Residential Comfort & Energy Efficiency

Written by Eric Gans
I have completed over 2000 Home Performance with ENERGY STAR® home energy audits in Maryland, and I like to write about my experiences.

 

 

When I pointed a thermal camera at my own boiler, I wasn't expecting a surprise.

The pipes feeding my domestic hot water system were over 145°F on a mild spring day—even though there was no need for space heating.

For years, my home used an oil boiler to provide both space heating and domestic hot water. It worked reliably, but after looking at it through the lens of a thermal camera, I discovered something I had never fully appreciated:

My boiler wasn't just heating water—it was heating my basement.

As a certified energy auditor, I spend a lot of time helping homeowners understand how heat moves through a house. This time, I decided to turn the thermal camera on my own mechanical room.

What I found completely changed how I looked at domestic hot water.
 

The Hidden Heat Source Most Homeowners Never Think About

When most people think about a water heater, they think about hot showers.

They don't think about what happens between hot showers.

In my case, the boiler, storage tank, and dozens of feet of copper piping remained hot throughout the day so they would be ready whenever someone turned on a faucet.

That means the system was constantly releasing heat into the basement—even during the warmer months when there was no need for space heating.
 

 

 

The thermal camera showed:

• Boiler temperatures exceeding 170°F

• Copper piping approaching 185°F

• Large sections of the mechanical room were acting like radiators

Every bit of that heat eventually became heat inside the house.
 

The Thermal Camera Changed My Perspective

I've recommended heat pump water heaters for years because of their efficiency and lower operating costs. But pointing a thermal camera at my own mechanical room taught me something I hadn't fully appreciated.

The biggest difference wasn't just the energy savings—it was the complete change in the space's thermal behavior.

Instead of seeing a boiler, storage tank, and dozens of feet of hot piping radiating heat into the basement, I saw a mechanical room that was much closer to the surrounding air temperature.

The thermal images revealed something most homeowners never notice: a domestic hot water system doesn't just affect your utility bills—it also changes how heat moves throughout your home.

Why This Matters During the Summer

In the winter, some of this heat isn't necessarily wasted because your home needs heating.

But during spring and summer, it's a different story.

In some cases, where the domestic usage is tied to the boiler, it continues to maintain hot water, which means:

• Hot pipes continue radiating heat.

• The storage tank continues losing heat.

• The boiler jacket continues giving off heat.

Your air conditioner eventually has to remove that heat from the house.

In other words, your water heating system may be making your cooling system work harder.
 

 

A Water Heater Is Part of Your Home's Comfort System

Most homeowners think of a water heater as an appliance that simply provides hot water.

From a building science perspective, it's much more than that.

Every appliance that produces, moves, or removes heat influences the comfort and efficiency of the entire house. A traditional boiler-fired water heater introduces heat into the surrounding space. A heat pump water heater removes heat from that same space while producing hot water.

That means your choice of water heater doesn't just affect energy costs—it can influence basement temperatures, humidity levels, and even how hard your air conditioning system has to work during the cooling season.

I didn't simply replace one water heater with another.

I changed the direction that heat moves through my house.
 

Heat Doesn't Disappear—It Has to Go Somewhere

One of the first principles of building science is that heat doesn't simply disappear. It always moves from one place to another.

With my old boiler-fired water heating system, some of the heat produced by burning fuel went into the domestic hot water where it belonged. But not all of it. The boiler jacket, storage tank, and long runs of uninsulated copper piping continuously released heat into the surrounding basement.

That heat wasn't "lost"—it simply became unwanted heat inside the house.

The heat pump water heater completely changes that equation. Instead of creating heat and allowing some of it to escape into the room, it removes heat from the surrounding air and transfers it into the water stored in the tank.

The result is the same hot shower, but a completely different path for the heat to travel.
 

Enter the Heat Pump Water Heater

Rather than creating heat, a heat pump water heater works like a small air conditioner.

Instead of generating heat directly, it transfers heat from the surrounding air to the water stored in the tank.

That one difference completely changes the room's thermal behavior.

After installing my heat pump water heater, I repeated the thermal imaging under similar conditions.

The difference was dramatic.

  

The bright, glowing boiler piping was gone.

Instead of multiple pieces of equipment operating well above room temperature, the mechanical room became remarkably uniform in temperature.

The heat pump water heater wasn't filling the basement with hot surfaces—it was removing heat from the air.
 

An Unexpected Comfort Benefit

Lower utility bills were expected.

A cooler basement was an unexpected bonus.

Every time the heat pump water heater runs, it removes heat from the surrounding air while producing hot water.

It also removes moisture as condensation, providing a mild dehumidifying effect.

That means one appliance is doing three jobs:

• Heating your water

• Cooling the surrounding air

• Reducing humidity

It's a combination that conventional boilers and standard electric water heaters simply can't provide.
 

What About Winter?

One question I often hear is:

"Doesn't the heat pump water heater steal heat from the house in the winter?"

Technically, yes—it moves heat from the surrounding air into the water.

But in homes like mine with a boiler, there's another interesting interaction.

The boiler naturally gives off heat through its jacket and piping whenever it's operating for space heating.

Instead of letting all that heat simply dissipate into the basement, the heat pump water heater can capture some of it and convert it into domestic hot water.

It's an elegant example of one system benefiting from another system's unavoidable losses.
 

My Home Energy Audit Predicted Significant Savings

Before making the upgrade, I modeled my home using approved Home Performance energy modeling software.

The projected results were impressive.

 

The model projected:

• 84.1% reduction in water heating energy

• 123 fewer gallons of heating oil consumed annually

• Approximately $481 per year in water heating cost savings

While every home is different, these projections illustrate why heat pump water heaters have become one of the most impactful energy upgrades available for many homeowners.
 

Maryland Homeowners Have Another Reason to Consider One

If you're a homeowner served by BGE or Pepco, replacing an aging oil, propane, or natural gas water heater with an ENERGY STAR® heat pump water heater may be more attractive than ever.

Recent updates to Maryland's Home Performance with ENERGY STAR® (HPwES) program now recognize heat pump water heaters as an eligible electrification upgrade. When included as part of a comprehensive Home Performance project, electrification measures can increase the program's incentive cap to 75% of the project cost, up to $15,000, depending on the improvements being completed and overall project eligibility.

For many homeowners, this means the cost of installing a heat pump water heater can be significantly offset when it's incorporated into a whole-home energy improvement plan rather than treated as a standalone appliance replacement.

That's one of the reasons I encourage homeowners to start with a professional energy audit. Instead of replacing equipment one piece at a time, an audit helps identify which upgrades work together to improve comfort, reduce energy use, and maximize available incentives.
 

Is a Heat Pump Water Heater Right for Every Home?

Not necessarily.

Like any building science upgrade, context matters.

A heat pump water heater performs best when:

• It has adequate surrounding air volume.

• The installation location can benefit from slight cooling and dehumidification.

• The home has sufficient electrical service.

• The homeowner is looking for long-term operating savings rather than simply the lowest upfront cost.

This is one reason I always recommend starting with a professional home energy audit instead of making decisions based on a single appliance.
 

Is a Heat Pump Water Heater Right for Your Home?

Like most building science questions, the answer depends on the house.

This type of upgrade is often worth exploring if you:

• Have an oil, propane, or natural gas water heater that's nearing the end of its life.

• Have a boiler that also provides domestic hot water, especially if it stays warm throughout the summer.

• Want to reduce energy costs without sacrificing hot water performance.

• Have an unfinished basement, utility room, or mechanical space where the slight cooling and dehumidification benefits can be an advantage.

• Are already planning energy improvements through BGE or Pepco's Home Performance with ENERGY STAR® program and want to maximize available incentives (Maryland).

On the other hand, a heat pump water heater isn't automatically the right choice for every home. Installation location, available space, electrical capacity, hot water demand, and your home's overall heating system all play a role in determining whether it's the best solution.

That's why I encourage homeowners to start with a comprehensive energy audit rather than focusing on a single piece of equipment. Looking at the house as a complete system allows you to prioritize the upgrades that will have the greatest impact on comfort, efficiency, and long-term value.
 

Final Thoughts

When I installed my heat pump water heater, I expected lower energy bills.

I didn't expect my thermal camera to reveal such a dramatic change in how heat moved through my basement.

The glowing boiler, storage tank, and hot copper piping were replaced with a system that quietly transfers heat rather than constantly radiating it.

For homeowners replacing an aging boiler-fired water heating system, this upgrade isn't just about efficiency.

It's about changing the way your house manages heat.

And once you see the difference through a thermal camera, it's difficult to unsee it.

Written by Eric Gans
I have completed over 2000 Home Performance with ENERGY STAR® home energy audits in Maryland, and I like to write about my experiences.

 

 

Laurie contacted me because she was planning to replace the HVAC system in her 43-year-old home.

She had already spoken with several HVAC contractors and noticed something strange:

The proposals varied dramatically in price, but nobody was asking why certain rooms were uncomfortable.

One upstairs bedroom was consistently too hot in summer and too cold in winter.

Several rooms felt drafty.

She could feel air around outlets and switches.

And despite talking to multiple HVAC companies, nobody mentioned Maryland's EmPower rebate program.

That led her to schedule a Home Performance Energy Audit.

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Shiny and new, but the air coming out is the same?

What Most Homeowners Assume

Most people assume comfort problems are caused by:

• An old HVAC system
• Not enough airflow
• Bad thermostat settings
• The need for zoning
• The need for mini-splits

Sometimes that's true.

But often the HVAC system tries to compensate for problems caused by the building envelope.

Think of it this way:

A bigger furnace doesn't fix an open window.

A more expensive heat pump doesn't stop air leakage.

A zoning system doesn't add insulation.

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What We Found

When we evaluated the home, we found something interesting.

The attic already had a reasonable amount of insulation for its age.

The bigger problem was air leakage.

Numerous openings throughout the attic floor were allowing conditioned air to escape:

• Electrical penetrations
• Plumbing penetrations
• Recessed lighting
• Top plate connections
• Attic access hatch

At the same time, the basement rim joists were allowing outdoor air to enter the home.

The house was essentially leaking air from both the top and bottom.

This is extremely common in homes built during the 1980s.

 

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Why The HVAC System Wasn't The First Problem To Solve

Laurie had been considering:

• HVAC replacement
• Zoning
• Mini-splits

Those solutions may have helped.

But they would have been treating symptoms rather than causes.

Before spending money on more equipment, it made sense to improve the building envelope.

That meant:

Attic Air Sealing

Seal the hidden openings in the attic floor.

Attic Insulation Upgrade

Bring insulation levels closer to modern standards.

Rim Joist Sealing

Stop outdoor air from entering through the basement perimeter.

Mechanical Ventilation

Provide controlled fresh air after tightening the house.

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The Result

The improvements were completed by late March.

By May, Laurie received a rebate check for:

$9,678.76

More than $6,000 of that came from the HVAC replacement she was already planning to complete.

The remainder helped offset the cost of air sealing and insulation improvements.

But the rebate wasn't the biggest win.

According to Laurie:

• The house is more comfortable
• The air quality improved
• The uncomfortable rooms perform better
• She gained a better understanding of how her house works

Check out the Google Review here.

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What Homeowners Can Learn From This

If you're considering HVAC replacement, ask yourself:

• Why is the room uncomfortable?
• Where is the house leaking air?
• Is the attic properly air-sealed?
• Are the rim joists sealed?
• Is insulation performing as intended?
• Are there rebate opportunities being overlooked?

A new HVAC system may absolutely be part of the solution.

But before replacing equipment, it's worth understanding whether the house itself is causing the problem.

The most expensive HVAC system in the world still has to fight an inefficient building envelope.

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Final Thought

Laurie's experience highlights something I see regularly during energy audits.

Many homeowners begin the process thinking they need a new HVAC system.

What they actually need is a better understanding of how their home works.

Sometimes that leads to new equipment.

Sometimes it doesn't.

Either way, the goal is the same:

Find the root cause first.

Then spend money where it will have the greatest impact.

Written by Eric Gans
I have completed over 2000 Home Performance with ENERGY STAR® home energy audits in Maryland, and I like to write about my experiences.

 

 

 

One of the most common calls I get from homeowners goes something like this:

"My heat is running… but the house still feels cold."

Sometimes it’s a single room.
Sometimes it’s a basement.
But in this case, it was something more unusual.

The entire middle level of a townhouse was cold.

The homeowner had lived in the home for nearly 20 years and recently started noticing something troubling. Even with the thermostat set to 65°F, the living level rarely felt comfortable. To compensate, he had placed three electric space heaters around the room.

The heaters helped a little, but his winter utility bills were climbing over $400 per month.

That’s when he scheduled an energy audit.

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What Is an Energy Audit?

An energy audit is essentially a diagnostic investigation of how a home loses energy.

Instead of guessing at the problem, we use a combination of:

• Visual inspection

• Pressure testing (blower door test)

• Building science principles

The goal is simple:

Find where energy is escaping and identify the most cost-effective ways to fix it.

Many homeowners assume the problem is something obvious, like windows or HVAC equipment.

But most of the time, the real issue is hidden.

 

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First Clue: The Stack Effect

Within minutes of walking through the home, one thing became clear.

This house was experiencing a classic building science phenomenon called the stack effect.

Warm air naturally rises.

When warm air escapes through the top of the house, it creates a pressure imbalance that draws cold air into the lower parts of the structure.

Think of the house like a chimney.

Heat escapes from the top.
Cold air gets sucked in from the bottom.

The result?

• Cold floors.
• Drafty rooms.
• And heating systems that seem like they can never catch up.

But to confirm the theory, we needed to check the attic.

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What We Found in the Attic

The attic told the whole story.

As soon as I climbed through the attic hatch, several issues became obvious.

1. Missing Insulation Above the Bathroom

Because the home has vaulted ceilings, the roofline slopes upward across the house.

However, the bathroom ceiling below is only about 8 feet high.

This created a large hidden cavity above the bathroom where insulation had been installed incorrectly.

Instead of insulating the vertical wall separating the attic from the house, the insulation had simply been laid across the floor joists.

The result was a large, uninsulated pocket directly above the living space.

 

Warm air from the house was escaping directly into this space.

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2. A Large HVAC Chase Open to the Attic

Next we discovered a major air leakage pathway.

The ductwork from the furnace travels from the basement up through a vertical shaft (called a chase) into the attic.

Unfortunately, this chase was completely open.

That means heated air from the home could freely travel up this pathway and escape into the attic.

Imagine cutting a hole in your ceiling and leaving it open all winter.

That’s essentially what was happening here.

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3. Insulation Installed… But Not Doing Its Job

The attic did contain fiberglass insulation.

However, insulation only works properly when it sits on top of a sealed air barrier.

Without air sealing, insulation behaves like a sweater in the wind.

Air simply blows through it.

In several places, insulation had shifted or been installed incorrectly, leaving gaps where heat could escape.

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The Blower Door Test

To confirm the problem, we ran a blower door test.

This test uses a large calibrated fan installed in the front door to depressurize the house.

When the house is under pressure, outside air gets pulled through every crack and gap in the building envelope.

That makes hidden air leaks visible.

During the test, we observed significant airflow entering through:

• attic bypasses

• rim joist areas

• framing penetrations

This confirmed that the home was losing a significant amount of heat through uncontrolled air leakage.

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Why Space Heaters Were Not the Solution

The homeowner had been using three electric space heaters to warm the middle floor.

Each heater produces about 5,100 BTU/hr.

Combined, the three units provide about 15,000 BTU/hr of heat.

But electric resistance heating is expensive.

In fact, electric space heaters can cost three times as much per unit of heat as natural gas heating.

So while the heaters provided temporary comfort, they were actually increasing overall energy costs.

The real solution was to stop the heat loss, not add more heat.

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The Real Fix

The good news is that problems like this are usually fixable.

The most effective improvements for this home included:

1. Attic Air Sealing

Sealing the attic floor and all penetrations to stop warm air from escaping.

2. Closing the HVAC Chase

Install an air barrier around the duct chase to prevent heated air from escaping into the attic.

3. Correcting the Knee Wall Insulation

Properly insulating the vertical knee wall around the bathroom cavity.

4. Sealing Rim Joists

Air-seal accessible rim-joist areas along the exterior walls.

These improvements help transform the house from a leaky chimney into a controlled, efficient structure.

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Why Energy Audits Matter

Many homeowners assume the solution to comfort problems is:

• replacing windows

• upgrading HVAC systems

• installing larger equipment

But in many homes, the real problem is the building envelope.

Energy audits identify the low-hanging fruit — the improvements that deliver the greatest benefit for the lowest cost.

According to the U.S. Department of Energy, air sealing and insulation improvements can reduce heating and cooling costs by about 15%.

But just as important, they make homes far more comfortable.

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The Takeaways

This townhouse had a good heating system.

The equipment was not the problem.

The house simply had a few hidden pathways allowing heat to escape.

Once those pathways are sealed and the attic insulation is corrected, the middle floor should feel dramatically different.

And those space heaters?

They can finally be retired.

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If you’ve ever wondered why your home feels cold even when the heat is running, an energy audit might reveal the answer.

Sometimes the problem isn’t the heating system at all.

Sometimes the house just needs a little help holding onto the heat it already has.

Surprisingly, many BGE and Pepco customers are unaware of the rebates available for energy-efficiency upgrades around the home. Through Maryland’s Home Performance with ENERGY STAR program, eligible homeowners can receive incentives covering up to 75% of project costs—up to $10,000 for traditional efficiency improvements like air sealing, insulation, duct improvements, windows, doors, and HVAC upgrades.

For projects that include qualified electrification upgrades—such as heat pump HVAC systems and/or heat pump water heaters—the incentive cap can increase to up to $15,000. The key first step is completing a comprehensive home energy audit, which identifies opportunities, establishes energy savings, and determines rebate eligibility before any work begins.

If you’ve ever walked into a room in your home and thought, “Why is it always freezing in here?”, you’re not alone. And the answer isn’t always what you think.

I was recently called out to a home in Maryland to do a complete energy audit for a family dealing with, you guessed it, cold floors, uneven temperatures, and high energy bills. It wasn’t a huge home, and from the outside, everything looked normal.

But what I found inside told a completely different story.

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The Setup: Drafty Room, High Electric Bills, and Suspicion About the Crawl Space

When I arrived, the homeowner mentioned that their electric bill had soared over $1,100 during the winter. And the kicker? They weren’t even using the entire house.

That’s when I started digging, literally and figuratively.

We ran a blower door test to see how leaky the home was. The air just poured through. But where it was leaking from… that’s where things got interesting.

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The Crawl Space: Moisture, Gaps, and Unwanted Guests

The crawl space wasn’t fully open but wasn’t encapsulated either. The homeowner thought it was semi-conditioned, but it was in limbo. There were signs of past rodent activity, visible air movement through cracks, and a vapor barrier that had been mostly sealed but not completely.

The biggest problem?

•  Massive gaps in the rim and band joists.
•  Holes were cut for ductwork that opened straight to the exterior siding.
•  No insulation in key areas.

When I say I could touch the back of the aluminum siding from inside the house, I mean it.

This wasn’t just an insulation problem. This was a major connection point to the outside and a straight shot for cold air infiltrating the home. No wonder they had high energy bills.

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Stack Effect in Action

Upstairs, I found classic signs of the stack effect. An invisible force where hot air rises and escapes through the top of your home, pulling cold air up from the bottom.

You could feel the airflow at the recessed lights and attic access hatch. Even the insulation looked as if it had been shifted by the wind, a phenomenon known as wind washing, which was happening above the daughter’s bedroom. The wind had pushed the insulation away from the edges, exposing the ceiling and causing severe temperature fluctuations.

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The Real Fix: Sealing the Bottom AND the Top

Here’s what we recommended, and why it works:

Crawl Space Encapsulation:

• Fully seal the vapor barrier (which was already partially installed, a good start!).

• Insulate the crawl space walls, not the floor above. This brings the space into a semi-conditioned zone.

• Use rigid foamboard and 2-part spray foam to seal rim joists and large cutouts.

• Eliminate outside air intrusion (and mouse pathways).

• Result: The ducts and subfloor stop losing heat, moisture drops, and pests stay out.

Attic Improvements:

• Targeted air sealing at top plates, bath fans, electrical cutouts, and chase ways.

• Install baffles to prep for possible future soffit ventilation.

• Add loose-fill cellulose to bring insulation levels to R-49.

• Insulate and weather-strip the attic access hatch to complete the boundary.

Bath Fan Venting:

• Reroute bath fans that are currently terminated at gable vents.

• Properly vent them outside, as required for rebate eligibility and indoor air quality.

 

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Unexpected Bonus: Loose Duct Discovered

While inspecting the attic, I found an unsecured elbow joint on a duct supplying a second-floor bathroom. It was barely attached and likely leaking heated air into the attic. We reconnected it, but it must still be sealed and appropriately fastened to improve duct pressure and conditioned air delivery.

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The Bigger Picture: What Makes a Home Truly Comfortable

You can buy the best HVAC system in the world, but it'll never feel right if your home leaks air like a sieve. Insulation is only part of the equation. Air sealing is the hidden hero, and it’s almost always overlooked.

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If You Live in an Uncomfortable Home, Start Here

Your home isn’t broken, it’s just misunderstood. That’s what energy audits are for.

• We diagnose the invisible issues
• We quantify how much energy (and money) you’re losing
• We build a prioritized plan, no fluff, just results

And with rebates available through Maryland's BGE & PEPCO Home Performance with ENERGY STAR® program, many of our recommended improvements qualify for thousands in incentives.

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Book your $100 home energy audit now
Schedule Online

Let’s find the comfort you’ve been missing, hiding in plain sight.