Heating my home with grow room exhaust?

J

Jay Dubs

Member
I once heard someone mention heating their home with exhausted grow room air, and i just blew it off as over complicating things. Now that i have recieved my second light bill over $300(without growing!), i have had a change of heart. I know it's the heat pump, because in the hottest month last year the bill was less than $175.

There is an a/c floor vent near the wall in my g-room, i had planned on just covering it, but i was thinking about exhausting my air into it during the cold season. All of the ducting is under the floor in the crawl space, if that makes a difference.

If you have heard of, or have done this, please let me know what issues you have had and what you did to solve them.

Jdubs
 
B

BYLROY

Member
I don't heat my whole house with my exhaust, but I do heat 2 or my rooms. My veg room is right next to my roommate's room, so I removed the ducting from both of the rooms' registers and installed a 6" inline fan right above my veg room and have it blowing air through his register. Same deal for my bedroom and flower room. The original ducting is still in place, so I can pop it back on at any time.
 
abe supercro

abe supercro

Well-Known Member
increased humidity and smell from this exhaust can create concerns in the living areas of your home.
in addition, visually, water may accumulate on windows and be an external indicator for unwanted eyes.
h2o can run down windows and create water damage particularly w/ wooden sills.
really depends on volume of h2o in yer setup.

a carbon filter or two may be needed to remediate smell from gro. still a great idea!
 
ExDex1x1

ExDex1x1

Active Member
Just make sure you're not venting into one of your return ducts or you're just running hot air into your furnace which wont do jack for you.
 
tat2ue

tat2ue

Well-Known Member
I have 6 x 600w in cool tubes in my flower room that help heat my home during winter. I have the cool tubes vented into my attic and during the winter I tap it into my central units main duct and exhaust my cool tubes in it. It helps out on the bill quite a bit these last two years.
 
legallyflying

legallyflying

Well-Known Member
abe supercro said:
increased humidity and smell from this exhaust can create concerns in the living areas of your home.
in addition, visually, water may accumulate on windows and be an external indicator for unwanted eyes.
h2o can run down windows and create water damage particularly w/ wooden sills.
really depends on volume of h2o in yer setup.

a carbon filter or two may be needed to remediate smell from gro. still a great idea!
Click to expand...

If your using an AC hood set-up and the intake is not within the grow space, none of these concerns are an issue. I heat the back three rooms of my house with exhaust air. Kind of silly to just exhaust money out into the cold :(
 
Dradden

Dradden

Well-Known Member
legallyflying said:
If your using an AC hood set-up and the intake is not within the grow space, none of these concerns are an issue. I heat the back three rooms of my house with exhaust air. Kind of silly to just exhaust money out into the cold :(
Click to expand...
Also if you exhaust back into the house rather than inside you don't create negative pressure inside the house. This makes a big difference especially in the winter. Your taking huge amounts of warm air that you already paid to heat and blowing it outside. In order to maintain pressure air is going to be sucked in from outside through every tiny little crack and hole. This makes a huge difference on your heating bill.
 
flamdrags420

flamdrags420

Well-Known Member
ExDex1x1 said:
Just make sure you're not venting into one of your return ducts or you're just running hot air into your furnace which wont do jack for you.
Click to expand...
Why would this be so bad? Wont the hot air just eventually get fed back into the system and at some point be spit back into the house?
 
abe supercro

abe supercro

Well-Known Member
flamdrags420 said:
Why would this be so bad? Wont the hot air just eventually get fed back into the system and at some point be spit back into the house?
Click to expand...
if u mess w/ the cold air return or furnace exhaust (back pressure) it is possible for the furnace to not cool properly and a fire hazard could result.
 
seasmoke

seasmoke

Active Member
yes, you can but keep in mind, that hot air is full of moisture. that causes problems....do it, but buy a dehumidifier to clear the moisture....it also gives off heat as a byproduct....and clean water...
 
J

jaded1958

Member
ExDex1x1 said:
Just make sure you're not venting into one of your return ducts or you're just running hot air into your furnace which wont do jack for you.
Click to expand...
This statement is incorrect.

I leave my furnace fan running 24/7 .... Why?

In the summer I close the basement vents (Cold air is heavier and migrates to lower level)
The furnace fan sucks cold air from lower level via the cold air returns and distributes it evenly throughout the house.
In the winter I open the basement heating vents.
The furnace fan sucks heat from the upper area via the cold air returns and distributes it evenly throughout the house.

By leaving the furnace fan on, while routing your filtered exhaust air from room, & lights into the cold air return, the heated air will be drawn into your furnace chamber then distributed evenly throughout the home. (Cut a piece of 3/8 plywood larger than vent, cut a hole in it and mount a flange to accept your vent hose. Seal this over your cold air return vent to prevent any unfiltered air from entering the cold air return.)

The little electricity it uses is offset by the A/C or Furnace not running as often due to a more even distribution of the heat throughout the home.

In a cold winter climate humidity is usually low so a little moisture coming from room will augment your humidifier. (I live in an arid area and my room humidity seldom exceeds 35%
(Because I draw air from inside the home I can regulate humidity via the furnace humidifier.)

If your winter consists of mostly rain then you may have to run an external dehumidifier in your room, or possibly your furnace already has a built in dehumidifier.

In the summer, I seal off the cold air return and vent the room and grow tube exhaust (still filtered to remain completely incognito) into the sewer line. Cold air is drawn into the room via the forced A/C vent as well as through a secondary passive vent that pulls the 72 degree temp air from the lower level.

If your winter consists of mostly rain then you may have to run an external dehumidifier in your room, or possibly your furnace already has a built in dehumidifier.

In the event of a winter power outage it would be a good idea to install an in-line back flow valve to prevent your house from filling with unfiltered grow room air. I am thinking of installing a 12V inline exhaust fan and diverter valve just in case of such an emergency. It may even be possible to use a relays that automatically turn on the auxiliary fan and open the diverter valve.
 
J

jaded1958

Member
flamdrags420 said:
good to know. I don't know a lot about heaters.
Click to expand...
I disagree.

The warm air you are feeding the cold air return is not going to affect the operation or safety of your furnace. The term "back pressure" would only result from forcing hot air into a rooftop exhaust vent.
The portion of the heating system through which this circulating heated air travels is entirely separate from the portion of the heating system in which combustion takes place and through which the combustion by-products are vented from your home.

The heated air from your exhaust vent will not build up any significant pressure because A it is entering a much larger duct. B. Traveling for some distance before it reaches the circulation chamber. It will then travel through your furnace fan will be distributed amongst the myriad of heating vents. If this return air was traveling faster than the furnace fan is sucking, (not possible) it will only lessen the load on the fan motor.
 
cues

cues

Well-Known Member
One added advantage is surely not being so obvious to the police choppers by blowing hot air outside.
 
Phaeton

Phaeton

Active Member
This is the third day in a row of minus 35 or colder, another week is predicted.

Early afternoon, almost the middle of the 'lights on' cycle, the furnace has not come on since the budroom's 5000 watts worth of electric heat kicked in.

I do this every year, reroute the heat for winter. I have it pretty easy up here, judging from all the problems getting posted from elsewhere.

1000 square foot house, easy to heat.
Zero percent humidity, plant moisture can only help that, not overcome it.
No smelly neighbors, suck the cold air off the floor and replace it with hot air from above.
Leave the fans on with the furnace at night to prevent temperature gradient when minus 10 and colder.

Straight cold without annoying additives, fairly simple target where I'm at, and I don't feel your pain, it's 35 stinking degrees below zero!
 
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