Whether you are replacing a rooftop unit, chiller, tower or fan coils, providing detailed information to the bidding contractors and accurately expressing the scope of work to be done will insure that you obtain apples to apples competitive bids and will reduce the need for bid contingencies.
However, if you simply call up the mechanical contractor and say that you need to replace the old 25 ton rooftop, are you sure that the contractor will include roofing, electrical, and fire alarm? Do you know if you really need a 25 ton rooftop? Could it be replaced with a 20 ton unit or do you need to upsize it to a 30 ton?
And what type of options should come with the unit? What efficiency should you purchase? Do you want the unit to come with a new curb or a curb adapter? What is the time table for the replacement unit or how long do you want the contractor to have to complete the project? Do they need to be bonded or insured? Who should bid on the project? How many bidders should bid? Should you pre purchase the equipment?
Without clear bid documents, these types of variables may be included in some bids and not in others—making comparison nearly impossible.
Any project that you anticipate should be well thought out. Contacting a wellversed consulting firm should be the first step to get dependable guidance. The consulting firm normally has years of experience in these matters, from asking the right questions and understanding your needs, to making sure that what was installed meets all applicable codes.
The consultant will be able to review your current or future building conditions. Load calculations should be made to confirm the replacement equipment sizing. They will verify if the equipment will fit or if any structural issues should be addressed. How will the new equipment be rigged into place or how it should be scheduled needs to be thought out.
All equipment manufacturers have a variety of options that can be specified. There are a variety of efficiencies/qualities available (good, better, best). The consultant can review these options for a payback based on energy savings. Disconnects, economizers, control interfaces, smoke detectors, hinged doors, throughthebase electrical are all options, which should be explored.
Will a new rooftop unit fit on the existing curb or should a new curb be included? The consultant will need to review the existing duct layout and compare it to the new unit. Roof structure and deck fillin may be required if the new unit does not fit the old curb.
A custom built unit may be an option. If the old unit serves a critical section of the building, the downtime to replace the unit should be considered. Custom units may cost more initially, but the replacement could be configured in hours not days.
Plans and specifications will need to be prepared to tell the story. This will allow for all of the bidding contractors to look at the project though the eyes of the consultant. Their bids should then be based on the same information. No verbal instructions should be given. You might inadvertently leave something out and then be unable to compare the bids.
A quality bid form and instructions to bidders should give you the proper feedback to qualify the bids. A breakdown of labor, materials and taxes may be required by your internal management. Requesting the completion date and equipment lead times are important to allow you to advise your tenants if downtime is required. Requesting insurance or bonding information will protect you in case the contractor fails to perform.
Payment methods to the contractor are equally important. Can you hold retention? What percentage and for how long?
The warranty period protects your investment. Extended compressor warranties are available from the manufacturer, but the cost needs to be included by the contractor. The contractor should also include all labor and materials warranty costs to provide complete replacement coverage.
A post bid meeting should be held to review the bids. Questions should be asked if there is any doubt on an item. It is better to know before issuing a purchase order if something was not covered by the contractor, rather than discovering it later.
Is there any fine print in your standard contract that the bidding contractor can not accept? Will that one item be a stumbling point that will prevent acceptance of the purchase order and the starting of the project?
The bidding documents should also address what you get in terms of training, final record drawings, operation and maintenance manuals, testing and commissioning. It’s like getting a new car. The factory issues a manual and the dealer describes all the features before you drive off the lot. Now that you have this new and improved equipment, you need to know what maintenance needs to be done to keep it working properly.
Having the consultant review the final installation will complete the project. Did the contractor install the equipment as specified? Did they finish the installation? Was the unit started up properly? Do you have the proper warranty papers?
Having a well thought out set of bidding documents will give you a quality project at the most competitive price and without any surprises to your budget.