GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Winter Ventilation in Steam Heated Home

Daniel McDonald | Posted in Mechanicals on

My partner and I are currently attempting a LEED renovation of a Victorian home in Cleveland, Ohio. The home has an existing steam radiator system in good condition that we are able to reuse, we are not installing AC. We’ll end up with about 2400 sf of living space.

We are having trouble making a decision on winter ventilation. An HRV system seems to be the most efficient, but we are concerned about costs and don’t have the room or desire to run ductwork through the house (the closets are small enough).

Another LEED home in the area has an inline fan connected to two bath and one kitchen vents. The fan is timed to run sufficient to move the required air changes, no heat recovery, simple and cost effective . But, that house is half our size, and insulated at twice the R that we are able to achieve. They (new construction) installed radiant floors.

Any suggestions on equipment type and placement of vents? Is there a way to put the kitchen exhaust hood on this system (I assume grease is an issue)?
Is there an option we’re not seeing?


GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Riversong | | #1

    The kitchen hood should be seperately ducted to keep grease out of the general ventilation system. With an HRV and particlarly an ERV, some recommend that bath exhaust fans also be isolated from the primary system to prevent overloading the heat exchanger with moisture (and potential frost). Without heat recovery, you could use a central fan for all baths as long as it can be controlled from each bath during use.

    You might consider upgrading the bathroom fans (if the existing ones are not highly efficient and quiet) and putting them on 24-hour programmable timers for an exhaust-only ventilation system. There are probably plenty of leakage points in the thermal envelope, but you should also install some passive make-up inlets in strategic locations, such as living rooms and bedrooms. I recommend the American Aldes Airlet 100. I recommend Panasonic bath fans or fan/CFL-light combos.

    Make sure that all exhaust ducting is rigid, well-sealed at joints (with mastic or foil/butyl tape), and pitched to the outside for drainage.

    While you won't recover the energy lost to ventilation air with an exhaust-only system, keeping a slight negative pressure in an old house prevents moisture-laden air from exfiltrating in the winter and causing mold or decay problems.

    Just be sure that all combustion appliances are direct vent, sealed combustion to prevent backdrafting. I would recommend setting the exhaust timers for 0.25 air changes per hour (average flow of 80 cfm in a 2400 sf house), which can be intermittent according to times of highest occupancy.

    You'll still need point-of-use switches or timers in the bathrooms for use during showering. Energy Federation now offers a timed-delay switch that will replace a standard wall switch.

  2. Daniel McDonald | | #2

    This is great, clear as day. Thank you

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |