Code compliance drives home ventilation performance
As building codes evolve to require verified performance, it's becoming more important for homebuilders and contractors to understand ventilation design so they can avoid costly mistakes.
In an exclusive interview with ProudGreenHome.com, Jim Shelton, director of sales and marketing for the Panasonic Eco Products Division, discusses the new code requirements for home ventilation and the changes facing builder and contractors.
How is the implementation of performance-based codes changing things for builders and contactors?
We're seeing there's more of an emphasis on performance, testing whether the equipment actually does what it's designed to do and what it needs to do.
It's being driven by code compliance with ASHRAE 62.2. Now ventilation fan performance is being verified with energy raters who test airflow, making sure if you're doing whole house continuous ventilation you do have the air flow that you need to meet ASHRAE 62.2, to the point that spot ventilation fans in bathrooms are at least moving 50 CFM.
How is that impacting builders and contractors on jobs in the field?
In some cases it's blind siding builders and contractors by them having to tear equipment out of a ceiling because it's not performing as required.
What's changed in the codes?
The 2013 version of ASHRAE 62.2 includes performance-based measurements – in the past you could say, OK the fan performs at the rated CFM at .25 static pressure, so it's representative of a typical installation. Also, with the charts could say, if you use 4-inch ducts, the fan will deliver so much air with X-feet of duct, and with a 6-inch duct it deliver this much CFM.
Now, you have to test the fans. It doesn't matter what the fan box said or the specs said, or what it tests at the Home Ventilation Institute. You have to test how much air it is moving in this installation. Installed performance is the issue now.
We're seeing a lot of inexpensive fans on the market that need to deliver 50 CFM in installed performance. But if you have long duct run, 40-50 feet of flex stock, then you're probably in trouble.
They were designed to barely meet Energy Star requirements, and if you have long duct run or multiple 90-degree turns or someone stepped on the duct, those fans are not getting close to 50 CFM and failing the inspection. We're seeing a lot of fan on the market that are more in the 30s for CFM.
Now Energy Star for Homes 3.0 and CalGreen have adopted ASHRAE 62.2 of 2013. It puts an emphasis on performance, what is the system doing in the house and just what it was advertised to do.
What does that mean on the job site?
Builders are having to get into a fight with the electrician and HVAC contractors. In single-family construction, the electricians are buying fans and the HVAC contractors are ducting it out. They start pointing fingers at each other, the HVAC guy says the electrician needs to buy better fans, the electrician says its Energy Star rated, he needs to duct it better. And so you find the HVAC guy comes back and tries to fix duct.
Now the builder has to call the rater back, which costs $100, to retest the fan. Worst case, they can't get it to meet the flow requirements and have to tear it out and put a bigger fan in.
If you did a whole subdivision that doesn't meet code, you're tearing a lot of fans out. A builder would rather not have to worry about that.
How is ventilation technology adapting to support performance-based codes?
Panasonic has introduced some technologies that make it easier to get the performance the builder needs.
We have fans with DC motor technology that has Smart Flow, it's self adjusting. You can set the fan at 50 CFM and regardless of the ducting the fan will sense that increase in static pressure and automatically adjust to make sure you're getting the desired 50 CFM air flow.
We have another Energy Star rated fan with a boost switch inside. It should deliver 50 CFM, but if something happens and the installation fails verification, allyou have to do is pull the grille down and set the boost switch and add 20 CFM. You can do that while the rater is there to test it again to make sure it passes.
Panasonic's WhisperGreen Select fan line features two new technologies, “Pick-A-Flow” and “Plug and Play”, allowing builders and contractors to customize the vent fan for a variety of applications.
The Pick-A-Flow speed selector is available via two base models – 50-80-110 CFM or 110-130-150 CFM, and the required air flow can be achieved with just the flip of a switch. Four unique Plug ‘N Play modules allow for further customization, providing the ability to choose from multiple features such as:
- Multi-speed operation, which allows the proper CFM setting to be selected to satisfy ASHRAE 62.2 continuous ventilation requirements.
- Motion sensor, which activates the fan when it senses a person and automatically returns to the pre-set lower speed when the occupant leaves the room. Once the module is inserted, the fan becomes truly automatic, making it the lowest installed cost solution for meeting ASHRAE 62.2 whole house continuous and spot ventilation. This sensor is also ideal for people with disabilities and assisted living environments such as nursing homes and retirement communities.
- Condensation sensor, which helps control bathroom condensation to prevent mold and mildew. The advanced sensor technology detects relative humidity and temperature to anticipate dew point, automatically turning the fan on to control humidity. When the condensation sensor is used in conjunction with multi-speed functionality, the fan will kick up to high speed when the condensation sensor detects moisture in the room.
- NiteGlo LED night light, which utilizes a specialized photocell feature that automatically turns on the 1W LED night light when darkness is sensed in the room. Hi/Low brightness switch enables users to fine tune the photo cell to work in conjunction with the darkness level of the bathroom. This module also activates an automatic 20-minute delay off timer for the fan.
Read more about home ventilation solutions.