Architrave installation

April 20th, 2014
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Restoring the architraves with what we had salvaged plus some replacement trim was a full success. After we sanded and lacquered the restored pieces it was time think about installation.

We had taken care of the trim around the windows and doors. Placing the architraves on top was straight forward.

I determined the location of the framing header above the door or window, pre-drilled the architrave, and attached it with two long finishing screws. A little bit of wood putty over the countersunk finishing screws, and you couldn’t tell where I attached the architrave.

Getting to this point – i.e. dealing with all the paint removal and refinishing – was tedious in parts. But the reward came once we could step back and look at the end product. Installing the trim and architraves ranks among my favorite tasks.

Furthermore, we now can put our work on the architrave restoration to the test: Is it possible to tell the difference between original and restored? And if so, when?

trim-020 trim-021

It turns out that one has to step up close to see the difference. But on first sight, they all look the same. Do I need to say that we are very happy with the outcome?

Related posts:

Architrave restoration

Window trim installation

Bathroom door trim

Lacquering what I like

Paint removal – Part 8: Sustained sanding

Paint removal – Part 7: Vertical trim

The race downstairs

Paint removal – Part 5: Battling baseboards

Salvaging casings and trims

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Architrave restoration

April 14th, 2014
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Let’s talk about something other than ventilation for a change. Let’s go back to the finishing touches to the 1st floor.

We installed the window trim and had sanded the salvaged architraves - or what remained of those original architraves.

trim-015

The architraves were made up of three pieces: (1) an oak board, (2) a trim piece at the bottom, and (3) a crown molding at the top. That crown molding was the most delicate piece, so much so that most haven’t survived the past 110 years.

trim-016

What we mostly had left was the oak board and bottom trim piece.

trim-018

I went on a mission to find a replacement for the crown molding. I browsed various print and online catalogues without finding a match. I went to a specialist mill shop that had a large collection of custom knives in the hope to find a match there. Again – no luck. This was truly a custom production.

Someone suggested that I could have a custom knife made to mill an exact match of the missing crown moldings. That didn’t seem reasonable, considering the small amount I needed.

The next best thing I could come up with was to cobble something together that would result in a close match. Back in the mill shop, and with some help of the staff, we figured that we could break down the original crown molding into three parts:

trim-019

  1. a small corner trim
  2. a small piece of board
  3. a piece of colonial crown molding

I had enough salvaged oak boards at home, so all I bought was the corner trim and colonial crown molding.

Putting the architrave back together was a little involved because I now had to deal with the extra pieces of trim. But it was worth it, because it turned out that the cobbling together process resulted in a remarkably close match to the original.

Related posts:

Window trim installation

Bathroom door trim

Lacquering what I like

Paint removal – Part 8: Sustained sanding

Paint removal – Part 7: Vertical trim

The race downstairs

Paint removal – Part 5: Battling baseboards

Salvaging casings and trim

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Looking at the ERV test data in a different light

April 4th, 2014
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The previous blog post covered the performance testing we conducted on the 1st floor ERV. The performance metric we used was the apparent sensible effectiveness (ASE) as defined by the CAN/CSA-C439-00 standard. To calculate the apparent sensible effectiveness we needed three data points:

  • Fresh air entering into the ERV from the outside
  • Fresh air entering the building from the ERV
  • Stale air exhaust from the building to the ERV

(see also illustration and charts in previous post)

But do I really need all three of those data points? Does the temperature of the fresh air entering the ERV from the outside really matter if all I am really interested in is to measure the actual heat exchange – the percentage of thermal energy that is transferred between the two air streams that connect to the building?

ERV-32

There is (1) the exhaust air that carries the thermal energy we have put into the building with our radiators. And all I want to know is how much of that thermal energy can be transferred over to (2) the fresh air stream, which enters the building. It began to dawn on me that I only needed those two data points.

To calculate that heat exchange, I divided the temperature of the fresh air leaving the ERV into the building by the exhaust air entering the ERV from the building. The results, expressed in percent, exceed those of the apparent sensible effectiveness method.

ERV-31

To me, these results begin to express the actual amount of thermal energy I can recover though the ERV, even during temperatures well below freezing. Although this method makes sense to me, I can’t find anyone else who took this approach. As a result, I am not sure about the usefulness of this data beyond my personal consumption.

Post script…

… or what would I have done differently, if I could?

I think having one temperature probe inside the ERV – in the actual air stream – and the other probe on the duct just outside the ERV was not ideal, even though the probe on the duct was covered with insulation. But because both the fresh air supply stream from the ERV into the building and the exhaust stream from the ERV to the building exterior are sealed, placing the probes into the streams was not an option (unlike in laboratory testing).

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ERV performance test

April 1st, 2014
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I have shared anecdotal evidence about the ERV performance.

Last fall, our heating season started a full month earlier, because our ERV was out of commission and in need of repair. At that point I got interested in actually measuring the performance – or to be more precise – measuring the heat recovery rate of the ERV.

Performance data is usually available through the manufacturer (UltimateAir). But that data can be a double sided sword.

The beauty of the standardized testing conducted on behalf of the manufacturers is that you can compare apples to apples–compare one product against a competing model. The beast is that the standardized testing doesn’t necessarily tell you what performance you can expect in your house. Laboratory conditions often have little in common with our homes.

When UltimateAir says the heat recovery rate is up to 96%, what would that mean in terms heat recovery on a particular winter day in our home? To find out, I purchased a temperature sensor with two probes and began measuring.

ERV-24

Methodology – so you know what I did…

I measured the air temperature on the side of the ERV that is connected to the building exterior. One probe was placed in the fresh air supply stream inside the ERV (1). The other was placed on the exhaust duct (2), as the exhaust stream inside the ERV is sealed off.

ERV-01

Once I got stable readings I switched the probes to the ERV side that connects to the building interior. One probe was placed inside the ERV, in the exhaust air stream from the building (3). The other was placed on the duct (4) that delivers fresh air from the ERV into the building.

ERV-25

I began the measurements with the ERV off, and at low speed (60 cfm), medium speed (97 cfm) and high speed (200 cfm). I had no means of measuring the actual air flow, but relied on the air flow rates published by UltimateAir.

For the duration of the testing I also recorded the temperature inside and outside of the building, relying on our thermostat and an outdoor thermometer. Items I did not measure, but which may impact the heat recovery rate, are humidity and dew point.

I expected the heat recovery to vary depending on the outdoor temperature, and thus picked different days for the testing to get a reasonable temperature spread.

Apparent sensible effectiveness (ASE)

I had the measurements. But how do you calculate the energy recovery rate?

First off, we need a unit, a metric – in this case the apparent sensible effectiveness (ASE). To get to an apples to apples comparison, the CAN/CSA-C439-00 standard sets forth a testing protocol, which includes information on how to calculate the apparent sensible effectiveness:

The temperature rise of the outdoor air passing through the ERV is divided by the temperature difference between the outdoor and indoor air. The results are expressed in percent.

ERV-26

With outdoor temperature at 48.2 F falling to 46.2 F, and indoor temperature at 65 F to 66 F, the calculated ASE was:

  • 96.7% at low speed (60 cfm)
  • 91.8% at medium speed (97 cfm)
  • 93.5% at high speed (200 cfm)

ERV-27

With outdoor temperature at 34.5 F falling to 32.4 F, and indoor temperature at 65 F to 66 F, the calculated ASE was:

  • 94.3% at low speed (60 cfm)
  • 93.5% at medium speed (97 cfm)
  • 91.6% at high speed (200 cfm)

ERV-28

With outdoor temperature at 20.7 F rising to 25.7 F, and indoor temperatures at 65 F to 66 F, the calculated ASE was:

  • 95.2% at low speed (60 cfm)
  • 90.0% at medium speed (97 cfm)
  • 88.4% at high speed (200 cfm)

ERV-29

With outdoor temperature at 8.5 F rising to 10.0 F, and indoor temperatures at 65 F to 66 F, the calculated ASE was:

  • 95.0% at low speed (60 cfm)
  • 87.7% at medium speed (97 cfm)
  • 82.7% at medium speed (200 cfm)

Cool looking graphs, but what does this mean?

The ERV performance falls in line with our anecdotal observations. We can expect plenty of fresh air with a heat recovery effectiveness around 95% at the low ventilation speed of 60 cfm. The effectiveness begins to drop off a little with colder outside temperatures, and even more so with higher ventilation rates (i.e. 97 and 200 cfm).

Because of the ERV’s effectiveness, we don’t open our windows during the winter. We never felt the urge! The ERV provides a comfortable environment with good indoor air quality (IAQ). It lets the stale air and the pollutants go, but keeps the thermal energy.

Is the published performance on track?

I am somewhat suspicious of performance data published by the manufacturer, as the numbers may be inflated to make the product look good. Our testing appears to indicate the the published performance data by UltimateAir is on track.

The RecoupAerator product literature claims an energy transfer rating of up to 96%. Our testing revealed that at the low ventilation rate of 60 cfm, it is reasonable to expect an effectiveness around 95%.

More detailed performance is published in the third party test report for the RecoupAerator. Our test results for apparent sensible effectiveness at 34.5 to 32.4 F came in just below the third party test report results for the RecoupAerator at 32F:

ERV-30

I believe that the slight discrepancy in results can be explained by my test procedure differing from the laboratory procedure, which makes an apples to apples comparison difficult. But I now feel confident that the third party performance data published by UltimateAir is on the mark.

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Jet overhead!

March 25th, 2014
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The layout of our 1st floor ventilation system is very different from that of the garden apartment, where we have an open floor plan. Here we have two fresh air supplies, one feeding the actual apartment and a second supplying the common area towards the rear.

On the 1st floor, we have four fresh air supplies to keep the fresh air moving through all the rooms. Each of the three bedrooms has one supply plus a fourth one in the foyer.

ventilation-20

The fresh air supply diffusers in the bedrooms are placed in the middle of the ceiling, more or less right above the bed.

We were in for a little of a shock the first time the ERV was running and we were in bed. It sounded like we had a jet taking off above the bed. It didn’t matter that if the ERV was running at low or high speed, the jet noise was too much white noise for us to tolerate.

ERV-23

Was something wrong again with the ERV? No, I cannot pin it on the ERV this time.

The ERV was actually running quietly, which added to the question of where all that jet noise could be coming from. We didn’t have the noise issues in the garden apartment, where the fresh air supplies and returns where basically silent.

I raised the issue during one of my many phone calls with the UltimateAir tech support this winter, and was pointed in an interesting direction.

There are a few ground rules when it comes installing the duct work for the ventilation system.

  • Size your ducts correctly
  • Use rigid metal ducts and fittings wherever you can
  • Avoid excessively long duct runs
  • Keep turns and tees to a minimum

The goal is to reduce friction and loss of velocity in the duct work. The easier the air can flow through the system, the more efficiently the ERV blower motors run.

Also recommended is to use a short piece of flex duct to connect the ERV to the rest of the duct work. The flex duct prevents any vibration from the ERV from propagating all the way through the building.

It turns out that I was a little overzealous when it came to reducing loss of velocity, and that I took “short piece of flex duct” too literally.

ERV-20

I used a 12 inch piece of flex duct to bridge the six inch gap between the ERV duct collars and the rigid metal ducts. That’s good for efficient air flow – but bad for noise!

Here is the recommendation from the UltimateAir 200DX RecoupAerator manual that I should have remembered:

“Insulated flex ducts tend to reduce air noise levels but add airflow resistance, and galvanized ducts provide the least resistance to airflow, but may amplify noise.”

“When installing the [ERV] unit, allow for a three-foot section of insulated flexible duct to go from the starting collar on the unit to the rest of the ductwork (on all four collars). This will help dampen noise being transmitted from the unit into the home or business, at the source.”

Three feet of flex duct! Not 12 inches! And including a 90 degree bend in the flex duct works wonders on cutting back on the jet noise.

While I was taking the ERV apart to replace the enthalpy wheel, I crawled into the closet, cut the rigid metal ducts back, and replaced them with three-foot sections of flex duct. Because of the crammed ventilation closet, I don’t have any photos I can share. But I will use the basement ERV to demonstrate the point.

ERV-22

The jet noise disappeared – gone! If you pay attention, you can still hear some airflow, but the difference from what it was before is like day and night.

I will file this under “good intentions that nip you in the butt” – or – “too much efficiency can get noisy.”

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ERV croaked – Part 4

March 19th, 2014
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Yes! The saga continues! For one more episode.

We have been living on the 1st floor for a few weeks, but still go frequently down into the garden apartment for laundry, etc. And I began to notice that it got really cold down there – but I thought that was OK since I had turned the heat down.

I also organized a dual probe temperature sensor to measure the ERV performance. I had planned to dedicate a blog post to it. I measured the temperature of the fresh incoming air at 26 F. The temperature of the fresh air leaving the ERV into the building measured 38 F. That is a total heat recovery of 12 F – which is appalling! You can’t even call that heat recovery!

At that point it finally dawned on me that something was wrong: cold apartment, next to no heat recovery in the ERV…

I was back on the phone with the UtlimateAir tech support and learned that they are two probable causes for failure of the heat recovery:

  1. The enthalpy wheel is not turning (as was the case in January and November. But this time, the wheel was running fine.
  2. One of the two blower motors is not working.

And as I found out, the blower motor that exhausts the stale air from the building to the exterior had taken a leave of absence.

To find out what exactly was wrong, tech support guided me through a process of elimination. We started with the fuses on the circuit board that control the blower motor. The fuses were good.

Maybe it’s the electronics on the circuit board? I took the existing circuit board out and replaced it with a spare one. Still, the motor was not running, so it wasn’t the board either. Conclusion: it is the blower motor itself that croaked.

I could tell by the reaction of tech support staff that this doesn’t happen often.

As usual, I promptly got a replacement motor in the mail, and I began to pursue one of my favorite hobbies: opening up the ERV.

ERV-15

To replace the motor, I had to disconnect all the wires, take the circuit board out, and remove the electronics plate.

ERV-16 ERV-17

On the other side of the electronics plate sits the impeller – the fan wheel that actually moves the air. To remove the motor, I have to disconnect the impeller from the motor shaft.

ERV-18 ERV-19

Sounds complicated, but is pretty straight forward. The good news is that after I installed the new motor, everything fit back into place and I had no leftover screws sitting around. The even better news that the new motor is running and we have a functioning ERV again.

This was the third time this winter that the basement ERV gave out on us. Plus the issues with the filter pies that took the 1st floor ERV out of service for about a week. That’s not a remarkable track record.

I wanted to know if this is normal and ask UltimateAir to comment. Here is the statement they kindly provided:

“The UltimateAir team is grateful to Marcus for his patience and understanding. Our engineers are continuously working to not only improve the performance of our technology but also raise the product’s reliability. In the world of specialty boutique manufacturing there are often unforeseen changes in batch supplies of parts that go undetected.

Despite quality control procedures, including incoming parts checks, running every unit 24 hours before shipping and following all UL protocol, issues are not always identified. Marcus’s 200DX ERVs have witnessed a “perfect storm” of issues and does not represent the vast majority of our ERV units. UltimateAir has over 4000 model 200DX ERVs in operation with an overall failure rate around 3%.

We offer a 5 year parts warrantee on all UltimateAir ERV systems to insure that consumers feel secure when making their ventilation purchase. Overall, we realize this has been inconvenient to Marcus and we apologize for the discomfort he has experienced. As Marcus has witnessed the UltimateAir team is always a phone call away and we will back our technology in every way possible.”

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ERV croaked – Part 3

March 14th, 2014
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Christmas and the new year came around. We made the move from the garden apartment up to the 1st floor - with a brand new ERV! I was expecting a smoother ride here, after the basement ERV gave out on us in October and again in November.

But it wasn’t meant to be.

I still had some trailing paranoia from the incidents with the basement ERV. I kept frequently checking to see if the units were running OK. And that is when I noticed a noise from the 1st floor ERV that I didn’t like.

By now, I can open up the ERV blindfolded and hanging upside down, which I did. Except I wasn’t blindfolded or hanging. But I was surprised when I took a look into the ERV, because one of the filter pies in the enthalpy wheel was missing!

After turning the enthalpy wheel very carefully, it turned out that the pie wasn’t missing but was partially pulled out from the wheel and got stuck.

ERV-10

The filter pies that go into the wheel are made of three fabric layers that are woven together. In my case, the three layers started to separate. The outermost layer peeled out and jammed the wheel.

ERV-11

But there is some smart design in this ERV. Whoever developed the product anticipated that the enthalpy wheel may get jammed. The driver belt that transfers the motion from the enthalpy wheel motor to the enthalpy wheel is designed to snap upon a certain amount of resistance. It is the sacrificial component because it is cheap and easy to replace.

ERV-12

UltimateAir promptly sent me a new belt and a new set of properly woven filter pies.The belt and pies were quickly installed, and the ERV was up and running again.

ERV-13 ERV-14

All this happened in January, amidst our delightful polar vortex. It was freezing cold outside, and we were again sitting there without mechanical ventilation, when we need it the most.

These incidents (the 3rd now this winter) have become somewhat unnerving. There is maintenance to any and every utility in a building; I get that. The ERV should be serviced after a cumulative 90 days of operation. In fact, the master control for the ERV has a little red LED light at the bottom that comes on to let you know that the cumulative 90 days are up and it is time for some maintenance. I love that little detail.

But right now, I feel I have to check on the units on an almost daily basis to make sure nothing is going wrong. Imagine if you had to check on your hot water heater every day to make sure it is still running OK.

The saving grace in this is the excellent customer service UltimateAir provides. Whenever I call them, they are very courteous and helpful. All the servicing they have done and all the replacement parts they sent me fell under warranty.

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ERV croaked – Part 2

March 11th, 2014
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In winter time, our ERV makes a big difference with its heat transfer – given that it is running.

And it has been running for a couple of weeks after we got it repaired. Right into November. But suddenly the ERV started to blow cold air into the garden apartment! No more heat transfer! Running the ERV or opening windows had the same effect. Cold fresh air. Yikes!

What was going on?

I opened up the ERV and noticed right away that the enthalpy wheel was not turning. The filter pies in the enthalpy wheel are responsible for the heat transfer. No turning wheel, no heat transfer.

ERV-05 ERV-06

I was back on the phone with the UltimateAir tech support. They suspected that the motor turning the enthalpy wheel gave out, or that the circuit board that controls that motor stopped functioning.

We went back into troubleshooting mode. I called Percy, our electrician, who arrived with his multimeter. We checked the voltage at the critical points of the circuit board. No voltage!

UltimateAir put a new board in the mail right away, and included a new motor too, just in case.
I installed the new board – et voilà, the enthalpy wheel was turning again. Because I didn’t need the new motor, I put it back in the mail to UltimateAir.

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ERV croaked – Part 1

March 4th, 2014
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We have two energy recovery ventilators (ERVs), both of them the RecoupAerator by UltimateAir. One services the garden apartment, and a second ventilates the 1st floor. Both ERVs have served us well and we have enjoyed their performance. That enjoyment shifted onto shaky ground late last fall.

Next to the heating and hot water system, I would count the ERV as one of the most important mechanical systems in the building. And as with heat or hot water, you find yourself in a pickle should the system croak. And unfortunately the ERVs croaked on us this winter.

It started back in early October 2013 when the ERV suddenly started running non stop on full blast. That was unusual as the ERV speed and runtime are controlled by the bathroom timer switch or master control switch.

ventilation-16 ventilation-17

The only way to stop the ERV was to turn off the power switch on the unit. Shortly thereafter the blower motors stopped running altogether, even if we powered the ERV back up.

ERV-09

I had some trouble with the troubleshooting, which didn’t help. I talked with the tech support at UltimateAir and we concluded that something was wrong with the blower motor circuit boards. Because the ERV was still under warranty, I disconnected it from the duct work and shipped it to UltimateAir for servicing. A week and a half later I had it back in the basement, reconnected to the ductwork, and – it started running again non stop at full speed, no matter what the wall control settings.

At this point we knew it wasn’t blower motor circuit board that was causing the problem. Tech support at UltimateAir pointed me to the wall controls. I disconnected one after the other until I could isolate the problem to the bathroom timer switch. I replaced it with a digital timer switch, et voilà, we again had a functioning ventilation system.

ventilation-41

Now, what do you do when you have an almost air tight home with a non-functioning ventilation system?

You turn to the old fashioned ways and open windows.

All this could not have happened at a more inopportune time. We were just at the beginning of the heating season. Opening windows to ventilate meant that we lost a lot of thermal energy that was still stored in the unit. Because of that, we turned our heat on a full month earlier compared to previous years.

That, in a way, is a testament to the effectiveness in heat recovery the ERV provides – when it is running.

Related posts:

ERV – keeping the heat

1st floor ventilation details

1st floor ventilation planning

ERV recap

Installing the ERV

Picking an ERV

Vetting ventilation

Blower door test – after insulation

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ERV – keeping the heat!

February 28th, 2014
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While we are on the ventilation theme, let’s stick with that subject for a little longer. But rather than fanfare to ceiling fans, how about shedding more light on heat recovery and indoor air quality (IAQ)?

Mechanical ventilation in a relatively airtight building like ours is important to maintain a good IAQ. The energy recovery ventilator (ERV) provides the necessary ventilation. It flushes stale air and pollutants out of the building, but without the usual energy penalty. That is thanks to a heat recovery process, which I schematically described in a previous post.

But how exactly is the heat recovered? Let’s take a closer look at the mechanics of the ERV.

There are two sides to the unit. One side connects to the building exterior with two ducts. One of the ducts delivers fresh air from the exterior to the ERV. The other duct exhausts stale air from the ERV to the building exterior.

ERV-02

I covered the fresh air supply and exhaust in previous posts.

If we turn the ERV around, we look at the side that connects to the building interior. One of the ducts supplies fresh air from the ERV into the building, while the other duct returns stale air from the building to the ERV.

ERV-03

Each side (exterior and building side) has an efficient ECM blower motor that is connected to an impeller. The impeller, like a fan, provides the velocity in the two air streams. The airflow can be modulated from 30 to 200 cubic feet per minute (cfm).

The key in this set up is that the two air streams, the fresh air stream and the stale air stream, are physically separated from each other. The fresh air cannot mix with the stale air.

ERV-04

The only connecting element between those two air streams is the enthalpy wheel, which is powered by its own small ECM motor.

ERV-05 ERV-06

Let’s take a winter scenario: The enthalpy wheel rotates across the two air streams when the ERV is running. In that process, it picks up the heat and moisture from the stale air stream coming from the building and transfers it to the fresh air stream entering the ERV. And vice-versa, it picks up the cool from the fresh air stream entering the ERV and transfers it to the stale air stream that is leaving the building.

ERV-07

What makes that heat and moisture transfer possible are the six filter pies in the enthalpy wheel. To learn more about the filter pies, I talked to Matt Baker at UltimateAir:

“ [The] material [of the filter pie] is a woven blend of nylon and a type of regenerated cellulose similar to rayon. The nylon is primarily responsible for heat [recovery] and the [regenerated cellulose] handles the moisture transfer”.

ERV-08

It’s amazing that these synthetic mesh pillows recuperate and transfer heat and moisture that effectively.

Did you know that the “E” in ERV is actually standing for enthalpy (recovery ventilator) and not energy (recovery ventilator). Because most people don’t know what enthalpy is, but have a concept of energy, that term stuck.

Related posts:

1st floor ventilation details

1st floor ventilation planning

ERV recap

Installing the ERV

Picking an ERV

Vetting ventilation

Blower door test – after insulation

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