Can I steal basement temperature air without placing increased demand on the furnace?

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Post by Guest »

Here's a word problem I would love to get some practical answers to. My greenhouse is 40 feet from my house. I plan to trench and bury 110 from the house out to the greenhouse.

If I were to also bury a conduit for air with an in line blower, can I steal basement temperature air without placing increased demand on the furnace? Basement stays about 58. Zone 5b.

Post by Victoria »

How cold is the ground and how large of a pipe? You may lose a ton of the heat just trying to get it to the greenhouse.

Post by Mark »

If your furnace/heat pump can handle the extra load. 40 feet is a good distance, but how much farther to your furnace? You'll lose a lot of heat between. You could install an inline fan to help move the hot air, but you'll lose a lot of heat before it even gets to the GH.

Post by Jason »

No. Because the air you remove from the basement will need to be replaced with air pulled from somewhere else. The replacement air will most likely be pulled in from outside therefore dropping the basement or house temp.

Post by Steph »

Maybe you could not run the "air" part of the conduit to the house but vent just outside the house. If you buried it 6 feet deep you would still get the benefit of geothermal heat in winter AND cooling in summer, toward a steady temp of 58 (ground temp) and not stress your furnace at all. You are digging the trench anyway right? Very little extra effort.

Post by Chris »

It would help the GH some, but would slightly cool the house and increase your utility bill, unless you have "free" heat, like a woodstove. Also, as others have indicated, the vent pipe would need to be deep enough to not re-cool the air, and of adequate diameter, to have enough volume to make it worthwhile. IMO, alot of work with little gain.
Research geothermal heating & cooling......if you have the ability to trench deeply, you'd likely need a longer run of pipe, but you wouldn't need it attached to the house.

Post by Heather »

So I asked my Dad who is a plumber/electrician and this was his answer:


So first off. If your pulling/ or pushing air from the house to the green house.

Remember that the air your removing from the house, will

create a negative pressure in the house. So that air your pulling out to the green house will need to be replaced some how. Basically you will

Be pulling in unconditioned sure from outside through cracks around doors and windows. Worst case would be that negative air will create a problem with your gas furnace or water heater being able to vent properly.

The other issue is, that conduit underground. The ground will suck all the heat out of what ever air you pulling through it.

Post by Omar »

Don't like it. Don't like it at all. I had greenhouses attached to the back of my home at basement level. The basement became essentially a 'headhousr'. Even though they had their own zones,the greenhouses could suck the heat from the entire house. I ended up adding insulated doors.

Post by Sonja »

Seems like if you also ran pipe to return greenhouse air to house would address a lot of lost vacuum & heat concerns. As well as gaining gh O2 to house. Still be cold air return but gh temp, not outside.

Post by Mark »

I'd bury a loop of water lines. Very easy and cheap. Whether they connect to a water heater or a boiler, that's way cheaper than other alternatives for heat. If connected to a water heater, one would have to be careful about using materials that are rated for handling potable water.

Post by Jeremy »

If your basement is 58 degrees, compare that to the average ground temperature below the frost line (50-57 degrees is typical)

As Heather Fisk mentioned, you can only create issues tapping into the basement and there is nothing to gain versus just putting tubes into the ground around your greenhouse and piping that in.

Large water tanks are great for storing heat during the day and then transferring it to the air at night.

Ground tubes and in-line fans require an excavator, and the fans need the 110v

We have ~500’ of gaht tubes under our current build, and 700’ additional tubing underground outside of the greenhouse

In-line 6” AC infinity blowers

Too early to tell how it’ll all work, but we’re close to knowing as we’re getting there little by little with a never ending build

Post by Ted »

What you describe put additional load on your furnace. Instead just trench in waterproof ducting below the frost line in a long loop (the longer the better) from the greenhouse and then back into it. Place a duct fan and use this "earth battery" for heating and cooling the greenhouse
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