---
title: FAQ
description: Frequently asked questions about ITM4 HVAC access doors, plenum wall panels, viewports, and accessories.
---

# Frequently Asked Questions

 How do I measure for doors?

Access doors are normally sized by your “rough opening.” This is the actual plenum or air handling unit opening the door and frame assembly fits into. For detailed information consult the ITM4 drawings for each door model.

 How do I measure for viewports?

Viewport kits come in a variety of standard sizes:

- 8″ × 8″
- 8″ × 12″
- 12″ × 12″

We recommend the amount of “viewable area” needed is determined. Then select the appropriate viewport model. Rough opening size in the door to be equal to nominal viewport size (view size) plus 1-5/8″.

**Example:** 8″ x 8″ viewport needs to have an 9-5/8″ x 9-5/8″ rough opening.

 How long does it take to get these products?

Our standard lead-time is two to three weeks based on the wide variety of standard inventoried components. For special materials and painted products, the lead-time could be longer based on availability.

 What about prices?

Contact ITM4 for pricing and quoting process. Call 763-497-0842, **[contact us](https://itm4.com/contact?hsLang=en)** or request a quote.

 How do I order?

**Customer service is very important at ITM4.**

When ordering doors, our order form asks all the right questions. We can also assist in quoting jobs for you until you’re comfortable with the process. All products are custom and built as needed. Once a purchase order is submitted, we will send you an Order Acknowledgment detailing what you are ordering.

 How do I get my order?

ITM4 is open to freight terms based on your preference. Freight Collect or Freight Allowed. ITM4 can also ship International if required.

 What about paint?

ITM4 has the capabilities for powder paint and wet paint applications. For more information regarding paint, call 763-497-0842 or **[contact us](https://itm4.com/contact?hsLang=en)**.

## **Questions?**

Please contact us with your question and we will get back to you soon!

[ CONTACT US ](https://itm4.com/contact?hsLang=en)