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  1. #1
    Join Date
    Dec 2005
    Posts
    3
    I am a partner in a New England construction management company. We have been invited at the last minute to submit a design/build proposal for a 30,000sf medical office building. We are competing against a firm that has a reputation for delivering the minimum quality permitted at the lowest possible cost. Our approach typically has been to get customers to focus on the long term cost of ownership, and not make envelope and MEP system decisions solely on first dollar cost.

    I am without the benefit of our usual MEP engineering consultants, as they are away for the holidays and won’t return until after the proposal is due. We typically work with an owner to develop performance, operating and life cycle criteria, which they use to prepare a prescriptive specification. This specification becomes the basis of our budget. My concern is that the specification we have been provided is so vague and conflicted that someone could design a POS system that meets the minimum requirements at a considerably lower cost. The owner has been led to believe that the system proposed is a Cadillac with state of the art controls. I was hoping that if I posted the specification here I could get some feedback to use in presenting our proposal.

    The Specification:
    Rooftop heating, air conditioning and ventilation units will be installed through the space as follows:

    Type: Fully enclosed rooftop mounted HVAC units.

    Distribution at finished ceiling areas: Air supply will be distributed through insulated galvanized steel duct to ceiling or wall mounted diffusers.

    Accessories: HVAC units will be equipped with adjustable outside air dampers which allow the introduction of fresh air into the building.

    Economizers: Units over 5 tons will be equipped with economizers which automatically introduce 100% outside air
    during periods when the outside air is cooler than the air within the building.

    Capacity: As required to cool the areas served based upon the following heat gains – 1) Applicable solar and building envelope gains, 2) People, ventilation and electrical loads applicable to the designed occupancy of the space.

    Control: Variable air volume system, individual thermostats in each room (48 on the first floor, 18 on the second floor), required temperatures 68-74 degree setpoint, +/- 2 degrees from setpoint.

    Ventilation: Bathroom ventilation will be provided.

    The Building:
    The owner operates a behavioral health and family counseling center. The building will be two stories. The first floor houses admission and records (25%), and the balance of the space is a series of small 10x10 to 12x15 counseling rooms. The second floor is primarily open office (75%) with a very high occupant load. The balance of the space is conference, training and private offices.

    I am interested in two perspectives here. First, what is the cheapest, lowest quality, lowest cost system you can come up with that meets these standards? Feel free to be perverse with your ideas, you have my word that we won’t build what you come up with. For instance, use all 4-1/2 ton systems and eliminate economizers.
    Second, what would you propose as a base system? We intend to focus the owner on the following issues:
    IAQ, occupant comfort, health and productivity, dynamic management of OA, occupancy management strategies, energy efficiency, utility rebates and tax credits, operating cost.

    Thanks in advance for any advice you may have!!

    Jeff


  2. #2
    Join Date
    May 2002
    Posts
    9,564
    Type: Fully enclosed.. Accessories... Economizers.... Capacity.....

    All those items are to be expected and are normal.
    Distribution is different if you know they install differently.
    Equipment selection may be different quality level.
    Medical building? - What about any increased OA to the space? HRV?
    What about perimeter radiation? Cold climate, big issue. Can it be added later? Will the VAV's support the extra I/O required?

    IAQ, occupant comfort, health and productivity, dynamic management of OA, occupancy management strategies, energy efficiency, utility rebates and tax credits, operating cost.

    I'd run with the OA HRV inclusion with perimeter hot water heating, especially if there is a fair amount of windows. I'd use wall mount hi-efficiency and put forth the possibility of doing distributed domestic heating for max savings. Break them out separately (to yourself). If you are good enough in controls setup email alarming and monitoring for them as a "standard". Honestly, if the other firm is as cheap as you say they are stick to your guns and pass on doing it their way. I'd tell the owner I'd rather not field the complaints on that type of system and if that other firm gets it to work well and be efficient more power to them.



  3. #3
    Join Date
    Mar 2004
    Location
    Vancouver, BC
    Posts
    125

    Envelope, envelope, envelope

    I won't even touch the "how cheap can it be done for" side of it. If you do your sums right, you should be able to sell a high performance envelope (high thermal resistance glass, exterior solar shading, etc.) and get a very low cost HVAC system based on any of the following systems:

    Hydronic heat pumps (little water cooled water to air heat pumps in the ceiling space) with an HRV DOAS unit, fluid cooler and condensing boiler. Possible long term maintenance costs though.

    Four-pipe fan-coils with an air cooled chiller, condensing boiler and HRV/ERV DOAS unit. Less long term maintenance risks compared to hydronic heat pumps.

    Any opportunity for a geo-exchange heat pump plant to make low energy warm and cool water to serve the hydronic heat pumps or the four-pipe fan-coil system?

    Or,...Go really high IAQ with a Euro system like an HRV/ERV unit supplying a low level displacement ventilation system, supplemented by radiant heating/cooling panels, or if the building will be concrete, radiant slab ceiling (concrete core conditioning) system.

    The cheapest "low energy system" in the building is proper envelope and window design. Reduce the heating/cooling loads first, then select a low energy HVAC system. None of the above described systems should be thought of as "premium" systems, since an astute HVAC designer will be able to keep first costs low enough to pay for the good glass and solar control, so the total net cost of the whole building will be the same as a "conventional" building, but it will provide superior thermal comfort at a very low energy consumption.

  4. #4
    That is the worst spec I have ever seen, it cannot be for real, if it is they will get what they deserve for being so stupid as to put that out as a spec, who wrote it ? their FED EX guy ?

    But it sounds like they want a couple rooftop packages with static control, VAV and VAV with electric reheat in the perimeter boxes in the space , and proper ventilation,

    The cycle that brings in 100 outside air when it is cooler than the space , should say enthalpy not referenced to temperature and only applicable when above changeover.Or they better have a lot of heat in the units for summer and winter,along with a lot of DX for dehum.


    Adjustable dampers in units over 5 tons, ? that's a good one, so is a manually operated min pos damper acceptable ? that's what they are asking for.Then you need low ambient on them,

    I wouldn't waste my time with this spec if I were you, if you can't get to the owner of this building and enlighten him about what he is buying and get the spec rewritten, I would scrap the whole thing, don't even bother bidding it the owners are clueless, why didn't they hire an engineer to lay out a spec ? I would be wondering about that. And controls ? Do they want any or not, I mean stats in each room is that their control spec ?

  5. #5
    Join Date
    Mar 2004
    Location
    Vancouver, BC
    Posts
    125

    Good call Titleless

    A 30,000 sf building is going cost upwards of $5 million by the time the dust settles, yet that outline performance spec has less teeth than a spec sheet for a Toyota Echo. That's being pretty irresponsible with a whole lotta money. You could walk away from this thing since it will be a boondoggle, or you could put together a proposal for the owner with a really good outline spec and be a lot more specific with what he should expect to get. Sell service and performance rather than just ripping off an obvious uneducated fool trying to play at contruction.

  6. #6
    Join Date
    Dec 2005
    Posts
    3
    Just to be clear, it is not our intent to take advantage of an obviously uneducated owner. Our competition, however, certainly will. Our strategy is to demonstrate to the owner the folly of the path they have chosen.

    This is unfamiliar territory for us as we are used to being the first point of contact with a potential client, and don't typically compete on a cost basis for our services as construction manager. We are here at the request of the bank financing the project. I am not fishing for ideas on how to low ball this system or the building envelope to get the job. We have no interest in that kind of work. They have been sold a bill of goods along with an unrealistic budget. For the record, the spec wasn't written by their FedEx guy; he would have done much better. It was written by their real estate broker. If you think the HVAC spec is bad you should see the envelope spec.

    Our goal is to convince them to spend their money on a smaller, high performance building that can be expanded later. If they are intent on trying to construct 30,000sf of medical office space for $2.8 million we will walk without a second thought. I am confident, though, that we can build a high quality, high performance 20,000sf building for that price.

    gmcd, I agree with your design ideas, but you are preaching to the choir when it comes to designing a high performance envelope coupled with a low energy HVAC system. We have several EnergyStar and LEED projects in our portfolio, and have advocated this approach years before oil hit $70/bbl. On a first cost basis, however, this strategy can't compete with a code minimum envelope coupled with a code minimum HVAC package, which is what we are up against.

    I'm not an engineer, and I was hoping you guys could give me some ideas on the way a spec like this could be abused. Thanks everyone for your ideas.

  7. #7
    Join Date
    Mar 2004
    Location
    Vancouver, BC
    Posts
    125

    Smaller Building

    Sounds like you have the right approach. Get the Bank on your side to help convince the Client the reality of what they can build and clearly get their expectations straightened out. That outline spec will get a system that "may" work to Code minimums, and likely be a mess after a year or two, but it will be an energy pig and have lousy comfort control. Note that the outline spec made no mention of what the design conditions/temperatures/ventilation rates or Code Reference Standards are supposed to be. Maybe the best approach is to just tell the Bank and the Client the straight goods- they can't get a 30,000SF building that will work for that kind of $$. You'll have to play teacher/educator with these folks to get the points across, using your past buildings as examples. A Minimum Code building is a rolling chassis with some tin bodywork, and it won't be any Cadillac.

  8. #8
    Originally posted by build
    I am a partner in a New England construction management company. We have been invited at the last minute to submit a design/build proposal for a 30,000sf medical office building.

    [ Why is last minute ? You have to know exactly what you're position is in this transaction, it could be as simple as they already have their contractor and need a second bid but those types of deals usually have some specifics about the design that puts other companies at a disadvantage, this spec looks real hokey, written by someone with no obvious experience who is also oblivious to building codes and general requirements of a building. It may also be a preliminary scope ? are you sure this is the spec ? or are they asking and talking about concepts in general ?




    We are competing against a firm that has a reputation for delivering the minimum quality permitted at the lowest possible cost.

    This one was born for them,



    Our approach typically has been to get customers to focus on the long term cost of ownership, and not make envelope and MEP system decisions solely on first dollar cost.

    You have to get some face time with them, get right to the guy or board who is writing the check,

    I am without the benefit of our usual MEP engineering consultants, as they are away for the holidays and won’t return until after the proposal is due. We typically work with an owner to develop performance, operating and life cycle criteria, which they use to prepare a prescriptive specification. This specification becomes the basis of our budget. My concern is that the specification we have been provided is so vague and conflicted that someone could design a POS system that meets the minimum requirements at a considerably lower cost.

    They will, it will be a pretty bad system



    The owner has been led to believe that the system proposed is a Cadillac with state of the art controls.

    The only controls mentioned were tstats in the rooms,


    I was hoping that if I posted the specification here I could get some feedback to use in presenting our proposal.

    [As many four ton units as it takes, with low ambient kits and manually adjustable outdoor air intakes, constant volume units with VAV boxes throw a few reheats around the perimeter, and you have a system.]

    The Specification:
    Rooftop heating, air conditioning and ventilation units will be installed through the space as follows:

    Type: Fully enclosed rooftop mounted HVAC units.

    [ got to use packages ]

    Distribution at finished ceiling areas: Air supply will be distributed through insulated galvanized steel duct to ceiling or wall mounted diffusers.

    [ typical]

    Accessories: HVAC units will be equipped with adjustable outside air dampers which allow the introduction of fresh air into the building.

    [ basically a hole in the unit with an adjustable cover, you can order them like that]

    Economizers: Units over 5 tons will be equipped with economizers which automatically introduce 100% outside air
    during periods when the outside air is cooler than the air within the building.

    [ Not written correctly, makes no sense at all.just don't buy anything over 5 ton, so you can do the entire job with 5 tonners, because a 5 tonner is not over 5 tons it will usually number out at a little less than 5 ton on the spec sheetsubmital]

    Capacity: As required to cool the areas served based upon the following heat gains – 1) Applicable solar and building envelope gains, 2) People, ventilation and electrical loads applicable to the designed occupancy of the space.

    [This says it needs to work to some degree and provide proper ventilation, it is telling you where your minimums ned to be set, but does not have to automatically adjust for them]

    Control: Variable air volume system, individual thermostats in each room (48 on the first floor, 18 on the second floor), required temperatures 68-74 degree setpoint, +/- 2 degrees from setpoint.

    [ Stand alone controls, no network, basically a stat/ sensor and a box

    Ventilation: Bathroom ventilation will be provided.

    [ an exhaust fan for each unless they are stacked then one with ducts for each,]

    The Building:
    The owner operates a behavioral health and family counseling center. The building will be two stories. The first floor houses admission and records (25%), and the balance of the space is a series of small 10x10 to 12x15 counseling rooms. The second floor is primarily open office (75%) with a very high occupant load.

    The balance of the space is conference, training and private offices.

    I am interested in two perspectives here. First, what is the cheapest, lowest quality, lowest cost system you can come up with that meets these standards? Feel free to be perverse with your ideas, you have my word that we won’t build what you come up with. For instance, use all 4-1/2 ton systems and eliminate economizers.
    Second, what would you propose as a base system?

    [You could probably get rid of a lot of boxes if you stuck 3 or 4 rooms on one box and averaged their stats, it would probably hold the 68 to 74 +-2, it would on paper anyway,]

    [So you could literally have one constant volume unit with gas or electric heat and dx cooling only, feeding one VAV box, and conrolling 3-5 of the rooms,]


    We intend to focus the owner on the following issues:
    IAQ, occupant comfort, health and productivity, dynamic management of OA, occupancy management strategies, energy efficiency, utility rebates and tax credits, operating cost.

    [ They defininitely need some advice here, you need to educate them, do you have comparable jobs to show them ? Have you written a preliminary spec for them to give them an idea of how much detail needs to go into it ? ]

    Thanks in advance for any advice you may have!!

    Jeff


  9. #9
    Join Date
    Jul 2001
    Location
    Canada
    Posts
    1,824
    PRICE CHECK AISLE 5 !

    By the looks of the poor spec you were given and when you were given it the other company likely already has the JOB.

    Adjustable outside air dampers is not always a MANUALLY adjusted damper , modulating dampers are known as ADJUSTABLE as well and plenty of units over 5 TON have them.

  10. #10
    Also, sounds like a Thermafus product might be worht looking at here, I don't have much experience with them but it would meet the stat and VAV requirements. I don't know how they control to index heat or cool out of the unit, but worth looking into.

  11. #11
    Originally posted by Control Man
    PRICE CHECK AISLE 5 !

    By the looks of the poor spec you were given and when you were given it the other company likely already has the JOB.

    Adjustable outside air dampers is not always a MANUALLY adjusted damper , modulating dampers are known as ADJUSTABLE as well and plenty of units over 5 TON have them.
    I didn't say that it meant manual, I said you get get away with manually adjustable dampers.

  12. #12
    Just curious, is this building being built by, a company that rythmes with "Fluke" realty ?

  13. #13
    Join Date
    Jul 2001
    Location
    Canada
    Posts
    1,824


    " So is a MANUALLY operated Min Pos damper acceptable ? Thats what they are asking for " sure sounds like you meant MANUAL.

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