Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Radiant heat + mini splits. Northern IL. ERV or HRV??

Sukhoi29SU
Sukhoi29SU Member Posts: 77
edited January 21 in Indoor-Air Quality
More confused than when I started after watching numerous videos with conflicting info online.  I have two contractors - one that’s recommended ERV and one an HRV.

I have a house project in northern Illinois right on the WI border.
Radiant hydronic heat throughout the entire house.  Plan on mini splits for cooling.  All ductwork was torn out of house during rehab.  2500 sf upper level with approx 1900 sf walkout lower level (50% below grade).  Large 1750sf garage addition with a mirrored sf workshop beneath garage. 

Concerned about moving air throughout house in absence of an A/C unit and no ductwork. 

One guy has recommended a Renewaire ERV Premium L as a solution that would have three boost switches in 3 bathrooms on east side of the house (2 upper level and one lower level) and have that system continuously run.  He thinks the ERV could bring in air high in a vaulted ceiling about 1/3 of way from east to west on main floor - and that it would be sufficient to move air throughout house and down centrally located stairway and to lower level west side of the house with no ductwork over there.

Other guy says I don’t want ERV in this climate and that I should go with an HRV. 

Thoughts ?  Need more info?  I’m stuck. 

Thanks in advance for any suggestions 

edit*** I failed to mention the insulation planned.  All exterior walls of the home will be spray foam with 3” closed cell.  Above the flat ceilings will be 3” of closed cell with fiberglass blown in over that.  Vented steel roof.  I have one main vaulted ceiling that will get batt insulation only with vented peak top of scissor trusses there.  The garage will be batt insulation and lower level garage addition is ICF.  I think the house will be well insulated, but there are a few areas where the house has a potential to breathe a bit. 

Comments

  • Hot_water_fan
    Hot_water_fan Member Posts: 511
    Probably unhelpful, but ductwork would make your life so much easier and should be reconsidered. Ductless mini-splits will significantly underperform comfort and efficiency-wise for cooling, especially if they're multi-splits.
    Sukhoi29SU
  • Jamie Hall
    Jamie Hall Member Posts: 18,907
    Neither an ERV nor an HRV are going to work well without ductwork to distribute the air and the returns.

    Now having said that, the two are quite different animals. An HRV recovers most of the sensible heat in the outgoing air flow, but does not recover the moisture. An ERV will recover the moisture. Unhappily, in the process of doing that, it will also recover most of the indoor air contaminants, such as molds, virus, many common chemicals, which the whole idea of outside air exchange is intended to eliminate or reduce.

    You appear to be trying to make a very tight house. You will need to have adequate outside air exchange to keep your indoor air quality reasonable. Therefore, a HRV is the correct choice.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Sukhoi29SU
  • Sukhoi29SU
    Sukhoi29SU Member Posts: 77
    Thank you both for your comments.  I might clarify that with the install of one of these systems, the contractor planned to add some ductwork - however - the ERV contractor was going to limit duct work to the near-vicinity of the system to service the three bathrooms and then push some air out into that central room of the house.  No ductwork was planned to go throughout the entire house, and there were some concerns over too much draw for the system if we were going to attempt to utilize the ERV for a fan on the west (opposite) side of the house - so he had me install a bathroom fan over there vs try and attempt to utilize the ERV from so far away.  

    The house hasn't been plastered yet so I still have some time to make some changes if need-be...
  • Sukhoi29SU
    Sukhoi29SU Member Posts: 77
    https://www.zehnderamerica.com/why-ventilation-should-be-separate-from-heating-and-cooling-systems/

    Short article - most of the contractors I’ve dealt with in my area are proposing integrating an HRV or ERV into the A/C system with an air handler.  

    This article makes sense to me.  Are the contractors who are proposing something in contrast with this article wrong?

    thanks