Exhaust vent distance from Freash Air vent?

[Fisher]

Hello,

We are in need of some advice as we plan to finish our basement.

Home is located in London Ontario and was built in 2005.

We are currently looking at adding a direct vent fireplace to the basement.
Were we would like to place the fireplace there are other vents along that side of the house currently.

We have the HVAC intake and exhaust pipes with the gas hot water heater exhaust pipe. (Note they are the old black PVC pipes - Should I update these to the new code white PVC Pipe?)

The HVAC system also has a freash air vent pulling air into the cold air return located on the same side of the house.

What is the code requirement distance between the HVAC exhaust, Freash Air vent, and gas fireplace exhaust?

Currently there is 15' from the HVAC gas vent exhaust to the fence. The Freash air vent is about 10' away from the current exhaust vents. The future gas fireplace would be about a 1' away from the fence.

See Photo attatched

[Admin]

There is no requirement to upgrade the ABS vent to ULC 636 until either the appliance is replaced, or the vent cracks.  Read the TSSA Q's and A's regarding plastic venting - Here

The fresh air vent should not be installed into the return air duct.

Clause 8.3.1(d) - The duct shall terminate within 1 ft above, and within 2 ft horizontally from, the burner level of the appliance having the largest input.

Clause 8.14.8 states we need 1' clearance from an appliance 100,000 BTU's or less from a fresh air vent, and 3' clearance from an applliance over 100,000 BTU's to a fresh air vent.

You cannot install the fireplace termination within 1' of the fresh air vent, assuming the fireplace is 100,000 BTU's or less.

What is the model of your water heater?  I'm assuming it's a power vent model under 50,000 BTU's.

Clause (8.2.3) - An outdoor air supply shall not be required for a single water heater with an input of 50 000 Btuh or less within an enclosure or structure where there are no other appliances that require an air supply.  Except for direct vent water heaters, when the water heater is contained in an enclosure, permanent openings shall be provided as described in Clause 8.2.6.

It looks like you have a direct vent furnace, in which case no fresh air is required (outdoor air supply).  Also if the water heater is 50,000 BTU's or less it does not require an outdoor air supply.

Following Clause 8.2.3, I would eliminate the fresh air pipe and install your fireplace vent beside it.  Simply stuff the fresh air duct with insulation and replace the outside termination with a closed exhaust vent termination.  Have the installer verify that in fact no outdoor air supply is required in your house.

The black furnace intake pipe must be 3' from your gas meter regulator vent, as per Clause 5.5.9.  It looks close in the picture.  If it is closer than 3', I would get the gas company to extend the regulator vent or install a low flow OPCO regulator.

[Fisher]

Thank you for the advice. We have setup three appointments for a quote on the install of a fireplace we like. They said they would look at the setup and provide ideas of what can be done. I was hoping to do the rough work like moving the vent if needed to keep labour cost to just the install of the fireplace.

The three ABS pipes are just three feet away from the gas meter.

Note the Freash air return is connected to the cold air return to pull in freash air for the house. It was roughed in like that with the option of us adding a HRV system later down the road. Even the duct work is roughed in various rooms.

The furnace has one ABS pipe that draws freash out door air and another that exhusts out. Hot Water heater is just as you noted.

We were told at the fireplace store the vent would be considered a mechanical intake as the furnace fan would draw air in. So it should be 6' away from all exhausts.

[Admin]

Clause 8.3.1 states the fresh air shall terminate beside the burner, not in the return air duct.  If your home needs fresh air then install an HRV.  Use the existing fresh air hole as your exhaust.  If you have room for the HRV fresh air on the wall you would need 6' from the water heater vent and fireplace vent and 10' from the gas meter regulator.  Also we usually need 6' from our HRV exhaust vent.

Pulling cold outdoor air directly into the return air is inefficient.

I would just remove the fresh air.  It doesn't look like it's required in your home.

We were told at the fireplace store the vent would be considered a mechanical intake as the furnace fan would draw air in. So it should be 6' away from all exhausts.

They are incorrect.  Clause 8.14.8 does not consider the furnace intake to be a mechanical air-supply.  Unlike an HRV there is no motor on the intake side.