ERV comparison – settings and controls

We were owners of several UltimateAir RecoupAerator 200DX energy recovery ventilators (ERVs), until they broke down. And like so many other former 200DX owners, we found ourselves hunting for some suitable replacements. We settled on the Broan ERV200TE and Panasonic FV-20VEC1 (Intelli-Balance 200).

In this post I am comparing the settings and controls of these two units. I hope you will find the information useful if you are in a similar situation.

Broan setting and controls

The Broan has no controls on the ERV itself, but has one main control terminal block and one auxiliary terminal block. To set up, balance, and run the Broan, I had to purchase the VT9W wall control, which got wired into the main control terminal block. The wall control is the main interface to run the ERV, and is user friendly.

The MODE button has four settings:

  1. STANDBY – which turns the unit off
  2. RECIRC – Recirculation mode, which could be used to even out temperatures in the apartment.
  3. 20 MIN/H –  which cycles between 20 minutes of low speed ventilation and a 40 minute pause.
  4. CONT – Continues ventilation at low speed.

The TURBO button ventilates at high speed for four hours before turning back to the previous setting.

The %HUM button (dehumidistat function) turns on the Turbo mode once indoor humidity exceeds a set limit.

I also purchased the VB20W Push Button Timer for the bathroom, which got wired into the auxiliary terminal block.

This switch does the job equivalent to that of a bathroom fan. Pressing the button turns on the turbo mode for 20 minutes to exhaust the air from the bathrooms.

While using the ERV over the past couple of years, I ended up using only four settings consistently:

  1. The STANDBY mode to turn the ERV on or off,
  2. the 20 MIN/H mode when we have low ventilation needs,
  3. the CONT mode when we have regular ventilation need, and
  4. the bathroom push button timer when the bathroom is used.

For a complete description of all the settings and functions, see the Installation and Owner Guide.

Because the Broan is a replacement unit for the UltimateAir RecoupAerator 200DX, I could reuse the existing low voltage wiring for both controls. It was just a matter of switching the old controls with the new ones and connecting them correctly to the terminal blocks.

Panasonic settings and controls

The Panasonic settings and functions struck me as odd, because they appear to follow a different paradigm compared to the old RecoupAerator or the Broan mentioned above.

The ERV has a small panel with three control dials directly on the ERV. One dial (the ASHRAE time knob)  sets the ventilation intervals in minutes, from 10 minutes per hour to 60 minutes per hour in 10 minute intervals (six settings).

The other two dials set the air flow rates for the supply air and exhaust air fan motor respectively, from 60 cfm up to 200 cfm in 20 cfm intervals. In short, it’s an ERV that has eight preset ventilation stages.

The small dials are not made for big fingers like mine.

Panasonic also offers an auxiliary wall control (FV-SW20VEC1) for the ERV.

FV-SW20VEC1 wall control

The settings appear very simple and straightforward on first sight:

  1. Standby mode (ON/OFF),
  2. Vent mode, for ventilation, and
  3. Boost mode to run the ERV at high speed for 20 minutes in the default setting.

But the devil is in the details! To use the vent mode effectively, the user has to jump through a number of hoops. One has to select and set the supply air volume out of the eight available settings, followed by selecting and setting the exhaust air volume. After that, the user has to select and set the ventilation intervals in minutes out of the six available settings.

There are only two modes available by one simple push of a button:

  1. ON/OFF
  2. Boost

Adjusting the ventilation from, for instance, continuous to a 20 minute interval requires programming (pushing three buttons in a certain order) and is not as simple as pushing one button like on the Broan ERV.

I would love to install an optional boost switch in the bathroom, similar to the Broan Push Button Timer. I understand that there are options available, but none that I saw that would be a simple installation such as with the Broan. And the options that are available appear to require line voltage, and not low voltage. That would require me to ditch the existing low voltage run I already have and install a new line voltage run from the ERV to the bathroom.

Panasonic may have good reasons to take the path they did on the controls and settings. I have not yet figured out what they could be. Considering that most people don’t even like to fiddle with their thermostats, the Panasonic wall control may not be loved by your typical user.

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ERV comparison – filters

We were owners of several UltimateAir RecoupAerator 200DX energy recovery ventilators (ERVs), until they broke down. And like so many other former 200DX owners, we found ourselves hunting for some suitable replacements. We settled on the Broan ERV200TE and Panasonic FV-20VEC1 (Intelli-Balance 200).

In this post I am comparing the filters of these two units, and hope you will find the information useful if you are in a similar situation.

Broan filters

The Broan comes with two washable filters MERV 6, one on the fresh air intake side and the other on the stale air exhaust side. The filters are easy to remove and clean, and they are reusable.

The Broan product literature points to a disposable HEPA filter for the fresh air intake side. The HEPA filter would reduce the overall airflow (increase the static pressure) and would require re-balancing the ERV. I will cover the balancing of the units in an upcoming post.

If we need to replace the two reusable MERV 6 filters, we could do so for around $80.00 at the time of this writing. The optional HEPA filter seems more difficult to find (special order) and retails around $80.00.

Panasonic filters

The Panasonic comes with a disposable MERV 13 filter on the fresh air intake side and a washable filter on the stale air exhaust side that has not a rating as far as I can tell. Panasonic also offers disposable MERV 8 and HEPA filters for the fresh air intake side.

I assume that the MERV 8 and HEPA filters would also require to re-balance the ERV, although there is no mention of it in the product literature.

The disposable filters should be replaced around every six months, according to the operating instructions. And they are not cheap. As per this writing, the MERV 8 filter costs around $115.00, the MERV 13 filter around $125, and the HEPA filter around $135.

I guess clean air has its price.

Related posts:

ERV comparison – placement and duct connections

We were owners of several UltimateAir RecoupAerator 200DX energy recovery ventilators (ERVs), until they broke down. And like so many other former 200DX owners, we found ourselves hunting for some suitable replacements. We settled on the Broan ERV200TE and Panasonic FV-20VEC1 (Intelli-Balance 200).

In this post I am comparing placement options and duct connections between the two units, and hope you will find the information useful if you are in a similar situation.

Placement options

The Broan and Panasonic are very similar in size to the old 200DX, which made it easy for us to fit them into their respective ventilation closets.

Both could be placed on the ground or a shelf/platform, but also had a wall mounting option, or chain mounting option (hanging from the ceiling). In our case both units were placed on a level platform in the ventilation closet.

Broan duct connections

All ERVs in our building have their own dedicated duct work, rather than being connected to an air furnace duct as we don’t have forced air heating.

The six inch duct ports on the Broan are all located on the top of the unit. The installation manual calls for insulated flex duct for the two ports connecting to the building exterior (fresh air intake and exhaust air). The two ports connecting to the building interior can use insulated flex duct, flex duct, or rigid duct work.

All duct ports are oval, which seemed odd at first. Because I used insulated flex duct for all connections, the oval shape was not a problem. Quite to the contrary, I ended up loving the port design for the ease of installation:

Each port has an inner and outer collar. The flex duct gets zip tied to the inner collars. The insulation is pulled down between the two collars. The flex duct jacket (vapor barrier) is pulled over the outer collar and sealed with port straps that come with the ERV. This makes for an easy and airtight duct connection, and does a fantastic job at avoiding common condensation issues during winter.

Panasonic duct connections

The six inch duct ports on the Panasonic are also located on the top of the unit. However, the fresh air port into the building and the stale air port from the building can be moved to the side of the ERV. Like with the Broan, the two ports on the Panasonic connecting to the building exterior (fresh air intake and exhaust air) require insulated flex ducts, while the ports connecting to the building interior can be connected to rigid ducts.

Even though the exterior duct ports have an insulated collar, connecting the insulated flex duct with an airtight and condensation proof connection proved challenging, compared to the Broan. The flex duct again gets zip tied to the duct collars, but so does the insulation and duct jacket. That creates a cold spot because of the compressed insulation under the zip tie.

To remedy the problem, I wrapped several layers of insulation foam tape around the collar, after I connected the flex duct. I pulled the insulation down to the foam tape insulation and pulled the duct jacket over the foam tape and zip tied it. Not perfect, but a better air seal and less of a cold spot than before.

The next post will compare the filter options of the ERVs.

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Dissecting space conditioning

Our January cold spell along with new data from the 2020 Residential Energy Consumption Survey inspired me to further dissect the issue of space conditioning. When it comes to energy use in a building, space conditioning is the 900 pound gorilla in the room. We reduced our space conditioning load through three steps:

First step: The deep energy retrofit, which significantly reduced our overall energy needs through building envelope improvements among other things. This blog is packed with information on insulation, air sealing, window selection, etc. And you can find a summary post here on steps to reduce your overall energy needs.

Second step: Adding a photovoltaic array to our roof top to cover our remaining energy needs. You can search this blog for “solar” or “photovoltaic” to find detailed information on this step.

Third step: Installing heat pumps (also known as minisplits) for space conditioning. You can find more information by searching this blog for “minisplit” and “heat pump”.

The first step was the heavy lifting, and got us the biggest bang for the buck. In fact, our building’s energy consumption for space conditioning ended up below the national average.

And in monetary terms, cooling our building in 2020 was “free” because of the second step: our photovoltaic roof array which provided the needed electricity. Heating our building was almost free. It cost us $173.40 to heat our 4,500 sf building in 2020.

If you would like to know about the nuts and bolts behind those numbers, keep on reading!

Parsing out space conditioning

I used the solar year 2020 (April 1st, 2020 till March 31, 2021), because it was a twelve month stretch where all our space conditioning needs were covered by our heat pumps (single head minisplits). I separated out the general electrical consumption from the energy used for space conditioning by looking at our electrical use on a monthly basis, plus factoring in data from our home energy monitors. The building’s average monthly electrical consumption for everything but space conditioning was 700 kWh.

Our building’s energy use for the solar year 2020 totaled 13,428 kWh. Assuming the average use of 700 kWh per month, we used an estimated 8,400 kWh during the solar year 2020 without accounting for heating and cooling, which took an estimated 5,028 kWh.

solar year 2020Building (kWh)One household in our building (kWh)
Total energy use13,428 (100%)4,476
General energy use (excluding space conditioning)8,400 (62.5%)2,800
Energy use for space conditioning5,028 (37.5%)1,676

2020 data from the U.S. Energy Information Administration shows that space conditioning consumes 46% of the building’s energy use in 2-4 unit apartment buildings like ours (or 52% on average per U.S. household).

Our deep energy retrofit allowed us to reduce that number from 46% to 37.5%, an estimated 8.5% decrease during the solar year 2020.

We are not talking about how much energy is used here, but how that energy use is distributed across various categories, from space heating to refrigeration and all other.

When comparing the 2020 data to that of 2015, we see that these numbers are fairly constant. They are actually hard to change, particularly in existing buildings, because of long established construction types, materials, and methods.

The fact that we were still able to shrink the percentage of energy going towards space heating and air conditioning by a whopping 8.5% for the solar year 2020 is a testament to the success of step number one: reduction of our overall energy load through building envelope improvements. And it pays off:

In terms of heating cost…

…how did I get to $173.40 to heat our 4,500 sf building for the solar year 2020?

From April through to December we only paid for fixed costs ($12.83/month for customer and meter charges) because our photovoltaic array combined with our net-metering agreement covered our electrical needs. For the last three months of the solar year (January, February and March) we had to purchase electricity and paid a total of $289 for the 2,038 kWh we used.

TotalkWh w/o space conditioningSpace conditioning
Jan 20211,839 kWh minus700 kWh =1,139 kWh
Feb 20212,139 kWh minus700 kWh =1,439 kWh
Mar 20211,254 kW minus700 kWh =554 kWh
Total5,232 kWh (or 100%)3,132 kWh (or 60%)
Total cost$289 (or 100%)$173.40 (or 60%)

Looking at the total kWh consumed and the breakdown between kWh for space conditioning and kWh for everything else, an estimated 60% ($173.40) of that energy went towards space conditioning (heating) our 4,500 sf building with the minisplits for the three months we ran a deficit.

There is nothing mysterious about this, as long as you don’t fall into the trap by starting your project with a heat pump.

Follow the three steps, and numbers like this (or better) can become a reality:

  1. Address thermal deficits in the building envelope first to significantly reduce the overall energy load of the building.
  2. Combine those improvements with a renewable energy project, such as a photovoltaic array, that now has the potential to cover 100% or close to 100% of your energy needs. 
  3. Install an efficient heat pump system that is small and compact due to the reduced overall energy load of your building, and subsequently is largely or entirely powered by your renewable energy system.

But there was something magical about this: We ended up with a very comfortable home!

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Energy Fair 2023

June is the month of the Midwest Renewable Energy Association’s (MREA) annual Energy Fair! This year, the event will take place Friday, June 23rd through Sunday, June 25th. The event location is, as always, at the MREA headquarters in rural Custer, Wisconsin.

If you are following this blog, you are probably looking to solve problems around the energy efficiency of your house, have green building or building science questions, or want to make your home more sustainable. I hope the blog will answer some of your questions. But I am sure that a day at the Energy Fair will answer a lot of your questions.

The Fair is a wonderful mix of educational sessions, entertainment, and exhibitors and vendors, many of whom show products that may become handy in making your home more energy efficient.

The educational sessions take place in large tents on the fairgrounds. There are eight to twelve tents (depending on the year) with sessions running parallel to each other all day long. Most sessions are an hour long.

The subjects covered include building electrification, energy efficiency, electrical vehicles and clean transportation, going solar, policy and community organizing, project finance, sustainable farms and food production, etc. You can take a look through the workshop schedule here.

Cathy and I attended the workshop the first time back in 2007. We were there just for the big day, which is always Saturday. It was a very long day, but worth every second. We came back home with so much useful information and so many of our questions answered. And even better, we came home with so many more questions generated. It was the jump off for our deep dive into our deep energy retrofit project.

The next time we attended, we opted to go for the full three days of the Energy Fair to take home as much information as we could, for the pure joy and fun of the event, to meet up with old friends, and to network and make new friends. And we’ve attended all three days just about every year since then, except when they paused the Fair during Covid.

Attending the event is surprisingly inexpensive. A one day pass at the gate cost you $20. A weekend pass at the gate costs a mere $45. I can’t remember a conference or fair I attended that only charged $45 for three days, and offered this amount and quality of workshops, exhibitors and entertainment!

If you would like to dip your feet into the MREA Energy Fair world to see if this is something for you, I would recommend driving up to Custer for Saturday, like we did back in 2007. I would not be surprised if we will see you again the following years on Friday, Saturday, and Sunday. Because this is an event one starts looking forward to starting in January!

And no, I have not been asked by MREA to write this post or promote the Energy Fair, nor am I paid compensated by MREA. This is a wonderful and fun resource that I believe is worthwhile sharing. I have, however, been honored to present some educational sessions over the past few years – and I’m presenting two sessions this year.

Hope to see you in Custer the weekend of June 23rd!