Q and A 132 HVAC 25 June 2021.pdf

RFI ? # Question Answer

Now that the official solicitation is out I would still like some clarification on what the basis of design boilers are and even what the specification/scope for the boiler itself is. Is all of this information going to be put out at the pre-bid? Is it just a like-for-like replacement or are you interested in additional vendors and/or newer technologies.

Currently installed is a: Make: Lochinvar, Model: Knight, 121,000 BTU boiler. As stated in the SOW, para. 3.2.4, the government is looking for equivalent equipment that communicate properly with existing equipment.

Could you please tell me if this is a new requirement, or if there is a current or previous contractor who has performed similar services? If available, can you please send along the incumbent contract or task order number?

This is a new construction effort for the replacement of an HVAC and boiler unit there is no incumbent information to provide.

3 Scope calls for a “compact unit”; What would be considered a “compact Unit” ? See Answer to RFI #5

The scope calls out for equipment to be able to be connected to a DDC controls system.

If the present controls are obsolete, do you want standalone controls for the new equipment?

As stated in the SOW, para 3.2.7, the HVAC system and equipment is adequate and fully functional with the ability to be connected and operable with a DDC system. Any equipment installed must be compatible with Niagara 4 DDC software. Stand alone controls will be required to make the system functional as this project begins around the same time the current software becomes obsolete.

The scope calls out for a “compact unit” By “Compact unit” are they referring to a packaged heat pump where the duct will go up the outside of the building and tie into existing duct on the inside?

Does the present unit pull in 100% outside air or is it mixed with inside air?

Yes, the intent is to have a "packaged heat pump unit" on the outside of the building that ties into the inside ducting.

Current unit is not 100% air, but is mixed with inside air.

The scope calls for “the ability to be connected to a DDC system” Will the new system be stand alone for the present time until a new controls system is installed? See Answer to RFI#4

The scope calls out for a “compact unit” By “Compact unit” are they referring to a packaged heat pump where the duct will go up the outside of the building and tie into existing duct on the inside?

Does the present unit pull in 100% outside air or is it mixed with inside air?

See Answer to RFI #5

The scope calls for “the ability to be connected to a DDC system” Will the new system be stand alone for the present time until a new controls system is installed?

See Answer to RFI #4 and 6

9 Is there a model number available for the existing boiler to be replaced? See Answer to RFI#1

Is a duct smoke detector required for the new unit and ducting, Will it be required to be tied into existing life safety requirements for this building. No, a duct smoke detector will not be required.

Will new duct require internal or exterior insulation? If external insulation, please define what insulation jacketing will be required.

Exterior, flexible blanket style insulation will be required with a minimum R-Value of 12 per para. 3.2.5.1.

The present AHU is 100% outside air. A packaged heat pump is unable to handle 100% outside air. Is the present system used for make-up air?

The current unit was found to not be 100% outside air, and is mixed with inside air. Per paragraph 3.2.6 in the statement of work an economizer is to be installed to aide in regulating the amount of outside air used.

Q & A W50S8Q21B0003