New Ductwork Not Heating

almostdone

I recently had my furnace replaced with a Carrier 8000 and ran new ductwork to the front of the house. The furnace is amazingly loud, and the new rooms receive little to no heat.

The prior system only had ducts to the rear of the house (covering about 800 of a total 1,900 sf) and the front of the house was uninhabitable in the Winter. We hired a contractor to run vents to the front and replace the gas furnace unit.

The furnace is installed in a laundry off the kitchen, and the cold air return is ducted directly to the furnace through an opening in a rear hall wall. It was so loud when it was first installed that it sounded like a 747 was taking off in the middle of our house.

The new ducts were run individually from the furnace (6" insulated duct) to the individual, ceiling-mounted registers in the front of the house. These new ducts give out paltry air that is meagerly heated.

Our condo is a long rectangle about 26 feet across and 75 feet long with a long central corridor.

Steve Wiggins

Sometimes these jobs go down the wrong way. The customer says I want a new furnace and some ducts added to my new room(s). Contractor says sure, here is my price.

The way it should happen is the customer says here is my situation....the front rooms are too cold what should I do? Then the contractor can recommend a heating solution. He might say you need a return from that new room or even a seperate thermostat on a zone damper etc.. You see we are gun shy to quote the correct solution for fear of not getting the job because of price.

Bjd

Steve I see the same thing all the time, they quote for price and not for needs.
Contractors will replace a system that may be way to small, as the home has been added too and the system was never upgraded. When replacement time comes the contractor will go by the size of the old unit and not take into account that the home may have doubled in size.
Or they will go by " Looks like the job we did last month, lets go with that size unit"
Sizing is a BIG deal and without it you have problems like this.

Bjd

able14

first off the contractor is the profesional and should educate the homeowner I would not install a system knowing that it wont work. I would do a heat loss and gain to see how big a unit you need .its probably big enough since you say it is so noisey the duct work is probably under sized also if those rooms are completly closed off with no return duct you are trying to presurize the room you should have the same amount of return air as supply air how long are the new runs you might have to damper down other registers to force air through them.also you could try installing a fan handler that will run the fan constant at a lower speed to circulate the air and when its calling for heat the fan will run at normal speed. sorry for the spelling and gramar

thom

The noise is a function of the newer style furnaces. Your old furnace probably had a burner that looked similar to the one in your grill. The new one shoots a torch down a tube. I hear the same complaint all the time when people move into a new house. That's the way life is now.

The lack of heat could be something as simple as inadequate return air or something more complicated like inadequate duct sizing or inadequate furnace capacity.

Start first with the return. Run the system with doors open so air can easily flow back to the furnace return from the new rooms.

If that doesn't do it, try damping down the registers in the rooms that are heating to increase flow to the other rooms. Keep in mind that all the "cold" air in those long runs must be pushed out before any warm air gets there.