Replace HVAC Systems

Dear Pros,

I have two 2.5 ton HVAC systems (heatpumps) for my 2 story house, which I bought a few yrs back that at are failing and need to be replaced. They are about 14-15 yrs old, RUDD systems. I live in central VA. I have an estimate for $7400.00 for the upstairs unit, a TRANE XL13i, 10 yr warrenty, variable speed, and then another 3K$ for duct work, as the company said the ductwork should be sized for even flow to each room and the flex duct should not be run over large distances. They also wanted to install returns in each room, as there is only one large one in the main hallway. While I am having a hard time swalling the cost, I not sure that the high SEER pays off at this price even if I do like here for the next 20 yrs. I have been told that the ones currently in the house were installed by a gentleman on the side and I can still get that done for what sounds like about 4K$ per system while the "bigger" outfits are in the 7-9K$ ballpark. I am not trying to cut corners, by 17K$ for both units is awful steep. I have spoken to other folks, many of which have the flex line and no returns in their rooms - is this a must now.

All feedback will be welcomed.

 

[CRG]

How long did the existing units last?
What caused the need for replacement instead of repair?
Did the existing units provide you the comfort level that met your expectations when they were working?
Did you get similar estimates from different installers?
Are there code compliant issues with the current installation?

 

The units were installed in 1991, so Approx. 14yrs. I purchased the home in Dec. 2000.
1,2)The drain system and what appears to be part of the condensor unit is rusting out in the upstairs unit (horizontal). The drains clogged at the end of last year and I ended up with water in the ceiling. I think I may be able to get it to operate for a short time longer, but since it has no shuttoff for water level, I am weary of it. The downstairs (vertical) unit has a similar rust problem, I think neither were serviced properly during the first 10 yrs. I have thought about rebuilding them but I have had a difficult time getting parts local due to the age.
3)They are both 2.5 ton, the downstairs unit does fine for heat/cooling. The upstairs has never been able to keep up on either. The emerg. heat comes on all the time, and it cannot maintain 74-75F when it is 90F outside. The insulation in the attic needs to be increased to R30 one company said, as it is only 19 now I think. All of the quoters said that the size is fine for the area, between the insulation and the condition of the compressor, it was in rough shape most said.
4) I have had 4 quotes on the systems, 2 from the bigger, complete, companies in the area, they want 7-8K$ for each system (both Trane), the other two were by local folks that do it on the side, they wanted 8K$ for both systems (Goodman, Carrier).
5) I have not heard that there are are any code issues. Just that to make it "right", the duct work mentioned should be done. One of quoters said that in Jan 06 systems will be required to be 13 CEER minimum. I checked the ACEEE site and they confirm this as well, not sure if it applies to existing homes or not.

 

[CRG]

I would go with the more qualified installers and write a performance specification for the installation. Have the installer guarantee, in writing, that the units they will install meet that performance specification. You may want to have an experienced engineer in your area write this for you unless you are comfortable with all of the details that should be included. Perhaps, someone in this group might be able to post a link with a good residential performance spec for ventilation, heating, and cooling. Then you would only need to change the winter and summer design conditions for your area. Without a detailed performance specification, you risk having the same problems after the installation.

The other route you could pursue is to hire a competent engineer to run a heat loss analysis and create a design for the new system with recommendations for insulation upgrades as required. With a fully developed design in hand, you can get completive bids that are easy to compare.

 

[imok2]

As we say "Knowledge is Power" so arm yourself and read all you can before you meke such a large investment. Go here

http://www.alpinehomeair.com/related/Ductwork.pdf.

As far as I know the SEER requirements are a federal mandate only to the manufacturers, not the homeowner. You should be able to get a lower Seer at a cheaper price from any distributer for at least a year after the higher seer goes into effect. If you ask specific questions I'm sure somebody will give you good food for thought.

 

[lilliput1]

Check into using a gas fired heating and cooling unit instead of heat pumps. Ask for written estimate & get contractors go give their price. Ask for references. Sometimes it is amazing how much price difference you can get. Chech the gas company if they will give $ incentice to convert from heat pump to gas.

 

Thanks for all the insightful comments, it has been a significant help. I will spend a week meeting and discussing with other contractors after reading over the materials and will report back in with the tentative solution arrived at.

 

[friartuck]

Hi FireFIghterVol

You mention the company who suggest putting return air into every room.

Whether you put return air in each space, really depends on a few things.

If we were putting AC into a large supermarket (which is simply a large open space), then sorting out the supply side is the most important consideration.We only put in one return point.

The simplest way to understand this is that you need to force the air into the space and circulate it (getting a good mixing airflow). You can only achieve a good room air mixing by 'jetting' the air in. One colleague once said to me that you can blow out a candle....now try sucking it out. Its almost impossible.
Extract points have virtually nil effect on the airflow pattern in a room.

However, if you put only one extract point in your house, you must make sure that the air path is 'easy' and without obstructions.
Closed doors will allow about 60 l/sec through with relative ease, open doors obviously have no real limits, but check your fire code.

We regularly fit door grilles (with fire dampers) and we get round fire code with that. (This may or may not be acceptable where you are)

If you can get away with it, I would suggest you don't need return air grilles everywhere..this obviously will cut your ductwork costs down significantly.


ciao

Friar Tuck of Sherwood

 

[krb]

In the southeast, I have used the number of $1500-2000 per ton for new construction installation estimates for a complete installation. Given that your job is on an existing residence, the price may be higher. For estimating purposes, the cost of the equipment is roughly $400 per ton.
I would look at doing a heat loss calculation, you can buy software for around $50 online that will let you check one house. It's cheap considering what you are looking at spending. I would also upgrade the insulation in the attic as well. As for long runs of flex, it is not ideal from an aiflow standoint, but I have seen alot of it installed in homes and no noticeable problems. I'd look over the info imok2 mentioned and apply it to your house.
As for who to get do the work, you could go either way. Alot of the mechanics in the place I work have outside businesses installing and maintaining residential HVAC systems. They are competent and qualified. Either way, I would investigate whoever you chose. There are good and bad full time contractors and good and bad part time installers. Good luck.

KRB

 

[KenRad]

I don't think that you have anything to lose by just replacing the units themselves. Sure, it's desirable to limit the amount of flex duct in a house. But unless the existing duct is in bad shape or is undersized for the airflow, it's hard to justify replacing everything. Plus, it's not like this work couldn't be done later. I would inspect the flex, looking for air leaks and tears in the insulation. Look for an R-value printed on it; 6 or above would be a good number.

As was said earlier, additional returns can help in rooms where the return path for the air is blocked. This is common in large rooms with doors that isolate the room from the return. Again, something that can be done later, and something that could be done whether or not you replace all of the other ductwork.

The $7400 just for replacement of the unit upstairs sounds steep to me, but may be typical in your area. The Trane unit proposed is a very good unit.

---KenRad