How can I introduce POSITIVE pressure in Basement?

[Short Circuit]

Hello all, I just sealed up my attic and super-insulated. 4400 sq' home on 2 floors - Rancher style. CFM50=3540 after sealing and insulating. Before work was done, it was >6600.

When hot water heater was smoke tested, it failed under worst conditions of all fans on, bedroom doors closed, furnace fan on. When a basement window was cracked open, the hot water heater drafted. BPI tested stated I needed to introduce positive pressure into basement.

These are the choices I see and I would appreciate the experts on this board to give me your best professional opinion as to how to best solve:

1. Skuttle-type solution. See: http://www.skuttle.com/makeupcontrol.html Specifically D-28-6 item.
2. ERV or HRV which can be configured for positive pressure injection if such a capability exists.
3. Tankless hot water heater.

First item is very cheap. 2nd item is prob 1/2 cost of 3rd item. I know the general costs...

Is there a solution I'm not aware of? What do you all do to solve this problem?

Thanks and MUCH appreciated.

[genduct]

BPI tested stated I needed to introduce positive pressure into basement.
What was their FIX?

[Short Circuit]

The tester gave me the 3 choices I listed. Not totally happy with solution as the first one would introduce cold air into basement in Winter, I presume, with no air/energy exchange. 2nd solution is an unknown because he did not, and I am not - aware of an ERV/HRV which can be set to produce positive pressures in the home. If one exists, I'm all ears. 3rd solution is most costly and I totally understand benefits of going to such a route but I **just** bought a new 50 gallon gas HW heater 6 months ago. Would hate to throw that out unless I really had to.

[bmathews]

Aprilaire makes a product we use. It appears to be very similiar to the first choice. It's a 6" normally closed damper and a controller. It won't open if it's above 100, below 0 or above 55% humidity. It wires into the furnace/air handler to run the blower if the thermostat doesn't have a call. It won't heat or cool the air though. But it is more controlled than a duct to the outside straight into the furnace. It works well in our climate of central texas. We usually only have 2 months of harsh heat and 3 days of harsh cold. The rest of the year we have very nice weather.

[Short Circuit]

Hmmm. I'll check this out right now. Thanks!

[wogpa67]

I use field controls fan in a can for make up air on atmospheric vented appliances

[Short Circuit]

http://www.aprilaire.com/index.php?znfAction=ProductDetails&category=16&item=8126 If this is the product you're talking about, I don't think it world work for me. What I need is controls to open up the duct based on barometric pressure rather than humidity...

[Short Circuit]

I use field controls fan in a can for make up air on atmospheric vented appliances

What product is this? Link??

[genduct]

http://www.tjernlund.com/Tjernlund%20CPC-3%20Submittal%208513016.pdf

Or just strip off everything except the Company name and look around

[dan sw fl]

Hello all, I just sealed up my attic and super-insulated. 4400 sq' home on 2 floors - Rancher style. CFM50=3540 after sealing and insulating. Before work was done, it was >6600.

Is there a solution I'm not aware of? What do you all do to solve this problem?

Thanks and MUCH appreciated.

http://www.rheem.com/products/tank_water_heaters/hybrid_electric/

[Short Circuit]

http://www.tjernlund.com/Tjernlund%20CPC-3%20Submittal%208513016.pdf

Or just strip off everything except the Company name and look around

Genduct, thanks much for this info. I'll call the company and see if they have a product which might fix my issue. Certainly looks like they can guide me to where I need to go.

[Short Circuit]

http://www.rheem.com/products/tank_water_heaters/hybrid_electric/

Dan, no doubt this is a sweet system. Since I already have my 6 month old gas HW heater, I was trying to save it if I could. I'd consider this if I had to get rid of it as a last choice. Thanks for the info however!

Do you install these? If so, are they loud in operation?

[teddy bear]

For green grass climates, I like taking air from the mainfloor with a small 200 cfm blower and pressurizing the basement space. This fan could operate 24/7 for 100 watts.
In for the deluxe install, use a whole house dehumidifier for the fan power and let the dehumidifier keep the basement <50%RH during the spring/summer/fall. This will pressurized the basement with mainfloor air while keeping the entire home <50%RH. Ultra-Aire/Santa Fe with a duct kit.
There is a merv 11 filter included. Also a small amount of fresh air can be added with an occupancy timer. This is important during calm winds and no stack effect to purge indoor pollutans.
Regards TB

[Short Circuit]

For green grass climates, I like taking air from the mainfloor with a small 200 cfm blower and pressurizing the basement space. This fan could operate 24/7 for 100 watts.
In for the deluxe install, use a whole house dehumidifier for the fan power and let the dehumidifier keep the basement <50%RH during the spring/summer/fall. This will pressurized the basement with mainfloor air while keeping the entire home <50%RH. Ultra-Aire/Santa Fe with a duct kit.
There is a merv 11 filter included. Also a small amount of fresh air can be added with an occupancy timer. This is important during calm winds and no stack effect to purge indoor pollutans.
Regards TB

VERY interesting, Teddy Bear. I'll research this option! Thank you. For winter months, how would the Ultra-Aire/Santa Fe w/duct kit operate? I wouldn't want to dehumidify in Winter. Can I operate this unit with fan on, only, and not dehumidifying in winter-mode?

If I introduced more supply, but not return, to the basement area, would that also "solve" a negative pressure basement? TIA.

[teddy bear]

VERY interesting, Teddy Bear. I'll research this option! Thank you. For winter months, how would the Ultra-Aire/Santa Fe w/duct kit operate? I wouldn't want to dehumidify in Winter. Can I operate this unit with fan on, only, and not dehumidifying in winter-mode?

If I introduced more supply, but not return, to the basement area, would that also "solve" a negative pressure basement? TIA.
That is the whole idea. The fan on the dehu will operate 24/7. The dehu only when the %RH is +50%RH. The fresh air damper opens on demand, like on occupancy timer during spring/summer/fall.
Regards TB

[Short Circuit]

That is the whole idea. The fan on the dehu will operate 24/7. The dehu only when the %RH is +50%RH. The fresh air damper opens on demand, like on occupancy timer during spring/summer/fall.
Regards TB

TB, what is the cost to operate a "typical" dehumidifier year-round? Are they designed for 24x7x365 operation, or is there a brand which is built more rugged than the others for this type of purpose?

[teddy bear]

TB, what is the cost to operate a "typical" dehumidifier year-round? Are they designed for 24x7x365 operation, or is there a brand which is built more rugged than the others for this type of purpose?

The fan on a Santa Fe/Ultra-Aire small dehumidifier uses 100 watts. This is 2.5 KW per day. This would be about $7.50 per month or $82 per year at $.10 per KWH. The fans are made for 25/7 operation. The dehumidifier maintaining <50%RH for medium size home is roughly 4 KWh per day for 6 months. Estimate $100 for the dehu part plus the fan operation. This gets you positive pressure on the basement, some fresh air, and dehumidification throughout the home for warm months of the year with $.10 per Kw electricity.
Going with regular residiential dehus may double the operating cost.
Regards TB

[chuckcrj]

Aprilaire makes a product we use. It appears to be very similiar to the first choice. It's a 6" normally closed damper and a controller. It won't open if it's above 100, below 0 or above 55% humidity. It wires into the furnace/air handler to run the blower if the thermostat doesn't have a call. It won't heat or cool the air though. But it is more controlled than a duct to the outside straight into the furnace. It works well in our climate of central texas. We usually only have 2 months of harsh heat and 3 days of harsh cold. The rest of the year we have very nice weather.

So it OK if the water heater spills when its above 100 or below 0????