Ventilation,Cost, & CO2 levels Chicago

[teddy bear]

Info on DOE sponsored research in Chicago for Nov with different concepts. Simple ventilation is reasonable cost.


For all the details http://www.carb-swa.com/PDF%20files/CNJanuary05.pdf

[mjballweg]

Hi teddy bear, Research always seems to raise more questions in my mind. The referenced article states the ventilation systems were programmed to meet the requirements of ASHRAE 62.2. I have not studied 62.2 but, in addition to its cfm requirements, does it contain a requirement regarding the distribution of ventilating air throughout a residence? If not, was that changed by 62.2-2004? If there is a requirement for the distribution of the air, do the results shown in the newsletter for the exhaust only system comply? Do you know if the air handlers used in the study are variable speed? If not, is the reference in the newsletter to reducing the energy consumption of the air handlers by up to two-thirds a reference to variable speed (ECM)? The newsletter states the research data will be extrapolated for different climates. Any speculation on what the extrapolation will show? Beyond the extrapolation of energy implications for climate and furnace efficiency, would an exhaust only system be appropriate for climates other than those which are heating dominated? How about for dry versus humid climates? In a mixed climate, would it be advisable to run an exhaust system in the cold months in an effort to try and create a slightly negative pressure during that time of year? How about coupling the exhaust system with an exterior thermometer so that it operates only below a pre-determined temperature? Okay, I'll stop now. Thanks!

[Xavier]

If I am reading the charts and report correctly, the best way to meet the new AHSRAE requirements is to run the bathroom exhaust fans periodically after installing a two hose make-up and combustion air system!

Sounds familiar!

Amazing what new studies and technology will determine!

[Carnak]

It sounds like constant ventilation being compared to intermittent ventilation costs, and the air cycler and ERV method include the cost of running the furnace fan constantly.

It would be interesting to see what it said for winter instead of the late fall. The furnace fan would be running for heat anyways and would be dropping out of the equation and the gas cost factor would be more significant.

The exhaust fan scenario appears to be point exhaust on timers, allowing the home to go negative.

The study makes a point for intermittent ventilation.

[uktra]

No Xavier that is NOT what it means. The exhaust only costs means NOT having a hole hooked up to a return to achieve those costs. The aircycler costs were more but still low because the duct to the return has a damper controlled by the aircycler. Adding a duct to the return via your "equalized-air" would increase energy costs far more than those on the above graph.

[Edited by uktra on 01-12-2005 at 10:55 AM]

[d big 1]

South Chicago vs South Carolina humidity would change the graph completely would it not?

[uktra]

The energy costs would be lower, but I think the purpose of the study was how much energy each system used relative to each other. The big problem I see with exhaust fans is the dirt, pollen, humidity, ect. this will pull into the home.

[Xavier]

Uktra, can you please explain your following two posts with data or examples?

1. “No Xavier that is NOT what it means. The exhaust only costs means NOT having a hole hooked up to a return to achieve those costs. The aircycler costs were more but still low because the duct to the return has a damper controlled by the aircycler. Adding a duct to the return via your "equalized-air" would increase energy costs far more than those on the above graph”

How will adding a 4 in duct to the furnace increase the energy costs far more then those on the graph when: A. the exhaust fans are on. B when the exhaust fans are off?

2. "The energy costs would be lower, but I think the purpose of the study was how much energy each system used relative to each other. The big problem I see with exhaust fans is the dirt, pollen, humidity, ect. this will pull into the home."

That is why I recommend we have an outside dampered duct connected to the furnace filtering system, so when the home requires “replacement” or ventilation air it is filtered before it enters the home. This is also, what the aircycler does at a much higher cost and it can pressurize the home.

[uktra]

Xavier--I have tried explaining to you before, and while I think you have the capability to understand, I don't think you want to. While you constantly put down other peoples contributions (aircycler: "rube goldberg invention") you fail to understand that progress has been made since 1978. Aircycler costs about $160.00 more than Equalized air. This extra cost is paid back in a very short time, because of two main features. 1. Savings on electricity--on and off times of air handler can be programmed. 2. Damper (in duct from outside to return on air handler) times can be programmed to prevent over-ventillating in winter and summer, and increasing ventilation in spring and fall. A third benefit to consumers in humid climates is that the microchip in aircycler records when the fan goes off during the cooling mode and allows the coil to drain before engaging the air handler fan for ventilation purposes. This is why over 5000 homes in the Build America use Aircycler.

[teddy bear]

Originally posted by mjballweg
Hi teddy bear, , was that changed by 62.2-2004? If there is a requirement for the distribution of the air, do the results shown in the newsletter for the exhaust only system comply? Do you know if the air handlers used in the study are variable speed? If not, is the reference in the newsletter to reducing the energy consumption of the air handlers by up to two-thirds a reference to variable speed (ECM)? Any speculation on what the extrapolation will show? Beyond the extrapolation of energy implications for climate and furnace efficiency, would an exhaust only system be appropriate for climates other than those which are heating dominated? How about for dry versus humid climates? In a mixed climate, would it be advisable to run an exhaust system in the cold months in an effort to try and create a slightly negative pressure during that time of year? How about coupling the exhaust system with an exterior thermometer so that it operates only below a pre-determined temperature? Okay, I'll stop now. Thanks!

My intent was to point out how low the cost to heat make-up air with simple ventilation using real test info. The heating cost is less than the fan operating cost of the more complex systems. The vent. standard is the 2004 ASHRAE. Keep in mind, during the coldest weather, need little supplemental ventilation. During mild weather, all the ventilation is from supplemental. These are conventional air handler fans. Exhaust vent. is ok in all climates during cold weather. Make-up vent. is best during warm humid weather in mixed climates. Make-up vent works in warm/humid and mixed all year. Inter connecting is ok but keep it simple for future service. They are not testing my favorite, whole house ventilating dehumidifier, because the initial cost is too high, although no more than an ERV. Hope researchers track %RH.