Skip to main content
21 votes
Accepted

Water heater exhausting inside house

What you've described is a very serious carbon monoxide hazard called chimney backdraft. You likely need to explicitly provide a fresh air intake so that chimney stack can work properly. That water ...
MonkeyZeus's user avatar
  • 16.7k
12 votes

Water heater exhausting inside house

Proper venting of a gas appliance should have nothing to do with the temperature indoors or out: the exhaust gas is hotter than either of those. It should naturally rise (draft) up the chimney (or &...
Greg Hill's user avatar
  • 31.3k
6 votes
Accepted

Direct stove/kitchen exhaust into kitchen sink drain

No. Your traps need to have water in them to prevent sewer gasses from getting into your home. If your vent "seal" was strong enough, you could "clear" the trap allowing gas into the home. Flammable, ...
noybman's user avatar
  • 2,025
5 votes
Accepted

Will a 4", 100CFM bathroom exhaust fan work with 3" exhaust duct?

Yes it will work. There are many different types of 4" to 3" reducers that will work with your fan. You will have to match one to the material of your vent and the duct. Below is a picture ...
JACK's user avatar
  • 82.3k
5 votes
Accepted

Is a 6" Hole through a 10" Rim Joist ok?

Yes you can drill your rim joist. The floor joists tie into it but really the rim joist is helping the floor joists resist twisting. The exterior wall has bottom plates that span the floor joists so ...
Fresh Codemonger's user avatar
5 votes

Replacing a compact fluorescent bulb in a bathroom exhaust fan with an LED bulb?

Regarding your specific question: the bulb itself will be rated for enclosed operation if it is capable of such. Most high-wattage LED bulbs are not rated for enclosed operation.
KMJ's user avatar
  • 12.1k
5 votes

Replacing a compact fluorescent bulb in a bathroom exhaust fan with an LED bulb?

If it is truly a compact fluorescent then there is no separate ballast, no rewiring, and this is a simple bulb replacement. How can you tell? If the bulb unscrews to expose an Edison base, has a large ...
manassehkatz-Moving 2 Codidact's user avatar
5 votes

Furnace Exhaust Flue Behind A/C

The outside unit does not interact with your inside air, Instead it compresses and condenses a refrigerant after which the liquid refrigerant gets pushed to the inside air handler where it is made to ...
ratchet freak's user avatar
3 votes

Size of insulated flex hose needed to install for bathroom exhaust?

Either follow "just about stright" to use hard smooth duct at 4", or figure the reason the builders used 5" was that increased size somewhat compensates for flex duct having ...
Ecnerwal's user avatar
  • 220k
3 votes

Will a 4", 100CFM bathroom exhaust fan work with 3" exhaust duct?

The less of the smaller-sized duct you have, the better - so run 4" as far as possible before reducing to 3" for the wall penetration - that reduces the extent of the friction loss from ...
Ecnerwal's user avatar
  • 220k
3 votes

Exhaust Fan Runs With No Power at All!

Some furnaces have more than one breaker Well, most honestly. The Air Conditioning unit has a breaker If present, electric heating elements (e.g. emergency heat) have one or more breakers The ...
Harper - Reinstate Monica's user avatar
3 votes

Bathroom fan too loud

Unfortunately the quietness is often determined by the air restriction. Yes a poorly made fan can rattle or the motor can hum or buzz but even the best fans with no hum no rattle no buzz can still ...
Joe Fala's user avatar
  • 6,374
3 votes

moisture problems in a 104 sq ft bathroom with 110 cfm fan

It is very possible that the termination of the duct work out a wall or on the roof is clogged or blocked. If you can reach it safely, check that any screen is open and free from lint, debris or ...
RMDman's user avatar
  • 32.5k
3 votes

Why does my bathroom exhaust fan blow downward?

It is installed incorrectly. Whether it is an electrical connection or incorrect positioning of the motor we cannot tell without any pics. A guess with high probability is that you installed the ...
RMDman's user avatar
  • 32.5k
2 votes

Move rangehood fan inline

This is done all the time. Just make sure you get one that is approved for range hoods. They do make some considerations for the grease. For a typical home system grease is generally of little concern....
user76730's user avatar
  • 1,616
2 votes

Move rangehood fan inline

Grease isn't any more of a concern than it is now if the existing traps remain in place. If it was, the original fan would also be in jeopardy. Airflow isn't really a concern, either. The original ...
isherwood's user avatar
  • 141k
2 votes
Accepted

Draft coming out of water heater vent intake

Yes terminating down is a code requirement. It'll be more problematic if it's windy for a few days and you can't get hot water because its pressure switch continually trips.
Joe Fala's user avatar
  • 6,374
2 votes

Cutting out existing steel duct in bathroom vent

One way to cut away the excess metal would be to use a rotary Dremel type tool with abrasive cutoff wheels. This method allows the metal to be removed without bending and deformation that other ...
Michael Karas's user avatar
  • 65.2k
2 votes

How can I prevent cold air from dropping down my bath fan duct?

I am going to answer this even though i should probably wait for more information. Bathroom, and dryer vent, outlet caps that exit a wall are generally attached to the exterior wall with screws, one ...
Alaska Man's user avatar
  • 13.6k
2 votes

How can I prevent cold air from dropping down my bath fan duct?

You could replace the soffit vent with one that has a flap to prevent air coming inside, maybe something like that. But if it's on the second floor, you'll need a tall enough ladder. Or you could ...
bobflux's user avatar
  • 10.1k
2 votes

Furnace Exhaust Flue Behind A/C

There are two concerns: Combustion Products - CO, CO2, particulates The outdoor A/C unit is sealed, so none of this can get into the house, and none of this will, under any reasonably anticipated ...
manassehkatz-Moving 2 Codidact's user avatar
1 vote

Hvac damper types - which one is quietest

Adding a damper to a squirrel cage blower either to the inlet or outlet may sometimes increase the noise due to the flow of air past that damper. Other ideas which may work better but will cost more ...
d.george's user avatar
  • 12.4k
1 vote
Accepted

Size of insulated flex hose needed to install for bathroom exhaust?

110 cm fan requires 5" by code and manufacturer's standards. I think you can possibly go up to 4" at 100 cm if you use rigid duct and it is a relatively short distance - probably 4-8' at ...
DMoore's user avatar
  • 49.2k
1 vote

Size of insulated flex hose needed to install for bathroom exhaust?

In HVAC an 8" insulated flex duct is equivalent to a 6" hard pipe so they maybe compensated for flex. Check the install manual for your bathroom fan exhaust and proceed accordingly. Do you ...
MonkeyZeus's user avatar
  • 16.7k
1 vote

Outside cap for exhaust fan

I have two bath fans that are the inline style, 1 for each bathroom. one fan is 4" solid duct end to end, the more powerful uses a 6" solid duct end to end. From the vent side in the ...
achao's user avatar
  • 379
1 vote

How can I prevent cold air from dropping down my bath fan duct?

You can try to find an outlet with spring-loaded flaps. (Sounds like you already have one for the kitchen vent.) Or, extend the outlet with a 90-degree elbow. That way the end will be facing sideways, ...
Mike Baranczak's user avatar
1 vote

Venting Two Bathroom Fans to Single Roof Vent

on/off at the same time Problem ?: NO. No problem with having two fixtures on the same switch. As long as the combined amp ratings of the fans (and anything else on the same circuit) is below the amp ...
Alaska Man's user avatar
  • 13.6k
1 vote

Combine two bathroom exhaust vents?

There are some companies that make zoned bath ventilation systems if you need such precise control. One fan unit, multiple register units at each location that has a damper control at the register. ...
achao's user avatar
  • 379
1 vote

Vibrating PVC exhaust pipe from high efficiency furnace

A couple of things- if it's started vibrating... you might have had a rodent or bug intrusion. That would create a 'dead zone' where air has to rush around (probably in the 3" section). The exhaust ...
J.Hirsch's user avatar
  • 543
1 vote

Could clogged exhaust cause codes 13/33 on my furnace, and how do I check and clear?

Try using a stiff wire to probe the exhaust, a hook on the end may able to pull something out if you find anything. Possibly an animal crawled in and died. I had a bird build a nest in a chimney flue;...
blacksmith37's user avatar
  • 8,321

Only top scored, non community-wiki answers of a minimum length are eligible