Fresh Air Intake W/O A Fan

Fred Almeida

I have a 130,000 BTU gas hydronic boiler, a 40 gal. gas water heater and a gas clothes dryer all in a utility room that's in the lower level of a new raised ranch. The boiler sooted up in the first year and nearly burned all the control wiring from flame roll out.

There's an integral 2 car garage that absorbs a large portion of the lower level area leaving inadequate adjacent room area for combustion air.

I have used the Fields "Fan In A Drum" in basements, but this situation may most likely cause a complaint due to noise and cold air.

I'm thinking of fabricating a motorized wall damper that will open and close with the burner circuit.

Has anyone done this before? Is there something out there rather than recreating the wheel?

bigugh_4

End switch?

If you did as you propose, you would need an end switch that would control the burners on the gas appliances such that a call for heat from any one of the units would then open the damper, and the damper end switch would then allow the unit to light. That way the system is redundant for operating only when fresh air is avaliable. Otherwise enclose the room tight. then install two Fresh air vents one near the cieling, and one near the floor open to the atmosphere outside, and have a combined openings for 1 sq. inch, for each 2000 BTU's, be sure to discount any registers that may be placed over the openings (animal and bug proofing).

Fred Almeida

Thanks for the info regarding the end switch, that only makes sense. I can't seal the room tight because it's a Utility/Laundry Room. This is why I expect a complaint from the noise and the cold draft from the Fields unit.

I'm wondering if there's a simple motorized louver wall vent with an end switch to tie into the burner circuit.

Weezbo

my thinking goes like this...

get rid of the gas dryer in the lower mech room area , change the gas water heater out for an indirect, seal the room from the residential.just like an outside wall. Passive make up air for your kind of boiler i think is best.

I type slow *~/:)


as an add on, the reason to consider the ideas that i mentioned is the new addition will likely have controled ventilation requirements ,and while there are a variety of ways to make certain determinations to size a means to balance pressure inside your home relative to outside, brings in other variables worthy of consideration.

in many instances , there is a minimum static air of 5 pascals, all of these minor technicalities vere one away from hacking a couple holes in a wall and calling it good. there really is some consideration to motorized schemes inside the mechanical room,they need safety lock outs and cannot be some By pass louver that you manually come over and crank wider on a whim. from what i have seen i particularily dislike dryers in a mechanical room. Clothes being moved all around the floor produces lint that finds its way into the combustion process of the boiler much in the same way Sheet rock dust and paint drift into the equasion during construction which then in turn requires to re clean the boiler after already setting the the burn to it cleanest most efficent operational parameters. Day to day useage is then someting that seems to blow by the habby homeowner who either never had the combustion air requirements explained in detatil to them or never seemed to hear the part about having the boiler checked at least once a year. I can probably ffind many people who say Yah Buh you can balance the combustion process with other appliances in the room provided you meet the code requirements for make up air for that appliance...well,i would like to haul them over to the home a few months later when....

Steve_35

You're talking about a BIG hole in their wall.

You've got about 185,000btuh input. That requires about 62 sq in free area with a single opening to the outside.

Tjernlund makes a unit as well. It may be quieter than the Field. Tjernlun Combustion Air Inforcer

Steve_35

You're talking about a BIG hole in their wall.

You've got about 185,000btuh input. That requires about 62 sq in free area with a single opening to the outside.

Tjernlund makes a unit as well. It may be quieter than the Field. Tjernlun d Combustion Air Inforcer

Steve_35

You're talking about a BIG hole in their wall.

You've got about 185,000btuh input. That requires about 62 sq in free area with a single opening to the outside.

Tjernlund makes a unit as well. It may be quieter than the Field. Tjernlund Combustion Air Inforcer

Brad White_6

Combustion Air

is not optional...
I know you said without a fan, but sometimes you just have to do what you have to do. If you follow NFPA-54 (ANSI Z223.1) for combustion air and you are ducting laterally not directly into the room, you need one "clear" square inch of free area for each 2,000 BTUH input. If directly in or vertical you can use a 1:4000 ratio. I take this as being the same total number high and the same low (within 12 inches of the ceiling/floor respectively), not divided among both. Just to be clear on the origin of the requirements in the other posting.

The fan-powered systems I like to specify (the Tjernlund one posted here is new and simple it seems) are the kind that work on a variable speed principle. They strive to maintain a positive pressure in the appliance room and vary the airflow to do that. A company called "Exhausto" in Atlanta, GA makes a nice line of draft inducers, dryer vent boosters and combustion air devices using VFD technology.

I think Tjernlund also has such a device; the one posted here I cannot tell if it has variable flow, perhaps it does.

Simple concept and draws in only what is needed to maintain oh, say 0.05" WG positive pressure in the enclosure. As more appliances come on and off, it speeds up/down respectively.

It has an interlock relay such that if flow/draft is not established the appliances are locked out. Of course if atmostpheric with a standing pilot that is not an option.

I suppose you could make such a device/system but at more cost and it would not be UL or ETL listed...

Hope this helps,

Brad

Todd_12

Dryers

Does anyone make a dryer with direct outside makeup air? I see way too many boilers in the laundry room(or laundries in the boiler room!) This seems like a no-brainer for tight homes/rooms, plus clothes would smell like fresh outdoor air!