Furnace and Central A/C Question!!!

anthony_7

Here is my question/situation to the pros.

My existing (OLD)furnace has a coil and all my boxes are low on the wall. I need to upgrade my furnace and a/c reasons are the equipment is dated and the A/C barely works in the summer and it was charged. A/C is unit is about 15 years old. Furnace is oil driven.

Also have no history of when the ducts were ever cleaned.

Ok you now have that to use so here is the question.

I am going to replace the furnace with a new RHEEM. So I am tossing the idea of either adding a 4 ton unit to my furnace and getting the ducts cleaned....OR....

Get two separate a/c units (1 2 ton and 1 2 1/2 ton so I can run two zones) Have new a/c boxes put in the ceiling and run it separate from my furnace.

So now I need to know for the addtl $4k it will cost to do this is it really worth it for the 3 months of a/c. Or will I be just as good as if I get the ducts cleaned and put a 4 ton unit on the furnace with coil (and put the $4k in my pocket)? I understand the electric bill will be higher and I will be cooling the entire house under 1 zone. But I think the time to catch up to the $4k in electric will take years.

All help is appreciated as always!

Thanks

ed wallace

new furnace a/c

ok 1st thing have a heat gain done on the house to see what you actually need for a/c stay away from rheem for oil fired furnace only a few good oil furnaces availiable top of the line is thermopride,then hallmark,you want a furnace with a steel welded heat exchanger not aluminized steel

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Justin Gavin

Options

I would say take your money and invest it in a condenser that has a higher SEER rating. That should save you money in installation and equipment costs. Also Invest in a variable speed blower motor (I don't know if they make one for oil) but if they do you can run you fan all the time to help balance the air.

But first have a "real" heat loss and energy audit done on your home. You may or may not be oversized with a 4 ton unit. A real energy audit may cost some upfront but having an unbiased opinion is always a good thing and keeps everyone honost.

Good Luck
Justin

anthony_7

Thanks

> ok 1st thing have a heat gain done on the house

> to see what you actually need for a/c stay away

> from rheem for oil fired furnace only a few good

> oil furnaces availiable top of the line is

> thermopride,then hallmark,you want a furnace with

> a steel welded heat exchanger not aluminized

> steel

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 256&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_



That was my other question. What brands of furnace to stay away from

Say the heat gain was done which way would still be good to go? Unit on furnace or separate units for $4k

anthony_7

Thanks

That was my other question. What brands of furnace to stay away from

Say the heat gain was done which way would still be good to go? Unit on furnace or separate units for $4k

techheat_2

In oil furnaces

Thermopride is the only way to go. As far as A/C zoning goes it depends on the size of the house and whether you consider this in comfort terms or strictly as a financial decision.

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Justin Gavin

I would say this

For 3 months of use I would install the 1 condenser and variable speed blower unit. If its in the budget go with a higher quality 12 Seer or better condenser or high SEER heat pump With the heat pump you could get 1st stage heat for spring and fall and the winter when the air to air effy of heat pumps decrease use your oil furnace.

Justin

ed wallace

a/c furnace

where do you live which state i ask because heat pumps are not very efficent in the north east how do you heat your hot water ??

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anthony_7

Ed

Located in Lovely Long Island NY. Hot water is heated by oil h/w heater. I appreciate any tips suggestions you have.

techheat_2

LIPA

Forget The Heat Pump idea,How about a nice boiler and hydro air system

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Tombig_2

System vs equipment efficiency

Is the delivery system 15 yrs old also or much older? Chances are your ducts were designed for heating only and cool very inefficiently regardless of the seer rating of the new condenser. Have a pro evaluate the heat loss/gain and delivery system for heating AND cooling. You could add some ducts and even zone dampers for a fraction of the cost of two seperate systems. Honeywell Trol-A-Temp for example. We don't put in two boilers for two zones do we. I've found single heat plant zoned duct systems easier on the fuel budget also. Hydro air is a great option with a lot of flexibility.

Brian_24

Don't forget the duct

If your duct is leaking and improperly sized you will not get any where near the seer your are buying. If you can't deleiver the cfm you can't deleiver the btus. To many contractors sell boxes and not complete systems. Have an airflow diagnostic done by a certifird test and balance contractor and see where the best place to put your money is. Just my humble opinion. Good Luck, Brian

jim lockard

depends

what the heat gain says.

B. Tice

Furnace/ac

Anthony, I will say I agree with Ed, stay away from the Rheem. Bottom of the barrel on oil furnaces.

Al D'Ambola

BKG right on money

I agree with everything he says. If you do not do an air diagnostic how do you know if you are getting that SEER capacity?

I have measured hundreds of of duct systems and have trained 1000+ contractors across the country and to this day it amazes me that most good contractors DO NOT measure static pressure and verify the air side!!

Anthony email me I can can give you the names and numbers of contractors who can measure field SEER ratings not just what it says on the unit. It is all about delivered measured performance.

Al D'Ambola

BKG right on money

I agree with everything he says. If you do not do an air diagnostic how do you know if you are getting that SEER capacity?

I have measured hundreds of of duct systems and have trained 1000+ contractors across the country and to this day it amazes me that most good contractors DO NOT measure static pressure and verify the air side!!

Anthony email me I can can give you the names and numbers of contractors who can measure field SEER ratings not just what it says on the unit. It is all about delivered measured performance.

Al D'Ambola

Zoning

I would recommend looking into Arzel Zoning great product great company & tech suuport www.arzelzoning.com

Dale

Duct blaster

Before you commit to equipment find out about the air side. Have a duct blaster tightness test done along with a blower door test for the entire house. The last thing you want to do is to put in too big an ac unit. That's how mold forms. Get the heat gain figured and get at least 10% less in tonnage than the heat gain, ac needs to run long enough to dehumidify which is what you need to feel good in the summer. The blower door and duct pressure tests make sure most of the cool air stays where you want it. Cleaning the ducts doesn't hurt although most of the time it's unnecessary. I say most because the last little house I looked at had 200 birds in it, in cages yes but feathers were flying.

Matt Undy

I agree that the duct work shoudl be looked at. Sometimes moving a few returns and changing some difusers can do wonders for a system's performance, especially when the registers are 50's style baseboard registers that direct the airflow at the floor and have 40 years of paint cloging them up. Also look for leaks, especially around the register boxes. Most I have seen send about 1/4 of the air into the basement though the cutout for the box. Foam in a can works well to seal up theese leaks.

Are you sure the unit is properly charged? Nearly all techs I have encountered don't understand the physics of how the system works and why just looking at a chart and a guage set won't properly charge it. I have also seen some articles suggesting that adding a larger evaporator and TXV (and a site glass so one knows what is really happening) can add the extra capacity to a somewhat undersized system.

Also, I would go with the highest SEER that you can get without going to a 2 stage compressor. Also check into rebates, I have seen some rebate programs that could make 2 stage competitive with high efficiency single stage. Of course if you have a sufficiently large house and sufficiently high elecric rates and intend to stay there a long time, the 2 stage could be worth it.

Oh, and thanks to whoever psoted the link for the firced air zoning, I have been looking at systems and thus far haven't seen ones that could claculate load from number of zones caling, outdoor temp, and rise needed in those zones to control the staging of the furnace. Anything that came close was far more expensive than installing multiple furnaces.

Matt