Draft PDS-01, RESNET/ICC 301-2022 Addendum E-202x, CFIS Systems

Entry Date: October 20, 2023 at 2:36 PM

Full Name: Derin Candas

Affiliation: US-EcoLogic

Address: 911 Maryland Drive Irving, Texas 75061

Phone Number: 3616589213

Email: derin.candas@us-ecologic.com

Page Number: 1

Section/Table/Figure Number:

Comment Intent: Not an Objection

Comment Type: General

Comment:

Very happy with this clarification on CFIS.

Proposed Change to Amendment:

Entry Date: November 18, 2023 at 8:25 AM

Full Name: Cindy Zeis

Affiliation: Northeast HERS Alliance (NEHERS)

Address: 950 Danby Road Ithaca, New York 14850

Phone Number: 2677610148

Email: czeis@psdconsulting.com

Page Number: All

Section/Table/Figure Number: All

Comment Intent: Not an Objection

Comment Type: General

Comment:

Given the complexity of this issue along with the timing with the RESNET conference, and holidays we are asking for an extension of the deadline. We believe 30 days would be appropriate to allow for stakeholders to discuss and respond to this addendum.

This proposal is being issued on behalf of our Standards Committee who is currently reviewing this addendum. NEHERS represents more than 260 Raters and 11 Providers from New Jersey to Maine (and a few beyond).

Proposed Change to Amendment:

Asking for time for working groups to fully discuss and prepare any additional comments. We thank you for your consideration.

Entry Date: November 22, 2023 at 8:21 AM

Full Name: Mike Moore

Affiliation: Stator LLC, on behalf of Broan-NuTone

Address: 5313 Fox Hollow Ct. Loveland, Colorado 80537

Phone Number: 3034087015

Email: mmoore@statorllc.com

Page Number: multiple

Section/Table/Figure Number: definitions

Comment Intent: Objection

Comment Type: Technical

Comment:

This suggested modification for the definition of CFIS System would clarify that a ventilation system that is integrated with the heating or cooling system’s ductwork but that does not rely on the heating or cooling system’s blower to introduce outdoor air would not be considered a CFIS System.

Proposed Change to Amendment:

Central Fan Integrated Supply System (CFIS System) – A Blower Fan of a Forced-Air HVAC System with a return-side outdoor air intake duct that supplies outdoor air to the Dwelling Unit[1].  Such systems exclude additional Ventilation fans unless the operation of those fans is coordinated with the Blower Fan through a common control.

Entry Date: November 22, 2023 at 8:37 AM

Full Name: Mike Moore

Affiliation: Stator LLC, on behalf of Broan-NuTone

Address: 531 Deckawoo Dr. Loveland, Colorado 80537

Phone Number: 3034087000

Email: mmoore@statorllc.com

Page Number: multiple

Section/Table/Figure Number: 4.2.2.7.2.13

Comment Intent: Objection

Comment Type: Technical

Comment:

Use “operational control mode” instead of “operational mode” for all such references in 301 and 380. This helps differentiate between coincidental operation and intentional operation. See also the proposed change to the footnote.

Use “specific fan power” when referring to a metric with the units of W/cfm. “Efficiency” metrics should be unitless (i.e., same units in the numerator as in the denominator).

Proposed Change to Amendment:

4.2.2.7.2.13.1.4 Ventilation airflows. For each operational control mode used by the CFIS System, software shall collect the corresponding Ventilation airflows of each fan.

4.2.2.7.2.13.1.5 Supplemental fan specific fan power efficiency. Where the CFIS System employs a supplemental Ventilation system, software shall collect the fan W/cfm of that supplemental fan.

4.2.2.7.2.13.2. Software shall simulate all CFIS Systems as follows:

4.2.2.7.2.13.2.1 Where a Rated Home has a CFIS System, duct losses for all non-heating and non-cooling Blower Fan run-time shall be included in the simulation.

4.2.2.7.2.13.2.2 Where the CFIS System automatically controls the flow of outdoor air, software shall simulate outdoor airflow through the inlet duct for all Ventilation runtime hours of the Blower Fan; where such control is absent, software shall simulate outdoor airflow through the inlet duct for all heating, cooling, and Ventilation runtime hours of the Blower Fan.

4.2.2.7.2.13.2.3 Ventilation fan energy.

The Blower Fan specific fan power efficiency used in the CFIS simulation shall employ the same W/cfm value used for simulation of heating and cooling by that Forced-Air HVAC System. The Blower Fan wattage shall be calculated by multiplying the fan specific fan power efficiency by the larger of the heating and cooling flowrates.

Where the CFIS System uses the Blower Fan outside of heating and cooling runtimes, software shall simulate that added Blower Fan energy.

Where the CFIS System control strategy runs the Blower Fan at fixed intervals regardless of heating and cooling runtimes, software shall simulate the added Blower Fan energy each hour using the following runtime equation: …

[1] (Informative Note) For example, one operational control mode may be only the Blower Fan operating while another mode may be only the supplemental ventilation fan operating.  A third mode may run both simultaneously.

Entry Date: November 28, 2023 at 9:41 AM

Full Name: Connor Dillon

Affiliation: Building Science Institute, Ltd. Co.

Address: 531 W. Court 406G Geronimo, Alabama 78115

Phone Number: 4238385171

Email: connor@buildingscienceinstitute.org

Page Number: 1

Section/Table/Figure Number:

Comment Intent: Not an Objection

Comment Type: General

Comment:

It is unfortunate that it has taken this long to clarify that CFIS are not sufficient whole house mechanical ventilation solutions. I support the modified language, but I’m worried for the many homes which were registered and certified for energy code and above-code programs like ENERGY STAR.

I propose RESNET Staff use their Registry data to review the impact, and whether people were actually modeling CFIS appropriately in compliance with ANSI 301.

Proposed Change to Amendment:

Entry Date: December 12, 2023 at 4:39 PM

Full Name: Elliot Seibert

Affiliation: US EPA

Address: 1200 Pennsylvania Ave NW Washington, District of Columbia 20004

Phone Number: 202-343-9643

Email: seibert.elliot@epa.gov

Page Number: 4

Section/Table/Figure Number: Table 24

Comment Intent: Objection

Comment Type: Technical

Comment:

We recommend providing an additional “no control/thermostat-only” strategy in the same subsection that assesses whether control uses a timer-based control or a ventilation controller that preferentially uses the heating and cooling runtime to meet the hourly ventilation target. This would obviate the need for the “Has no strategy to meet the remainder” option in the following section. We believe it is necessary to distinguish between having a fan operate purely on a thermostat, particularly when a damper or an auxiliary fan is interlocked, compared to having a dedicated ventilation controller. The thermostat-only strategy, of course, is liable to overventilate in some seasons and underventilate in others. We believe it will also be more logical to Raters to have all control options included in a single list.

Proposed Change to Amendment:

Example from MRF Table Item 24, with similar changes to other parallel sections:

b) Determine whether the CFIS has no control beyond the thermostat, has an automated CFIS ventilation System controller that operates the Blower Fan on a fixed timer interval regardless of heating and cooling runtimes, or has an automated ventilation controller that preferentially uses the heating and cooling runtime to meet the hourly ventilation target.

c) Where the control strategy of the CFIS System relies on heating and cooling runtimes, determine whether the CFIS System has a strategy for meeting the remainder of the design Ventilation target when heating and cooling runtime is too brief to do so. Strategies include:

i. operating the Forced-Air HVAC System’s Blower Fan.

ii. operating a supplemental Exhaust Ventilation System.

iii. operating a supplemental Supply Ventilation System.

iv. Has no strategy to meet the remainder.

Entry Date: December 12, 2023 at 4:46 PM

Full Name: Elliot Seibert

Affiliation: US EPA

Address: 1200 Pennsylvania Ave NW Washington, District of Columbia 20004

Phone Number: 202-343-9643

Email: seibert.elliot@epa.gov

Page Number: 4

Section/Table/Figure Number: Table 24

Comment Intent: Not an Objection

Comment Type: Editorial

Comment:

We recommend replacing “supplemental” with “auxiliary” to describe fans other than the Blower Fan. Supplemental might inadvertently imply that it’s purpose is necessarily to provide the make-up ventilation to meet the target, in terms of supplementing the time already called for by the thermostat. We understand this not to be the intention and suggest that “auxiliary” is less likely to lead to this confusion.

Proposed Change to Amendment:

Example from MRF Table Item 24, with similar changes to other parallel sections:

… Strategies include:

i. operating the Forced-Air HVAC System’s Blower Fan.

ii. operating a supplementalan auxiliary Exhaust Ventilation System.

iii. operating a supplementalan auxiliary Supply Ventilation System.

iv. Has no strategy to meet the remainder.

Entry Date: December 12, 2023 at 4:57 PM

Full Name: Elliot Seibert

Affiliation: US EPA

Address: 1200 Pennsylvania Ave NW Washington, District of Columbia 20004

Phone Number: 202-343-9643

Email: seibert.elliot@epa.gov

Page Number: 4

Section/Table/Figure Number: Table 24

Comment Intent: Not an Objection

Comment Type: Editorial

Comment:

We recommend clarifying that the ‘third question’ about make-up strategy is only applicable when the ‘smart’ ventilation controller is present, per the prior question. In other words, this section does not apply if either a) it is a thermostat-only control strategy or b) it is timer-based. The current wording could be read to apply to thermostat-only control strategies, which we do not believe to be the intent or be appropriate (in part, because the question of make-up runtime is moot if the control is thermostat-only).

Related, logically, if the control is a ‘smart’ ventilation control present, the question can assume that a make-up strategy will exist. Therefore, the question should be what the strategy is, not whether there is a strategy.

Proposed Change to Amendment:

Example from MRF Table Item 24, with similar changes to other parallel sections:

…

c) Where the control strategy of the CFIS System relies on heating and cooling runtimes has an automated ventilation controller that preferentially uses the heating and cooling runtime to meet the hourly ventilation target, determine whether the CFIS System has a strategy for meeting the remainder of the design Ventilation target when heating and cooling runtime is too brief to do so. Strategies include

Entry Date: December 12, 2023 at 5:13 PM

Full Name: Elliot Seibert

Affiliation: US EPA

Address: 1200 Pennsylvania Ave NW Washington, District of Columbia 20004

Phone Number: 202-343-9643

Email: seibert.elliot@epa.gov

Page Number: 4

Section/Table/Figure Number: Table 24

Comment Intent: Objection

Comment Type: Technical

Comment:

We recommend distinguishing between scenarios where an auxiliary fan runs during all heating and cooling periods (e.g. by thermostat interlock) versus just that portion of the heating and cooling period necessary to meet the ventilation target (as most ‘smart’ controllers would be configured).

More editorially, we also recommend reorganizing the subsections to address everything occurring during the heating/cooling runtimes first, before moving on to what happens during ‘make-up’ mode periods.

Proposed Change to Amendment:

Example from MRF Table Item 24, with similar changes to other parallel sections:

…

a) Determine whether the automated CFIS System controller operates a mechanical damper or other flow control to block outdoor air when Ventilation is not required.
b) Determine whether the automated CFIS System controller operates the Blower Fan on a fixed timer interval regardless of heating and cooling runtimes, or preferentially uses the heating and cooling runtime to meet the hourly ventilation target.
c) Determine whether the CFIS System uses an auxiliary Ventilation system and, if so, determine whether the auxiliary Ventilation system operates simultaneously with the Blower Fan during heating and cooling runtime, and whether that operation occurs during all heating and cooling runtimes, or just the portion necessary to meet the Ventilation target.

d) Where the control strategy of the CFIS System relies on heating and cooling runtimes, determine whether the CFIS System has a strategy for meeting the remainder of the design Ventilation target when heating and cooling runtime is too brief to do so. Strategies include
i) operating the Forced-Air HVAC System’s Blower Fan.
ii) operating a supplemental Exhaust Ventilation System.
iii) operating a supplemental Supply Ventilation System.
iv) Has no strategy to meet the remainder.
d) Where the CFIS System uses a supplemental Ventilation system, determine whether it also operates the supplemental Ventilation system simultaneously with the Blower Fan during heating and cooling runtime.
e) Where the CFIS System employs a supplemental Ventilation system, measured airflow and fan wattage shall be obtained for that system in addition to the CFIS System airflow.

Entry Date: December 12, 2023 at 5:21 PM

Full Name: Elliot Seibert

Affiliation: US EPA

Address: 1200 Pennsylvania Ave NW Washington, District of Columbia 20004

Phone Number: 202-343-9643

Email: seibert.elliot@epa.gov

Page Number: 4

Section/Table/Figure Number: Table 24

Comment Intent: Objection

Comment Type: Technical

Comment:

We recommend clarifying that make-up mode strategies are non-exclusive and multiple strategies may be present. For example, the blower fan may run. Or an exhaust fan may run. Or the blower fan may run simultaneously with an exhaust fan.

Proposed Change to Amendment:

Example from MRF Table Item 24, with similar changes to other parallel sections:

…

c) Where the control strategy of the CFIS System relies on heating and cooling runtimes has an automated ventilation controller that preferentially uses the heating and cooling runtime to meet the hourly ventilation target, determine whether the CFIS System has a strategy/strategies for meeting the remainder of the design Ventilation target when heating and cooling runtime is too brief to do so. Also determine whether there is a single strategy or multiple strategies operate simultaneously. Strategies include:

i. operating the Forced-Air HVAC System’s Blower Fan.

ii. operating a supplemental an auxiliary Exhaust Ventilation System.

iii. operating a supplemental an auxiliary Supply Ventilation System.

iv. Has no strategy to meet the remainder.

Entry Date: December 12, 2023 at 5:34 PM

Full Name: Elliot Seibert

Affiliation: US EPA

Address: 1200 Pennsylvania Ave NW Washington, District of Columbia 20004

Phone Number: 202-343-9643

Email: seibert.elliot@epa.gov

Page Number: 4

Section/Table/Figure Number: Table 24

Comment Intent: Objection

Comment Type: Technical

Comment:

For consistency and completeness, we recommend adding the following elements that are currently missing from the on-site inspection procedures:

• Address auxiliary system presence
• Address auxiliary system control strategy
• Address fact that “remainder of ventilation target” is relative to the ventilation already delivered during heating and cooling call periods, and is only applicable when a ‘smart’ controller is used.

Proposed Change to Amendment:

On Site Inspection Procedures:

A CFIS System is a Blower Fan of a Forced-Air HVAC System combined with a return-side outdoor air intake duct that supplies outdoor air to the Dwelling Unit. However, such systems come in a variety of configurations (e.g., with or without a mechanical damper, the ability to optimize runtimes, or the ability to control a supplemental Ventilation system) and only some of these configurations meet the definition of a Dwelling Unit Mechanical Ventilation System.

All CFIS Systems must be properly characterized to accurately simulate their energy impact. For each system, record the following:
1) Characterize whether the system has automatic flow control of outdoor air, whether the system has an auxiliary Ventilation system in addition to the Blower Fan, its primary Blower Fan control strategy and auxiliary Ventilation system control strategy (if applicable), and, for control strategies with an automated ventilation controller that preferentially uses the heating and cooling runtime, its strategy for meeting the remainder of the Ventilation target not already satisfied during the heating and cooling runtime, per ANSI / RESNET / ICC 380.
2) For each operational control mode used by the CFIS System, test and record the corresponding ventilation airflows of each fan, per ANSI / RESNET / ICC 380.
3) Record the Blower Fan model number from the nameplate data of the Forced-Air HVAC System. This links the CFIS System to the correct Forced-Air HVAC System.