[jeffnc]

I've had what I consider to be pretty high heating and cooling bills (relatively). My power company says I have higher than average bills compared to my neighboring homes. This is despite the fact that I keep the heat way down in the winter (like 66-67) and AC down in the summer (like 80). I don't mind that as long as it keeps my bills lower, but it's like the opposite.

I'm ready to do a complete walkthrough of my home - whatever it takes. But I want to do absolutely as much as possible myself. This will be DIY, although I'm very handy. I actually do home improvement for a living - it's just that HVAC happens to be one of the things I don't know much about. I can replace an insualated duct with similar, but beyond that I hire that stuff out.

I live alone (with my son half time). My house is over 2,000 sf, but the second floor is mostly closed with a weather sealed door. I sometimes don't go up there for a week, although it has a guest room that does get used fairly regularly, and also my stereo and home theater room. That is on a separate unit, and I keep the thermostat even lower/higher up there. When I need to use it, I turn it back, for example I keep it at about 62 when not in use, then turn it up to 66 when using it for a day.

A couple years ago, I replaced my "high end" pleated filters with old fashioned cheap fiberglass ones, the idea being that airflow would be greatly increased. This doesn't seem to have helped as far as I can tell. I was also told this might do more harm than good in the sense that the coils will get more dirty.

So, I'm looking for a "checklist" type of thing I can go through to better insulate or investigate my house. I have a crawlspace. The more I can do myself the better, and the less I have to buy, the better. Thanks for any process I can follow.

 

[Bob Sanders]

What kind of heating system do you have and what does it run on (oil.... gas....)?

 

[user_12345a]

Every case is unique, wouldn't know where to begin.

Here are some potential causes:

1. ductwork in unconditioned space
2. crawlspace that's ventilated, not insulated, especially with equipment in it
3. Dehumidifier running in crawlspace, but not sealed off, crawlspace has dirt floor
4. High air leakage, especially from recessed can lights improperly installed in attic ceiling.
5. Heatpump running with aux heat - constantly turning up and down thermostat. leave it alone
6. Heating//cooling system not properly designed or setup - refrigerant charge, airflow, oversized, not providing rated capacity due to installation problems.

 

[roughneck]

What kind of systems do you have?

 

[jeffnc]

My main unit is a gas pack. Amana PGD36C0902E
http://www.johnstonesupply9.com/TechDocs/Amana/Package%20Units%20Gas-Electric/PGD%20Pkg%20Gas%20Ele/PGD%20Tech%20Info.pdf

My upstairs unit is a Goodman CPLT24-1A
http://johnstonesupply9.com/TechDoc...Heat Pump/13 Seer CPLT Spec Sheet SS-342D.pdf http://www.alpinehomeair.com/viewproduct.cfm?productID=453054753&displaytab=instructions_brochures

 

[user_12345a]

where are your ducts?

 

[HDS]

where are your ducts?

In a row... sorry couldn't resist.

Have you had an energy audit? Blower door test would help pinpoint air leaks. Your energy company might do them for free or reduced rate. Outside company would be about $2-300.

 

[Bob Sanders]

You mention heat pump on the 2nd floor and you turn it up and down. That can get very expensive if you have electrical back up heat and the wrong type of thermostat.

It's expensive to run the back up heat and if you have a cheaper thermostat which doesn't allow precise control of the back up heat, then any time you make too large an adjustment on the thermostat at one time, the back up heat also comes on with the heat pump for a faster warm up.

 

[jeffnc]

I understand that Bob, but that really isn't the problem. I usually only change it 2-3 degrees when I change it, and if I have a chance I do it a degree at a time. It's a digital thermostat. Over the course of the last couple years, I just don't think that's much of a contributor.

 

[jeffnc]

where are your ducts?

At the risk of sounding like a smartass, I'll just ask what you're getting at with that question.

 

[jeffnc]

Have you had an energy audit? Blower door test would help pinpoint air leaks. Your energy company might do them for free or reduced rate. Outside company would be about $2-300.

My energy company seems to offer a rebate. I was hoping to avoid costs like this, but if you think it's really helpful....

https://www.progress-energy.com/car...-efficiency-improvements/heip/hvac-audit.page

 

[user_12345a]

Depends on what kind of energy audit it is, who you get.

Lots of audits are likely based on speculation, for example guessing at what kind of insulation is in the walls.

If you have a problem with your hvac system, an audit won't find it and neither will the typical "check the freon pressures", "check the delta-t" contractor.

Lots of things you can do yourself such as checking for a temperature rise across the ducts in an unconditioned space, checking spit across condenser (assuming coil is clean) to see if it's removing the correct amount of heat.

A lot of guys will have something to sell you. You could have ten different opinions from 10 different auditors. The worst advice anyone can give is "change your windows" or "upgrade to 20 seer hvac equipment".

This stuff is tricky and there's no holy grail. Your house could have multiple problems.

 

[user_12345a]

This is an example of the type of thinking that will get you in trouble...

A couple years ago, I replaced my "high end" pleated filters with old fashioned cheap fiberglass ones, the idea being that airflow would be greatly increased.

...a question of filter size vs airflow. Pleated filters may cause problems if the filter area is low for the airflow.

Pretty much have to do testing; temperature split is a good measure to compare different filters with.

 

[HDS]

The blower door test is different than the hvac testing. They will attach a blower to an exterior door and pull a vacuum. Then using an infrared camera, look around for where there is outside air infiltration into the house. You want it done when there is a good difference in outside air temp and indoor too so that the differences are easier to pick up. It was about 70 inside and out when we had ours done which made it tricky.

A few areas that were really bad in our house was the basement and crawlspace rim joists. We had fiberglass batts I them but in a couple of areas there was no rim joist or sheathing, just straight aluminum siding. One rim joist bay's 2x10 had a knot missing that was half the area!

Another area that was bad was the fireplace brick and ceiling drywall interface.

A surprising area was the second floor return hvac ducts. They are built into the wall with that wall opposite the unconditioned attic. The top of the return wasn't sealed and the blower door test/ir camera revealed the top plate leaking air in.

In another return there was a pvc vent stack going up it and out the roof. Big air leak there as well.

Oh, and back to rim joists, the sill plate also leaked a huge amount.

And if you have light fixtures in the ceiling to the attic probably a lot of leaks there too.

Hit some of those big likely areas and you will probably be okay.

 

[beenthere]

Check both your return and supply duct for leaks. A return that leaks, pulls in unconditioned air, that cost more to condition then the air in your house.

A supply that leaks, blows air to the outside or to another unconditioned space. And then that air is replaced by outside air infiltrating your home, and your unit has to run longer to either heat or cool that air.

 

[ddawg16]

N Carolina? Not exactly the coldest of weather.

I'd look at heat loss first. Feel for drafts. Inspect those ducts as noted above. I'm guessing the floor between your 1st and 2nd floors is not insulated.

At night, go outside and feel along windows, doors and transitions for any warm spots. If it's warm, that is heat loss.

Do you have heavy curtains over the windows? That will do wonders for heat loss at the windows.

 

[jeffnc]

Hmmm, you have a point about the floor between not being insulated. Guess there's nothing I can do about that, although I'm sure I'm losing something there.

I don't really have too much window area. They are covered by a mix of curtains and mini blinds.

 

[user_12345a]

The location of the ducts is very important - conditioned vs unconditioned space. that's why i asked.

We don't even have a complete picture of the house.

At night, go outside and feel along windows, doors and transitions for any warm spots. If it's warm, that is heat loss.

Do you have heavy curtains over the windows? That will do wonders for heat loss at the windows.

That's a great way to cause condensation on windows. Unless the windows are single glass they shouldn't be a major concern.

Interior floors/ceilings are never insulated, nor do they need to be.

 

[jeffnc]

Interior floors/ceilings are never insulated, nor do they need to be.

The point is, the top and bottom floors have different units and different temperature settings most of the time. In the winter, if the upstairs is supposed to be 10 degrees lower, I lose heat to it from the bottom floor which might be keeping the upper temperature above the limit. Right?

 

[mcmakotomc]

I live in Las Vegas and just bought some real wood window blinds to block the sun to reduce AC usage, hopefully that help. Bought mine on ebay from a seller call Americandecoda.