Products
Latest Product Roundup
Check out this versatile fresh-air-supply fan, durable masonry screws, a wildfire sprinkler system and more.
1 MIN READ
Indoor Air Quality
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Products/Tools
Versatile Fresh-Air-Supply Fan
1 MIN READ
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Products
Latest Product Roundup
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Products
Whole-House Air Quality
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Products
Fresh-Air Intake
1 MIN READ
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Products/Tools
Efficient Energy Recovery Ventilator
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Products/Tools
Single-Room Air Purifier
1 MIN READ
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How To
Practical Ventilation for a Warm, Humid Climate
14 MIN READ
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On the Job
Running a Bath Fan Exhaust Through Metal Roofing
2 MIN READ
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Tools of the Trade
Give Your Shop Vac a Mullet
3 MIN READ
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Tools of the Trade
Filter-free Air Scrubber
4 MIN READ
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Products/Tools
Smart Control Switch
1 MIN READ
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Products/Tools
Smart Airflow Control
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HVAC
Humidifying Homes
9 MIN READ
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Energy Vanguard
Box Fan Air Cleaner Update
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Energy Vanguard
Bad Advice About Indoor Humidity in Cold Weather
1 MIN READ
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Products/Tools
Energy Star Dehumidifier
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How To
Mobilizing for a Small Abatement Project
3 MIN READ
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Remodeling
Managing Asbestos During a Remodel
4 MIN READ
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Q&A
Pre-piping for Radon
2 MIN READ
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Products/Tools
Whole-House Ventilation Control System
1 MIN READ
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HVAC
How to Size an HRV or ERV
7 MIN READ
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Energy Vanguard
We Need Higher Ventilation Rates. But How High?
1 MIN READ
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Products/Tools
High-Tech, PM-Monitoring IAQ
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Products/Tools
Whole-House, Two-Stage Filtration System
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How To
A Troubled Tiny House
5 MIN READ
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How To
Health-Based Ventilation Rates
2 MIN READ![1. International Residential Code (IRC) ventilation requirements are calculated using the formula: [7.5 cfm x (number of bedrooms + 1)] + (sq. ft. x .01). 2 The ASHRAE 62.2 (2013) ventilation rates are calculated using the formula: [sq. ft. x .03] + [(number of bedrooms + 1) x 7.5 cfm]. This air-flow rate remains in the 2016 and 2019 versions of the 62.2 Standard. 3. Formula for Hayward Score (HS) recommended ventilation rates: 20 cfm x (number of bedrooms + 1) + [(sq. ft. - 1000) x 0.3]. a. Formula assumes 9-ft. ceilings b. Occupancy dictates ventilation rate for the first 1,000 sq. ft., then add 30 cfm per 1,000 sq. ft. (at 9-ft. ceiling height), as smaller volumes are quickly overcome by occupant CO2 c. It matters where you put the air: Bedrooms must get their 20 cfm per occupant, as healthy air at night is priority number one. d. As home square footage increases, two or more systems will be required. Focus on the "casita" (core area) first - the main bedroom and primary occupancy area, which includes the kitchen, baths, and home offices. As occupancy increases (families grow) additional systems can be added. e. Supply air to bedrooms, home office, living space, fitness/wellness room. Exhaust air from kitchen, laundry room, bathrooms and closets. Balance by zone. f. The Hayward Score (HS) recommendations assume stand-alone, balanced, energy-recovery ventilation (ERV), and are based on experience with high-efficiency ERV at 90% energy recovery and 60% moisture recovery with additional dehumidification where climate dictates. g. For best ventilation performance, consider the following: i. Design ventilation system to deliver HS recommended ventilation at 50% of capacity to optimize energy consumption. ii. In winter climates with increased levels of ventilation, supplemental humidification may be necessary to maintain 35-55% RH. iii. Installing a 4-inch MERV-13 filter in the main forced-air HVAC system can assist significantly in reducing dust and particle count indoors. It helps if the HVAC system is a variable-speed system that can operate continuously between heating and cooling cycles. iv. Infiltration air (natural leakage) is typically contaminated and needs to be diluted as well as cleaned. v. In the first two years after construction, chemical off-gassing from building materials and new furnishings is higher and may require running the ventilation system at higher than 50% operating speed. vi. Ideally the envelope of the house should be built to an air tightness of less than 2 ACH @50p. (Code maximum is 3 or 5 ACH, depending on climate.) It doesn't make sense for healthy, conditioned air to compete with infiltration air. Airtightness must be central to this discussion. This example that illustrates the importance of the envelope: A home built to airtightness limit of 3 ach @50Pa. has a natural leak rate (with no wind or significant temperature differential) of .17 ach - more than 50% of the air being introduced and conditioned by the ERV. 4. While four and five bedrooms are unlikely in these smaller houses, air-flow numbers have been provided here because the number of bedrooms often serves as a proxy for house occupancy. It is not uncommon for smaller houses to have 5, 6 or more occupants, and as we have learned human occupancy is a more important driver of ventilation need than house size.](https://jlconline.stg.zonda.onl/wp-content/uploads/sites/4/2021/hs-recommended-corrected.jpg?w=232)
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How To
A Builder’s Guide to Breathable Indoor Air
15 MIN READ
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Business
The Hayward Score: A Rating of Home and Human Health
2 MIN READ
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HVAC
Ventilation Code Simplified
2 MIN READ
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HVAC
Retrofitting Forced-Air HVAC With High-MERV Filtration
7 MIN READ
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Products/Tools
Smart Air Cleaner
1 MIN READ
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Energy Vanguard
Why IAQ May Be More Important Than You Think
1 MIN READ
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BUILDER
2021 Product Guide: Systems
4 MIN READ
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Centers for Disease Control and Prevention
Fighting the Coronavirus With Better Home Ventilation
1 MIN READ
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Business
Future-Proofing Your Business, Post-Covid Edition
1 MIN READ
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Remodeling
Seeing Through the Fog of Covid-19 Info
1 MIN READ
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HVAC
Seeing Through the Fog of Covid-19 Info
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Energy Vanguard
A Portable Air Cleaner
1 MIN READ
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Energy Vanguard
Humidity, Health, and the Sterling Chart
2 MIN READ
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Energy Vanguard
My Low Pressure-Drop, MERV-13 Filters
1 MIN READ
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How To
A Simple, Cost-Effective Ventilation Strategy
8 MIN READ
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Products/Tools
Compact Air Quality Monitor
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Products/Tools
Energy-Efficient Radon Fan
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How To
Makeup Air for Kitchen Range Hoods
6 MIN READ
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Restoration
Restoring a Fire-Damaged Home
7 MIN READ
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How To
Reinventing Indoor Cooling
9 MIN READ
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Tools
Radon: The Origin Story
2 MIN READ -
Troubleshooting
Cleaning Up Moldy OSB
2 MIN READ
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Troubleshooting
Fixing Summertime Moisture Problems
13 MIN READ
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How To
Humidity Control: A Closer Look
9 MIN READ
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Products/Tools
Bacteria-Killing Light
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How To
Don’t Forget to Breathe
3 MIN READ
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Products/Tools
In-line Ventilation Fan
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Products/Tools
A Smart Ceiling Fan
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Remodeling
RM550 Preview: The Projects Keeping Full-Service Firms Busy
1 MIN READ
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How To
Controlling Humidity in Warm Climates
11 MIN READ
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Products/Tools
A Compact Home Comfort System
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How To
Simple Fresh Air for Tight Houses
7 MIN READ
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How To
First-Look at Radiant Cooling
1 MIN READ
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How To
Air Conditioning for Humid Climates
10 MIN READ
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Remodeling
Breathing Easy: An Introduction to Healthy Homes
9 MIN READ
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Remodeling
Is the Future of AC Ductless?
4 MIN READ
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How To
Killing Odors in an HVAC System
1 MIN READ -
How To
Ductwork and Combustion Vents: Dangerous Interactions
7 MIN READ
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How To
Effective, Retrofit ERV
4 MIN READ
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Remodeling
Looking for Winter Work? Clear the Air
4 MIN READ -
Products/Tools
Panasonic Expands Total Home Comfort System with Exterios E
1 MIN READ
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Energy
The Science of Kitchen Ventilation
6 MIN READ
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Good Form
Checklist to Reduce Airborne Health Hazards
1 MIN READ -
Q&A
Panned Bays
4 MIN READ
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Energy
Solving for Comfort With a ‘Smart’ Thermostat
7 MIN READ
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How To
Part 2: Choosing a Whole-House Ventilation Strategy
13 MIN READ -
Energy
More Than ‘Tips’ Needed to Improve Energy Efficiency
Brought to you by Enertech Global4 MIN READ -
How To
A Drywaller’s Approach to Air Sealing Homes
10 MIN READ
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Projects
Perfection is Possible: Zero-Leak Ducts
5 MIN READ
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How To
Can a UV Lamp Improve Indoor Air?
3 MIN READ