HVAC replacement for old home? Chronic illness (air quality) being key importance...

Niki Harrison Published: Sept. 6, 2019, 4:32 p.m.Last updated: Sept. 12, 2019, 2:53 p.m.

Our home was built in '45, most things updated in 60's/70's but with my health issues need to continue improving air quality- some return air/vents were completely blocked off by some not very intelligent homeowners - so air isn't moving properly in home.

The electric isn't grounded (tech North America's electrical grounding isn't grounded properly anyway (need to lower EMFs), gain access to attic, remediate, add air exchanger (with filter and dehumidifier if that's possible?). Anyway, a bio-home inspector would be ideal but all funds need to go towards the actual updates. HVAC right now is not efficient, full of dirt (despite having cleaned) and new furnace/AC with extra filtration and UV  light. Without knocking down the house, is there a way to replace old metal dirty hvac (suspect mold caught in joints etc.)? Local HCAV didn't offer a good suggestion - just air exchanger and that's not enough... need to remove source of issues.

Also welcome the best insulation (in Ontario) for cubbies 16", 2-3" thick. Has to be super clean, no off gassing, mold resistent. 

Also, suggestions for best air exchanger set up for someone with chemical and mold sensitivies. 

And any tips on setting up proper air pressure for air flow in home, don't want the attic air coming into home which I suspect is happening.


Responses (2)

Ecohome Sept. 12, 2019, 2:52 p.m. Reply


Hi Niki, 

We will try to go through this point by point, butt seems your main issue in there is trying to repair / clean / replace the duct work? We of course can’t speak to how difficult or costly that would be without seeing it.

If your HRV or ducts were cleaned but they are still full of dirt afterwards, then they weren’t cleaned.

If you had an HVAC contractor come in and they didn’t offer you solutions, then call another,  However, that first person may have been correct in diagnosing the fix to your problem as replacing the HRV, I say that because you say it was cleaned but is still dirty, and clearly the previous owners weren’t big on air quality so it’s highly unlikely you have a good quality HRV that is performing well.

Blocked vents – unblocking the was wise, but it’s possible that the HRV was damaged by that move.

Electrical issues in a home is a serious matter for safety and should be addressed immediately.  

Air will naturally leak in the bottom of a home and leak out the top, so if air from the attic is leaking down into the conditioned space then your home may be depressurized due to problems with your HVAC system. I hate to be the bearer of bad news, but I do think you need to get some proper ventilation work done, that starts with getting a second, and maybe third opinion. 

Niki Harrison Sept. 13, 2019, 12:18 p.m. Reply

Thanks, yes we had another HVAC specilaist in this morning. It was more of what I expected with suggestions. While he also suggested an ERV (not HRV) to use all year around given our humidity zone in Ontario... it's exactly what I wanted to hear from a professional - I shouldn't know more than the contractor coming in based on a 5 min online search ;) We've had the vents cleaned 3 times by 3 different companies (not cheap ones and researched their equipment/cleaning process) and it was still dirty smelling after 2 weeks.

I think it has more to do with age, the previous old furnace (currently have 3 stage filter with UV) and inability to get decades of gunk out that may have caught on metal joints etc. It looks like we'll replace what is accessible at some point, change the direction the furnace to reduce the number and length of HVAC needed, flip the set up so that return is on the inside and heat/cooling on the outside. So I think we are on a better track. Electrical, still need to find someone who understand EMF issues, likely background in EU set ups, they have an appropriate grounding system with bedroom switch off at night. The rest aside from attic remediation is sorted so we are getting there....thanks for your input ;)