Both bring in fresh air while reclaiming energy, but only one is built to handle Texas humidity, and picking the right one changes how comfortable your sealed home feels.
Once you seal a home tight with spray foam insulation, you need a way to bring in fresh air without throwing away the energy you just saved. That is the job of an energy recovery ventilator (ERV) or a heat recovery ventilator (HRV). They look almost identical and install the same way, but they handle moisture very differently, and that single difference is what decides which one belongs in a Dallas-Fort Worth home. This guide explains how each device works, why humidity is the deciding factor in Texas, how to size and maintain one, and where these systems fit in the larger fresh air ventilation picture.
A leaky old house gets its fresh air by accident, through cracks and gaps driven by wind and the stack effect. When you seal a home with foam and complete thorough air sealing, that accidental airflow largely stops. The house becomes efficient and comfortable, but fresh air now has to be supplied on purpose.
You could simply run an exhaust fan and let outside air seep in, but in a Texas summer that means importing hot, humid air with no treatment. A far better approach is balanced ventilation, where equal amounts of fresh air come in and stale air go out through a single unit that reclaims energy from the outgoing stream. That unit is either an ERV or an HRV.
The core promise of both devices is the same: fresh air without the full energy penalty. As stale indoor air leaves, it passes its temperature (and in the case of an ERV, some of its moisture) to the incoming fresh air, so the fresh air arrives close to indoor conditions. The difference between them is exactly what gets transferred.
A heat recovery ventilator moves heat only. Inside the unit is a core where the outgoing and incoming airstreams pass close to each other without mixing. In winter, the warm outgoing air preheats the cold incoming air. In summer, the cool outgoing air pre-cools the warm incoming air. Either way, only sensible heat, the temperature, is exchanged.
What an HRV does not do is transfer moisture. Whatever humidity is in the incoming outdoor air comes straight into the house. In a cold, dry northern winter that is actually desirable, because indoor air can get too dry and you may want to keep every bit of the incoming (already dry) air. HRVs shine in heating-dominated climates where the outdoor air is cold and dry for much of the year.
In a humid climate, that same behavior becomes a liability. An HRV running in a Texas July would pull in muggy outdoor air, cool it down a bit, and deliver all of its moisture into your living space, leaving your air conditioner and any dehumidifier to remove it. That is why HRVs are rarely the right pick for DFW homes.
An energy recovery ventilator does everything an HRV does, and one more thing: it transfers moisture along with heat. Its core is built from a material that allows water vapor to move between the airstreams, so the exchange is both sensible (temperature) and latent (moisture). This is called total energy recovery.
In a Texas summer, this is exactly what you want. As the ERV brings in humid outdoor air, it hands much of that moisture off to the drier, conditioned air being exhausted. The fresh air that reaches your home is not only cooler than raw outdoor air but also noticeably drier. That reduces the load on your HVAC and helps with whole-home humidity control.
The moisture transfer works in the other direction too. In the occasional dry Texas winter stretch, an ERV helps retain some indoor humidity rather than dumping it outside, so the house does not get uncomfortably dry. That two-way moisture management is why the ERV is the workhorse of humid and mixed climates.
The single most important climate fact for this decision is that Dallas-Fort Worth is hot and humid for a large part of the year. Our comfort problems are driven as much by moisture as by temperature. That tilts the choice firmly toward the ERV.
Think of it this way. An HRV controls the temperature of your incoming fresh air but ignores its humidity. In a climate where humidity is often the harder problem, that is only doing half the job. An ERV manages both, so the fresh air arrives closer to comfortable in the way that matters most here.
There are narrow exceptions. A home with very high indoor moisture generation and a strong need to expel humidity, or a specialized application, might change the math. But for the overwhelming majority of sealed Texas homes, the ERV is the correct default. If you want the broader reasoning on why humidity dominates comfort here, the moisture and building science overview lays it out.
Because the hardware and installation are so similar, choosing correctly costs nothing extra; it just requires understanding your climate. In DFW, that means an ERV in nearly every case.
An ERV only helps if it delivers the right amount of fresh air. Sizing follows ASHRAE Standard 62.2, which sets a target based on the home's floor area and number of bedrooms. For a typical DFW home that lands in the range of a few dozen to around a hundred cubic feet per minute of continuous fresh air.
Bigger is not better. An oversized unit run too hard would import more moisture than the recovery core can handle and waste energy. An undersized or poorly commissioned unit leaves air stale. The sweet spot is a modest, steady exchange that keeps the air fresh without overwhelming your dehumidification. This is why sizing and balancing should be done by an installer who understands both the standard and the Texas climate.
Airflow balance matters just as much as volume. A balanced ERV moves equal air in and out so the house is neither pressurized nor depressurized. If the streams are unbalanced, the home can pull in unconditioned air through remaining cracks or push conditioned air out, undoing part of the benefit. Proper commissioning with measured airflow is what makes the system perform as designed.
An ERV can be installed in a few ways. A fully ducted system has its own supply and return runs, drawing stale air from moisture-prone rooms and delivering fresh air to bedrooms and living spaces. This gives the best control but costs the most to install. A simpler approach ties the ERV into the existing HVAC ductwork, sharing the distribution network. This is more affordable and works well in many homes when designed carefully.
In a sealed home, the ERV should draw stale air from areas that generate the most moisture and pollutants and deliver fresh air where people spend time. Even so, it does not replace the dedicated source-control fans in your wet rooms. Good bathroom venting and kitchen venting still handle the big, fast moisture spikes, while the ERV handles the steady background exchange.
Location matters too. In a home with a conditioned attic created by roof deck foam, the ERV and its ducts live in comfortable, semi-conditioned space rather than a scorching vented attic, which protects performance and efficiency. That is one more reason the sealed envelope and the ventilation system work best when planned together.
ERVs are low-maintenance but not no-maintenance. They have filters that need periodic cleaning or replacement, and the recovery core benefits from occasional cleaning per the manufacturer's schedule. Neglected filters reduce airflow and efficiency, so a simple reminder a few times a year keeps the system healthy.
A well-maintained ERV runs quietly and continuously in the background, and most homeowners forget it is there. What they notice is the result: fresh-smelling air, steadier humidity, and none of the stuffiness that closed-up tight homes can develop. Because the unit recovers most of the energy it would otherwise waste, the operating cost is small.
As with any mechanical system, the payoff depends on the whole picture. An ERV on a leaky house fights a losing battle, because uncontrolled leakage still dominates the airflow. An ERV on a properly sealed home performs exactly as intended. That is why we treat sealing and ventilation as partners, and why a blower door test is useful for confirming the envelope is tight enough for controlled ventilation to work.
Which is better for a Texas home, an ERV or an HRV? In almost every case, an ERV. Dallas-Fort Worth is hot and humid for much of the year, and the ERV manages both temperature and moisture in the incoming fresh air. An HRV controls only temperature, which leaves the harder half of the Texas comfort problem unaddressed.
Does an ERV act like a dehumidifier? Not exactly. It reduces the moisture entering with fresh air by transferring it to the outgoing stream, which lowers the humidity load. It does not remove moisture already generated inside the home the way a dedicated dehumidifier does. In some humid homes the two work together, with the ERV handling ventilation moisture and a dehumidifier handling the rest.
Will an ERV cancel the efficiency I gained from spray foam? No. The whole point of energy recovery is to keep most of that efficiency. The fresh air arrives close to indoor conditions, so you add only a small ventilation load while keeping the large savings from your sealed envelope.
Can I add an ERV to my existing HVAC ductwork? Often, yes. Many homes tie the ERV into the existing duct system to share distribution, which lowers installation cost. A fully ducted standalone system offers more control, and a qualified installer can recommend the best fit for your layout.
How much fresh air should the ERV deliver? Sizing follows ASHRAE 62.2, based on your floor area and bedroom count, adjusted for the local climate. For most DFW homes that is a modest, continuous flow rather than a large volume, so it freshens the air without importing excess moisture.
Do I still need bathroom and kitchen fans if I have an ERV? Yes. Those source-control fans handle the fast, concentrated moisture and odor spikes from showers and cooking, while the ERV handles the steady background air exchange. They complement each other. You can start planning the whole system with a free instant estimate for the sealing work.
ERVs and HRVs both bring fresh air into a sealed home while reclaiming most of the energy that ventilation would otherwise waste. The difference that matters is moisture: an ERV transfers it, an HRV does not. In the hot, humid Dallas-Fort Worth climate, where humidity often drives comfort more than temperature, that makes the ERV the clear choice for nearly every home.
Get the sizing and balancing right, keep the filters clean, and pair the unit with a properly sealed envelope and good source-control fans, and an ERV will quietly keep your home fresh, dry, and efficient for years. When you are ready to build the tight, healthy home that an ERV is designed for, a free instant estimate is the best first step, and the fresh air ventilation guide shows how it all fits together.
Fresh Air Ventilation: Why Tight Homes Need Controlled Fresh Air
Build tight, ventilate right. Why sealed spray foam homes need controlled fresh air and the ventilation options that work in Texas.
Humidity Control in Texas Homes: Getting to Comfortable and Staying There
How to control indoor humidity in a Texas home: air sealing, right-sized HVAC, dehumidification, and ventilation working together.
Indoor Air Quality: What Your Home's Air Is Really Carrying
What affects indoor air quality in Texas homes, how attic and crawl space air leaks pollute living spaces, and how a sealed envelope helps.
Air Sealing: The Most Overlooked Upgrade in Texas Homes
Why air sealing matters more than adding insulation alone, where Texas homes leak, and how spray foam seals and insulates in one step.
Blower Door Testing: Measuring How Leaky Your House Really Is
How a blower door test measures air leakage, what ACH50 numbers mean, Texas code requirements, and typical results before and after foam.
Get a free instant estimate for your Dallas-Fort Worth home and see how a spray foam sealed envelope paired with the right energy recovery ventilator delivers fresh, dry, comfortable air all year.