Passive House NW Conference Friday May 20th - Register before it fills!

[Albert Rooks]

Hello all you Wonderfull People on the Passive House Northwest Google Group!

When I think back through my professional career, some of the most important days for me personally were at a Passive House Conference -somewhere in the world-. Often right here in the Pacific Northwest.  These events have given me both the deepest personal challenges, and created some of the most enduring personal friendships. 

Im hoping that you will join me for the day on Friday May 20th in Olympia WA. We’ve been inside. Take a day off and let’s get together. 

Register before it fills!

See you soon!

Albert Rooks

LET’S CONNECT…at the Spring 2022 PHnw Conference!

Wed 5/4/2022 7:03 AM









To:

---

From: Albert Rooks <Alb...@smallplanetsupply.com>
Sent: Wednesday, May 4, 2022 6:56 AM
To: albert...@mac.com <albert...@mac.com>
Subject: Fw: LET’S CONNECT…at the Spring 2022 PHnw Conference?

 

 

We can’t wait to connect with you Albert on May 20th! @ This year’s Spring PHnw Conference!  SIGN ME UP!  LET’S CONNECT! PHnw is back for our first in person gathering since 2019! This one day "micro" conference is laser focused on the rapidly growing panelization market. We will have several panels, a keynote, great food and drink, and lots of extra time to network and socialize including a fun After Party at one of Artisans Group’s nearby projects…A special “Micro-Tour” to close out the day! Register now as space is limited for this gathering to ensure everyone's health and safety. Thank you to this years generous sponsors! Passive House Northwest, 8036 River Drive SE, Suite 200, Tumwater, WA 98501, United States Unsubscribe

Reply

Forward

[Hayden Robinson]

I’m in a 780 s.f. Seattle cottage with electric resistance heat.  Has anyone had luck combining a ducted min-split system with a heat-recovery mechanical-ventilation system?

 

Any tips?

 

If the two systems are independent, it seems like it would be a challenge to balance each of them. If the two are integrated, I wonder if the controls would get to be more complicated than I want?

 

Hayden

 

 

[Rob Harrison cPHc]

I’ll be darned, this list still works? Cool!

I’m not sure I understand the problem Hayden. Ducted or not, a minisplit is not drawing air from outside. So the HRV will be balanced separately, no? We’re looking at transfer ducts/grills for a current project, if you’re pumping more air into a closed room than you’d like. I imagine you know all this…and there is something else I’m missing. 

Rob Harrison cPHc

(he/him)

HARRISON architects

(206) 794-2738

via iPhone….

http://harrisonarchitects.com/

lyrical sustainable design  ::  passivhaus

I acknowledge that I live on the unceded ancestral lands of the Duwamish people. A people that are still here, continuing to honor and bring to light their ancient heritage.

On Dec 2, 2022, at 9:31 AM, Hayden Robinson <em...@haydenrobinson.com> wrote:



--
You received this message because you are subscribed to the Google Groups "Passive House Northwest" group.
To unsubscribe from this group and stop receiving emails from it, send an email to PassiveHouseN...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/001701d90673%24e40be210%24ac23a630%24%40haydenrobinson.com.

[Tessa Bradley]

Hey Hayden,

We are doing an interesting hybrid mash up for some habitat for humanity projects we are doing, where they hook the HRV up to the ducted heat pump in the return air, so the HRV uses the existing ducting and only the exhaust is ducted separately, don’t know if that helps.  Just figuring it out so happy to give you more info as I learn it.

Hop everyone on the string is well!

Tessa

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/9B878458-9C35-4C26-9581-83E68D17F6D4%40harrisonarchitects.com.

--

Sent from Gmail Mobile

[Edward Louie]

Hello,

Have the folks on this thread looked at  MINOTAIR?

https://www.minotair.com/home_us/ 

Thank you

Best

Edward Louie

Affordable Housing, Sustainable Cities, Energy Efficiency & Building Science Aficionado

MS Energy and Environmental Policy

BS Civil and Environmental Engineering

Portland, OR

loui...@gmail.com

503-961-3652

https://www.linkedin.com/in/edward-louie-5a58a13b/
https://www.beyondnetzeroenergyhomes.com/

--

[Olė Ersson]

Amazed that I might actually offer something useful after lurking on this list for years.

Check out the Minotair combined HRV and heat pump.

We are quite interested in this unit since it has no outdoor compressor unit. It has only an outdoor air intake and indoor exhaust portals so there are just 2 penetrations in the thermal envelope.

We live in a 32 unit apartment building and having 32 outdoor compressors and all the external piping to them would result in far too much clutter.

I imagine that it is potentially more efficient since it has no outdoor devices that could result in heat loss during transport. But that is speculation.

I understand its ability to heat spaces is somewhat limited compared to the usual heat pumps with outdoor compressors. Typically 500 sq ft is quoted as a maximum living space it can accommodate for Portland's climate. However, given the excellent thermal performance of passivhaus design this might be significantly higher.

I have not seen one of these working other than in videos featured in Solar Oregon's series on building performance. Reportedly, Green Hammer in Portland has installed these units.

I'd love to hear of anyone's experience with it.

On Fri, Dec 2, 2022 at 9:31 AM Hayden Robinson <em...@haydenrobinson.com> wrote:

--

You received this message because you are subscribed to the Google Groups "Passive House Northwest" group.
To unsubscribe from this group and stop receiving emails from it, send an email to PassiveHouseN...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/001701d90673%24e40be210%24ac23a630%24%40haydenrobinson.com.

--

a model for sustainable intentional community in inner SE Portland, Oregon

Experiments in sustainable urban living
 

[Tessa Bradley]

We are using it on some projects, Jeremy with birdsmouth construction has the most experience with them in my opinion!

Thrive Inside,

Tess

	Tessa Bradley |  Principal AIA CPHC LEED AP cell: (360) 870-6280 artisansgroup.com Artisans Group Architecture and Planning, PS. 6504 Capitol Blvd SE Tumwater, WA 98501

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/CADUFuqTPAKro%2BJCYVQn36NYjXXJNtN6H6dTqusKRy-s9VB06cw%40mail.gmail.com.

[Hayden Robinson]

Hi, Rob.

 

If I had a forte, mechanical systems wouldn’t be it. The picture I have in mind may be way off. But here goes:

 

The fan for a ductless mini-split is very local and doesn’t really pressurize or depressurize spaces, so wouldn’t interfere with the HRV system.

 

 

An HRV system provides fresh air to inhabited rooms, thus positively pressurizing those rooms, and exhausts air through kitchens, bathrooms, and laundry rooms by negatively pressurizing those spaces. Obviously the positive and negative pressures equal each other and keep fresh air circulating properly throughout the house.

 

A ducted mini-split system uses an air handler (with a bigger fan than an HRV) to distribute heated air to more or less all spaces and usually has a single return air grill.

 

I’m picturing that the HRV and air handler would sometimes run at the same time and sometimes not. Both systems need to be balanced for air to circulate properly. Wouldn’t the two systems interfere with each other?

 

 

Hi, Tessa.

 

I’ve tried to diagram the system that you describe, but I confess it’s beyond me. I’d be super-curious to see what your team comes up with.

 

 

Yours, Hayden

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/CANw2fSjE%2BF%2Bao1QzLNoXfBfjpa9JS9eXb2gv-gojh%3DmA2Zt0hw%40mail.gmail.com.

[Hayden Robinson]

Edward, Ole and Tessa,

 

Thank you for the Minotair lead. I will take a closer look at this when I’m not so tired!

 

Hayden

 

From: passive...@googlegroups.com <passive...@googlegroups.com> On Behalf Of Tessa Bradley
Sent: Friday, December 2, 2022 3:59 PM
To: Passive...@googlegroups.com
Subject: Re: Ducted mini-split and HRV?

 

We are using it on some projects, Jeremy with birdsmouth construction has the most experience with them in my opinion!

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/CANw2fSgHF3ejFcF_5X%2B%3D8%2BfniWEEyz%2BGSoXOqtt5tMvf2d6kBA%40mail.gmail.com.

[Edward Louie]

Hello group. I'm in support of ducted mini-splits because you can put a BIG return grill on it and install a big disposable MERV filter. 

I've disassembled, bib kitted, pump sprayed with nu-calgon evap-fresh, dishwashered the blower wheel, and scrubbed with a tooth brush the nooks and crannies of wall mounted ductless mini heads enough to call it a maintenance unfriendly form factor designed product. 

The mesh filters don't filter enough to keep gunk from building up on the coil, vanes, blower wheel, air path, and condensate tray. I vacuum the mesh filters every month and the internals still gunk up and require a yearly deep clean. If I paid a HVAC tech to do this glorified janitorial work for me it would cost me $300-400 yearly. Nullifying any energy dollar savings from ductless mini-splits.

If you don't keep an eye on the gunk inside and deep clean as needed. Ductless mini-splits become an indoor air quality hazard in my opinion. I doubt many people with ductless mini-splits will be happy to pay $300-400 annually.

I feel like I've cleaned enough ductless mini-split heads to be experienced. I can do it without breaking anything in the process of disassembly and reassembly. But I'm unhappy it is a 3 hour process.

Comfort is not great, the air velocity of ductless is too high if you're near it. And thermal distribution is not great. And small bedrooms and bathrooms are too small to put a dedicated mini-split head into. 

Carrier's Performance series ductless mini-split head has made huge progress in making it easy to service. But it isn't an energy performance leader. And that is just one make and model line. All the other brands are still making heads that are a pain to clean.

The turn down ratio for multi-split/multi-head ductless mini-splits are terrible. Better off using multiple single head to single outdoor unit systems. 

That's all I have to say about ductless mini-split heads. 

Thank You
Best
-Edward Louie

Affordable Housing, Sustainable Cities, Energy Efficiency & Building Science Aficionado
MS Energy and Environmental Policy
BS Civil and Environmental Engineering
Portland, OR
loui...@gmail.com
503-961-3652
https://www.linkedin.com/in/edward-louie-5a58a13b/
https://www.beyondnetzeroenergyhomes.com/

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/008a01d906d2%24eb531610%24c1f94230%24%40haydenrobinson.com.

[Adam Cohen]

Hayden, we have been using Minotair for years and have found them to be quite effective.  You do need to follow pretty specific duct layout to get optimum performance.  If you use Minotair make sure you are clear on the required duct type, size and configuration that will work best for this piece of equipment.

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/CADUFuqTsjR%3Df6rmgYUX0A43Y%2BuFWXUJJMp0UkO0r28q16zZ1%2BA%40mail.gmail.com.

[Ole Ersson]

Hi Edward,

I appreciate your practical orientation for the ductless heat pump devices and the big problems you have experienced with just about all models in keeping the heat exchanger portion clean.

Having regularly used HRV/ERV technology, I have found their design makes regular cleaning a cinch. ( I have used Panasonic ERV and Venmar Eco 1.5 HRV)

Would you say the Minotair does or does not suffer from the same problem? That is, are they easy to keep clean without a nightmare disassembly/clean/reassembly process?

Thanks.

Ole

[Edward Louie]

Thank You
Best
-Edward Louie
Affordable Housing, Sustainable Cities, Energy Efficiency & Building Science Aficionado
MS Energy and Environmental Policy
BS Civil and Environmental Engineering
Portland, OR
loui...@gmail.com
503-961-3652
https://www.linkedin.com/in/edward-louie-5a58a13b/
https://www.beyondnetzeroenergyhomes.com/

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/2c892b9a-d482-440f-b960-90066f3a0e67n%40googlegroups.com.

[Edward Louie]

Hello Ole,

See attached screenshots from the manual. It is much better filtering MERV8 & MERV15 filters. I imagine it will gunk up much less than ductless mini-split heads.  

Perhaps someone on here who has owned one and has ran it basically 24/7 for several years can chime in on their maintenance experience with the Minotair.

Thank You
Best
-Edward Louie
Affordable Housing, Sustainable Cities, Energy Efficiency & Building Science Aficionado
MS Energy and Environmental Policy
BS Civil and Environmental Engineering
Portland, OR
loui...@gmail.com
503-961-3652
https://www.linkedin.com/in/edward-louie-5a58a13b/
https://www.beyondnetzeroenergyhomes.com/

On Sat, Dec 3, 2022, 9:14 AM Ole Ersson <ole.e...@gmail.com> wrote:

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/2c892b9a-d482-440f-b960-90066f3a0e67n%40googlegroups.com.

[Albert Rooks]

Hayden,

Good to hear from you :)

If you choose the ducted ASHP with an HRV: One approach you can take is to place the HRV supply flow into the return of the ducted unit. To prevent the the air handler of the ducted unit from throwing the HRV out of balance, place an AAB valve on the HRV supply flow and use a steady HRV flow rate rather than including a boost rate. This will limit the flow into the ducted unit regardless of the air handler operation. 

AAB valve link: https://www.airflowbalancing.com

You won’t get full distribution like you would with a fully ducted system, but at least the flow from a single supply point will be pulled back to the return points. That will provide some mixing. It seems like a fine idea for a small building. We are doing that same approach in our new offices with two Q600’s. One upstairs and one down stairs. Not perfect since the farthest points won’t get full fresh flow, but all I can manage on a new leased building.   Pic attached. 

Best,

Albert.

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/008a01d906d2%24eb531610%24c1f94230%24%40haydenrobinson.com.

[Hayden Robinson]

Thank you, Albert—it’s good to hear from you, too!

 

This sounds like the system Tessa was describing. I’ll take a closer look at this and Minotair and comment back to the group.

 

Hayden

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/90157986-C080-431F-AF84-7F5E7E13F173%40mac.com.

[Hayden Robinson]

Albert,

 

I’m trying to parse one of your sentences:  “…the flow from a single supply point will be pulled back to the return points.”

 

In this system, does the ASHP’s air handler have a single supply diffuser and multiple ducted returns?

 

Or is fresh air from the HRV fed into an air handler’s single return and then distributed through multiple air-handler supply ducts?

 

In either case, is the HRV’s return air conventionally ducted (from bathrooms and laundry)? If so, do those spaces also get supply air from the air handler?

 

Hayden

 

From: 'Albert Rooks' via Passive House Northwest <Passive...@googlegroups.com>
Sent: Monday, December 5, 2022 5:53 AM

To: Passive House NW GG <Passive...@googlegroups.com>
Subject: Re: Ducted mini-split and HRV?

 

Hayden,

 

Good to hear from you :)

 

If you choose the ducted ASHP with an HRV: One approach you can take is to place the HRV supply flow into the return of the ducted unit. To prevent the the air handler of the ducted unit from throwing the HRV out of balance, place an AAB valve on the HRV supply flow and use a steady HRV flow rate rather than including a boost rate. This will limit the flow into the ducted unit regardless of the air handler operation. 

 

AAB valve link: https://www.airflowbalancing.com

 

You won’t get full distribution like you would with a fully ducted system, but at least the flow from a single supply point will be pulled back to the return points. That will provide some mixing. It seems like a fine idea for a small building. We are doing that same approach in our new offices with two Q600’s. One upstairs and one down stairs. Not perfect since the farthest points won’t get full fresh flow, but all I can manage on a new leased building.   Pic attached. 

 

Best,

 

Albert.

On Dec 2, 2022, at 8:51 PM, Hayden Robinson <em...@haydenrobinson.com> wrote:

 

Edward, Ole and Tessa, 

 

Thank you for the Minotair lead. I will take a closer look at this when I’m not so tired!

 

Hayden

 

From: passive...@googlegroups.com <passive...@googlegroups.com> On Behalf Of Tessa Bradley
Sent: Friday, December 2, 2022 3:59 PM
To: Passive...@googlegroups.com
Subject: Re: Ducted mini-split and HRV?

 

We are using it on some projects, Jeremy with birdsmouth construction has the most experience with them in my opinion!

Thrive Inside,

Tess

 

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/90157986-C080-431F-AF84-7F5E7E13F173%40mac.com.

[Albert Rooks]

While I’m not sure of your specific application in layout and terminations… generally… The ASHP will be neutral to the envelop. I would assume that you might take advantage of the potential to duct return air from kitchens and bath to the HRV - and therefore create a negative balance to the envelope. 

A single (or multiple) HRV supply point to the return pathway of the ASHP (with a flow balancing valve) would create a matching positive pressure to the envelope. Therefore, in my mind (that happily is not restricted to reality), the positive fresh air contribution would eventually show up at the negative pressure return points and be pulled from the building. It way wander… and tour slowly…along it’s way… but if you can achieve a reasonable building ventilation ACH, it will eventually leave - like an unwanted guest.

Albert.

Sent from my iPhone

On Dec 5, 2022, at 20:53, Hayden Robinson <em...@haydenrobinson.com> wrote:



Albert,

 

I’m trying to parse one of your sentences:  “…the flow from a single supply point will be pulled back to the return points.”

 

In this system, does the ASHP’s air handler have a single supply diffuser and multiple ducted returns?

 

Or is fresh air from the HRV fed into an air handler’s single return and then distributed through multiple air-handler supply ducts?

 

In either case, is the HRV’s return air conventionally ducted (from bathrooms and laundry)? If so, do those spaces also get supply air from the air handler?

 

Hayden

 

From: 'Albert Rooks' via Passive House Northwest <Passive...@googlegroups.com>
Sent: Monday, December 5, 2022 5:53 AM
To: Passive House NW GG <Passive...@googlegroups.com>
Subject: Re: Ducted mini-split and HRV?

 

Hayden,

 

Good to hear from you :)

 

If you choose the ducted ASHP with an HRV: One approach you can take is to place the HRV supply flow into the return of the ducted unit. To prevent the the air handler of the ducted unit from throwing the HRV out of balance, place an AAB valve on the HRV supply flow and use a steady HRV flow rate rather than including a boost rate. This will limit the flow into the ducted unit regardless of the air handler operation. 

 

AAB valve link: https://www.airflowbalancing.com

 

You won’t get full distribution like you would with a fully ducted system, but at least the flow from a single supply point will be pulled back to the return points. That will provide some mixing. It seems like a fine idea for a small building. We are doing that same approach in our new offices with two Q600’s. One upstairs and one down stairs. Not perfect since the farthest points won’t get full fresh flow, but all I can manage on a new leased building.   Pic attached. 

 

Best,

 

Albert.

<image001.jpg>

On Dec 2, 2022, at 8:51 PM, Hayden Robinson <em...@haydenrobinson.com> wrote:

 

Edward, Ole and Tessa, 

 

Thank you for the Minotair lead. I will take a closer look at this when I’m not so tired!

 

Hayden

 

From: passive...@googlegroups.com <passive...@googlegroups.com> On Behalf Of Tessa Bradley
Sent: Friday, December 2, 2022 3:59 PM
To: Passive...@googlegroups.com
Subject: Re: Ducted mini-split and HRV?

 

We are using it on some projects, Jeremy with birdsmouth construction has the most experience with them in my opinion!

Thrive Inside,

Tess

 

<~WRD0000.jpg>

<~WRD0000.jpg>

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/003d01d9092e%2491d9b590%24b58d20b0%24%40haydenrobinson.com.

[Albert Rooks]

And to clarify- I imaging it’s just a ducted head with supply air from the HRV dumped into the return pathway of the head that is serving the  room or living space being served. The ventilation rates are typically low to the point that you could only really do this to one head in any meaningful way.

Do those two attempted answers help?

A.

Sent from my iPhone

On Dec 6, 2022, at 19:15, 'Albert Rooks' via Passive House Northwest <Passive...@googlegroups.com> wrote:

While I’m not sure of your specific application in layout and terminations… generally… The ASHP will be neutral to the envelop. I would assume that you might take advantage of the potential to duct return air from kitchens and bath to the HRV - and therefore create a negative balance to the envelope. 

[Hayden Robinson]

Albert, you are being super-generous about trying to teach me. I may not be sophisticated enough to  completely understand via email, but this gives me enough to start with... (I talked to SPS’s Tom Dooley today—seems like a good guy!)

 

I’m beginning to really appreciate why matching heat load with the heat capacity of ventilation-only air is such a sweet spot!

 

By the way, for including in PHPP calcs, what are people using for Minotair’s Annual COP-Heat Pump and Efficiency of Heat Recovery? I talked to a very helpful and knowledgeable rep at Minotair, but could not net out the actual heat-recovery efficiency minus the waste heat from the fan motor and compressor.

 

It seems like in a Minotair vs mini-split-plus-HRV horse race, it may be hard to generalize. Minotair’s heating-performance numbers are not great, but I like how it manages humidity. And of course, incorporating thermal comfort, ventilation and humidity management in one package is compelling.  

To view this discussion on the web visit https://groups.google.com/d/msgid/PassiveHouseNW/2ABBB692-A39E-4CFF-AE9B-0D18906A0E9C%40mac.com.