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Q: According to your Services page, your load calculation prices only apply to new construction projects. How much do you charge to do a load for a renovation project?

A: Optimal Building Systems specializes in high performance homes. We accept existing homes on a case-by-case basis, provided the home meets our criteria. Pricing will be somewhat higher than for new construction due to the additional complexity and time required to gather the necessary data to model the home. As with new construction projects, accurate floor plans and specifications are required. Please contact Optimal Building Systems for further information.

Q: How long does it take for you to finish my load calculations?

A: As with any small business, our work backlog varies. Turnaround varies from 4 days to a couple of weeks. We realize tight schedules are a way of life in construction so we'll make every effort to complete your project as quickly as possible. That said, it's always best to submit projects as soon as key specifications are firm. And we always appreciate knowing if you're *not* in a hurry so we can provide faster service to those who are.

Q: Can you check my mechanical contractor's load calculations to see if he's doing it properly?

A: Yes, but we must first do an independent load calculation on which to base a comparison. In addition to the normal project submittal, you'll need to provide a detailed load report from your contractor (preferably from a job he's already bid) showing the load breakdown -- ceilings, walls, floors, windows, ducts, and infiltration -- along with the model numbers for proposed or installed equipment. We'll prepare a comprehensive report based on our analysis. Note: Nothing thrills me more than to find a mechanical contractor who takes the time to do an accurate load calc and equipment specification!

Q: Do you offer Manual D duct designs?

A: No. In my experience, few residential HVAC installers are willing or able to build a duct system according to plans provided by a 3rd party. At a minimum, close supervision is necessary. The best approach is to select a contractor with a proven track record designing high performance duct systems. Ask to see copies of duct designs for previous projects. We can provide general guidance on duct design strategies and/or review and comment on your contractor's duct design submittal.

Q: Which construction drawing pages do you need and in what format?

A: We need floor plans and elevations, preferably in PDF format at full scale (typically 1/4"). Major sections are helpful if the house has vaulted, volume, or clipped ceilings. Plans must include final window and exterior door sizes. Any discrepancies between elevations and final window sizes should be noted.

Q: None of the HVAC contractors I've worked with over the years require such detailed information to do load calculations.

A: Exactly. The sad fact is, many HVAC contractors still don't do proper load calculations. Those who do typically take short-cuts by using the default or worst-case assumptions. In most cases, equipment is sized during the bidding process. Without a contract in hand, it's difficult for them to justify the time required to gather all the necessary data to do a proper load calc. Once a job is secured, it's the rare contractor who goes back to adjust the loads based on actual specifications. See 10 Reasons Why Oversizing Persists.

Q: What if some of the specifications have not yet been finalized?

A: This is not uncommon. Ideally, load calculations should be completed before soliciting mechanical bids so the equipment can be specified. However, at this stage, all the required building specs may not be nailed down. In this situation we can produce a preliminary load report for the purpose of obtaining bids and vetting prospective contractors. Then, before mechanical rough-in, the pertinent specs should be provided so we can update the load calc model and issue the final load report. A nominal revision applies (typically around $60 to $90, depending on the extent of the changes). Alternatively, we can wait until all the specs are nailed down. We're available on an hourly basis to help you quickly identify the optimal combination of efficiency improvements for your project.

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