hrv help

[indep]

hi all,
we recently bought a new house that will be constructed very soon located in canada (ontario so cold winters) and our builder recommended getting an hrv system. he told us that since nowadays houses are so airtight an hrv would help with the exchange of air flow.

i would like to ask you guys if it's worth it or not? the price is 3500 for the full system and 2100 for a bypass... is this something we need or can we get it later since right now we're on a tight budget.

Thanks

[larobj63]

Prices are a no-no on this site.

That sounds expensive, though.

HRV's are great, and they do save energy AND provide a constant sourse of fresh air, which is a quality of life improvement.

But at those prices - you could buy alot of fuel for that money - meaning a slooow payback.

Maybe shop around on the install? A tight modern house does benifit from an HRV, especially in a cold climate. I might suggest exhauting from a full bathroom and supplying to the return of your furnace - works well.

[indep]

hi, sorry about the prices, thanks for the reply. So it is possible to buy one later on then? also we are getting a double stage furnace so it would get air from the outside so that should help as well no?

[ampulman]

hi, sorry about the prices, thanks for the reply. So it is possible to buy one later on then? also we are getting a double stage furnace so it would get air from the outside so that should help as well no?

If you're talking about a high efficiency furnace (90+%), the 'air' that you mention is for combustion, only. Having outside combustion air will minimize outside air infiltration.

AM

[larobj63]

If you're talking about a high efficiency furnace (90+%), the 'air' that you mention is for combustion, only. Having outside combustion air will minimize outside air infiltration.

AM

Exactly. And yes - it could be retrofit later on. People have been getting buy with operable windows for the last several hundred years (although the houses weren't as tight), so you could "rough" it until funds become available.

[beenthere]

It may cost more to install later.

[firecontrol]

Where I live it is a code requirement that every new home must have either a barometric damper arrangement installed into the return air ductwork of the furnace or an air-to-air heat exchanger, homeowners/builders choice.

To build a new home and not put one form or the other in is in my opinion just asking for serious health and structural problems.

A new home is full of building materials that give off VOC's that are unhealthy to breath at sometimes even very low concentrations. Every thing that gets let loose in the home will stay in the home. This includes cooking smells, candle soot, propellant from sprays, carbon dioxide from breathing, chemicals from cleaning chemicals, the list goes on and on. If your home is built tightly like most new homes are these days there is no means for these contaminates to be diluted and/or expelled to the outdoors.

The next thing is that every bit of moisture that is in the home will not have a way to be dilluted. This can cause mold problems in the home on windows, closets and any place the insulation for whatever reason isn't as good as other places.

Find something else to "put off" buying and put in an HRV so that you have full control of your indoor air quality and the health of yourself, your family and your new home.

[indep]

ok that's what i thought, thanks for the replies, i am going to get it with the house... now my issue is should i go with the dedicated system or the non dedicated (bypass) one, he explained to me that dedicated is more expensive but it's the best way since it's connected to the bathrooms (not very sure i understand it fully) but maybe you guys understand the difference between the two and if so which one woudl you recommend

thanks

[larobj63]

Where I live it is a code requirement that every new home must have either a barometric damper arrangement installed into the return air ductwork of the furnace or an air-to-air heat exchanger, homeowners/builders choice.

To build a new home and not put one form or the other in is in my opinion just asking for serious health and structural problems.

A new home is full of building materials that give off VOC's that are unhealthy to breath at sometimes even very low concentrations. Every thing that gets let loose in the home will stay in the home. This includes cooking smells, candle soot, propellant from sprays, carbon dioxide from breathing, chemicals from cleaning chemicals, the list goes on and on. If your home is built tightly like most new homes are these days there is no means for these contaminates to be diluted and/or expelled to the outdoors.

The next thing is that every bit of moisture that is in the home will not have a way to be dilluted. This can cause mold problems in the home on windows, closets and any place the insulation for whatever reason isn't as good as other places.

Find something else to "put off" buying and put in an HRV so that you have full control of your indoor air quality and the health of yourself, your family and your new home.

Well - I have to agree with you, good points.

[larobj63]

ok that's what i thought, thanks for the replies, i am going to get it with the house... now my issue is should i go with the dedicated system or the non dedicated (bypass) one, he explained to me that dedicated is more expensive but it's the best way since it's connected to the bathrooms (not very sure i understand it fully) but maybe you guys understand the difference between the two and if so which one woudl you recommend

thanks

I'm not familiar with his lingo, but have designed a number of HRV set-ups.

HRV's work by exchanging heat from one air stream to another via a heat exchanger. You need four terminations, if you will, as follows:

EA = Stale air exhausted to outside
OA = Fresh air from outside
RA = Stale air from the house
SA = Fresh air to house

The best way to do it, IMO, which sounds like your pricier option, is as follows:

EA = On outside wall exhausting out
OA = On outside wall (not near EA) pulling air in
RA = Pulling air from a full bathroom
SA = supplying air to the return of your furnace/air handler near the furnace

It is wise to exhaust from a bathroom because it "kills two birds with one stone" due to the fact that you need an exhaust fan in a bath anyhow to remove odor and moisture.

It is wise to connect the SA to the return of the furnace for two reasons:

1) the fan in the furnace can mix the fresh air through-out the home threw the duct system, and

2) while this air has gone threw the heat exchanger - it can still be potentially cooler or hotter than waht you would want to dump directly into the home in any one spot. If the heat exchanger were 100% efficient (they are usually around 70%-80%), the SA temp would equal the RA temp. In reality the SA temp will fall short because of the limits of the heat exchanger.

There's the nickle tour of HRV land...

[mrlighturfire]

Minnesota it is code here to install HRV it would never get pass inspectors. Might be code in Canada also not sure though. It is code for new construction I should say but I am having people calling me that has existing homes wanting HRV's.

[teddy bear]

hi all,
we recently bought a new house that will be constructed very soon located in canada (ontario so cold winters) and our builder recommended getting an hrv system. he told us that since nowadays houses are so airtight an hrv would help with the exchange of air flow.

i would like to ask you guys if it's worth it or not? the price is 3500 for the full system and 2100 for a bypass... is this something we need or can we get it later since right now we're on a tight budget.

Thanks

What do you expect as a return on a investment? Fresh air can be simple like a fresh air inlet on a small fan. Your home breathes at some predictable rate. A tight well built home is usually .1-.2 air changes per hour on an average winter day. Most home need .25-.3 ACH when occupied to be healther year around. During the extreme cold weather, your home will probably breathe enougn. During the summer with light winds, expect very little fresh air.
Operating an HRV during extreme cold usually overventilates your home saving nothing. From average winter to mild winter to summer ventilation is needed but saves little money. Carefully matching the operation of a HRV to your home's needs may save a couple hundred dollars a year campared to non heat recovery make-up air fan. The most over looked problem is getting fresh air into a home during the mild weather. Also ventilating during mild weather introduces moisture to the home that must be dealt with. The Northly green grass climates do not have enough cooling load to remove the moisture from the fresh air/occupants. Supplemental dehumidification is a must for In WI (similar weather), I feel that a ventilating dehumidifier is a more complete solution to the fresh air/humidity control problem of the modern home. The original cost is about the same. If return on investment has nothing to do with this get the HRV and a good whole house dehumidifier. Both would be the first class way to go. If limited investment is important, ventilating dehu is more practical. Regards TB

[indep]

Thanks for the detailed answer teddy bear,
for the dehumidifer I was thinking of getting a portable one for the basement to get rid of all the humidity there. I didnt' really think of upstairs and so on since the HRV would take care of that, no?
honestly i am no expert and this has me confused, i just want something that will take care of the fresh air, so from what i understand, i should get something similar to: Ultra-Aire 150H Whole House Ventilating Dehumidifier?