Looking for a cost-effective HRV or ERV system or design
user-943386
| Posted in Energy Efficiency and Durability on
Building in South Eastern Washington State. Very tight envelope. Using a combined HVAC System (ductless Heat pump and ducted) Thank You
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Cost effective is realtive to payback time you are looking for ..
the pros will need to know a few things to help you out :
- air leak test results
- maybe projected heat load?
- what you consider as a good payback term in your position
- any current ductworks provision for the system ?
There are few DIY solutions which are usually much cheaper
in usa, installed HRV/system is expensive ( from what i read here )
Yes, you have to define cost effective.
An HRV or ERV installation with dedicated ductwork is going to cost more than an exhaust-only or supply-only solution. You can probably get more benefit from a good recovery ventilator installation, in terms of comfort and air quality, and that part is not something you can put a price to.
You can also get some energy savings from the heat recovery part of the equation, compared to a system without heat recovery. The amount of that savings has to do with the quality of the installation (are the ducts in unconditioned space?), the amount of ventilation you need, and the price you pay for heating and cooling.
The first thing I'd look at is where the ventilator and the ducts are going to go. If the installation is going to be in a hot/cold attic, not so good, if it's inside the envelope, much better.
If your heating cost is high, then the heat you save has more value. If it's on the low side--and I suspect it is if you're in the Bonneville service area--then you save less. It's fairly easy to run the numbers using your expected heating cost and efficiency, and your ventilation rate.
I would be looking more at the ventilation effectiveness in a tight house. You are going to want dry air delivered to the bedrooms and removed from the bathroom and kitchen areas. You are going to want a system that's almost silent. If you don't have the right equipment to manage air quality in a tight house, it can be a real hassle.
If the house isn't too big, and cost is very important, then you have to consider the Panasonic Whispercomfort ERV.
Now selling for $353 at WalMart, it doesn't cost significantly more than an exhaust only solution.
http://www.walmart.com/ip/WhisperComfort-Spot-ERV-Ceiling-Insert-Ventilator-with-Balanced-Ventilation-and-Patent-Pending-Capillary-Core/17420463
How well are those things going to mix the air? The simplicity is appealing, but all the air moves through the same single grille.
Reply to David Meiland,
In some of their literature, Panasonic mentions whole house ventilation, even though they call it a "spot ERV" The specs of the unit match up with ASHRAE 62.2.
Here's my take: If there were a small breeze inside your home, the fresh air would mix pretty well, right? Well the air coming in from the ERV is usually at a different temperature than the rest of the room. That temperature difference causes convective currents that create that small breeze. Doors must be left open as necessary. Fick's Law also helps diffuse the fresh air to the not so fresh remainder of the house.
Understood. My experience is that the bedrooms tend to be where humidity accumulates (assuming proper bath fan use) and that fresh air should be supplied there. I think the Panasonic unit could work well in small spaces (studio apartments?) but that houses may need more.
David: i haven 't gone through the panasonic litterature yet ( will do at home tonight ) but it looks like it flows up to 40cfm ?? which is probably more than enough for most small/medium houses
if you consider leaks + kitchen hood exhaust nah ??
Anyone has the recoup/efficiency numbers on the panasonic fan ?
looks like a very cheap setup for a tight house on a budget ...
Heat recovery efficiency ratings for the FV-04VE-1:
Heating % 66% @ 30 CFM
Cooling % 36% @ 29 CFM
Dan,
If you are interested in more information on the question of HRVs and cost effectiveness, I suggest you read the following article: Are HRVs Cost-Effective?