Re: ASHRAE Urges Standard 62.1 Inclusion in International Mechani...

[Guest guest]

Hi All,

I am not understanding this correctly, I don't think. I would think that one would want higher outdoor rates in an effort to provide fresh, circulating air being added to the IAQ. What am I missing?

Thanks,

Sharon

“Ventilation systems designed using the new procedure will result in somewhat lower outdoor rates for most occupancies compared to the current code, reducing first costs and energy costs,†he said.

[Guest guest]

Ventilation rates have been all over the board in the past 35 years. Its a fact that cooling entering air is expensive .Cost and energy avoidance is what has gotten us into IAQ problems in the first place.

Figure this . Lets say 5 cfm per person "low" X 60 min. = 300 cfm . Outside air temp at 85 f

and 80%rh = heat content is 53.1 btu. Now cool that too 75 f at 50% = 32.4 btu.

1lb of outside air = about 20 cf . 20 into 300 = 15. 53, 1btu - 32.4 btu = 20.7 btu

15 X 20.7 = 310.5 btu. Now if you figure 1kw per ton. "very conservative" 12000 / 310.5 =

..026 kw or 26 watts of power per person.

So now we have an office building with 300 people. 26 X 300 or 7.8 kw per hour.

Now comes the real catch. What is the electric rate? $0 .08 $0.10 This really doesn't sound like a lot does it.

Now for reality . Demand charges will most likely apply since the system runs during demand periods. Demand charges vary from area to area. Lets use S. Fla. $ 9.00 per kw. So now that 5 cfm per X 300 people can cost as much as an extra $70. per day " Power co. will discount the first 10 kw demand 7.8 X 30 days = 234 kw - 10 = 224 kwh demand X $ 9.00 =

$2016.00 not including the fuel adjustments and normal kwh used.

It is only recently personal health has become an issue. Mainly do to the litigation factor .

You have a triangle, Quality , Service , and Price. If you don't like the price, then one of the other factors has to go.

Ok. I'm off my soap box

Valin

[Guest guest]

Hi Group

re: 's Post

You are correct. Multipoint control of entering air dampers will control CO 2 levels,but there again it becomes part of the triangle .

As outside air burden decreases , air off the evaporator coil conditions change. A drop in temp also means a rise in rh. So not only control of outside air becomes a factor but a variable control of equipment ( compressor ) will be required . Chillers by there vary nature will have no problem, as their load control is by motorized water regulating or bypass valves and unload or shut down by water temperature set points, so air brought in at the return of the air handler is no problem.

Air to air units, as found in most office rented office situations, do not offer this option. You have multiple 5 too 25 ton package units supplying conditioned air to VAV boxes or a single duct systems. Its' fresh air is normally taken within 3 ft of the roof top. ( 120+ F in summer or 85 F Saturated after a rain storm ) either way its a very large load to shed without ramping down the compressor. I have replaced many compressors and contactors due to short cycling after a local HVAC man sold the after market idea that stage 2 could be shut down by the motorized outside air damper . Not to mention the effect on structural pressures. ( Its amazing how much water gets sucked into a buildings' walls when in neg. pressure. Even the 1 st floor concrete slab on grade becomes a factor due to partial pressure relationships unless the concrete has been vapor sealed .)

Solution : 1. Design a functional, dedicated, economical , service friendly , variable speed outside air unit . Its really nothing more than a dehumidifier with sensors on the entering and supply side of the coil. Its' purpose is to just remove moisture. It is not to add or subtract from the building load nor is it to pressurize the return ducts of the existing or proposed equipment. The extra heat of rejection created by compressor operation should be put to use elsewhere (hot water). It must also be responsible for maintaining building pressures. All the parts are out there right now, but the cost of putting them together , building it to fit a small situation, and finding an normal hvac mechanic to work on it when it dies could be a financial burden most building owners will avoid.

Solution : 2 I'm working on it as a retrofit. So is everyone else.

Have a good day!

G. Valin

[Guest guest]

Hi ,

Thanks for your reply. It helped to confirm to me that I was correct in my understanding. Its back to the same old issue "Your money or your life". I would agree and think understand all that you are saying. There is only one aspect that I would have to strongly disagree with. It is your statement of :

It is only recently personal health has become an issue. Mainly do to the litigation factor .

I am of the opinion that the need for fresh circulating air within a building is not based on concerns of litigation. It is based on the need for buildings to be able to breathe in order to limit microbial and bacterial growth - that promotes an environment of poor indoor air quality - that greatly increase potential for human illness.

Are you of the opinion that all of the Leed, Healthy Schools, Surgeon General's Workshop, etc. info is only to limit financial liability within the courtroom? I say "Poppycock!"

Here is an idea to lessen the effects of the Rule of 1000:

Put in lots of windows that open.

Wear a sweater when its cold and a bathing suit when its hot.

Plant trees outside for shade and insulation to help control the temp inside.

Never use PVC pipe.

Design structures so the plumbing pipes are in as few areas as possible.

Buy the new green building materials.

Limit soft porous goods wherever possible and reasonable.

Clean frequently.

Have building inspections on regular basis.

WR

Sharon

http://www.hhs.gov/surgeongeneral/topics/indoorenv/intromat.htm

[Guest guest]

Dear Colleagues:

Problem: Under ventilate and degrade IAQ and waste money by lowered

productivity, over ventilate and waste energy and money.

Solution: Have accurate diagnostic feedback on the amount of ventilation

provided to the building occupants so that the ventilation component of the HVAC

system can be more optimally managed to balance the competing goals of providing

a healthy and productive indoor environment and conserving energy.

This diagnostic feedback on actual ventilation performance can be achieved by

multipoint monitoring of CO2 and humidity at the boundary layer of the occupied

spaces.

Sincerely,

W. Bearg, PE, CIH

--

Director of IAQ Programs

AIRxpert Systems, Inc.

www.AIRxpert.com

-------------- Original message ----------------------

From: gval102@...

> Ventilation rates have been all over the board in the past 35 years. Its a

> fact that cooling entering air is expensive .Cost and energy avoidance is what

> has gotten us into IAQ problems in the first place.

>

> Figure this . Lets say 5 cfm per person " low " X 60 min. = 300 cfm . Outside

> air temp at 85 f

> and 80%rh = heat content is 53.1 btu. Now cool that too 75 f at 50% = 32.4

> btu.

> 1lb of outside air = about 20 cf . 20 into 300 = 15. 53, 1btu - 32.4 btu

> = 20.7 btu

> 15 X 20.7 = 310.5 btu. Now if you figure 1kw per ton. " very conservative "

> 12000 / 310.5 =

> .026 kw or 26 watts of power per person.

>

> So now we have an office building with 300 people. 26 X 300 or 7.8 kw per

> hour.

> Now comes the real catch. What is the electric rate? $0 .08 $0.10 This

> really doesn't sound like a lot does it.

>

> Now for reality . Demand charges will most likely apply since the system

> runs during demand periods. Demand charges vary from area to area. Lets use S.

> Fla. $ 9.00 per kw. So now that 5 cfm per X 300 people can cost as much as an

> extra $70. per day " Power co. will discount the first 10 kw demand 7.8 X 30

> days = 234 kw - 10 = 224 kwh demand X $ 9.00 =

>

> $2016.00 not including the fuel adjustments and normal kwh used.

>

> It is only recently personal health has become an issue. Mainly do to the

> litigation factor .

>

> You have a triangle, Quality , Service , and Price. If you don't like the

> price, then one of the other factors has to go.

>

> Ok. I'm off my soap box

>

> Valin

[Guest guest]

:

You did good!! Most “environmentalists” don’t get the big picture and they often assume that improving the environment is without significant cost, or it is priceless. Both positions are unrealistic. By your calculations, $2,016 represents conservative energy costs per month. How many cooling months are there in south Florida? What is the life-expectancy of the office building? When multiplied out, the energy costs to condition 5-cfm per person of outside air, over the life-time of the structure, becomes a significant chunk of change; and 5-cfm is low. I can hear the environmentalists beginning to grown...”But, the price is worth the health benefit!” Yes....and we had better start building more nuclear power plants, and coal-fired power plants (which involves strip mines), and our dependence on oil (which means drilling off-shore and the north slope) to power oil-fired power plants, and allow the air pollution to increase, CO2 concentrations to increase, and the nuclear waste to accumulate, because, energy is not free and readily available.

Doesn’t the cycle of energy use and demand have some interesting twists?

For what it is worth...

--

Geyer, PE, CIH, CSP

President

KENTEC Industries, Inc.

Bakersfield, California

www.kerntecindustries.com

Ventilation rates have been all over the board in the past 35 years. Its a fact that cooling entering air is expensive .Cost and energy avoidance is what has gotten us into IAQ problems in the first place.

Figure this . Lets say 5 cfm per person " low " X 60 min. = 300 cfm . Outside air temp at 85 f

and 80%rh = heat content is 53.1 btu. Now cool that too 75 f at 50% = 32.4 btu.

1lb of outside air = about 20 cf . 20 into 300 = 15. 53, 1btu - 32.4 btu = 20.7 btu

15 X 20.7 = 310.5 btu. Now if you figure 1kw per ton. " very conservative " 12000 / 310.5 =

..026 kw or 26 watts of power per person.

So now we have an office building with 300 people. 26 X 300 or 7.8 kw per hour.

Now comes the real catch. What is the electric rate? $0 .08 $0.10 This really doesn't sound like a lot does it.

Now for reality . Demand charges will most likely apply since the system runs during demand periods. Demand charges vary from area to area. Lets use S. Fla. $ 9.00 per kw. So now that 5 cfm per X 300 people can cost as much as an extra $70. per day " Power co. will discount the first 10 kw demand 7.8 X 30 days = 234 kw - 10 = 224 kwh demand X $ 9.00 =

$2016.00 not including the fuel adjustments and normal kwh used.

It is only recently personal health has become an issue. Mainly do to the litigation factor .

You have a triangle, Quality , Service , and Price. If you don't like the price, then one of the other factors has to go.

Ok. I'm off my soap box

Valin

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[Guest guest]



Sharon,

Simply put, there is a balancing act going on here. What a number of different disciplines are trying to do is refine the most appropriate indoor-to-outdoor air exchange rates based on the particular occupancy of the structure. Different types of occupancies will have differing needs in regard to controlled air exchange between indoors and outdoors in order to maintain comfort, health, and economy.

Occupancies in this context by the way refers to the type and general usage of the structure and is a term born of the building codes (Single family vs. multi-family, residential vs. commercial, etc. ) Obviously a single family home with 1 person per 1000 square feet of living space does not have the same fresh air intake needs as a movie theater that intermittently has several hundred occupants in that same amount of space. This is a process of refinement and tweaking that has been ongoing for many years and will continue into the future because the dynamics of the built environment are always in flux as new products and materials are introduced that effect indoor air quality.

Because of this, these numbers are going to change from time to time and seeing them go in (what might seem to be) the wrong direction from your perspective is not necessarily a bad thing. If we can get the health and comfort we need for less money by reducing fresh air intake, then those numbers are going to go down to reflect the collection of that available economy. If that in turn has a negative impact on health and comfort, then you will see the pendulum swing in the other direction.

The degree of that pendulum’s swing however should get narrower and narrower over time as the opposing forces of health and economy strike an equilibrium of sorts. Even still, there will always be some impetus for motion one way or another because of the dynamics involved. That’s just how the process works.

By the way, your raising of objection is part of that dynamic process as well so keep up the good work!

Stojanik

Re: ASHRAE Urges Standard 62.1 Inclusion in International Mechani...

Hi All,

I am not understanding this correctly, I don't think. I would think that one would want higher outdoor rates in an effort to provide fresh, circulating air being added to the IAQ. What am I missing?

Thanks,

Sharon

“Ventilation systems designed using the new procedure will result in somewhat lower outdoor rates for most occupancies compared to the current code, reducing first costs and energy costs,†he said.

[Guest guest]

Dear colleagues:

It interesting to hear recognition that:

" ASHRAE's ventilation standards primarily focus on

occupant perception of indoor air quality, not health. "

Now that there is research into the issue of how much ventilation should be

provided to provide a healthy indoor environment, I feel that the next areas for

research and discussion should include:

What is the best way to accurately determine how much outdoor air for

ventilation is actually being delivered to the building occupants?

How important is it for a healthy indoor environment to have a complete

overnight flushout of the previous day's bioeffluents?

Just some thoughts for the future.

Sincerely,

W. Bearg, PE, CIH

White Pond

Concord, MA, USA

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