1,153 posts, read 2,496,428 times 2,387 posts, read 3,215,403 times Why not in attic...my husband wants it up thete snd I don't Originally Posted by deeds multiple studies by ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) as well as studies by the National Renewable Energy Laboratory have shown that ductwork in the attic of residential dwellings is one of the single most in-efficient portions of an HVAC system + installation. In an NREL study, they estimated 15-25% energy savings purely ductwork being run in the conditioned envelope versus in the attic. This is a significant improvement even over increasing wall insulation the R19 or higher or attic insulation to R50, and also still better than even jumping all the way to a SEER 17 unit. It is done because it is easy and cheap, but it is inefficient and a huge energy waste in operation. If you are building new, you should do what you can to run the ductwork in chases / boxed out trusses etc.

Even a crawl space is better than running them in the attic. Think about it: during the cooling season, you are running your coolest air (off the evaporator coil) through the hottest part of your house (the attic). During the heating season you are running the hottest air (off the furnace or coil) through one of the coldest parts of your house (the attic). Poor sealing of ductwork and minimal insulation lead to dumping a lot of wasted conditioning directly to your attic space. Husband wants heating unit also in attic due to damp space under house Originally Posted by harry chickpea I'd argue they are not concerns on the same level. I've never had rodent issues with hvac ductwork in the crawl space in any of my parents' houses I grew up in nor in our house. I prefer it inside the insulated envelope instead of the crawl space anyway; I was just saying crawl space is typically better than the attic in terms of energy efficiency. But in either case, I would say that I would take guaranteed energy efficient improvements (that will help evry time the unit is running) vs the small chance that you may ever have rodent issues with crawl space ductwork.

deeds: You need to get help from a licensed, local HVAC contractor. We can give you some information on here, but none of us are going to design and install your system. make up air handling unitThere is really no use fretting about it on here until you have gone to 2-3 licensed contractors and gotten each of them to give you their opinion and quotes.ac unit fan covers Yes, there are a lot of bad contractors who only know rules of thumb and not the science; can you finance a new ac unithowever, they are going to be the ones to do the work. It will be more useful if you come back to this thread with OPTIONS from 2-3 contractors for people to help provide input on. 19,448 posts, read 36,978,478 times 5,105 posts, read 5,676,513 times

HVAC (Heating and Cooling Systems): Right-size Heating and Cooling EquipmentThere are 12,000 Btu’s per ton. The number 24 in the model number indicates the unit is 24,000 Btu’s, divided by 12,000 Btu’s per ton, equals 2 tons. 24,000 Btu’s/12,000 Btu’s per ton = 2 tons If you’re still unsure which system size is right for you, or if you’re having difficulty downloading the Air Conditioner Size Calculator , please e-mail us or call us toll free number at 1-855-634-5588. (Hint: Use the larger of the two numbers above if you’re unsure of your home’s insulation) Simply multiply the appropriate factor above by your home’s total heated square footage to arrive at your approximate required heating capacity. For example, if a furnace has a listed input rating of 100,000 Btu’s and an efficiency rating of 80%, it will produce For this example, using an 80% efficient furnace, the 2000 square foot home above would require a 100,000 Btu input furnace which will produce the necessary 80,000 Btu’s output of heat.

If you’re still unsure which system size is right for you, please e-mail us or call our toll free number at 1-855-634-5588. Variables such as your insulation, type and number of windows, number of stories, construction type, etc. will greatly affect the required Btu’s per square for both heating and cooling. The less insulated and more windows within the environment, the more likely you will experience greater air and heat loss. What is the most efficient thermostat setting for air conditioning? The best setting is the highest temperature at which you are comfortable. We recommend 78 degrees when you're home and 80 degrees while you are away. As a rule, raising the thermostat setting just two degrees will reduce cooling costs by five percent. When I replace my central air conditioner, would it be more efficient to get a larger unit? Will it make the house more comfortable? It is best to get a properly sized unit. Although a larger unit may run for shorter periods of time, it will use more electricity due to its larger size.

It may also fail to properly dehumidify the home. A properly sized unit will control both temperature and humidity, making the home more comfortable. What does the "EER" or "SEER" rating on an air conditioner mean? Both EER (Energy Efficiency Ratio) and SEER (Seasonal Energy Efficiency Ratio) are indicators of how efficient the unit is. The higher the number, the more efficient the unit and the lower the operating cost. SEER is used with central air conditioners, while EER is used with room air conditioners. For new central systems, SEERs of 12 or higher are generally considered high-efficiency units. For room units, EERs of 11 or higher are considered high-efficiency. What is the recommended SEER rating for a central air conditioner? The current minimum requirement is 10.0 SEER. This is significantly more efficient than older units. Ratings of 11.0 to 12.0 are common, and will have lower operating costs. Units with SEERs as high as 15 are available. The more you use your central air conditioning, the more you will benefit from higher SEER ratings, and the more likely that the additional cost will be offset by energy savings.

I have one room in my home that is always too hot in the summer. What can I do to make that room more comfortable? If the room has a large area of exposed glass, keep curtains or blinds closed during daylight hours, particularly at times when the sun would shine directly in. You might also ask your air conditioning contractor to check whether you are getting enough air in that room. There may be a problem with your duct system. Will ceiling fans help cool my home in summer, and should I run them constantly, even when my air conditioning is running? Ceiling fans can help make the home more comfortable, either alone or in combination with your air conditioner, by creating more air movement, which makes the air feel cooler. But remember that they do not actually cool the air, so there is no point in running them in unoccupied rooms or when no one is at home. What is a "whole-house fan" and is it a good option for cooling my home? A whole-house fan is a large ventilating fan, typically mounted in a ceiling between the living space and attic.