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HRV or ERV or neither?

Erik Olofsson | Posted in General Questions on

we are building a small 600 sq’ house in valemount, b.c.. we are planning to make it airtight via the plywood sheathing. should we use an hrv or erv or exhaust-only with passive air inlets? anyone care to recommend a cost-efficient manufacturer? also, interested in a detail of a ground loop for the intake air…thanks
other site info: 800 metre elevation, 5623 HDD

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  1. GBA Editor
    Martin Holladay | | #1

    Have you read these two articles?

    Designing a Good Ventilation System

    HRV or ERV?

  2. Erik Olofsson | | #2

    martin, we have installed a couple of hrv's in the town where we are presently building. my father, the plumber, and the heating guy still debate the merits of the system to this day. i am NOT a HVAC contractor nor are there any around where we are building so that is why i am hoping some of the guys at gba might be able to help me chose a model. does it make any sense to duct the cold intake air through the ground before it reaches the hrv? i am referring to a really low-tech detail here...

  3. Aj Builder, Upstate NY Zone 6a | | #3

    Erik, low tech that works equals using a Panasonic bath fan when needed either semi automatically or manually. All other ideas cost more and are more complicated and some ideas sound good but are horrible in practice too often such as ground tubes.

    Keep it simple, to keep it functioning, and cost effective.

  4. GBA Editor
    Martin Holladay | | #4

    Q. "i am hoping some of the guys at GBA might be able to help me chose a model."

    A. If you read the article I linked to -- "HRV or ERV" -- you'll see that I recommended two possibilities. I wrote, "If energy efficiency is your most important criterion — and I believe it should be — choose either the UltimateAir RecoupAerator 200DX ERV (which draws 40 watts to deliver 70 cfm, or 1.75 cfm/watt) or the Venmar EKO 1.5 HRV (which draws 24 watts to deliver 49 cfm, or 2.04 cfm/watt)."

    Q. "Does it make any sense to duct the cold intake air through the ground before it reaches the HRV?"

    A. No. To understand why, see Belgian Passivhaus is Rendered Uninhabitable by Bad Indoor Air.

  5. Erik Olofsson | | #5

    does anyone have any experience with hrv's made by eneready..?

  6. Aj Builder, Upstate NY Zone 6a | | #6

    Panasonic Whispercomfort FV-04VE1

  7. Jerry Liebler | | #7

    It's time to update your data on ERV- HRV performance image!
    For example the EV450 with ECM motor simply blows away the competition in CFM / watt with 200CFM on 60 watts ( 3.33 CFM/watt) with 0.2" wc duct loading. This is normally a "commercial unit & designed to move 450CFM but can be operated at 200 CFM. Even at 450CFM if duct resistance is 0.16" WC it only draws 327 watts or 1.38 CFM/watt. This unit needs to flow at least 200 CFM, if less is needed it must be done by 'duty cycle' so any less than 200 CFM is still 3.33CFM/watt.

  8. GBA Editor
    Martin Holladay | | #8

    That's a commercial unit, and is seriously oversized for most homes. You're right that it can be operated with a timer, so that (for example) it comes on for 20 minutes each hour -- an option that is worth considering for those who like the cfm/watt rating.

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