Category Archives: ventilation

ERV comparison – unit balancing

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 balancing protocol of these two units. I hope you will find the information useful if you are in a similar situation.

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.

Why balancing?

When using mechanical ventilation, it is a good idea to avoid negative pressure (exhausting more air than comes in) and positive pressure (forcing more air into the building than can leak out). Depending on the weather conditions, negative or positive pressure has the potential to cause condensation where air leaks into or out of the building, which in turn could lead to mold formation.

A balanced mechanical ventilation system, such as many ERVs, avoids this risk by balancing the supply air with the exhaust air. However, because the supply and exhaust duct systems may have different lengths and a different number of fittings, such as elbows, it may create different static pressures. Balancing the ERV should compensate for the difference in static pressures.

To proceed with the balancing process, I had to purchase a magnehelic gauge, which allows me to measure the pressure on the supply and exhaust sides of the ERV. The pressure gets converted to cubic feet per minute (cfm), which is the metric used to adjust the airflow until the unit is balanced.

Broan Balancing

To balance the Broan, the user has to access the programming mode through the VT9W wall control. This wasn’t much of an obstacle, as I needed the wall control anyway in order to run the ERV.

The Broan has four small ports, two on the supply side and two on the exhaust side. The magnehelic gauge tubing gets connected to the ports to take pressure readings and determine the air flow rate for the various settings (turbo speed, continuous speed, timer speed, and recirculation speed). Through the wall control, I could enter the program mode and then adjust the airflow, or motor speed, for the various settings in 1% increments until the unit was balanced.

I found the instructions in the installation guide intuitive and easy to follow, and recorded each setting for future reference.

Panasonic balancing

The Panasonic is balanced with the controls that are on the unit. Like the Broan, it has four small ports for the Magnehelic Gauge tubing to take pressure readings and determine the air flow rate.

The balancing instructions (or start-up procedure instructions), are incomplete and confusing – so much so that I ended up calling tech support. Tech support tried their best to help me with my questions but didn’t have the answers on some of the technical details. I was referred to the Panasonic engineers, but never heard back from them, despite repeatedly contacting them for a month. In short, it took a lot of research to partially wrap my head around the balancing procedure for the Panasonic.

To balance the Panasonic I measured the airflow on the supply and exhaust side for all eight ventilation stages.

CFMSupply pressure (PA)Exhaust pressure (PA)
6019.627.5
8024.538.2
10034.348.1
12041.258.8
14048.173.5
16062.873.5
18075.574.5
20079.474.5

I then had to pair the supply and exhaust air volume based on the closest matching airflow readings.

SupplyExhaust
80 cfm (24.5 Pa)60 cfm (27.5 Pa)
100 cfm (34.3 Pa)80 cfm (38.2 Pa)
120 cfm (41.2 Pa)80 cfm (38.2 Pa)
140 cfm (48.1 Pa)100 cfm (48.1)
160 cfm (62.8 Pa)120 cfm (58.8 Pa)
180 cfm (75.5 Pa)180 cfm (74.5 Pa)
200 cfm (79.4 Pa)200 cfm (74.5 Pa)

If I want to run the ERV at 60 cfm, I need to set the supply side to 80 cfm and the exhaust side to 60 cfm. If I want to run the ERV at 80 cfm, I need to set the supply side to 100 cfm and the exhaust side to 80 cfm. And so on…

This process seemed rather crude compared to the Broan where I could adjust the airflow in 1% increments. That said, Panasonic advertises in their product literature something called  SmartFlow™ technology:

Intelli-Balance®200 uses two (2) ECM brushless motors with built-in SmartFlow™ technology for precision ventilation. When the ERV senses static pressure, its speed is automatically increased to ensure desired output; regardless of a complicated duct run.

I was unable to find more technical information that would shed light on how the SmartFlow™ technology exactly works. Some suggested in discussion forums that the SmartFlow™ technology auto balances the Panasonic as long as the pressure differential does not exceed 0.4” WG (99.5 Pa).

Bottom line, after I paired the correct airflow settings as per the table above and tested the Panasocnic again, I got the same pressure readings on the supply and exhaust side, which indicates that the SmartFlow™ technology seems to do its job.

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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.

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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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Hunting for replacement ERVs

It was time to research replacement ERVs (Energy Recovery Ventilator) after two of our units broke down in 2020. A couple of key aspects re-emerged in that process.

  1. The heat recovery efficiency of our Recoupaerator 200 DX was unmatched based on HVI (Home Ventilation Institute) data, which was confirmed with my own testing.
  2. It looked like the Recoupaerator 200 DX was the only residential ERV on the U.S. market that used an enthalpy wheel for the heat and moisture transfer.

Other residential ERVs use a static core heat exchanger, or core in short. Unlike an enthalpy wheel, the core functions on the principle of cross flow.  The exhaust and fresh stream flow across each other in the core without mixing. In the process thermal energy is transferred through the core’s membranes. And if we want to get all technical, we are talking about sensible energy (heat) and latent energy (moisture).

The cores come in two shapes: square and hexagonal. And this apparently small difference has a big impact when it comes to energy recovery. A hexagonal core has more surface area and thus provides more opportunity for sensible and latent energy transfer.

A quick review of product specifications led me to conclude that an ERV with a square core would be out of the question for us, because of the rather poor energy recovery rates.

Looking at products with a hexagonal core, I was left with three available options:

  • Zehnder CAQ350 ERV
  • Panasonic FV-20VEC1, and
  • Broan ERV200 ECM (also sold under the Venmar brand name).

To help in the decision making process, I pulled the HVI performance data for each product so that I got a good comparison.

The three hexagonal core options appeared to be all in close range of each other. Zehnder seems to be a little bit of an outlier on the net air flow side for the test data, while the Panasonic and Broan are in close range.

Looking at the power consumed in watts, it was a close race, where Broan emerged with the least power consumption.

As for the energy recovery rate – or if you prefer the technical term, the Adjusted Sensible Recovery Efficiency (ASRE), we have another close race with Zehnder squeezing into first place, closely followed by Panasonic and Broan.

These were useful data to have, but I still was left without a clear preference between the three options. So I began to look at cost. And remember, these were pre-inflation prices. Zehnder came in just above $3,000, Broan landed just under $3,000, and Panasonic just under $2,000.

It looked like I was left with two favorites in this horse race: Panasonic and Broan.

Between the two, the Broan ERV seemed to be the most compatible. It has similar dimensions to the old Recoupaerator 200 DX and as such would fit nicely into the ventilation closet. It also had very similar controls and low voltage auxiliaries, just like the Recoupaerator 200 DX.

The Panasonic also had very similar dimensions to the old Recoupaerator 200 DX and as such would fit nicely into the existing ventilation closet. But its controls seemed rather primitive, and the auxiliary controls for some reasons all required line voltage. And it was unclear what advertised auxiliary controls would actually be available.

Based on my past experience, I was not in the mood to bet all my money on one horse. Diversifying my investment seemed to be a safer path to take. So I ended up ordering one Panasonic FV-20VEC1 and one Broan ERV200 ECM to replace the two failed Recoupaerator 200 DX.

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