Guide to Energy-Efficient Systems for Luxury Residential Project

Energy-efficient, luxury homes require three specific elements:

The construction industry is highly dynamic, and the requirements and expectations for energy conservation are constantly evolving. This is why architects, general contractors, engineers, and design teams feel challenged to meet current efficiency expectations.

In this guide, we’ll highlight everything you need to know about energy-efficient mechanical systems for luxurious residential homes, including the most relevant considerations.

How Does One Design and Install a Highly Efficient Mechanical System While Meeting a Client’s Expectations?

Home construction and design can support energy conservation, but it’s the overall mechanical system that is the critical piece to improved efficiency. At DMA Engineering, we pay close attention to the mechanical system’s operation, maintenance, installation, and overall design to deliver true energy efficiency.

Here’s how we design and install mechanical systems that are highly efficient and also allow us to meet our client’s expectations.

Understand the Client’s Expectations: Client Intake Form

Understanding our clients helps us produce projects that simultaneously exceed industry standards and satisfy their expectations.

At the beginning of every engagement, we discover what matters most to our clients. We gather critical information, determine expectations, and educate our clients about what’s possible. Our client intake form then guides us throughout the entire lifespan of the project, directing us toward a final product that truly meets client needs and expectations.

Owner’s Project Requirements

We take all the details from the client intake form to craft and share an Owner’s Project Requirements (OPR) form that documents client expectations and seeks to truly understand their must-haves. This OPR is a living document, updated whenever needed to ensure all their energy-efficient mechanical systems expectations are met when the client moves into their residence.

Trade-Off Analysis

At the start of each project, the possibilities for creating a stellar design are endless. To determine the best technologies and strategies for each project, we conduct a trade-off analysis. The goal of this analysis is to share with the clients and design and construction teams the best systems to heat and cool the residence, balancing financial paybacks with desired outcomes.

This trade-off analysis is used to design the best possible building envelope, keeping in mind factors like:

Because every luxury residential project is unique, each feature must be evaluated to discern which option offers the biggest impact. Our trade-off analysis generates each scheme’s energy consumption and corresponding costs, surpassing standard code regulations for exceptional results. Once armed with each cost data scenario, we can perform a payback analysis of each scheme. We also weigh certain elements to add intrinsic value, including comfort-enhancing features like radiant floor heating and other architectural details to add luxury.

Using trade-off analysis, we help our clients make educated decisions that fit their values and goals for the project. This ultimately allows us to develop the proper sytems to meet client expectations.

Building Envelope

In the same way a building is supposed to keep water out, it is just as important for it to keep energy in, using emerging tools and methods to create a reliable barrier or building envelope.

One of the key elements of resilient luxurious residential homes is the building envelope. High-quality design calls for more than just insulation. When executed correctly, a tighter envelope makes a building inherently more efficient, creating a comfortable space and reducing energy consumption, making drafty homes a thing of the past. Complicated construction can lead to: 

When it comes to luxury residential projects, the architecture should exceed code minimums for insulation schemes to enhance the functionality of the building envelope. Almost every feature contributes to the efficacy of the building envelope including:

• Final trim levels for high-performance windows
• Exterior wall insulation to eliminate thermal breaks
• Truss and rafter heel height
• Materials used to limit thermal bridges and reduce substantial energy losses

Special considerations in the building envelope should be made for luxury residences with features like:

Improper installation of these features can result in premature failure of the room, and in some cases, failure of the entire building. However, the proper selection of materials and careful construction prevents moisture transport from these high-humidity areas.

With the use of these complex assemblies and non-standard materials, the DMA team performs advanced modeling called finite element analysis (FEA). This assessment calculates the temperature throughout an assembly in the face of varying exterior air temperatures accounting for saturation pressure, relative humidity, and dew point throughout the assembly. This analysis ultimately ensures that even under the most extreme design conditions, the assembly will still perform as expected.

Often overlooked in engineering a building envelope is the consideration for a high-performing assembly that reduces exterior noises and limits interior noises like mechanical systems. After all, a luxury home should be comfortable, efficient, and peaceful. We carefully identify the areas that generate noise and factor these considerations into the envelope design for a tranquil space.

Indoor Air Quality

Homes breathe the same way we do, and the quality of the air we breathe is directly related to our health and well-being. An inappropriate air turnover rate can result in:

A home’s design should regularly replace stale interior air with fresh, filtered, conditioned air from outside. We employ Heat or Energy Recovery Ventilators to control the precise amount of filtered and tempered fresh air that gets into the residence. This ultimately ensures the residence has energy-efficient and high-level indoor air quality (IAQ).

Through the OPR, we gather information regarding the residence’s occupants; whether they have allergies or sensitivities, then use this data to design the proper filtration scheme and provide the highest possible indoor air quality that’s on par with hospital operating rooms.

We integrate technology to monitor IAQ with distributed sensors that constantly sample the health of your living environment while advanced data analytics interpret the results and adjust the zone turnover rates accordingly. The technology also:

• Combats carbon dioxide and VOC buildup
• Provides a ventilation performance metric for home sensors
• Informs occupants about the ongoing IAQ

Ground Source Heat Pump (Geothermal)

Geothermal heat pumps (GHP) harness energy from beneath the earth’s surface, then use it to heat and cool buildings. They’re also referred to as earth energy systems, ground source heat pumps, and geo-exchange. Geothermal heat pumps leverage the near-constant temperature below the earth year-round to maintain optimal building temperatures.

Although many parts of the country suffer seasonal temperature extremes, ground temperatures generally remain consistent. This ground temperature, like that of a cave, is warmer in the winter than the air above it and cooler in the summer.

• During winter, the heat pump system removes heat from the exchanger and supplies it into the indoor spaces to warm them or to heat water.
• This process is reversed during summer, with the heat pump transferring heat from the inside air to the heat exchanger.

Here’s what you should know about GHPs:

• They are four to six times more efficient than the finest air-source air conditioners
• They are approximately 300-800% more efficient than the top-rated gas furnaces and boilers
• Their emission levels are lowest in comparison with any HVAC applications
• They have the lowest emissions on the market
• They reduce carbon emissions from a building’s energy use by up to 300-800%
• They release almost no on-site emissions on-site when coupled with a solar photovoltaic system

Ultimately, the increased usage of GHPs would significantly cut global emissions for a healthier, cleaner planet. Many incentives are available to buildings that use geothermal systems, including federal tax credits and energy rebates.

For instance, the federal tax credit for renewable energies is a 30% tax credit of the installed system

Owners can also apply for these incentives because customers who install energy efficiency initiatives are eligible. In some instances the payback can be instant when applying for all available tax credits and rebates.

Air Source Heat Pump

Air source heat pumps can be used to heat and cool your home all year. They are:

These pumps are powered by electricity, but they are inexpensive to run because of their high efficiency, making them an energy-efficient alternative to furnaces and air conditioners. They transfer heat from cold to warm spaces using electricity to make cool spaces cooler and warm areas warmer. Even in very low temperatures, air-source pumps are remarkably effective at drawing heat from the outside air. In winter, they capture and condense heat from the outside air and bring it indoors. However, in summer, they work just like an air conditioner, absorbing heat from inside the home and ejecting it outdoors.

During cold weather, air-source heat pumps may heat a home with efficiencies exceeding 400 percent, more than quadrupling the efficiency of conventional heating systems that run on gas, oil, or propane.

The usable heat produced via air-source pumps is substantially greater than the energy purchased at the meter when the heat pump efficiency is assessed. For instance, the complete winter’s efficiency is normally in the 200-250 percent range in cold climates. This means that homeowners get between two and three times the amount of heat for the home than they pay for at the meter throughout the winter. In addition, cooling efficiencies are also significantly high, and heat pumps with variable speed capacity for cold climates cool at two times the efficiency of standard window air conditioners.

Because of their high efficiency, heat pumps are the cleanest alternative available for people that prioritize lowering their carbon footprint. Unlike burning oil or gas, which will always emit carbon dioxide and energy from the grid, air-source heat pumps tend to become greener every year. In the northern US, their average carbon emissions are substantially lower than any other fuel.

Net-Zero (Solar Photovoltaic, Solar Thermal, and Offsets)

A Net-Zero Energy Building can be defined as:

A type of design and construction that tries to create an electricity-efficient, grid-connected building that can generate enough energy from renewable sources to meet its own demand.

These structures have near-zero energy consumption, which means that the total energy required by the building every year is roughly equal to the amount of renewable energy generated on-site or nearby.

Today, buildings account for about 40% of all US energy consumption and greenhouse gas emissions. Net Zero buildings:

• Emit fewer greenhouse gasses into the atmosphere
• Consume far less nonrenewable energy
• Reduce energy consumption and emissions elsewhere by the same amount

Almost all Net Zero Energy Buildings are connected to the electric grid. This allows residents to use electricity from traditional energy sources when the renewable energy they generate cannot meet the energy load of the building. And when the energy generated on-site surpasses the energy requirements of the building, excess energy often redirects to the utility grid to offset days when there’s excess energy demand.

The result? Net-zero energy consumption. The DMA team even evaluates the differences in how jurisdictions calculate the payment for the energy and utilities exported into the grid, factoring these considerations into the project.

Reducing energy consumption by creating an efficient building design always ranks among our core objectives. This is because focusing on energy efficiency is usually the most cost-effective method to guarantee the highest ROI and reduce the overall cost of the project.

Some of the energy-saving design methods and features that we consider include:

After efficiency measures have been effectively adopted, renewable energy technologies can be used to meet the remaining energy requirements. While microturbines, fuel cells, and combined heat & power systems do not create renewable energy, they transform traditional fossil fuel energy into electricity and heat, which can be classified as energy-efficiency measures.

Solar PV

Photovoltaic (PV) cells convert sunlight into electrical energy. Individual photovoltaic cells are often connected in arrays to form larger units known as solar panels to boost their solar power output.

Solar panels can either be used individually or joined together to create arrays. These are then connected to the electrical grid as part of a solar-powered system. Because of this modular structure, solar-powered systems can be built to meet almost any electric power need.

Solar Thermal Systems

A solar thermal system converts energy from the sun into heat. It is an effective, dependable, and low-maintenance way to heat residences and commercial spaces.

Solar thermal panels work in tandem with an immersion heater, collector, or boiler:

1. The collector keeps the water from freezing in the winter by using the sun’s rays to warm up a transfer fluid (usually a mixture of glycol and water). 
2. This heated water is delivered to a heat exchanger that’s located in a water cylinder, and the water inside is warmed by the heat from the exchanger. 
3. The water then returns to the collectors for reheating after the liquid has released its heat.

When there is enough heat available, a controller ensures that the fluid circulates to the collector.

Swimming Pool and Spa Design

Pools and spas have become integral to the enjoyment of luxury residential projects. Especially when combined with outdoor kitchens and sliding doors, these features create a cohesive indoor/outdoor living experience.

But to be truly enjoyable, pools and spas must easily achieve comfortable water temperatures during the desired season or time of the day. This is where the Client Intake Form and the OPR come into play; to establish preferred operating temperatures and seasons of the pool and spa.

Each pool and spa design must meet client expectations, exceed local building codes, and give the homeowner the chance to save money through energy-efficient design. Improperly designed water features may result in: 

• Water heating systems with high fuel, gas, or electricity usage
• Failure to meet desired water temperatures
• Prohibitively expensive features that go unused or abandoned
• Undesired high temperatures that jeopardize the health of the occupants

The best way to reduce the energy consumption of the pool and spa is by using state-of-the-art technologies that combine the home’s cooling system with the pool heating system, allowing for overall efficiency. These solutions require careful planning, collaboration, and analysis to reduce the lifecycle costs, reach acceptable payback periods, and reduce carbon dioxide emissions without compromising comfort.

Radiant Heating and Cooling

Ultimate home comfort can be achieved through radiant heating and cooling technology.

Radiant heating is similar to the concept of standing by a campfire. When you’re facing the fire, it warms the front part of your body because of the heat being radiated to your body. The difference? Radiant heating only warms the surfaces and not the air. Surfaces are more stable than air, which means radiant heating causes minimal temperature fluctuations.

One of the most popular heating technologies is radiant floor heating, which not only warms the floor but the temperature of the room since hot air rises and becomes more buoyant as it is heated. In many cases, radiant floor heating helps occupants set their thermostats lower and use less energy.

Radiant cooling is a relatively new concept and is emerging in popularity throughout the luxury residential market. In the same way radiant heating heats the surfaces, radiant cooling cools them. But radiant cooling requires a good design and a sophisticated control scheme and system and can be supplemented with either a partial radiant ceiling or forced-air system to achieve maximum comfort and energy efficiency.

Since cool air falls, radiant ceilings are an essential part of the modern, energy-efficient cooling process. They are also highly crucial in the heating process because it offers a larger heated surface compared to the floor, which significantly helps overcome the lack of air heating.

Snowmelt Design

Snow accumulates everywhere: On driveways, walkways, exterior steps, and patios. Traditional snow removal methods such as salting or plowing could be detrimental to construction and can create unnecessary hazards. For instance:

Modern snowmelt systems provide automated snow and ice removal using thermal energy, eliminating the need for plowing or salting. As the snow melts, it doesn’t create banks or piles of removed snow. This not only looks better, but it’s also safer; reducing the risk of slips, falls, and accidents.

Snowmelt systems consist of nonmetallic tubing embedded into the concrete of exterior surfaces like driveways, walkways, or patios. Using a heated antifreeze solution that circulates through the pipes, these systems heat the surfaces to melt ice and snow. Programmed controls are triggered by temperature and humidity sensors, which heat the surfaces until they are free of snow or ice.

DMA provides high-efficiency automated snowmelt systems powered by innovative software tools to ensure the system operates under proper conditions without wasting excess energy.

Controls Above the Audio-Visual System

Most modern homes use automation systems to control lighting, audio, and visuals. The DMA team employs the use of additional home automation systems in place of unsightly wall-based thermostats to control temperature and humidity. These home automation systems have a built-in thermostat function that acts as the interface with the heating, cooling, and ventilation systems for an effortlessly comfortable home experience.

The key to high-performing heating, cooling, and ventilation systems is a building automation system (BAS). These robust systems harness data to operate independently but can integrate with the home automation system, balancing energy monitoring with the weather, interior climate control, and irrigation. Many modern heating and cooling systems must serve multiple areas simultaneously. The BAS system allows for advanced control sequences that enable it to meet the required demands.

The luxury residential market faces increasing expectations regarding noise, energy, and occupant comfort. So, using systems that modulate to precisely meet the demand is critical. BAS systems modulate precisely and allow engineers and technicians to monitor a system remotely. The systems can also self-diagnose and email technicians when a component malfunctions or fails.

DMA can implement advanced sequences to support ultimate occupant comfort through indoor air quality monitoring systems and weather systems, and optimize operation through advanced algorithms and machine learning. All this results in a residence with a lower operating cost throughout its lifecycle.