When is it time to replace a furnace / AC Unit

My recent gas bill has got my mind racing on doing some home improvements, including getting a new furnace. I'm looking for advise on when you know its time to spend the money. I'm in the middle of finishing my basement, so I'm thinking it would be time to replace everything before I box it all in.

My house is 20 years old, all orginal HVAC equipment. We have a two story house with separate systems for each story. One A/C unit has needed freon 2 of the last 3 years. I have had water leaking out of the furnaces before due to a clogged drain, but have been able to clean that out when it happens. Other than that no major issues. My gas and electric bills do seem high, though.

How long is a HVAC system suposed to last? Should I do it now and get the benefits of a more effecient system now or just wait until it breaks down.

Thanks in advance for any advise!!

 

My recent gas bill has got my mind racing on doing some home improvements, including getting a new furnace. I'm looking for advise on when you know its time to spend the money. I'm in the middle of finishing my basement, so I'm thinking it would be time to replace everything before I box it all in.

My house is 20 years old, all orginal HVAC equipment. We have a two story house with separate systems for each story. One A/C unit has needed freon 2 of the last 3 years. I have had water leaking out of the furnaces before due to a clogged drain, but have been able to clean that out when it happens. Other than that no major issues. My gas and electric bills do seem high, though.

How long is a HVAC system suposed to last? Should I do it now and get the benefits of a more effecient system now or just wait until it breaks down.

Thanks in advance for any advise!!

 

If those units are 20 years old then you would do nothing but benifit by replacing them now. You've surpassed the life expectancy of the a/c by about 10 years and if the furnaces are gas fired forced air then you're right at the end of their life.

 

It is a gas forced air system.

Thanks for the advise. Any recommendations on brands, systems, dealers, installers, etc.

 

20 years is pretty good for an HVAC system. where are you located? do you run the a/c or heat more?

 

I'm in St. Louis, Mo... so we run both heat and A/C a good amount each.

 

Most importantly, make sure you get a heat loss and gain calc done.

That said, using properly sized equipment as an example, going from an 80% to a 90% will result in about a 10% savings in gas usage.

Is it worth it?

A dual fuel system (heat pump and gas backup) could eliminate gas consumption for heating when the temperature is above 30 degrees or so. That might be worth looking into.

A variable speed motor can save substantial amounts of electricity year round. That may be a more cost effective upgrade than going from an 80% to a 90%.

There is a payback to high efficiency HVAC equipment, but better windows and insulation may be a better investment.

 

beads

You have reached the end of the average life of a typical gas furnace/AC split system.

As far as replacement,there are several different ways to look at this. If systems are currently operating and giving little to no trouble, then leave them alone until you are faced with a significant repair. Or you could look at replacing these systems with high eff equipment that will save you on operating costs and probaby provide you improved comfort. Any idea of the AFUE efficiency rating of your furnace? I suspect it is in the neighborhood of 65 to 70%. You may want to consider replacing one floor now, another floor next year.

Nat Gas is no longer a value fuel for winter heating and if you have reasonable and stable electric rates, I would look at today's high eff heat pump systems. Danski makes a good suggestion about a dual fuel sytem-high eff heat pump with nat gas furnace backup. These systems are great and they do save $$$. The var speed blowers are a wonderful feature.

I would encourage you to have a Manual J heat/cool load calculation performed for correctly sizing new equipment and also have ductwork inspected for size,condition,insulation properties, etc. Now would be the time to discuss any comfort problems with existing system so dealer can address these issues with the new system.

If you elect to stay with gas, insist upon a 92+ AFUE efficiency rating and a SEER rating for an AC unit of 13-14.If you decide on a heat pump, then a SEER rating of 13-14 for cooling with 9+ HSPF rating for heat.

My Opinion.
Good LucK!

 

Thanks for all the advise. What is the cost differences between heat pump & nat gas up front? If I decided to replace both systems, what ballpark cost am I looking at? $5,000-7,000????

 

The best way to go about it is to get at least three estimates from established dealers in your area. Make sure each one does a heat load/loss calculation to determine the proper size of equipment needed and if size needs adjusted they may need to do a "manual D" to size the duct work.

I lean toward American Standard, but there are several others that would fill the bill just fine. Trane, Rheem, Carrier.

Just remeber that the install is actually more critical than the brand of equipment. So ask your friends and neighbors who they use and trust.