Latest Discussions : HVAC

nstonehouse

01:17PM | 06/14/04
Member Since: 05/20/01
11 lifetime posts
I own a 30 year old one-story house in Texas. Once the temps get into the 90's, our A/C runs all day (no exaggeration), just trying to keep the house at 78. We already know that our 2 ton A/C unit is too small for our 1500 sq ft house. Without replacing the furance and A/C (which we don't have the $$$ to do right now), we are trying to do smaller improvements to help the A/C unit out.

The furnace and evaporator coils are in a half closet in the hallway. Where this leads into the above attic is a big hole covered with mesh (to presumably keep critters out).

My question is this: Does the furnace and evaporator coils need to be vented like this or can I close up this hole and help reduce air loss into the attic? Our thermostat is nearby this half closet...

My wallet thanks you in advance (you should just see our elec bills in the summer!)

-- nicole --

tomh

01:52PM | 06/14/04
Member Since: 07/01/03
549 lifetime posts
There are not enough details in your post to determine if the hole above the furnace has any useful purpose. Assuming the unit is properly vented for exhaust and air intake, the hole in the ceiling does not likely serve a function, and may be there due to routing of ducts from a previous unit.

A unit that maintains a desired temperature, and runs constantly is operating at peak efficiency. If heat in the house goes above 80 degrees in warmer temps, that might indicate inadequate size, or a need to tighten the thermal envelope.

Other questions that might lead to savings:

Is the air return in the closet? If so, is door louvered?

Have you inspected air ducts to ensure they are intact?

If ducts are in the attic, are they insulated?

How much insulation on you ceiling?

Roof has adequate ventilation?

Do you keep filters changed?

Condenser coils are cleaned and unit serviced?

nstonehouse

03:38PM | 06/14/04
Member Since: 05/20/01
11 lifetime posts
I'll need to do some research into what the different parts of my furnace, etc. are before I can tell you if the unit is properly vented.

There is air return to the closet at the bottom on three sides of the 'closet'. But the door is not louvered. Does the door need to be louvered? Is this not code or is it just more efficient?

I have not inspected the ducts in the attic but can only assume (especially since the house is 30 years old) that they are inadequatley insulated. Is insulating the ductwork a huge task? One a DIYer can do?

The insulation is pitiful in the attic. We do need to roll out new insulation.

We had a new roof installed this year and we had a ridge vent put in. We have a long place in the roofline where the roof is peaked. Should we also have an attic fan?

I faithfully change the air filter each month.

I have no idea what the condenser coils look like and have thus not cleaned them. Again, another job for the DIYer?

thanks so much for your help. My husband isn't the handyman type, so a lot of projects tend to be my responsibility since I tend to have more of a desire in this area.

-nicole


tomh

04:34PM | 06/14/04
Member Since: 07/01/03
549 lifetime posts
Boy, do you ever have a lot of opportunities to save big bucks by spending a little. First off, you live in a 30 year old house and no one has even looked at the ducts. Those need to be sealed with UL 181 sealant and tape. Don't use just duct tape, look for the UL 181 stamp. Disconnected and leaking ducts can waste 20% to 40% of your cooling and heating dollars. I recently replaced our heating and cooling system, but found the main cold air return in the crawlspace was disconnected, and other ducts were damaged. This was costing me big-time, so, duct replacement and repair was a priority.

Those ducts are running through your HOT attic. Insulate them. Imagine running a refrigerator with sheet metal sides and no insulation. It would cost a lot. Use unfaced fiberglass blankets or batts over the ducts, or buy duct insulation made for the job.

Insulate the ceiling to R-30. This is the easiest DIY job and has a very high return.Insulation is fairly cheap. In your case, the payback should be in the first year. These small steps will save you at least 30 to 50 percent on total cooling and heating costs, and possibly more. You will probably find your 2-ton unit is more than adequate for the 1500 square foot house.

Finally, scrape together $150 for a service call. The technician will clean the condenser coil and inspect the evaporator coil, air handler and other systems. He should also check the coolant charge. As Harold Kestenhotz replied, this is not a DIY service. The coils are fragile and by this time, should be looked at by a pro. Also, the air handler and coil sections should be well sealed.

Back to your original question...I think you can plug the hole to the attic, but be sure there is a source for combustion air supply. This is something you can ask the furnace tech.

nstonehouse

04:46PM | 06/14/04
Member Since: 05/20/01
11 lifetime posts
THANK YOU to both tomh & HKestenholz !!!

Thank you, thank you, thank you. You have been so helpful. I can't thank you enough!

-- nicole --

BV016982

06:38AM | 07/30/18
WHAT ARE THE CHANCES THAT THE HOLE IN THE CLOSET COVERED BY THE MESH IS THE UNIT RETURN AND THEY HAVE USED THE ATTIC AS THE RETURN PLENUM.


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