I would use your ductwork, and that is typical. It is very hard/messy to retrofit ductwork in a finished house, unless it's a bungalow with full access to the floor or attic.

 

EVR ? - You mean Energy Recover Ventilator ?

Why are you getting an ERV ?

I would think a 1984 house would be leaky enough that you are getting plenty of air changes

 

sorry I didn't mention it for brevity, I got a new high efficiency furnace, and these new windows, a few years ago and the air has been very stuffy since. To the point where I had to crack open a window on every floor to get some air flow going through, but I've gotten some buckling on the floors from that so I need to fix that.

---> I wasn't sure if my contractor wasn't offering new duct work because it was harder or if he thought I wouldn't go for the extra cost. But knowing that is normal is reassuring.

It's wise to duct an erv or hrv so that the stale air is taken from the house (1 vent only) and fresh air is put into the return.

If the stale air is taken from the return, you must run the furnace fan whenever you run the erv/hrv to get any ventilation. It can be interlocked so it automatically comes on.
The operating cost of running a furnace fan is high unless you have a ecm motor and it runs on very low speed in continuous fan mode.

When stale air is taken from the house and fresh air put into the return, when the furnace fan is not running, the fresh air will find its way into the house through the returns.

What problem are you trying to solve with an ERV?
You should only be getting one if the house is tight enough to need one.

Sealing accessible ducts and adjusting dampers can help with this.
However, if you have inadequate ductwork going to the top floor, no amount of balancing and sealing will fix it.

Yes this was what I was wondering. The air was fine before the high efficiency furnace, so I wouldn't have checked if the vents were outputting differently at the time, so I'm not sure if just adding an ERV would change it back. But the house has been like breathing in a paper bag since then so I was hoping the furnace would be the main cause.

I do have duct work going to the top floors, not sure if they're inadequate. How do I know if there's something wrong with the ducts? Or why the air wouldn't be getting up there a well as it should? Is there test I can ask for?

As for sealing ducts...would that be similar to closing vents? I closed a few floor vents on the bottom floor but it didn't make much of a difference. I have one of the 'return air' registers, the bigger ones along the wall, that is blocked by furniture. I wasn't sure if that would help or hinder air getting pushed up? It's just one register so I wasn't sure how much of a difference it would make.

 

Before I had the EVR connected to ANY ductwork I would be getting the install instructions for the unit. When I put mine in I used 5" pipe less than 10 feet long to vent and acquire fresh air
Ignoring the MFG instructions is a good way to have poor performance.

 

It's wise to duct an erv or hrv so that the stale air is taken from the house (1 vent only) and fresh air is put into the return.

If the stale air is taken from the return, you must run the furnace fan whenever you run the erv/hrv to get any ventilation. It can be interlocked so it automatically comes on.
The operating cost of running a furnace fan is high unless you have a ecm motor and it runs on very low speed in continuous fan mode.

When stale air is taken from the house and fresh air put into the return, when the furnace fan is not running, the fresh air will find its way into the house through the returns.

What problem are you trying to solve with an ERV?
You should only be getting one if the house is tight enough to need one.

There's air flow issues to begin with. Some vents seem to be pushing out more air than others. The air up on the top floor feels thinner or stuffy year round. When I turn the continuous fan on it doesn't make much of a difference.

Sealing accessible ducts and adjusting dampers can help with this.
However, if you have inadequate ductwork going to the top floor, no amount of balancing and sealing will fix it.

 

new furnace, bad air, HRV/EVR discisions

Hi I got a new high efficiency furnace which don't 'draw in' as much fresh air into the house as the older models (I'm told). Newly built homes in Canada come mandatory with an HRV to compensate, but my house is 30yo and doesn't have one.Now the air is very stuffy. Also, I have a heart...

www.diychatroom.com

 

If you have high humidity in the house in the spring and fall, you need an HRV, not an ERV.

The ERV transfers both heat moisture from the stale air exiting to the incoming fresh air during the heating season and will not dry out the house as effectively.

If you have normal or low humidity during these periods, an ERV should be used to prevent over-drying out the house.

By duct sealing, I meant sealing the joints - all those that are accessible.
Take-offs leak the most.

You can adjust vent dampers to try and get more air upstairs, but not do outright close the vents.

Evaluating a duct system is tricky - there is not just one basic thing to look for.

 

If you have high humidity in the house in the spring and fall, you need an HRV, not an ERV.

The ERV transfers both heat moisture from the stale air exiting to the incoming fresh air during the heating season and will not dry out the house as effectively.

If you have normal or low humidity during these periods, an ERV should be used to prevent over-drying out the house.

Yes I have asked about this before so I've repeated some things here, I apologize for that, but my OP was mainly about the installation because I'm actually moving forward with getting one. (I have money now.)

I'm in Ottawa Canada so humidity in spring and fall is moderate. I thought because the summers are humid an ERV would reduce humidity from the incoming air, and help with the dry winters. Which I gathered from last year's discussion, unless I misunderstood.

Is Life Breath a good brand? That's what he's offering. Any other brands considered best I should look out for?

 

An erv will still bring in humidity in summer, just not as much as an hrv.

What matters is the humidity inside the house - some houses are very dry inside by fall and in spring, others are humid and need ventilation just to control humidity.
An HRV is good for the latter, and ERV is good if the air is stale, has high co2 but normal or low humidity during heating season.

Keep in mind that if your problems are caused by pressure, not an iaq problem, an hrv or erv isn't going to help you.

Going from a mid efficiency or natural draft furnace to a condensing furnace with combustion air from outside alters pressures and flow of heat, air, moisture.

 

I don't think there's a big difference between brands, it is a simple device - a recovery core and two fans, filters, a control board.

 

Yea, but you'll want something with local availability, including parts. They make them far more complicated then they need to be.

 

The primary variable that the controller will use to turn the HRV/ERV on and off is indoor humidity. If you don't have sufficient air changes, indoor humidity will go up.

Your "air pressure" inside the house is exactly the same as the air pressure outside the house. Even "stuffy" is a meaningless term. Indoor relative humidity can be measured. You can buy a humidity meter and track your humidity. If your windows don't sweat much in January, I don't see how you have much of a problem.

 

You can have changes in pressure and higher vocs and co2, which some may be sensitive to.