"powerzoning"

[rj_mitchell]

Went to a customers house for maintenance and opened the blower door. I look through 2 - 14" square holes into his basement. I look and also find an original return on an oposite wall. He tells me he had Power Zoning installed and it helps with more air flow.
Any Knowledge on this?

www.powerzoning.com

BTW Whats up with the pro forums locked?
I have a 4 month old now and haven't been here in a while

[rjm78]

Thats because i have dual names......whoops

[uptrend]

Originally Posted by rj_mitchell

Went to a customers house for maintenance and opened the blower door. I look through 2 - 14" square holes into his basement. I look and also find an original return on an oposite wall. He tells me he had Power Zoning installed and it helps with more air flow.
Any Knowledge on this?

www.powerzoning.com
while

rjm78,
I have a two storey house. The second floor is hot during summer. My basement is cold during winter. During my search for the solution to my problem. I came across powerzoning.com too. Their website does not explain very well how this powezoning works.

But they have a YouTube video that explain everything.
Part 1 --> http://www.youtube.com/watch?v=HVq1rRL7mwU
Part 2 --> http://www.youtube.com/watch?v=MJkO0l1_-PQ
Part 3 --> http://www.youtube.com/watch?v=1TpvOym7to4

Is this make sense to you as a HVAC professional?

The building code said that the air return to the furnace must be 10 ft away from the furnace and the hot water tank to prevent back draft. The new air return in the powerzoning video goes through a wall and is only one to two feet long. But the path for the air to travel around the wall may be 10 ft. Is this a normal practice in the HVAC trade?

[rjm78]

We "the techs" had a long debate over powerzoning and we all concluded that it will not do it's job but also cause safety problems. Do not trust miracle cures.

[gonekuku]

Patented or not, I smell a thermal engineering error. I have nothing else to do today, so I'll do some community service thermal mathmatics to prevent people from wasting their money on this....

From their web site:

Our system is a new innovation that uses the free thermodynamic cooling power of the earth to cool the air and pump the cold air from the basement to the hot rooms in the house.

Fine, you can take advantage of a cold basement. Lets say we have a 1000 sq ft basement, 8 ft tall. Soil temperatures are a large factor.


Summer - Basement walls and floor are insulated to R4
Inside Temp F 75
Soil Temp F 65
Temp Delta F 10
Basement Walls & Floor R-Value 4
Wall & Floor Sq ft 2056
BTU Loss 5140

Summer - Basement walls and floor are insulated to R1.5 (building materials only)
Inside Temp F 75
Soil Temp F 65
Temp Delta F 10
Basement Walls & Floor R-Value 1.5
Wall & Floor Sq ft 2056
BTU Loss 13706.66667

In an older building, you could gain over 1 ton of cooling.

In the winter, our system creates a cozy, warm basement with even temperatures everywhere, so furnaces and heating dollars don’t have to work as hard. The patented process makes it a simple upgrade to an existing furnace in just a few hours

The same homes during the winter using "Power Zoning"

Summer - Basement walls and floor are insulated to R4
Inside Temp F 68
Soil Temp F 55
Temp Delta F 13
Basement Walls & Floor R-Value 4
Wall & Floor Sq ft 2056
BTU Loss 6682

Summer - Basement walls and floor are insulated to R1.5 (building materials only)
Inside Temp F 68
Soil Temp F 55
Temp Delta F 13
Basement Walls & Floor R-Value 1.5
Wall & Floor Sq ft 2056
BTU Loss 17818.66667

Conclusion: During the summer you could gain some cooling from a cool soil, largerly varied by the R-Value of your basement walls and floor; however, during the winter, your thermal losses would be much greater, offsetting any savings during the summer.

Other factors - You would distribute moisture from the soil to the living space. During the summer this would be undesired. If you live in a region with high radon concentrations, you would blow radon through the home, increasing your risk in lung cancer, unless your basemnt was radon proofed.

That's my mathmatical opinion.

[hearthman]

If you suck basement air into the return plenum, you can severely depressurize the basement to the point you backdraft water heaters and Cat.! furnaces or boilers. If you don't provide warm supply air back into the basement, you severely imbalance the house. The high pressure upstairs may tend to drive moisture into the interstitial wall spaces. Meanwhile, the negative pressure in the basement is bringing foul basment air into the rest of the home.

If you cut a large opening into the return plenum, you risk losing the returns at the far end of the system. Therefore, you get air stagnation in the far corners of the house. Conditioned air is being pumped in with mainly passive returns. Not a good setup. The best systems employ balanced venting--period.

Hearthman

[mark beiser]

I watched the whole video. Looks like some slick marketing polish on adding return air and air balancing by closing off supply registers, with a little misguided(for some climate zones) building science tossed in.

I wonder how many heat exchangers and compressors have been killed by his recommendation to close all the vents in the house, except the ones in the problem areas?

Do they measure total system airflow before and after?

[uptrend]

Thank you rjm78, gonekuku and hearthman for your input. Sorry for not giving details of my house in my original post. That is why I got a general answer.

I live in Canada. The basement of newer house has concrete floor. There is no radon gas problem in my area. Most people in my area develop their basement. They put bedrooms and family room in the basement. Some people even rent out their basement. Because of our winter weather, house in Canada is R20 insulated as minimum. There is an outside 6" combustion air duct located next to the furnace and hot water tank. Therefore, the basement is not depressurized. Also, there is fresh air duct coming into the return plenum. Therefore, fresh air is always mixed with the air from the house to be heated by the furnace.

I have concern on a point that hearthman pointed out. By the law of physics, air flow uses the path of least resistant. Therefore, the new 10 ft powerzoning duct is the least resistant path. Air from the second floor may not be sucked back down to the furnace at the basement.

My main object is to have even temperature in all three level especially during the winter.

Last year, I have installed motorized damper on the combustion air and the fresh air ducts to prevent cold winter air from coming into my basement 24/7. The combustion air damper has limited switch feed back to the furnace. If the combustion air damper does not open, it will prevent the furnace from firing. I run my fan continuously. The fresh air damper will open during the furnace heat cycle. This will prevent the fresh cold air from pumped in after the heat cycle. This does not improve basement temperature that much.

I followed the instruction from the video by closing all registers for 24 hours. Then, open only the registers in rooms that need more heat. Now my basement temperature is only 2 deg C lower than the upper floors without adding the new air return to the furnace. All rooms in the main floor and the second floor are the same. Hoping this simple adjustment will continue to work when winter sets in a couple of months.

The video said most of the furnace are choking of air. How can I increase air flow without adding the extra return air duct to the furnace in order to get the power blending effect discussed in the video? My furnace is rated 110,000 BTUh and is 80% efficient.

Any suggestion that I can use to talk to my heating contractor intelligently. I like to eliminate the 2 degree C different between the basement and the upper floors. I like to know what works and what does not. I do not want to waste money on things like the damper. The damper may save my energy bill but I still have a cold basement!

[markf57]

What type of device was the guy using to measure airflow at the registers?

[elkhvac]

The most ignorant statement made in the video was that the furnace has a pressure safety switch so negative pressure situation will not occur. Of course there is no safety switch to save your ass when the water heater back drafts. Then he says code officials and other contractors don't know what we are talking about. That is a law suit waiting to happed.

Mark--Vane anemometer