Find costs to replace an air handling unit in an attic or closet. The PB&J of HVAC The air filter needs to be changed; The blower is going bad or out of balance; Refrigerant leaks, resulting in your air conditioning freezing up. What is suggested if mold has grown around the vent boxes and ducts? The HVAC contractor is saying I need to put condensers on the outside with the pump in the attic. Unfortunately, it's far from obvious to most home designers how to make this happen. The table below shows that moving the ducts inside is the first thing you should do to save the amount of electricity you use.In addition to saving on air conditioning operating costs, the upfront cost of cooling equipment is lower in efficient homes. In ranches on slabs, you have to create soffits (fur-downs), that are isolated from the attic. You’ll not only save money on your electric bill, but the move will also help you save energy, further reducing your household’s carbon footprint.Relocating your attic air handler can more than pay for itself in lower energy bills not to mention improved comfort. An attic can get up to about 130° F in the summer, and the conditioned air entering the ducts is about 55° F or so.
If it’s conditioning not cooling, this could be why. When your air handler and ductwork are located in an area this hot, the cooled air can heat up before it ever has a chance to reach your living space. There are some folks working really hard to change that, but it is difficult convincing contractors why they should do this, especially if they've been getting "good enough" results by running ductwork in attics and just oversizing the equipment.
©2020 Michael Bonsby Heating & Air Conditioning. Is it worth it to replace the ducts if they are over 20 years old? I am told there was a class action lawsuit involving 260 plaintiffs, involving a major builder who had many roof deck failures using foam at the roof line in a hot-humid climate.
"Heat exchangers," they write, "are designed to transfer as much heat as possible from one fluid to another." Ira, that's a great point regarding the cost and maintenance. As its name suggests, an air handler “handles” the air inside your home and delivers warm or cool indoor air throughout your entire home.
I live in Montreal and had a Lennox air conditioner and ducts installed in the attic. This isn't just an efficiency hit. Hard to get builders on board with this, but in my experience, it doesn't cost as much as closed attic, and has better performance. Allison, have you looked at the costs associated with installing duct inside conditioned area vs. sealing off the attic (spray foam?). Any opinions? There is also at least one manufacturer pushing high velocity systems utilizing 2" ductwork. There are only a few causes of a leaking air conditioner, the first one being a clogged air filter. Frozen Evaporator Coils. This one had great references but is not clear when you need an explanation.I agree that central HVAC ducts in the attic are ridiculous. Is the chemical spray only temporary? Its a band-aid approach. I thought it was all one unit. I'm sure it is pricey... Graham, my house with the temperature measurements was built in 1989.This is quantitative proof that in new buildings the duct work HAS to be placed in the conditioned space. People pay for extras they can touch.In warm climates, moving ducts out of the attic is probably the lowest hanging fruit there is, at least in new construction. We just purchased a 1955 ranch-style home here in Dallas. Did you know that your attic can get as hot as 130 degrees during Maryland’s hot summer months? Maybe try not using duct work at all as a retrofit...try ductless mini-splits instead...For new buildings, in the NW we are stating 18 inch between floors, which is more then enough room for larger duct work and part of the envelope.There are alot of comments directed at builders. Please advise.I believe that moving ducts out of the hostile temperature environment of the attic is obvious. This blog is very interesting and eye-opening. When we went to look, we saw the location is where there is ductwork. I do know Pulte Homes built with this design at one time in Cinco Ranch (Houston TX), and will not build that way today. @Brandon, if ducts are original, they're unlikely to be sealed. We owned another home with old crawlspace ductwork in place that had been abandoned in favor of attic flexduct, so this isn't our first time looking at this. The air handler is in the attic and about two months after installation, we saw water damage in the ceiling. They chose Houston, Phoenix, and Las Vegas as the locations for their modeled houses. But lately, we’re starting to see more and more HVAC companies install the unit in a conditioned room.
Wish I could cite some good references, but hearsay is just about all I have. Thank you for the great blog. This is a difficult thing to get nearly any builder to do, even on new houses where the cost to do so is minimal compared to what it would cost in a retrofit situation- basically an upgraded truss or floor package, a little planning/design work, and some extra sheetrocking.
@Erc, you may be boxed into a bad situation with no other alternatives. Most often, air handlers are located in the attic, basement or a dedicated closet, and may closely resemble the shape of a gas furnace.
Jerry, whether or not a given room needs supply air depends on wall, floor and ceiling exposures, and especially window exposure. And that the settlement included a requirement that the plaintiffs not discuss the matter. @Mariann: a heat pump can either be a package system, which has one cabinet mounted against foundation or on rooftop, or it can be a split system, with two cabinets. What I've observed @Alberto, discharge air temperature shouldn't exceed about 15C (59F). Ducting is all new runs. If they are black, is that mold or is that wear from freon passing over them for 30 years?Can someone advise me on the proper way to clean A/C ducts? @Alberto, a low refrigerant charge cannot explain the wide variance in supply air temperature you observed. In such a scenario, your attic air handler has to work harder, using more energy than if the unit were located in a cooled space. Any info? Does this work and is it feasible to do this?We have lived in Spring Texas since 1977 and due to two hail storms in that period have had two roofs installed.