Have you asked your HVAC contractor?

I have. He is looking into it. Doesn’t seem to have much experience with air exchangers.

He should have the resources (including talking to the distributor, which most HVAC contractors do frequently) to get the right information.

“Doesn’t seem to have much experience with air exchangers.” is a big red flag that you have the wrong HVAC contractor. These are not obscure machines. They are commonplace in every new build in cold locations.

Your HVAC contractor should be familiar with the applicable building code in your area.

Most statewide or local building codes are derived from the International Residential Code (IRC.) The 2015 IRC includes prescribed ventilation rates based on the size and occupancy of homes. Ditto for the 2018 IRC. If you're a fan (pun intended) of ASHRAE, their standard 62.2-1019 gives ventilation rates. The ASHRAE ventilation rates are higher than those specified in the IRC. Take your pick.

There are some HVAC-specific forums you should be able to find if you run a google search. I'm not at home now or would share some links. Green Building Advisor and Energy Vanguard also have useful information.

I always love the replies that tell the OP they have the wrong contractor or designer or whatever sort of professional. Some of us have to make do with what's available, and even the less informed or up to date may be the best around. Over a decade ago, I had to explain to our HVAC guy how an ERV works. He'd never heard of it. He was willing to learn, which is more than I could say for several others. I went through quite a few HVAC company owners in two counties before I found one who knew how to do a Manual J calculation for a new house. Most have not heard of the need for makeup air for a high CFM vent fan.

Also, not all counties or municipalities have adopted the most recent building codes. Some don't care about building codes at all. In the small city where we're having our (hopefully last) house built, we are just a few minutes away from the next county where no building inspections have been done until recently. It was only when our new city annexed some land in that county and it became subject to city regulations that any new builds there were inspected.

The primary focus of building codes is life safety. Meeting the requirements is generally a good idea, irrespective of whether building codes have been adopted or are enforced in your particular area. I grew up in a rural area with no codes, no permits, and no inspectors, but no trade contractor worth his salt wanted to take on the liability of doing something that would not pass inspection. There were lawyers even in rural America in the 1960's.

In recent years, building codes have added requirements about energy efficiency and occupant health/comfort. Probably because the folks who develop the codes got tired of debating the same old mundane stuff.

With respect to home ventilation, I think you'll find Green Building Advisor and similar resources will refer to IRC code requirements. The OP can access (read only) copies of the 2015 IRC, the 2018 IRC and the ASHRAE standard 62.2-2019 on the web with a couple of clicks. I don't think the ventilation requirements of the two IRC codes are different, but they are less than the ASHRAE standard as previously noted.

OP, where are you located? How much of the time will you have windows open for fresh air? How many people will be living in the house (including frequent numbers of guests)? Do you entertain often with the house closed up? For how many people?

Keep in mind that building codes are "the worst that you can legally get away with building". They are not intended to be adequate but only minimums. Do some research on how much ventilation is needed to keep CO2 levels under control and specifically in bedrooms at night with doors closed.

Make sure you understand the differences between an ERV & HRV before deciding which one.

Make sure you understand the differences in different ducting configurations. Many contractors in the U.S. will pull stale from the return duct and throw the fresh back in to the return - understand why many countries and manufacturers instead recommend dedicated ducting (from baths/kitchens to bedrooms) for ERV/HRV's in cold climates.

Some good resourced mentioned above.

Agree that location is super relevant.

I have to admit that I have a 1.7 ACH50 house without ERV/HRV. Code didn't require anything (including blower door test). Energy star required ventilation - just basic fresh air. This is NC and we tend to follow fairly recent codes but not as strict as CA.

Number of occupants matter.

I look for an explanation for something. Why does a huge house, ie 7500+ with 1 bedroom require more ventilation than a small house with 7 bedrooms. In my mind, a bigger house will leak more air and so should need less ventilation. I personally don't worry about CO2 if I lived by myself in 8,000 sqft but I sure would if I lived with 10 others in 1500 sqft.

I completely get that CO2 is not the only (or main) issue.

Ventilation requirements need better specificity. CO2 is not an issue in a large house with few occupants. VOCs would depend on age of house and materials used.

Often times ventilation is for smells - and that is certainly occupant dependent.

The IRC requirements are so low, you would have to live in an extreme temp area or a very high cost of energy area, to justify using an ERV/HRV rather than just fresh air.

Alternate Ways to Size ERVs / HRVs.

https://www.heatair.org/

Traditionally, square footage of a home was needed to correctly size an ERV or HRV (Energy Recovery Ventilator, Heat Recovery Ventilator). If you don't know the square footage of your home, there is an easier way to size the HRV or ERV that you need to get the job done.

Either of the methods below give a result that relates to the CFMs (cubic feet per minute) that the ventilator unit can move with it's internal fans. For example, the Honeywell HR150B 1005 Heat Recovery Ventilator is rated at 150 CFM. The Fantech Heat Recovery Ventilator Model SHR 2005R will do 168 CFM.

Traditional Method - Square Footage

HRVs/ERVs are typically sized to ventilate the whole house at a minimum of .35 air changes per hour. To calculate minimum CFM requirements, simply take the square footage of the house (including basement) and multiply by the height of the ceiling to get cubic volume. Then, divide by 60 and multiply by .35.

Alternate Method - Room Count

With the room count method, each room in the home is assigned a certain number of CFMs. When the values from the rooms are added together - the total number of required CFM's are the result. Use the chart below to figure the number of CFM needed to properly size your HRV or ERV.

@David Cary,

I don't believe that installation of fresh air ventilation systems is required under the IRC. However when they are installed, fresh air ventilation systems need to meet the requirements of the applicable section of the code. If the OP opts to install an HRV they will be well served to comply with the applicable code requirements, if any, in their area.

The IRC sizing method for fresh air ventilation systems has both an area component and an occupancy component. The area is simply the area of the living space. The number of occupants is inferred from the number of bedrooms (the assumption is one person per bedroom plus two in the master bedroom.) ASHRAE recommends a minimum fresh air ventilation rate of .35 to 1 ACH which is a better way of specifying the fresh air ventilation rate.

The residential building code is gradually integrating indoor air quality as a code requirement. The IRC calculation method is simple, and is based on certain assumptions. If it follows the path of most code revisions, you can safely bet meeting the indoor air quality standards will get more complicated over time.

Installation of HRVs and ERVs are not strictly economic choices; both devices serve to introduce a controlled flow of fresh air and to temper it--both of which effect loads on other components of the HVAC system. Because of interactions between various components in an overall HVAC system, design and specification is best left to professionals.

I guess I always think of the ventilation options as HRV/ERV vs unconditioned fresh air (by a fan that controls the flow). That to me is an economic one because you can always get all the ventilation you want from fresh air, it just costs more to condition it. That cost is pretty minor in a mild climate. Especially when considering the cost of an HRV/ERV.

But I totally understand that most HRV/ERVs are ducted to do a better job than most fresh air systems.

I know that I looked into it and it was expensive for what it did. Solar panels were much more economic. But I bet I would get more fresh air if I had an HRV in Jan. Just doesn't matter much for 9 months out of the year (when we literally have a window cracked).

What is interesting is that we have wood burning folks in our neighborhood and in Jan, I would rather be inside from an AQ standpoint. We can't open the windows - even when we want to. Running our hood can make the house smell worse (and feel worse for our lungs even if not true).

I would be super mad if I paid $2500 for an HRV and had to shut it off most of the winter....

Always like to be educated, what happens to an HRV if the outside air is unacceptable.....

Fresh air ventilation where outdoor air quality is an issue is addressed in the ASHRAE standard.

Thank you everyone! All of your expertise and advice is really helpful. We live in southeast Pennsylvania and we have some cold winters.