Replacing Furnace and AC
I've decided to take advantage of the soon to expire tax credit and replace my furnace and AC. The AC is the original unit from when the house was built 27 years ago (3 Ton). To qualify for a local utility rebate a contractor recently did a test on the unit and concluded it's operating at 7.8 EER (after adding a lb of Freon). My furnace is an 8 year old Frigidaire 80% AFUE. While it's not nearing the end of its life, I want to replace it with a more efficient unit.
I've had several contractors out to give me bids. Those that didn't do a load calculation I won't consider. I've had three perform load calculations, but how does a layman know whether a load calculation was done properly? I've had two contractors tell me I need a 4 Ton AC unit even though my current unit is a 3 Ton.
The general consensus between the contractors is that I'd be happiest with a heat pump and a variable speed, two stage furnace. My lists of priorities, in order, are: apply for the tax credit, lower utility bills, and increase comfortability (especially in two upstairs bedrooms).
The one bid I've received so far is the following:
York YP9C Furnace
York YHJF Heat Pump
Is York a decent brand? I really have no idea since there doesn't seem to be a lot of manufacturer comparison information on the web.
The one contractor that I received a bid from is at a great price (I think), but I have concerns about the company since it's an electrician company that recently decided to expand into the HVAC business. The reviews I've read about the company are all good, but they're all for electrical work.
A little extra info if it helps: I live in the Kansas City area. My house is two stories with a total of about 2000 sqft. All windows are double pane.
Any advice is appreciated.
York makes good equipment.
4 ton for 2000 sq ft in KC sounds a bit excessive. We are almost as hot as you guys in the summer and we've got 2000 sq ft 2 story homes cooling fine on 2.5 ton. Other consideration is the duct system. Most are borderline or too small for what you have. Go 33% larger in cooling capacity and you better be adding at least that much to the duct system. Which I bet they aren't. Also, bigger unit will cool the downstairs faster leaving the upstairs even hotter! Do you want that?
Does a duct system with 1600 cfm capacity sound reasonable for a 4 ton AC?
Originally Posted by BaldLoonie
I was told that if a 4 ton is too much on days when it's not too hot, they can simply turn down the blower speed.
If you are taking out a 3 ton unit, odds are your duct system is sized for 1200 CFM. Or in our experience, probably even less. So if you are going 33% bigger, better plan on adding 33% more capacity to the duct system or you can have noise issues. Like living in a wind tunnel. Or if you have a 100K 95% furnace that can't move enough air, plan on limit failures leaving you without heat. That furnace will also want to move around 1600 CFM and even with variable speed blower, probably won't with your existing duct system.
Lowering the blower speed is not a solution to an oversized A/C!
Have you had trouble keeping the house cool in 100° weather with the 3 ton? And I mean downstairs, upstairs on the same system will always be hotter. And as I said in my previous post, going bigger tends to make the upstairs even hotter and the whole house more humid. The unit runs less, cools the downstairs quicker, shuts off leaving the upstairs warmer and dehumidifies less.
When I first started selling, had a guy wanting bigger than his 3 ton for a 2300 sq ft on a basement. Upstairs too warm. So I put in a 2.5 ton. He let me, skeptical but he did. Afterwards he agreed his house was more comfortable due to the long run times making temps more even between the floors. I only downsize when my load calc says I can.
I don't think I've ever had a problem cooling the downstairs when it gets that hot, but the AC seems to stay on non-stop all day (thermostat set at 77).
Originally Posted by BaldLoonie
Is there an incentive for companies to install larger units (e.g. $$)?
York Makes A good product
I would follow your gut the guy will oversize your cooling and doesn't Know or care that it will increase your discomfort. good price is one thing good quality is always worth a little more. Go with a proven hvac contractor.
Load calcs. are great, unless you can't get the air where it's needed.
You have a 3 ton (27 yrs.) and someone wants to install a 4 ton. Mistake....in so many ways.
Sounds like a 3 ton 2-stage H.P. and the 2-stage V.S. furnace would be nice for your home.
Make sure to get the HW IAQ stat.
However, if the second floor ductwork is not adaquate, then maybe a 2.5 H.P.
is in order. So much for load calcs. (many times).
Id take the guy that gave 3ton
oversizing a unit is the most inefficient thing you might be able to do, more electricity drawn, more frequently turns on and off because its too powerful
Also take into account your windows and insulation seem to be decent from what you have said which limit heat loss and gain so 3 ton is most likely more than enough.
I had another company come by this evening to give me the results of their calculations and their recommended systems. This company recommends a 3 ton system. He showed me some numbers he used to come to that conclusion, but I didn't write them down.
This company suggested an 80% AFUE furnace instead of a 95%, since the temperature is above 30 degrees for 70% to 75% of our heating season.
Although the price is about the same as the first company that included a 95% AFUE furnace, I feel more comfortable with this company since they've been in the HVAC business for 50+ years, and they're not recommending a 4 ton system. The one reservation I have is that their BBB rating is only a B. I suspect this may be because they do a lot more business than the smaller companies I've had come over.
I'd still want a 95% or higher.
No reason not to save as much as you can on the heating bill.
Or do you like the idea of spending 15% or so more for heating then you need to.
Last edited by beenthere; 11-13-2010 at 04:15 AM.
Keep in mind that only members of the better business bureau are even rated by them.At least where I live.If you ask about a non member company they will have little to no info.So it is a darn if I am a member and I get a ding,or dare if I'm not a member and perhaps turn off a customer.With the tax credit and insecurity on energy prices,the more efficient the system the better.Usually has a better warranty as a bonus.
You are on the right track, but need to tweak your approach to get those referrals.
Originally Posted by Greenmaze
Your original install may not have been done with a load calc, and that may explain the difference in tonnage. There are many choices you can make, but referrals and load calcs by a company that has a history of good installations is the way to go.
[Avatar photo from a Florida training accident. Everyone walked away.]
2 Tim 3:16-17
RSES CMS, HVAC Electrical Specialist
AOP Forum Rules: