do what we love: share our knowledge and experiences.
For quite some time now, we’ve been in the process of compiling videos and ideas to produce our own video series called “Follow the Experts.” We’ll update you on the newest technologies, tips to keep your system in ship-shape, and awesome projects we’re working on. Let us know what topics you’d like to know more about, and maybe we’ll turn them into our next video.
Whether you believe the EPA’s carbon standards will have a positive impact on this country’s economy or a negative one, it’s hard to deny the environmental benefits they will cause. The EPA announced earlier this month they were investing effort into reducing pollution from coal-fired power plants. These rules are new, but the laws are not—due to political pressure, the Obama administration has chosen to create the rules and enforce the law.
The new carbon rules, which the EPA unveiled on Monday, June 2nd, are directly modeled after the success of the Regional Greenhouse Gas Initiative (RGGI), which is a market-based regulatory program in the North East to reduce greenhouse gas emissions from the power sector. All New England states participate, along with New York, Delaware and Maryland. RGGI, the first program of its kind in the United States, auctions carbon dioxide (CO2) allowances, also known as carbon credits. A carbon credit is a term for a tradable certificate or permit representing the right to emit one ton of CO2 or other greenhouse gas equivalent to one ton of CO2. Proceeds from auctions benefit energy efficiency programs in the region, for example, a great partner of ours, Efficiency Maine.
Last Friday, June 6th, was an important day for Maine’s growing green economy. Over 200 people gathered with Senator Angus King to celebrate Maine’s Climate progress and the new EPA carbon standards. Joining Senator King were Maine business and community leaders, the Deputy Administrator of the U.S. Environmental Protection Agency (EPA) Bob Perciasepe, Economist Charlie Colgan and others.
Senator King impressed upon attendees that, “Countless scientific reports have sounded the alarm on global warming, and right here in Maine we continue to see the impacts every day. The facts are simply undeniable: climate change is real, it’s caused by humans, and it poses a significant threat to public health and to our state’s and the nation’s economic livelihood.”
Climate change is a severe threat to Maine’s economy, and as Charlie Colgan explained, the EPA regulations are important to Maine for myriad reasons; Colgan states, “[The proposed EPA regulations] would reduce Maine’s electricity price disadvantage compared with other parts of the U.S., enhancing our economy’s competitiveness […] Maine and New England are very well prepared to meet the new regulations quickly and efficiently because we helped design the model for the national policy […] climate change is a clear and present danger for Maine that needs to be addressed as quickly as possible.” As the easternmost state, we’re particularly vulnerable to carbon pollution. Bar Harbor, for example, has some of the highest recorded concentrations of ozone, due to pollution piggybacking on the jet stream.
It’s been a long time coming, but finally, climate change has been acknowledged by all political parties. Even the Pentagon recognizes climate change as a national security threat, along with many businesses including General Electric, Wal-Mart, and Nike. Ben and Jerry’s Ice cream are supporters of reducing greenhouse gases, as they, “know how messy things get when they melt.” Gina McCarthy, Administrator of the EPA, says of the new standards, “This is not about disappearing polar bears or melting ice caps. It’s about protecting our health and our homes. This is about protecting local economies and jobs.”
An additional 565 gigatons of CO2 is an approximate 20% increase of current levels, which will result in a 2°C (3.6°F) rise in the average global temperature. At that point, we’ll have significant and irreversible planetary damage. Both ice caps will have melted, elevating the sea level and widespread drought will lead to famine, animal extinction and widespread human despair. Alarmingly, publicly traded global energy companies currently report 2,795 gigatons of CO2 in their balance sheets—five times more than the disaster limit.
Implementation of a national carbon credit system would effectively determine who wants to pay to pollute. For example, General Motors has recently purchased $500,000.00 worth of carbon credits from the University of Illinois, and since 2010, they have reduced 7.7 million tons of carbon from entering the atmosphere. They purchase the credits so they are no longer on the market and to minimize their carbon footprint as well.
In an effort to burn cleaner fuel and save money, we’ve seen a rush to convert to natural gas over the last year. Due to limited pipeline availability and demand from Europe, prices and shortages are on the rise. Though the U. S. does not currently export natural gas, the US Energy Department has begun issuing permits to American companies to export, starting in 2015. Six out of twenty one applications to build port facilities in the US to export liquefied natural gas (LNG) have been approved. Currently US natural gas prices are one-third the cost what they are in Europe. The “landed” price for LNG in Europe will still be roughly 50% cheaper than Russian gas, improving their economic and political security.
There are a multitude of steps that can be taken to shrink your carbon footprint that won’t significantly impact your daily life, and a lot of them start with your HVAC system. If you’re unable to completely replace your equipment, make sure the system you currently have in place is maintained by a professional. In Energy Star’s guide to energy efficient heating and cooling, they express the importance of system maintenance. They go on to say that the average household spends more than $2,200 annually on energy bills, and the typical commercial building spends 40% of its energy on HVAC, and the other 20% on lighting.
Sadly, we find that less than 1 out of 20 buildings maintain their systems to the minimum industry consensus standards. Worse is that those non-compliant buildings usually perform less than 25% of the minimum preventive maintenance tasks, and resort to “belts and filters” approach.
Give the Experts a call at 1 (800) 649-4197. We’ll keep your system running at industry standards, and help reduce your greenhouse emissions.
Most commercial buildings use some form of time of day control for the heating and cooling systems. Larger buildings are often equipped with centralized building management systems (BMS); however, the vast majority of buildings that are not large enough to justify these often costly systems must rely upon programmable thermostats.
Programmable Thermostats come with a very wide variety of features, ease-of-use and functionality. Their price range varies, starting anywhere from $50 for a simple unit to $500 for “fully loaded” models. Almost all of them are able to accept unique programs for each day of the week. Some thermostats even allow for extraordinary events such as holidays.
The newest generation of programmable thermostats are called “smart thermostats” and include features such as electric meter communicability, remote access control via a computer or cell phone, and in some cases they may even learn and adapt to occupancy profiles. Although growing in popularity, smart thermostats represent only a very small fraction of the installed base in commercial buildings. Many of the more popular ones still have somewhat limited applicability to commercial HVAC systems.
So what’s the problem with programmable thermostats? It’s basically this: rarely are they properly programmed or fully utilized. Almost universally, their utilization isn’t optimized. There are a variety of reasons for this, so let’s explore a few.
If you have ever had teenagers living in your house, you know how maddening it can be to find lights illuminating an empty room, doors ajar, computers and televisions left on and even windows open while your heater or air conditioner is running. This isn’t because they are bad people; it’s just that the month’s utility bill doesn’t come from their allowance.
The same problems usually exist in commercial buildings. The occupants most directly affected by the HVAC systems don’t see them, and are very rarely the ones to pay the bills. Those of us who are “comfort professionals” can attest that there are many varying opinions as to what the “right” temperature is.
We certainly all have seen this: an occupant sneaks by the thermostat, cranking the temperature up to where only inhabitants near the equator might find it comfortable. A few minutes later, another staggers over, and before mass dehydration sets in, drops the temperature to where the windows begin to frost.
This causes building owners and managers to resort to imprison thermostats in silly looking cages, which often exacerbates the frustration that occupants feel over their comfort control. Some occupants become very creative, and find clever ways to trick and open these thermostat covers, or trick the thermostat’s thermometer. So, at minimum, there is often a conflict between the interests of the occupants, and those who foot the bill.
Let’s examine another major—yet simple—reason why programmable thermostats don’t work well to save energy: the person with the vested interest in the energy costs isn’t the one programming the thermostats. Well-intentioned owners, managers and maintenance staff usually will input a basic program at the time of installation, but rarely is there someone to regularly review these programs, which is necessary to tweak them to reflect the current schedule and usage of the building. As the saying goes, “out of sight out of mind.”
Unfortunately, many programmable controls aren’t intuitive to use, let alone program. Documentation gets misplaced, and the previously trained operators forget, get transferred, or simply aren’t available. Service providers typically don’t have access to the key person who can make decide on the necessary programming parameters of daily, weekly and annual schedules, let alone what the “appropriate” temperature levels are.
When I write my memoirs, there will be at least one large—and very amusing—chapter devoted to the many “thermostat wars;” creative approaches to tricking controls (i.e. car keys, lighters and bags of ice) and occasional outlandish requests for set points or systems performance, “Madam, we sympathize over your hot flashes, but please understand, your air conditioning systems isn’t designed to hold your office at 55 degrees; the industry considers that refrigeration.”
It’s extraordinarily uncomfortable for the service provider and or installer, such as us, to be asked to install a “dummy thermostat.” Simply, these are thermostats that are placed for the occupants to fiddle with, yet don’t control anything except, often their perceptions. Thankfully we very rarely get these requests.
Some of the newest smart thermostats are relatively inexpensive and accept basic time-of-day programming, yet will automatically reduce HVAC system operation when there is no activity observed. We call these occupancy based smart thermostats. They allow the occupant to easily adjust the temperature and override a setback program (i.e. working late or on weekends) while still allowing the building manager to pre-program set point limits to reasonable levels. They can be networked via innovative wireless networks, have remote accessibility, can be connected to the HVAC unit with wireless connections, track energy utilization and consumption, and even look attractive.
A lack of maintenance, faulty installation and poor designs are often the cause of discomfort within a building. Thorough and comprehensive maintenance will identify and eliminate many of these maladies, but the newest generations of occupancy-based smart thermostats are useful tools in minimizing wasteful operation and delivering optimal occupant comfort. Most of them compile and display information about current and historical usage enabling owners and occupants to make more informed decisions about system usage. Allegedly it was this type of occupant activity and usage that attracted Google to recently buy Nest for a whopping $3.2 Billion.
Call one of our personal energy conservation and comfort specialists here at Thayer today for an evaluation of your building. Additionally, send us your favorite picture of an antiquated, “user-modified,” interesting, worst location and/or downright wacky thermostat for a chance to win a free iPad Mini!
It’s a strange time to be traveling in Europe, and no stranger was a visit to Berlin, which is becoming the new epicenter for what a local paper coined today, “Cold War Two.” Germany has accused Russia of tearing Europe apart (read more here). Yesterday I visited Friedrichstraße, or as it’s better known, “Checkpoint Charlie.” that, along with the Berlin Wall, symbolized the divisiveness and threat of tensions between Russia and the world. Following Putin’s fabricated “crisis,” the Russian invasion, and soon-to-be annexation of Crimea, the west once again finds itself asking itself collectivity, “how could this be?” If you look beyond the media hype and blame games, the reasons are quite evident and implications chilling.
The original Cold War rose along lines of political ideology. Today, it’s more about Russia’s most valuable currency: energy. Like the US, Europe has a thirst for cheap energy, the opiate of modern economies. Putin has skillfully leveraged Russia’s vast energy reserves to make much of eastern Europe dependent on Russian energy, mostly natural gas. For example, approximately 90 percent of Bulgaria’s gas comes from Russia, 70 percent in both Hungary and Poland, 35 percent in Germany and 25 percent in Romania. As we can now see, the strategy has been very steady and highly effective.
The mainstream press hasn’t covered much about what may be the biggest reason for the Russian annexation of Crimea: the South Stream Pipeline Project. For approximately seven years, Putin has been negotiating a path from southern Russia south-easterly to eastern Europe extending Russia’s influence, control and income from gas. A main spur of this pipeline was blocked by the Ukraine from passing over their Exclusive Economic Zone in the Black Sea without a large scale environmental impact study and Ukrainian permits possibly allowing the competitive White Stream Pipeline Project from neighboring Georgia to beat them to the prize. Although the South Stream pipeline could be re-routed around the Ukrainian continental shelf, it would be far more expensive and take longer to complete. This is just my left-field theory, but control of Crimea and the Ukrainian Navy could now allow Putin a prize that’s far more valuable than Crimea: access to more wealth and influence. That’s how “petrodictators” gain and maintain control.
EU leaders are meeting now discussing ways to reduce their energy dependence on Putin. The most favored strategy is to accelerate importation of relatively cheap American shale gas. Today, Germany is paying approximately 300% more for gas than US consumers pay. The US gas industry is ready to leap on this opportunity for significant and profitable gas trade to Europe, but investment and infrastructure are being held up by Washington lawmakers. This trade would benefit not only producers but also the many pipeline owners, shippers and refiners. Natural gas would need to be pressurized and converted to LNG for shipping. This is a an energy intensive process.
There are those in Washington that feel that cheap American gas should be reserved for the US market while opposing views favor profitable, sustainable US foreign trade. This is also likely one of the best strategies for diminishing Russia’s influence and overt power plays that is destabilizing all of Europe. This, along with significant banking sanctions could break the choke-hold Putin has on the region. Without a steady flow of income from energy, petrodictators seldom retain power. Just ask Gaddafi, Chavez and Ahmadinejad.
So what does this all mean to Thayer and our customers? Expect gas prices to rise steadily and relatively quickly. Natural gas is still a great choice for buildings, but shouldn’t be favored over you best investment; comprehensive preventive maintenance: the “lowest hanging fruit” of your conservation program.
