Improving Air Quality on a Ducted Heat Pump
T.I.P.
| Posted in General Questions on
First time poster but love reading the discussions and would really appreciate some feedback.
I have a 2 storey home that I’ve only recently learned that the electric furnace is undersized AND that it uses a very poor duct design so we will be putting in a Mitsubishi Zuba ducted central heat pump as well as a Panasonic Intellibalance ERV (connected to the ductwork) and improving the duct design. At the seame time in an effort to do things right, I’m looking at the best way to improve the indoor air quality but I’m questioning what actually works vs what is a gimmick or producing ozone.
My installer is against adding anything extra but has recommended adding a HEPA filter to the return and they use Direct Air – DA-DMHEPA400-VS based on other installs they’ve completed. A quick online search shows that many brands offer this exact unit. The reasoning provided is that adding a HEPA filter on the return side shouldn’t affect the airflow compared to beefing up the furnace filter to Merv 13. I’m also thinking that it would make sense as well since it will pick up the air from both the ERV and the house air.
My question is – does it make sense to install the upgraded version that includes a UV lamp – DA-DM900V-VO-VS.
My simple thought is that although the unit cost will increase with the UV model, the installation cost should stay the same since it’s basically the same unit.
I’m also seeing other products like the I wave R or the Halo in-duct filters but it’s hard to know what actually works…most info online seems to be paid promotion disguised as reviews.
Happy to hear your thoughts on the best way to improve air quality since with the heat pump, the fan will be continuously circulating the air.
Thanks!
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
> The reasoning provided is that adding a HEPA filter on the return side shouldn’t affect the airflow compared to beefing up the furnace filter to Merv 13.
I think that's backwards. HEPA is even higher filtration than MERV13 (the equivalent of MERV17+), so all else equal will cause more air resistance, making your equipment work harder.
Also, you don't need a HEPA filter unless you need to filter virus particles, and the best way to deal with viruses is to dilute the indoor air , which your ERV will handle, or if the weather is good, open a few windows.
> My question is – does it make sense to install the upgraded version that includes a UV lamp – DA-DM900V-VO-VS.
Why do you think you need a UV lamp? Read this before making that decision:
https://www.energyvanguard.com/blog/do-uv-lamps-really-improve-indoor-air-quality/
Thanks for your reply, that link was very helpful. I have dropped the HEPA and UV off my list. I posted a separate question today about how big of an air filter my Zuba Central ducted system can handle. My installer seems to think that the system can only handle a low MERV 1" filter.
There are MERV13 1" filters available. That's not low in my opinion. Beyond MERV13 you would be making your fan work very hard for little marginal filtration benefit.