Using attic heat to warm up basement

[buffalobillpatrick]

Sorry, I thought that I read somewhere in this thread about plastic covering vents?
BBP

[Xringer]

Originally Posted by buffalobillpatrick

Sorry, I thought that I read somewhere in this thread about plastic covering vents?
BBP

From above:
"I do have the new ridge vent obstructed about 3 or 4 feet on either side of the air intake in the peak..
Otherwise, I end up pulling cold outdoor air into the basement.. "

Found it.. Up in Post #19 above, I posted:
"I just took some plastic shopping bags up and stuffed them into the slots in the attic peak.
Got 3 or 4 feet blocked off on each side of the intake.. Might help a bit.."


My air intake seems to have been sucking cold outdoor air right thru the ridge vent.
Now that the area around the in-take has been blocked, warm air can accumulate, and be pumped down to the basement.

I might remove the plastic bags during the hot summer (if that ever happens)..
So that 140F air isn't pumped down..

If the air up there gets too hot, and over-heats my basement, I will re-write the program
to limit the max temp of the basement.
I can also change the time-of-day limits and allow night operation
and only use the min/max temperature limits, and max relative humidity limit.

[buffalobillpatrick]

So in my mini-attic situation, I would probably suck in too much outside air thru ridge vent?

BBP

[Xringer]

If your air intake is close to the peak, it will create a low-pressure area, right under the ridge vent.
Especially if other air sources (vents) aren't close enough to the low-pressure
area to normalize the pressure.

The amount of outdoor air pulled in, will depend on the type of ridge vent.
If it's designed for a lot of flow thru, back-wards flow will happen.

That might not be good during a windy rain storm.
Make sure you have a humidity sensor on your blower control hardware.

My ridge vent is 40 feet long, so the blockage is a small percentage of the total.

I've never had any moisture problems in the attic, during the 35 years,
before we had the ridge vent installed..
So, I could block up a lot more of the vent if I really needed to.

Anyways, you can use sensors and tell if back-wards flow is occurring.
If the sensor near the vent shows 70F air, but 60F air is being pumped down,
there is cold air mixing going on.
After I plugged up the ridge vent close to the intake,
the heat of the air being pumped down, was the same as the peak sensors were showing.

[Xringer]

After a few days of cold rain, the sun is out!!



That's more like it!!

Since it's so damp in the basement (sump pumps are running),
I set the differential to 5F.. It's now back to 20F..

The basement air temp is up 4 deg F, since this morning..

I've got the logging started..

The hot water tank sensor is now showing 125.9 F up from about 90 this morning..
That PV is working nicely right now.. Running about 1200 watts.

[Xringer]

Temperature Sensors

1. 57.3 F Basement air temp
2. 119.1 F H2O tank
3. 52.8 F Outdoors
4. 80.6 F Attic
5. 70.1 F Living Room
6. 52.1 F Oil burner ~ Basement floor temp


That oil burner temperature is at 52.1, because it's got an HX coil inside
that cools down the water-jacket (76 gallon), every time we use hotwater.



So, the actual basement slab temp is about 52.1F, or ground water temp.
Since the current water table is only about 2 feet below the slab.

It's kinda nice to see it's warmer in the basement, than it is outdoors..
We are moving in the right direction.. Towards a warm dry basement work shop!

[Xringer]

In the warmest part of the day, on the basement stairs it's HOT!
However, even if it's 80F on the stairs, the over-all basement temp
isn't going up that much..
But it is going up.. Yesterday it was 57F and this morning it's 57F..
That means the thermal mass is finally warming up..

The blowers are running a lot during the day and the Radon alarms
have stopped beeping. (High counts may have been caused by high water table).

Since the A7 (ASHP DHW heater) isn't dehumidifying the basement very much,
it's good to have warm dry air down there every sunny day.

The blowers are using a lot less power than a dehumidifier.

[Xringer]

At 22:00 it's cooling off and the rain is moving in.. (72% RH)

Temperature Sensors

1. 67.8 F Basement air temp
2. 129.7 F H2O tank
3. 64.9 F Outdoors
4. 77.5 F Attic
5. 76.2 F Living Room
6. 62.7 F Oil burner ~ Basement floor temp


It was great to see the air temp in the basement at 7.3 deg F higher than the ground water (slab) temp..
Actually very comfy down there today.
Radon level is low too..

[Daox]

Cool stuff. I just unplugged my attic heat fan last week due to warm enough ambient temps.

[Xringer]

I want the basement to be warm, at least in the mid 70s. I want to keep it dry too.
Pumping down warm dry air is my goal for the summer.

But, trying to use the basement stairway as a duct isn't working real well.
Yesterday, the air at the top of the stairs was over 100F..
Not enough is being pulled downstairs into the basement.

If I had been able to install a 6" duct between attic and basement,
it would have worked a lot better than it is now.

Lately, I've been running a large floor fan during the sunny part of the day,
to blast the stairway with cool air from the basement.
That keeps it from getting too hot at the top of the stairs.

At least, I'm running the floor fan off solar PV power, so no money is going to NStar..