(a) Cooling and heating must be provided, as necessary, for resident comfort. Heating systems in resident use areas must be capable of maintaining a minimum temperature of 68 degrees Fahrenheit, and cooling of 81 degrees Fahrenheit maximum, with humidity in the normal comfort range.
(b) The facility must be well ventilated using windows, mechanical ventilation, or a combination of both. Rooms and areas which do not have outside windows and which are used by residents or staff must be provided with functioning mechanical ventilation to change the air on a basis commensurate with the room usage.
(c) Air systems must provide for the induction and mixing of at least 10 percent outside fresh air into the facility unless otherwise approved by the Texas Health and Human Services Commission (HHSC), that is, 100 percent continuous recirculation of interior air in most areas is not acceptable; or the system must be designed to meet the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) requirements.
(d) Operable outside windows must be provided with insect screens that prevent insect entry.
(e) Rooms such as baths, toilets, soiled linen, trash or garbage rooms, soiled utilities, janitor's closets, and other such areas which produce odors, fumes, excessive moisture, etc., must be provided with an exhaust system ducted to the exterior, meeting nationally recognized standards for capacity and function.
(f) Electrical and mechanical systems must be safe and in working order. HHSC may require the facility sponsor or licensee to submit evidence to this effect, consisting of a written report by the local fire marshal, city/county building official having jurisdiction, or a registered professional engineer.
(g) Use of electrical appliances, devices, and lamps must be such as not to overload circuits.
(h) Portable heaters and open-flame heating devices are prohibited. All fuel burning devices must be vented. Working fireplaces are acceptable if of safe design and construction, and if screened or otherwise suitably enclosed.

Source Note: The provisions of this §551.70 adopted to be effective July 1, 1996, 21 TexReg 5328; transferred effective May 1, 2019, as published in the Texas Register April 12, 2019, 44 TexReg 1883; amended to be effective February 24, 2022, 47 TexReg 787