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Talgonadia 08-01-2012 10:07 AM

Heating and cooling issue
My wife and I bought our first home last September. It's a ranch style manufactured home with basement. The house had trouble heating in winter and with an ac system installed its having trouble cooling in summer.
3 bed 2 bath, about 1280 square feet. Basement not finished. Furnace located in corner of house near the garage.
We live in wi and in winter the bedrooms furthest from the furnace would not stay warm and now in summer they won't stay cool.
I fixed some ductwork issues but it's still not how I would expect it to be.
House built in 2002, mobile home furnace with the return air located only at furnace.
I had an energy audit done and doing a blower door test my home is at 5.5 air exchanges per hour.
He suggested I seal the leaks between my windows and trim which would help but mentioned my furnace placement is the main concern.
I added register boosters to the 2 bedrooms furthest away to help push more air.
My elec bill seems very high and my central air runs pretty much continuously because it's not cooling. The air coming out of my vents is 60 at the furthest away register.
I'm tempted to buy a new furnace and have it installed in the basement and have return ducts installed but that's 6k that I'm not wanting to spend...
Any ideas?
Oh yah the energy guy did a cfm test on all my vents and said the 2 bedrooms are half the rating of my others and said either their is leakage or the blower isn't powerful enough to cool the house.

bobinphx 08-01-2012 10:14 AM

A couple of more bits of info would help.
1. what size (tons or BTU's) is the HVAC system
2. what size is your return
3. what size are you supply ducts
4. what are the ducts made of (metal, flex, fiberglass ductboard)

and pictures of the system and drawings of the duct runs would really help too...

Talgonadia 08-01-2012 10:27 AM

1) is a 2.5 ton 13 seer central air. The furnace is original for when house was built.
2) my return part of the furnace? Not sure what you want? Filter size?
3) I'll get back to you, I think they are 4x9. Built like a double wide in the floor. So whatever was standard
4) metal with branch off to flex for all the registers in the floor. The flex is 6 or 8.
I'll get pics. What would you like for pics?

scottmcd9999 08-01-2012 10:37 AM

You've got a typical mobile home system - small 4X9 or 4x12 "supply" duct that runs down the center of each "side" of the house. Return is nothing more than an open cabinet on the furnace.

Is that correct?

We don't often see these systems with flexibile runouts. Most commonly they're just registers cut out of the top of those supply ducts, and penetrate the floor with a 4 x 10 grill or something of that nature.

How many "crossover" ducts do you have? "Crossover" ducts are the big ducts (ususally 10" - 14") that connect the halves of the home. If you're having airflow issues, we've found having crossovers on both "ends" of the runs (in essence, creating a big loop) sometimes will even out the airflow.

Note too that when dealing with mobile home ductwork, you'll need to insure that you have a system that can manage the high static duct system. Standard home air handlers designed to work with .5 static won't work too well in your system - so you are either stuck with mobile home euipment, or you install all new ductwork with standard hvac equipment.

Talgonadia 08-01-2012 10:46 AM

Yes that is correct and I only have one crossover located directly below the furnace.

What do you mean by high static duct system?? Cause my new central air is not mobile home variety...

REP 08-01-2012 01:47 PM

You may be able to pick up anywhere of 10-30 pecent in cfm's by converting to hard metal runs to replace the flex runs.

ben's plumbing 08-01-2012 01:55 PM

agree with rep ..but if the flex is accessable you could disconnect run and strecth the runs tight that will smooth out the inner linning of duct....ben..:yes:

scottmcd9999 08-01-2012 02:08 PM


I only have one crossover located directly below the furnace
IMO this isn't the best way to handle the high static system. It would be best if you moved that crossover away from where it is (5 - 6 feet away from where it is now), and patch the hole. Then add another crossover at the other end of the duct system. As I mentioned earlier, the goal is to have a big loop.


What do you mean by high static duct system?? Cause my new central air is not mobile home variety
Most mobile homes have a very small supply system (i.e around 4 x 10 inches or so), which results in a very high static pressure (i.e. "backpressure").

Your condensing unit (the outdoor unit) doesn't care whether it's on a mobile home or not, but the blower system (the one that blows the air through the house) must be capable of handling high static pressures.

Talgonadia 08-01-2012 02:25 PM

I just had a contractor bid a new furnace and ductwork for 6900. New furnace, all new ductwork for return and supply. The comPany has good reviews. He did mention one thing though, is it true propane burns worse than natural gas? I want w modular blower furnace but he recommended using a 2 stage blower and only using the high speed lower because of the sud propane produces?

Talgonadia 08-02-2012 07:40 PM

So our energy bill was 280. Does this seem high for a 1280 square foot single story home? I'm trying to find ways to justify a new system...
Our electric regularly is 80-90.

ben's plumbing 08-02-2012 07:51 PM


Originally Posted by Talgonadia (Post 980084)
So our energy bill was 280. Does this seem high for a 1280 square foot single story home? I'm trying to find ways to justify a new system...
Our electric regularly is 80-90.

don't take this the wrong way...I have 2500-3000 sq ft...1- 3ton system.....1-2 ton system ...2 furnaces....2-window units..... electric dryer..and stove....and lights out the you know what...our budget is 138 per month....our actural bill last month was ..your 280 would seem high to me....was that and actural or estimate read....

Talgonadia 08-02-2012 08:01 PM

That's the bill we paid... It was 200 more than normal almost

ben's plumbing 08-02-2012 08:05 PM


Originally Posted by Talgonadia (Post 980103)
That's the bill we paid... It was 200 more than normal almost

wow that seem high something is drawing some serious power in your house...:yes: actural or estimate....what was last months bill:yes:

Talgonadia 08-02-2012 08:14 PM

230. Just had the ac installed. Last fall when it was cool our bill was 70-90 depending on how much time I spent on the pc. I know central air will increase the cost. I'd like to know what should be the cost. My ca is a 2.5 ton system and if my hvac is working properly what kind of bill should I see. Pretty much if I spend the 7k I'd like a rough idea of the roi :)

Talgonadia 08-03-2012 06:51 AM

One more question. My wife suggested we get a furnace capable of handling the basement. We expect to finish it in the next 5 years. Is this possible to do?.. It would require a bigger btu furnace but until we finished the basement we wouldn't need the additional furnace size.

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