OT - Does anyone here know about HVAC systems?

**wickedsolo** · 04-20-2013, 07:29 PM

The house that we bought has central air (dual zone), but is still running oil with an oil furnace for heat...

Since the duct work is already run throughout the house because of the central air, and the air blower is already installed, and the exterior fan units are already there, what exactly would we need to get central heat added to that system?

The oil furnace, while efficient, is older and probably will need replaced in a few years. Plus, I'd rather not spend the $1,000-2,000 per season to fill the oil tank up.

Thoughts?

**drunkmormon** · 04-20-2013, 07:35 PM

1 to 2 K for heating for a year is not really that bad... but to give advice I would ask, do you have natural gas service, who provides your electricity? Heat pump would be easy to add, but you may pay more than what you are paying on oil depending on the efficiency of the oil furnace versus electrical rates.

Although the optimal solution is oil furnace when outside temps are below about 45 and heat pump above that.

**knots** · 04-20-2013, 07:47 PM

if you have gas service in your neighborhood, put in a gas furnace. The blower and duct work is already in place. I have separate AC and heating units. I am not a big fan of heat pumps.

**Greg** · 04-20-2013, 08:25 PM

Originally Posted by wickedsolo

The house that we bought has central air (dual zone), but is still running oil with an oil furnace for heat...

Since the duct work is already run throughout the house because of the central air, and the air blower is already installed, and the exterior fan units are already there, what exactly would we need to get central heat added to that system?

The oil furnace, while efficient, is older and probably will need replaced in a few years. Plus, I'd rather not spend the $1,000-2,000 per season to fill the oil tank up.

Thoughts?

Does the oil system provide you with hot water as well? If so you have a hot water heater that won't run out. Might want to keep that in mind if it applies.

**Ravenswintitle** · 04-20-2013, 08:58 PM

Yeh I'd recommend trying it for a season. In the meantime you can always get estimates from some locals

**wickedsolo** · 04-20-2013, 09:46 PM

Originally Posted by Greg

Does the oil system provide you with hot water as well? If so you have a hot water heater that won't run out. Might want to keep that in mind if it applies.

There is no hot water heater. It runs the water through the furnace and that is where the hot water comes from.

We are actually going to install a tankless water heater. Probably electric.

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**ballhawk** · 04-20-2013, 10:38 PM

Originally Posted by wickedsolo

There is no hot water heater. It runs the water through the furnace and that is where the hot water comes from.

We are actually going to install a tankless water heater. Probably electric.

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I'm a plumber with plenty of experience with tank less water heaters. If you are going that rout, get a gas one. The electric ones draw too much power. Way less efficient (more expensive) than gas.

**GOTA** · 04-20-2013, 10:38 PM

Oil is going to cost a lot more than $1,000 to $2,000 a season. Oil this winter cost me around $700 a month and I don't live in a large house. Oil heat sucks.

**Greg** · 04-20-2013, 10:42 PM

Originally Posted by GOTA

Oil is going to cost a lot more than $1,000 to $2,000 a season. Oil this winter cost me around $700 a month and I don't live in a large house. Oil heat sucks.

That sounds like an insulation problem. It would be more pertinent to know the square footage of the house, the age of it, and the amount of fuel in gallons, not dollars, to see if you are an average case.

**RavenScallywag** · 04-20-2013, 11:42 PM

Originally Posted by GOTA

Oil is going to cost a lot more than $1,000 to $2,000 a season. Oil this winter cost me around $700 a month and I don't live in a large house. Oil heat sucks.

I hear you on that one...we have 1700 sq ft house, using radiator heat, oil boiler that was JUST replaced this year...we ended up with about 2700+ on heat oil this winter, and this is WITHOUT it doing hot water heating as well.

**RavenScallywag** · 04-20-2013, 11:43 PM

Originally Posted by Greg

That sounds like an insulation problem. It would be more pertinent to know the square footage of the house, the age of it, and the amount of fuel in gallons, not dollars, to see if you are an average case.

My case:

1704 sq ft
Home built in 1925 (but updated from last owner)
632.3 gal oil

**RAPHENS** · 04-21-2013, 12:08 AM

I have a 2700 sq ft home. Built in 1981. 2 zones. We were paying $400/mo. year-round (so about $5k per year) to heat our home. Fucking brutal. oil fire water furnace too. We had heat pumps as well for when it wasn't freezing, but in this climate, that's not all that often.

after 2 winters we converted the 2 oil furnaces to gas. had gas line installed. BGE charged 1k to run the line. after lots of searching, I found a decent HVAC contractor to work with. finding the right guy to do the install was by far the hardest part. put in the 2 new furnaces. replaced 2 heat pumps with a/c units. after we burned the rest of the oil in our tank, we put in a gas fired water heater. Right now, with financing, my monthly payment is the same as it was with oil (so my prior monthly payment for heat alone is the same as my new heating payment plus payment for financing the new system). I will make my money back w/in 3 years. of course, a large part of that is the new higher efficiency system.

In short, gas is cheap compared to oil right now. Heat pumps do not operate efficiently in this climate during the winter months. Find a contractor who will calculate the proper load that your house requires and go from there. The contractor that you want will measure every opening in your house, duct size, etc. He will spend about 2 hours in your home and then have to get back to you with the proper equipment size/BTUs, etc.

DO NOT TRUST A CONTRACTOR WHO DOES NOT DO A PROPER LOAD CALC. I CANNOT STRESS THIS ENOUGH. IF THEY DO NOT DO A PROPER LOAD CALC THEY ARE ESSENTIALLY GUESSING. OLD OIL FURNACES ARE NOTORIOUSLY OVERSIZED WHICH LEADS TO INEFFICIENT HEATING. GOOD LUCK!