Grille on return plenum

[Mark Nicholet]

Any issue with return grill on return plenum? I know it is not allowed for combustible furnaces. This is interior of condensor/evaporator for heat pump. I am thinking that if this grille is open it will not pull as much air from the return grilles through-out the home.

[cbottger]

[quote=mnicholet;430716]Any issue with return grill on return plenum? I know it is not allowed for combustible furnaces. This is interior of condensor/evaporator for heat pump. I am thinking that if this grille is open it will not pull as much air from the return grilles through-out the home.[/quote]

Your thinking would be correct the blower will draw from the path of least resistance. It appears to me that the furnace is located in a basement is this correct. Most every basement That I know of has a musty smell that I would not want distribuited through out my home. If there are no gas combustibles appliances within ten feet of the furnace one cannot get into a code fight over this. Its just a dumb install IMHO

[Brian A. MacNeish]

[quote=cbottger;430749]

Originally Posted by mnicholet

Any issue with return grill on return plenum? I know it is not allowed for combustible furnaces. This is interior of condensor/evaporator for heat pump. I am thinking that if this grille is open it will not pull as much air from the return grilles through-out the home.[/quote]

Your thinking would be correct the blower will draw from the path of least resistance. It appears to me that the furnace is located in a basement is this correct. Most every basement That I know of has a musty smell that I would not want distribuited through out my home. If there are no gas combustibles appliances within ten feet of the furnace one cannot get into a code fight over this. Its just a dumb install IMHO

Mark:

The red is a US requirement.

It is a dumb location for a return grille unless they are trying to use the AC (if it is a reversing HP/AC) for summer basment/crawlspace dehumidification. Depending on summer conditions and the amount of AC needed in your area, it may be better/cheaper to use a dehumidifier in an unfinished crawlspace.

[Marcel Gratton]

[quote=Brian A. MacNeish;430874]

Originally Posted by cbottger

It is a dumb location for a return grille unless they are trying to use the AC (if it is a reversing HP/AC) for summer basment/crawlspace dehumidification. Depending on summer conditions and the amount of AC needed in your area, it may be better/cheaper to use a dehumidifier in an unfinished crawlspace.

There is nothing unsafe about the location of this return; my only concern is that it appears too large.

Brian,

Wouldn't adding a dehumidifier in this situation result in more energy being used as opposed to having a *Reversing/HP/AC* unit properly balanced.

My thoughts only,

[Brian A. MacNeish]

[quote=mgratton;430936]

Originally Posted by Brian A. MacNeish

There is nothing unsafe about the location of this return; my only concern is that it appears too large.

Brian,

Wouldn't adding a dehumidifier in this situation result in more energy being used as opposed to having a *Reversing/HP/AC* unit properly balanced.

My thoughts only,

Marcel:

Just lost 3 paragraphs to cyberspace on why I think the dehumidifier was the better choice in this crawlspace situation. In general, it may or may not cost a bit more but IMO, it will do a better job as a dedicated unit than the general HP/AC system.